Automotive A-Z Lane's Complete Dictionary of Automotive Terms

DICTIONARY OF AUTOMOTIVE TERMS "A" [Home][A] [B][C] [D][E] [F][G] [H][I] [J][K] [L][M] [N][O] [P][Q] [R][S] [T][U] [V][W] [X][Y] [Z] [A] [Ab] [Ac] [Ad] [Ae] [Af] [Ag] [Ah] [Ai] [Al] [Am] [An] [Ap] [Aq] [Ar] [As] [At] [Au] [Av] [Aw] [Ax]

A: Abbreviation or symbol for absolute temperature, absorption coefficient, acceleration, adenine, ampere, amplitude, angular acceleration, area, attenuation coefficient, fine-structure constant, helium nucleus, Helmhotz free energy, magnetic vector potential, relative atomic mass, a stereoisomer of a sugar, substitution on a carbon atom next to one common to two condensed aromatic nuclei, substitution on the carbon atom next to the hetero-atom in ahetero-cyclic compound, and substitution on the carbon atom of a chain next to the functional group

A-2 tire: A term used for tire sizes 16.00 and larger in nominal cross section. Also called "earthmover" or "off-the-road" tires AA: Abbreviation for "Automobile Association" a term used in Great Britain aa: A term of Hawaiian origin for lava flows with a rough, jagged surface AAA: Acronym for "American Automobile Association" or "Alberta Automobile Association." AABM: Acronym for "Association of American Battery Manufacturers, Inc." AAE: Acronym for "Association of Automotive Employers" (Poland). AAIA: Acronym for "Automotive Aftermarket Industry Association" AALA: Acronym for "American Automobile Labelling Act." Aalenian: The oldest stage of the Middle-Jurassic AAM: Acronym for "Alliance of Automobile Manufacturers" AAP: Acronym for "auxiliary acceleration pump"

A arm: See A-arm. A-arm: A suspensionlinkage formed in the shape of an "A" or "V" found commonly on the front suspension. The sides of the two legs of the A-arm are connected to the chassis by rubber bushings and the peak of the A-arm is attached to the wheel assembly. In this way, the wheel can freely move up and down. Sometimes there is an upper A-arm, a lower A-arm, or both upper and lower A-arms. The British call it a "wishbone." Also see twin A-arm suspension A-arm suspension: See twin A-arm suspension AAS: Acronym for "air aspirator system" abacus: [1] The uppermost part of a colurnn capital or pilaster, on which the architrave rests. [2] A bead frame. Used as an arithmetic calculating aid. abampere: A unit of electric current in the CGS electromagnetic system of units. One abampere equals 10A. abamurus: A supporting wall or buttress, built to add strength to another wall. abandonment: A voluntary surrender of legal rights or title to a mining claim. abatjour: An opening to admit light and generally to deflect it downwards; a skylight abaxial: Rays of light which do not coincide with the optical axis of a lens system. Abbe refractometer: An instrument for measuring directly the refractive index of liquids, minerals and gemstones. ABC: [1] Acronym for "aerial bunched conductors." [2] Acronym for "automatic beam control" ABDC: A term used in timing the relation of the spark and the crankshaft. It stands for after bottom dead center. Abegg's rule: Empirical rule that the solubility of salts of alkali metals with strong acids decreases from lithium to caesium, i.e., with increase of relative atomic mass, and those with weak acids follow the opposite order. Sodium Chloride is an exception to this rule, being less soluble than potassium chloride. Abegg's rule of eight: A rule that the sum of the maximum positive and negative valencies

of an element is eight, e.g., sulphur in SF6 and H2S. Abel flashpoint apparatus: A petroleum-testing apparatus for determining the flash-point Abelian group: A group in which the group operation is commutative. It is important in the study of rings and vector spaces. abelite: An explosive, composed mainly of ammonium nitrate and trinitrotoluene. aberration: [1] An apparent change of position of a heavenly body, due to the speed of light having a finite ratio to the relative velocity of the source and the observer. [2] In an image-forming system, e.g., an optical or electronic lens, failure to produce a true image, e.g., a point object as a point image. Geometrical aberrations include spherical aberration, coma, astigmatism, curvature of the field and distortion. See chromatic aberration abhesive: A substance which prevents two materials sticking together, e.g., teflon on frying pans.

ability: See climbing ability cold cranking ability ABL: Acronym for "atmospheric boundary layer" panel ablation: [1] Any one of the processes by which snow and ice are lost from a glacier, mainly by melting and evaporation (sublimation). [2] Removal of surface layers of a meteorite and tektites during flight. ablative polymer: A material which degrades controlably in an aggressive environment, especially on re-entry space-craft. Extreme temperatures are reached on heat shield, so it is protected with ablation shield made of e.g., silicone polymer. The same principle is used in intumescent paints for fire resistance Abney law: A rule stating that if a spectral color is desaturated by the addition of white light, and if its wave length is less than 570 nm, its hue then moves towards the red end of the spectrum, while if the wavelength is more than 570 nm its hue moves towards the blue. Abney level: Hand-held instrument in which angles of steep sights are measured while simultaneously viewing a spirit-level bubble. Abney mounting: A form of mounting for a concave diffraction grating, in which the eyepiece (or photographic plate holder) is fixed at the center of curvature of the grating and the

slit can move around the circumference of the Rowland circle, to bring different orders of spectrum into view. abnormal glow discharge: A discharge carrying current in excess of that which is required to cover the cathode completely with visible radiation. Abnormal reflection: Reflection from the ionosphere of a radio wave whose frequency is greater than the critical frequency. aboard: See lighter aboard ship aboard ship: See lighter aboard ship A-bomb: See atomic bomb A bone: Model "A" Ford. abort: To terminate a vehicle's flight either by failure or deliberate action to prevent dangerous consequences; if manned, a predetermined sequence of events is followed to ensure the safety of the crew. ABPV: Acronym for "air bypass valve" abradant: A substance, usually in powdered form, used for grinding. See abrasive abrade: To scratch or tear away two surfaces in contact by relative motion. Abram's law: A rule that the ratio of water to cement for chemical action to impart strength to concrete is 0.85:1. abrasion: [1] Wearing or rubbing away some surface because of friction. [2] Mechanical wearing away of rocks by rubbing during movement. abrasion hardness: Resistance to abrasive wear, under specified conditions, of metal or mineraL abrasive: A hard grit used for sanding or grinding. It is usually in powdered form, used for the removal of material by scratching and grinding, e.g., silicon carbide powder (carborundum). Also see bonded abrasive coated abrasive non-woven abrasive abrasive blast cleaning: A method for preparing steel for painting whereby abrasive particles, e.g., copper slag, are projected under pressure through a nozzle. Very effective in

removing rust and mill scale, leaving an anchor pattern (a pattern of minute projections) on the substrate affording good paint adhesion. abrasive cleaner: A cleanser with some hard grit used to remove the grime and oils from a surface. abrasive disc: A circular plate (often made of plastic with hard grit embedded into it) used for grinding or sanding. abrasive paper: Sandpaper (a paper upon which sand or hard grit has been glued) used for sanding or grinding. abrasive wear: A mechanism of wear due to the presence in one or both surfaces of hard particles (e.g., carbide in steels), or to hard particles trapped between them. A/B roll editing: Video editing using two source players (A and B) enabling dubbing from both. Necessary if scenes are to be superimposed. A/B roll printing: A method of film printing with alternate scenes assembled in two rolls, each having black spacing equivalent in length to the omitted scene; double printing from the two allows the inclusion of fade and dissolve effects and avoids visible splice marks between scenes in 16 mm printing. ABS: [1] Acronym for "anti-lock brakes. [2] Acronym for "acylonitrile-butadiene-styrene." Also see copolymer abscissa: For rectilineal axes of coordinates, the distance of a point from the axis of ordinates measured in a direction parallel to the axis of abscissae, which is usually horizontal. The sign convention is that measurements to the right from the axis of ordinates are positive, measurements to the left negative. absolute: [1] A conic (a quadric in three dimensions) formed by the assemblage of the points at infinity on a line (in general two points). Its form determines the metrical properties of the geometrical system being operated. Thus in Euclidean geometry, the absolute is the degenerate conic comprising the line at infinity taken twice, while in nonEuclidean geometry, the absolute is either a real conic (hyperbolic geometry) or an imaginary conic (elliptic geometry). Also see manifold absolute pressure sensor pilot operated absolute absolute address: A computer code designation of a specific memory location as determined by the hardware.

absolute age: The geological age of a fossil, mineral, rock or event, generally given in years. absolute alcohol: Water-free ethanol; rel.d. 0.793 (15.5°C); bp 78.4°C; obtained from rectified spirit by adding benzene and refractionating. Very hygroscopic. absolute ampere: the standard MKS unit of electric current; replaced the international ampere in 1948

absolute ceiling: The height at which the rate of climb of an aircraft, in standard atmosphere, would be zero; the maximum height attainable under standard conditions

absolute configuration: the arrangement of groups about an asymmetric atom, especially a tetrahedrally bonded atom with four different substituents

absolute electrometer: A high-grade attracted-disk electrometer in which an absolute measurement of potential can be made by weighing the attraction between two charged disks against gravity

absolute filter: A filter which removes most particulate matter from gases

absolute humidity: the mass (actual amount) of water vapor present in a unit of volume of moist air

absolute instrument: An instrument which measures a quantity directly in absolute units, without the necessity for previous calibration

absolute permeability: See permeability

absolute potential: The theoretical true potential difference between an electrode and a solution of its ions, measured against a hypothetical reference electrode, having an absolute potential of zero, with reference to the same solution

absolute pressure: pressure measured from a starting point of zero in perfect vacuum. When measured by the absolute pressure scale, atmospheric pressure is 14.7 psi or 29.92 inches of mercury (in-Hg). Also see manifold absolute pressure sensor absolute pressure sensor: See manifold absolute pressure sensor

absolute reaction rate: The reaction rate determined from statistical thermodynamics; uses the assumption of the theory of absolute reaction rates that the rate of a chemical reaction is governed by the rate of crossing an energy barrier or of forming an activated complex

absolute temperature: Temperature measured with respect to absolute zero, i.e., the zero of the kelvin thermodynamic scale of temperature, a scale which cannot take negative values

absolute temperature scale: also called the "absolute scale temperature" as measured on a scale in which the hypothetical lowest limit of physical temperature is assigned the value zero. The Kelvin scale is an example of the absolute temperature scale

absolute units: Units derived directly from the fundamental units of a system and not based on arbitrary numerical definitions. The differences between absolute and international units were small; both are now superseded by the definitions of SI units

absolute wavemeter: A wavemeter in which the frequency of the injected radio-frequency signal is by calculation of physical properties (circuit elements or dimensions) of a resonant circuit line or cavity

absolute weight:

The weight (or mass) of a body in a vacuum

absolute zero: The point at which there is a total absence of heat, minus 459.67°F (-273.15°C)

absorbance: [1] The logarithm of the ratio of the intensity of light incident on a sample to that transmitted by it. It is usually directly proportional to the concentration of the absorbing substance in a solution. [2] The capacity of materials such as textile fibers and paper to absorb liquids

absorbed dose: Quantity of energy imparted by ionizing radiation to a unit mass of biological tissue. Unit is the gray

absorber: Any material which converts energy of radiation or particles into another form, generally heat. Energy transmitted is not absorbed. Scattered energy is often classed with absorbed energy. Also see air shock absorber damper direct-actingshock absorber double-tube shock absorber friction shock absorber gas shock absorber impact absorber lever-type shock absorber monotube shock absorber self-levelling shock absorber shock absorber single-tube shock absorber telescopic shock absorber UV absorber absorber rod: See control rod

absorber tower:

See shock absorber tower

absorbing: See energy absorbing steering column energy absorbing bumper absorbing bumper: See energy absorbing bumper

absorbing material: any medium used for absorbing energy from radiation of any type

absorbing steering: See energy absorbing steering column

absorbing steering column: See energy absorbing steering column

absorptance: A measure of the ability of a body to absorb radiation; the ratio of the radiant flux absorbed by the body to that incident on the body

absorptiometer: An apparatus for determining the solubilities of gases in liquids or the absorption of light

absorption: The use of reagents to remove unwanted antibodies or antigens from a mixture. Also see sound absorption absorption band: A dark gap in the continuous spectrum of white light transmitted by a substance which exhibits selective absorption

absorption capacitor:

A capacitor connected across a spark gap to damp the discharge

absorption coefficient: [1] The volume of gas, measured at stp, dissolved by unit volume of a liquid under normal pressure (i.e., one atmosphere). [2] The fraction of the energy which is absorbed. [3] The reduction of amplitude, for a beam of radiation or other wave system incident on a discontinuity in the medium through which it is propagated, or in the path along which it is transmitted. [4] In a medium, the natural logarithm of the ratio of incident and emergent energy or amplitude for a beam of radiation passing through unit thickness of a medium.

absorption discontinuity: See absorption edge

absorption dynamometer: A dynamometer which absorbs and dissipates the power which it measures, e.g., the ordinary rope brake and the Froude hydraulic brake

absorption edge: The wavelength at which there is an abrupt discontinuity in the intensity of an absorption spectrum for electromagnetic waves, giving the appearance of a sharp edge in its photograph. The transition is due to one particular energy-dissipating process.

ABS override button: A button or switch which disengages the automatic anti-lock braking system so that the driver can operate the brakes himself.

ABS relay valve: An electrically controlled valve which modulates the air pressure in the ABS.

abut: The action of two gear teeth making contact.

abutment: [1] A part which stops the motion of another part from proceeding any farther. [2] A cement raised shoulder secured to the side of the road to prevent a vehicle from going over the edge.

[3] The contact made between opposing teeth of two gears.

abutting edge: The side or edge of a panel which joins another panel.

ABV: Acronym for "air bypass valve"

A/C: [1] An abbreviation for air conditioning or air conditioner. [2] An abbreviation for "across corners" which indicates the distance on a nut (for instance) from one corner to the opposite corner rather than the distance from one flat surface (A/F) to the opposite (which would be the size of wrench needed to install or remove the nut). The purpose of the A/C dimension is to know how large a hole might be needed to insert a recessed nut.

AC: [1] A vehicle brand of which the 1925-48 models are classic cars. [2] Acronym for "alternating current." [3] Acronym for "air conditioning" or "air conditioner."

AC Ace: A vehicle brand of which the 1954-61 Ace models are milestone cars.

AC Aceca: A vehicle brand of which the 1955-61 Aceca models are milestone cars.

ACAP: Acronym for "Associação do comércio automovóvel de Portugal"

AC Buckland: A vehicle brand of which the 1949 Buckland Open Tourer is a milestone car.

acc: Abbreviation for "accessories."

ACC:

[1] Acronym for "Automatic Cruise Control." [2] A term found on a cruise control switch which indicates the direction the switch needs to be moved to increase the speed (accelerate) of the vehicle.

ACCC: Acronym for "air conditioner clutch compressor" signal

accelerate: To increase the speed of a vehicle. Opposite of decelerate.

accelerating-well ports: these ports prevent momentary leanness during the period that occurs between the opening of the air valve and the actual discharge of fuel from the secondary nozzles

acceleration: The rate of change of velocity or speed. Velocity is steady and is measured in distance per time (e.g., feet per second, miles per hour, kilometres per hour). Acceleration keeps increasing and is measured in velocity per time (e.g., feet per second per second or feet per second squared). Also see lateral acceleration sluggish acceleration yaw acceleration acceleration enrichment: The action of increasing the fuel/air mixture during acceleration in order to improve the vehicle's speed and its smooth response.

accelerator: [1] In automobiles, this is the "gas pedal" which is attached by linkage to the throttle in the carburetor or to the fuel injection system. It regulates the amount of fuel which is sent to the engine. In motorcycles, the accelerator is located on the right-hand twist grip or an actuating lever. [2] A chemical which is added to something to make a process happen more quickly. For example, a chemical may be added to paint to cause it to dry faster. The opposite is "retarder." Also see depress the accelerator

ease up on theaccelerator step on the accelerator take foot off the accelerator accelerator interlock: A connection between the gas pedal and the automatic transmission.

accelerator pedal: The accelerator, gas pedal, or throttle pedal.

accelerator pump: A small pump usually located inside the carburetor that sprays an extra amount of fuel into the engine during acceleration. It improves acceleration by giving more boost and reducing a momentary lag in power. It is actuated by depressing the pedal.

accelerometer: An instrument which measures the amount of acceleration.

acceptable quality level: (AQL) A manufactured good that may not be perfect but does reach a level of shape, size, and performance, etc. that will make it work and last as long as the manufacturer expects.

acceptance test: An examination of a part or its assembly to determine if it meets a prescribed standard.

access: A way of reaching something that is usually hidden or covered. Also see access panel access hole: An opening through which you can reach something. It is usually covered with a panel.

accessories:

Items and packages of equipment which are beyond the standard equipment supplied in a new vehicle.

accessory: See accessories.

accessory package: A set of features or appointments which may be ordered at extra cost on a new vehicle.

access panel: The cover which conceals the engine on a mid-engine vehicle. Also called "engine cover." Also see hood accident: See car accident

accident damage: The destruction caused to a vehicle's bodywork when it is involved in an accident.

Accord: A model of automobile manufactured by Honda Click for books on Honda Accord accumulator: [1] A storage battery for an electric car. [2] A pressurized container for an automatic levelling suspension system. [3] A part of the hydraulic system which is charged by the fluid pump, absorbs fluctuating fluid delivery, stores fluid at pressure, and can provide a rapid flow of fluid under pressure. Also see accumulator piston fuel accumulator hydraulic accumulator pressure accumulator accumulator battery:

A storage battery (i.e., the main battery in your vehicle).

accumulator drier: A device which is part of the air conditioning system. It is made up of a tank, filter, drying agent, and a vapor return tube. It is usually found on the evaporator outlet. It stores the excess refrigerant and removes the moisture from the refrigerant (thus the name "drier"). Also see receiver drier accumulator piston: A unit found in the automatic transmission to assist the servo to apply the brake band quickly and smoothly.

accumulator system: In an automatic transmission, it includes a hydraulic accumulator piston which is controlled by a valve.

accumulator valve: A device which operates the hydraulic accumulator piston in an automatic transmission.

Ace: An American trucker's colloquial term for someone with a class "A" licence. Also see AC Ace ACEA: Acronym for "Association des Constructeurs européens dAutomobiles" (i.e., European Automakers Association)

Aceca: See AC Aceca.

acetylene: A gas composed of two parts of carbon and two parts of hydrogen. When burned in an atmosphere of oxygen, it produces one of the highest flame temperatures obtainable for welding.

Also see oxygen acetylene cutting acetylene bottle: See acetylene cylinder

acetylene cutting: See oxygen acetylene cutting

acetylene cylinder: A specially built container manufactured according to I.C.C. Standards. Used to store and ship acetylene. Also called "acetylene tank" or "acetylene bottle"

acetylene hose: A flexible medium used to carry gases from regulators to the torch. It is made of fabric and rubber.

acetylene regulator: An automatic valve used to reduce acetylene cylinder pressures to torch pressures and to keep the pressures constant.

acetylene tank: acetylene cylinder

AC generator: A generator produces direct current (DC) while an alternator produces alternating current (AC). Because alternators were introduced to automobile electrical systems after generators had been in use for some time, some people referred to the new alternator as "AC generator."

ache: See head ache rack

ache rack: See head ache rack

acid:

Also see battery acid chromic acid oxalic acid acid rain: When the smoke created by factories and vehicle exhausts is taken by the wind and joined with rain clouds, the mixture is often acidic. As a result the rain that falls to the ground (and even on your car) may damage whatever it strikes.

AC Ignition System: See continuous AC Ignition System

Ackermann: See Ackermann steering.

Ackermann steering: A double-pivoting steering system where the outer ends of the steering arms are bent slightly inward so that when the vehicle is making a turn, the inside wheel will turn more sharply than the outer wheel. This is done to compensate for the greater distance the outside wheel must travel. Ackermann angle: The toe-out or toe-in of a vehicle with Ackermann steering when the wheels are positioned straight ahead.

Ackermann axle: In a vehicle with Ackermann steering (at the front of the vehicle), it is a nonrotating axle that is steerable and has two pivot points (one on each end of the axle) with vertical kingpins.

ACL BI-MET: Acronym for "air cleaner bi-metal sensor"

ACL DV: Acronym for "air cleaner duct and valve vacuum" motor

acquisition fee:

A charge for processing a lease and is probably not negotiable. On a shorter term lease, the acquisition fee can have a large impact on the cost of the lease.

across corners: (A/C) The distance on a nut (for instance) from one corner to the opposite corner rather than the distance from one flat surface (A/F) to the opposite (which would be the size of wrench needed to install or remove the nut). The purpose of the A/C dimension is to know how large a hole might be needed to insert a recessed nut.

across flats: (A/F) The distance on a nut (for instance) from one flat surface to the opposite flat surface, i.e., this is the size of the wrench needed to install or remove the nut. Also see across corners. acrylate: A polymer used to strengthen rubber (e.g., ethyl acrylate).

acrylic: A term relating to a type of paint made by polymerizing acrylonitrile.

acrylic finish: A final coating of paint which uses acrylic paint, often where the pigment and an acrylic paint are mixed together. Also see two-pack paint. acrylic paint: A type of paint made by polymerizing acrylonitrile.

acrylic resin: A thermoplastic synthetic polymer made by polymerizing an acrylic derivative such as acrylonitrile, acrylic acid, ethyl acrylate, and methacrylate. It is used for adhesives, protective coatings, and paint finishes.

AC Shelby Cobra: A vehicle brand of which the 1962-67 Shelby Cobra models are milestone cars.

ACT: Acronym for "air charge temperature."

Act: See motor Vehicle Safety Act

acting: Also see double-acting dual-acting single-acting action: Also see capillary action caster action mist action oscillating action parallel action locking pliers reciprocating action action brakes: See servo action brakes

action locking: See parallel action locking pliers

action locking pliers: See parallel action locking pliers

activated: See cable activated

activated carbon: A highly porous carbon which is able to absorb gases and fluids. It is usually found in small pellets so that the surface area is greater than a large chunk of it. Also it has a number of pores on each pellet to increase the surface area more. Thus the greater surface area means greater ability to absorb. Also called "activated charcoal."

activated carbon canister: An automotive filter in which activated carbon has been placed so that gas tank fuel vapors, which have accumulated when the vehicle is not running, are trapped in the filter. When the engine is running, hot air is forced into the filter and push out the vapors into the engine. In this way, pollution is reduced and conservation of the fuel is maintained. Also called "activated charcoal trap" or "charcoal canister."

activated charcoal: Also see activated carbon charcoal activated charcoal trap: See activated carbon canister.

activator: A substance which is used to speed up the process of curing a tire.

active braking time: The length of time (excluding the driver's reaction time) a vehicle takes to come to a complete stop after the brakes are applied.

active material: in a storage battery, peroxide of lead (brown) in positive plates and metallic lead (gray) in negative plates upon which sulphuric acid acts

active noise control system: See anti-noise system.

active safety: The opposite of passive safety. Passive safety involves seat belts, airbags, bumpers, etc. so that in the event of an accident the passengers are protected. Active safety involves factors which will assist the driver in avoiding an accident. They include brakes, steering, handling response, acceleration, etc.

active suspension:

While conventional suspension uses springs and shock absorbers to isolate the vehicle from the bouncing movement of the wheels when it contacts rough roads, active suspension uses power actuators which are controlled by a computer. These actuators place the wheels of the vehicle in the best position to accommodate rough roads as well as compensate for different load levels.

Activities: See Kaizen Activities

activity: See catalytic activity low temperature activity specific activity ACTS: Acronym for "air charge temperature sensor"

actual cash value: (ACV) The amount of money a dealer has invested in the purchase of a used vehicle and any additional costs to repair the unit in order to get it ready for resale.

actual throat: A welding term which describes the distance from the face of a weld to the root of the weld

actuate: The action of bringing a part or assembly into operation.

actuating lever: A triggering device used to bring a part or assembly into operation.

actuating switch: A triggering device used to bring a part or assembly into operation.

actuation:

See variable valve actuation

actuator: A device which controls or operates another device. Also see hydraulic actuators actuator arm: An arm connecting the diaphragm to the contact breaker platform in an advance mechanism. Also called "diaphragm link."

Acura: A vehicle brand from the Honda manufacturers

Click for books on Acura

ACV: [1] Acronym for "actual cash value." [2] Acronym for "air control valve"

ad: See classified ad

adapter: (Also spelled "adaptor") A connector which links two items usually of dissimilar structure or size. Also see bit adapter carburetor adapter engine adapter increasing adapter ratchet adapter reducing adapter transmission adapter wheel adapter. adaptor carburetor: a device attached to a gasoline carburetor which permits an internal combustion engine to run either on gas or liquefied petroleum gas (LP gas)

adapter plate:

(Also spelled "adaptor plate") A plate which is placed between two different parts in order to link them. Also see transfer plate additive: A substance (liquid or powder) which is added to gasoline or oil and is intended to improve the characteristics of the original product. Also see anti-knock additive fuel additive oil additive ADEFA: Acronym for "Asociacion de Fabricas de Automotores" (Argentina)

adhere: To stick or be glued to something.

adhesion: [1] The ability of paint, primer, or glue to stick to the surface to which it is applied. [2] The ability of a tire to grip the surface of the road. Also see intercoat adhesion failure limits of adhesion adhesion failure: See intercoat adhesion failure

adhesive: A substance (like glue) that is used to join two substances. Also see automotive adhesive impact adhesive separate-application adhesive adhesive tape: A tape with a sticky substance on one side. It usually comes in a roll of various widths. Sometimes used to insulate electrical wires (e.g., electrical tape) or to wrap a larger object (e.g., duct tape). Often the non-sticky side is shiny (but not always).

adhesive weight: Lead wheel weights which have a sticky backing. It comes in strips and is applied to a wheel rim. Also called "tape weight."

adiabatic: A property of being able to maintain heat evenly. It does not gain any heat or lose it. Also see thermal efficiency adiabatic engine: An engine which is very efficient in transferring combustion heat to those parts of the engine which are being cooled by the flow of anti-freeze coolant -- thus maintaining an even temperature of the engine. In this way the engine is warm enough for efficient running and it does not overheat.

adjust: The action of putting something into its proper alignment or position. It may involve one component (e.g., He adjusted the gasket to fit properly.) or a series of components (e.g., He adjusted the poor idle -- might mean he set the ignition timing, adjusted the carburetor screws, changed the choke setting, cleaned or replaced the spark plugs, etc.) Also see tweak adjustable: A characteristic of something that can be changed, removed, or give different properties. Also see height adjustable steering column adjustable cup: The left-hand cup in a bottom bracket of a bicycle, used in adjusting the bottom bracket bearings and removed during bottom bracketoverhaul. The other cup is the fixed cup.

adjustable off-idle air bleed: some emissions-era Rochester carburetors have a separate air passage to bleed air past an adjustment screw into the idle system. this screw is preset by the factory to produce precise off-idle air/fuel mixture ratios to meet emission-control

requirements

adjustable part throttle: (APT) a supplementary circuit on some carburetors that can be adjusted to control part-throttle mixtures more accurately than a fixed orifice. The APT detours around the main jet, going directly from the float bowl to the discharge nozzle feed well.

adjustable rocker arm: a type of rocker arm with an adjusting nut that can be tightened or loosened to adjust valve lash

adjustable shock: See adjustable shocks.

adjustable shock absorbers: shocks with adjustable jounce and rebound characteristics can be stiffened to compensate for wear or to fine tune a suspension for a particular application such as rough roads, heavy loads, or racing

adjustable shocks: Shock absorbers which can compensate for varying needs of stiffness or softness. Manual types require that you physically make the adjustment from one level to another. Automatic types are controlled by a computer as it senses particular changes in road condition.

adjustable spanner: British term for adjustable wrench.

adjustable steering: See height adjustable steering column

adjustable steering column: See height adjustable steering column

adjustable variable exhaust port: A device used on two-stroke engines which automatically alters or varies the exhaust port size.

adjustable wrench: A crescent wrench or pipe wrench. A tool which has a fixed jaw and a movable jaw which is controlled by a spiral gear. It is used to install or remove bolts and nuts of various sizes. The wrench itself comes in a variety of lengths and jaw sizes. A crescent wrench has smooth jaws while a pipe wrench has serrated jaws. British term is "adjustable spanner."

adjusted: See factory adjusted

adjuster: A device for moving something into the correct position or into a different position such as a seat adjuster. Also see automatic wear adjuster brake adjuster horizontal adjuster jet adjuster ride-height adjuster adjuster cam: A device for moving the shoes on drum brakes closer to the drum itself so that there is less travel when the brakes are applied.

adjusting: Also See electrode adjusting tool headlight adjusting screw self-adjusting adjusting gage: See adjusting gauge.

adjusting gauge: A tool used to determine the small distance between two parts so that they can be brought within specifications.

adjusting screw:

A small screw usually found on carburetors, brakes, or headlights which change the way something operates, such as increasing or decreasing the amount of fuel entering the engine; or changing the idle speed; or tightening up the brakes; or changing the setting on rocker arms; or the level of the headlights. Also see headlight adjusting screw tappet adjusting screw valve adjusting screw adjusting shim: A thin washer or plate which reduces or increases the clearance between two components (depending upon where they are placed). While some valves are adjusted by screws on the rocker arm, others are set by inserting a shim to make the same adjustment.

adjusting sleeve: A small cylinder on the end of the tie rod which shortens or lengthens the rod to make changes in the toe-in and toe-out.

adjusting spanner: See brake adjusting spanner

adjusting tool: See brake adjusting tool electrode adjusting tool adjusting wrench: See brake adjusting wrench

adjustment: [1] changing or modifying the position or alignment of two components. [2] the distance of travel that a component has. Also see fore and aft adjustment idle mixture adjustment screw idle speed adjustment adjustment screw:

See idle mixture adjustment screw

Adler: The brand name of a vehicle. With required application the 1925-48 models are classic cars.

a-dos: See dos-a-dos

A-drier: See a-dryer.

A-dryer: A paint dryer which has the heating elements below the paint drying line.

ADS: Acronym for "Association of Diesel Specialists"

adsorption: The bonding that takes place when a gas or vapor comes into contact with a solid. The opposite is desorption.

adsorption canister: See activated carbon canister.

advance: [1] The act of changing the ignition timing so that the spark occurs earlier in the cycle. The opposite is retard. [2] It may refer to the device which makes this adjustment. Also see automatic advance centrifugal advance electronic spark advance ignition advance mechanical advance ported vacuum advance spark advance

speed control vacuum advance vacuum advance advance capsule: See vacuum advance.

advance curve: As the speed of the engine increases the ignition advance also increases. On paper, a pattern is drawn as a curve to represent this relationship.

advanced: [1] A condition in which something occurs early. [2] A product which is on the cutting edge of technology and shows the latest in new ideas and concepts.

advanced rim taper: A rim where both bead seats are tapered 5°.

advance mechanism: See vacuum advance mechanism

advance unit: See vacuum advance unit

advance weight: One of two small weights located in a centrifugal advance assembly.

advertising: A colloquial term for a police car with its emergency lights flashing.

AEA: Acronym for "Automotive Electric Association" or "Automotive Electronic Association"

AERA:

Acronym for "Automotive Engine Rebuilders Association."

aeration: A foaming of a liquid because air has been introduced into the fluid. When it occurs in certain liquids, it decreases the efficiency of the liquid.

aerial: British term for antenna. Also see retractable aerial whip aerial aerobic sealer: a substance (such as room temperature vulcanizing (RTV), a common silicone rubber sealing compound) that requires the presence of oxygen to hold parts together. See anaerobic sealer

aerodynamic: The efficient flow of air around an object.

aerodynamic drag: The resistance of the air to forward movement, sometimes called "air resistance." This is a factor of the shape of the vehicle (drag coefficient and frontal area), the objects which stick out (i.e., mirrors, mufflers, bumpers), the amount of turbulence at the rear of the vehicle, the nature of the vehicle's skin surface, and the amount of air going through the vehicle for cooling and ventilation. The faster you go, the greater the air friction (air friction = velocity x velocity). The faster you go, the greater the amount of power needed to overcome this drag (power = velocity x velocity x velocity).

aerodynamics: The study of the flow of air as it passes over and around a moving object as well as the forces which the air makes on the object. An airplane, for instance, needs positive lift to get it airborne and negative lift to help it land. Thus the shape of a land vehicle (car, bicycle, etc.) either promotes positive or negative lift. Race cars may use spoilers and wings (air foils) to control lift. In vehicle design, the airflow is monitored in a wind tunnel. As well, aerodynamics also studies the most efficient shapes for increased speed and fuel economy.

aerodynamic stance:

In order to create less drag, the vehicle is lowered closer to the ground. This improves the flow of air over the vehicle. A better aerodynamic stance helps the vehicle to go faster when it is going in a straight line as well as give better fuel economy. Also, when a vehicle sits lower to the ground, it has a low center of gravity which makes it more stable when going through turns and enables the driver to maintain a higher speed.

aerofoil: A body shaped like a wing so as to produce lift. See air foil.

A/F: [1] Abbreviation for "across flats" which is the distance on a nut (for instance) from one flat surface to the opposite flat surface, i.e., this is the size of the wrench needed to install or remove the nut. Also see across corners. [2] Abbreviation for "air/fuel." See air-fuel ratio.

AFB: Acronym for "Aluminum four-barrel," as in Carter AFB carburetor.

AFC: Acronym for "air flow controlled"

affected zone: See heat-affected zone

A-Frame: A chassis frame which is shaped like the letter "A" where the crossbar is often the axle. It is usually found as the frame of a trailer.

A/F ratio: See air-fuel ratio.

aft: The back of a vessel. Also see fore and aft adjustment aft adjustment:

See fore and aft adjustment

after bottom dead center: (ABDC) The position of the piston as it starts its way up.

afterburner: A device for burning excess carbon wastes produced by the engine so that air pollution is reduced.

aftercooler: A device in a diesel engine which removes the relatively warm air which enters the engine.

afterglow: the period during which the glow plugs of a diesel engine continue to operate after the engine is started

aftermarket: All products and services used in the repair and maintenance of vehicles after the vehicle has been sold.

aftermarket equipment: Accessories and replacement parts added to a vehicle after it has been sold.

aftermarket overdrive: An overdrive device which is not original equipment, but has been added after it has been sold.

aftermarket part: Goods not for use as original equipment in the production of light-duty vehicles or heavy-duty vehicles, i.e., products and services used in the repair and maintenance of these vehicles.

aftermarket rustproofing: Although most vehicles come from the manufacturer with some rustproofing, there is no guarantee that every part of the exposed chassis and frame will be protected from the elements and the possibility of rust. Therefore rustproofing is applied by the owner of the vehicle to reduce the possibility of rust. If this rustproofing is not

done when the vehicle is new, it might seal in the rust and create a greater problem.

afterpeak bulkhead: First main transverse bulkhead forward of the sternpost

after perpendiculars: A vertical line at the intersection of the summer load line and the after side of the rudder post or sternpost, or the centerline of the rudder stock if there is no rudder post or sternpost

after-start enrichment: When an engine is first started, it needs a little richer fuel-air mixture (i.e., more fuel, less air). In a carbureted engine, this is accomplished by the choke (which restricts the amount of air). In a fuel injected engine, the after-start enrichment device increases the amount of fuel. As the engine warms up, the device gradually reduces the amount of enrichment. Some devices just reduce the amount gradually over time without sensing the temperature of the engine.

after top dead center: (ATDC) A term used in timing the relation of the spark and the crankshaft. The position of the piston as it starts its way down.

AG: Acronym for "air-guard"

aged catalyst: A catalyst which has already been in service. Opposite to a fresh catalyst.

age-hardening: Aluminum and some metal alloys will become hard and even brittle with age which is an unwanted characteristic. On the other hand when paint or cement harden over time, this process may be a desirable characteristic.

ageing: See aging.

Agency:

See driver and Vehicle Licensing Agency energy Protection Agency agent: An intermediary with legal authority to operate on behalf of the manufacturer. Also see aggressive agent anti-knock additive anti-knock agent bonding agent degreasing agent oxidizing agent reducing agent release agent rustproofing agent softening agent agent fee: Although you can register your vehicle and obtain your licence from a government office, some states and provinces permit an agent to perform that same service and allow the agent to collect an extra fee for the service. In this way the lineup at the government office is reduced.

aggressive: A French expression to indicate the reinforced front, rear, and side safety structures of a vehicle. If the strengthened structure causes more than normal damage to another vehicle, a pedestrian, or the occupants of the vehicle, then that structure is aggressive.

aggressive agent: A corrosive material or chemical which attacks metal to pit them. Also called "aggressive medium."

aggressive medium: A corrosive material or chemical which attacks metal to pit them.

aggressivity: See aggressive.

aging: [1] The deterioration of rubber properties by oxidation over a period of time. [2] A change in the properties of some metals after heat treatment or cold working (i.e., hammering or bending when metal is cold). See tire aging

agitation cup: A type of spray gun paint container which has an agitator.

agitator: A device for mixing paint by shaking the container.

Agreement: See Free Trade Agreement of the Americas General Agreement on Tariffs and Trade North American Free Trade Agreement Agreement of the Americas: See Free Trade Agreement of the Americas

Agreement on Tariffs: See General Agreement on Tariffs and Trade

Agreement on Tariffs and Trade: See General Agreement on Tariffs and Trade

aground: See hard aground

AGVS: Acronym for "Automated Guided Vehicle System."

a.h.: Abbreviation for ampere-hour.

AHAI:

Acronym for "Association of the Hungarian Automotive Industry"

AHAP: Acronym for "As High As Possible."

AHARA: Acronym for "As High As Reasonably Achievable"

ahoogah: The sound of a particular kind of horn.

AHRA: Acronym for "American Hot Rod Association."

AH Rim: A wheel rim which is able to run even when the tire is flat and provides safety in case of a puncture.

AIADA: Acronym for "American International Automobile Dealers Association"

AIAM: Acronym for "Association of International Automobile Manufacturers"

AIA-SAP: Acronym for "Automotive Industry Association" (Czech Republic)

AIA-ZAP: Acronym for "Automotive Industry Association" (Slovakia).

aided: See computer-aided

aids:

See suspension aids

AIMA: Acronym for "Associação dos Industriais de Montagem de Automóveis" (Portugal).

aimer: A tool for aiming headlights.

aiming: Adjusting the direction of the headlight beams to shine without blinding oncoming traffic and yet providing the maximum illumination whether in low beam or high beam.

air: [1] Abbreviation for "air conditioner." [2] A gas containing approximately 80% nitrogen, 20% oxygen, and a small portion of other gases. One of the essential factors in a combustion engine (fuel, air, proper proportion of mixture, compression, timing, and spark). Also see ambient air bath air charge air cold air driver air bag electric air control valve electric air switching valve

external mix air cap fuel air mixture fuel air ratio heater air pipe idle air bleed screw idle air jet internal mix air cap

L-jetronic air flow meter lateral air passage low-profile air cleaner modular air strut oil bath air cleaner paper air cleaner passenger-side air bag

proper proportion of air and fuel pulse air principle pulse air system ram air secondary air

AIR: An acronym for "Air Injection Reactor" system of reducing objectionable exhaust emissions. Also see air injection air and fuel: See proper proportion of air and fuel

air aspirator system:

(AAS) A passive air injection system that uses a one-way valve instead of an air pump to introduce extra air into the exhaust stream

air bag: A device which is part of the passive safety system. In the event of an accident, sensors will cause the airbag to be deployed so that your head will be pillowed by the bag instead of hitting the dash. Also see driver air bag passenger-side air bag side impact air bag airbag: A device which is part of the passive safety system. In the event of an accident, sensors will cause the airbag to be deployed so that your head will be pillowed by the bag instead of hitting the dash. Also see driver air bag passenger-side air bag side impact air bag airbag module: All the components that make up the airbag system: Airbag, inflator, cover, and sensor. Also called "airbag unit."

airbag restraint system: A system which uses an airbag to restrain occupants in the event of a collision. They may be placed on the dash or doors or even in the shoulder strap. Also called "passive restraint system."

air-bag system: See supplemental restraint inflatable air-bag system

airbag unit: All the components that make up the airbag system: Airbag, inflator, cover, and sensor. Also called "airbag module."

air bellows: A rubber bladder or sleeve filled with compressed gas or air. Found on some suspension systems to provide cushioning. See air suspension.

air bleed: See compensating jet idle air bleed screw air bleed screw: See idle air bleed screw.

airbox: The container which holds the air filter.

air brake: A system of braking which is usually found on large truck in which compressed air pushes against a brake piston or diaphragm in order to apply the brakes to stop or slow the vehicle.

airbrush: [1] A paint spray gun used for precise detailing work and custom painting. [2] The act of using an airbrush.

air bypass valve: (ABPV or ABV) a backfire-suppressor valve used in air injection systems. During high engine vacuum conditions such as deceleration, it vents pressurized air from the air pump to the atmosphere in order to prevent backfiring. At other times, it sends air to the exhaust manifold. On vehicles with a three-way catalyst, it sends air to the oxidation catalyst only when the engine warms up. Also called an antibackfire valve, diverter valve, or gulp valve

air cap: See external mix air cap internal mix air cap air capacity: See breathing capacity.

air charge temperature:

(ACT) The temperature of the air being forced into the carburetor or fuel injection system. An ACT sensor measures this temperature

air charge temperature sensor: (ACTS) a thermistor sensor that inputs the temperature of the incoming air stream in the air filter or intake manifold to the computer. It can be located in the intake manifold (EFI systems) or the air cleaner. On carbureted vehicles, if the air is cold, it signals the choke to let off slowly. It then alters engine speed after the choke is off and below a certain temperature, dumps air from the air injection system to the atmosphere for catalyst protection

air cleaner: A device which filters the air entering the engine to remove dust, dirt, and bumblebees. Also called "air filter." Also see bath air cleaner low-profile air cleaner oil bath air cleaner paper air cleaner thermostatic air cleaner air cleaner bi-metal sensor: (ACL BI-MET) a component of a thermostatic air cleaner system. It senses the temperature of incoming fresh air and bleeds off vacuum when the air is warm. When the air is cold, the sensor directs vacuum to the air cleaner vacuum motor.

air cleaner duct and valve vacuum motor: (ACL DV) a component of thermostatic air cleaner systems. It opens and closes the air duct valve to provide heated or unheated air to the engine in accordance with the temperature of the incoming air

air cleaner element: The replaceable filter which prevents impurities from the air which enters the combustion chamber. Also called "air filter element."

air cleaner horn: Many air cleaner canisters have a spout or horn extending from the edge of the canister into which the air is taken in. See heated intake.

[Ba] [Bb] [Bc] [Bd] [Be] [Bh] [Bi] [Bl] [Bm] [Bo] [Bp] [Br] [Bs] [Bt] [Bu] [Bw] [By]

BA: An abbreviation for "British Association" which is a term used to describe a series of fine, small diameter threads for electrical and precision equipment

babbitt: An alloy of tin, copper, and antimony having good antifriction properties. Used as a facing for bearings.

babbitt metal: See babbitt

baby seat: A specially designed seating device (which is not generally standard equipment) to hold safely very young children (usually under the weight of 10 kilograms).

BAC: Acronym for "Blood Alcohol Content"

back: See blow back die-back die back kamm back popping back spine-back back axle: The rear axle

back axle ratio: See final drive ratio

backbone:

See backbone frame.

backbone chassis: See backbone frame

backbone frame: A frame, having the cross-section of a rectangular box, that runs along the center of the vehicle and occupies the space between the seats. This box generally divides at the front, running along each side of the gearbox and engine up to a crossmember to which the front suspension pieces are attached. At the rear a similar triangular frame encloses the final-drive housing and provides attaching points for the rear suspension. Lightness combined with high torsional rigidity are features of this frame design, made famous by Colin Chapman with the Lotus Elan. Also see tubular backbone frame backfire: [1] Passage of unburned fuel mixture into the exhaust system where it is ignited and causes an explosion (backfire) prematurely. [2] Sometimes ignition takes place in the intake manifold by a flame from a cylinder because the intake valve leaks. Burning of the fuel mixture in the intake manifold may be caused by faulty timing, crossed plug wires, leaky intake valve, etc. [3] A welding term referring to a short "pop" of the torch flame followed by extinguishing of the flame or continued burning of the gasses

backfiring: Repeated backfires in the exhaust or the cylinders

backflow scavenging: See loop scavenging

backflushing: See flushing the cooling system.

backhand welding: Welding in the direction opposite to the direction that the gas flame is pointing. Also called "backward welding."

backing: Some material placed on the root side of a weld to aid control of penetration. Also see steel backing backing pad: A rubber disc which is secured to a spindle which in turn is attached to a drill or other tool which rotates the spindle. An abrasive disc or polishing disc is secured to the backing pad.

backing plate: See brake backing plate.

backlash: The amount of "play" or clearance between two parts. In the case of gears, it refers to how much one gear can be moved back and forth without moving the gear into which it is meshed.

backlight: The rear window of a vehicle.

backlight heater: Heated rear window

backlight defogging system: Heated rear window

back panel: The panel of the body shell set underneath the trunk lid. It is sometimes referred to as the rear valance if the area below the trunk lid consists of only a single panel that extends down to the bottom of the body; in many designs, however, the rear valance is a separate horizontal panel that extends from the rear bumper area downward. The British term is "rear panel"

backplate:

British term for brake backing plate

back pressure: The resistance to the flow of exhaust gases through the exhaust system. By rerouting the exhaust gases for noise suppression, a muffler causes back pressure, but a straight pipe alone causes only minimal back pressure. Some engines require back pressure, so that removing the exhaust system will cause internal damage. Also see exhaust back pressure negative back pressure valve negative back pressure modulated valve back pressure modulated: See negative back pressure modulated valve

back pressure modulated valve: See negative back pressure modulated valve

back pressure valve: See negative back pressure valve

backpressure variable transducer: (BVT) a system combining a ported EGR valve and a backpressure variable transducer to control emissions of NOx

backrest: The back (upright) part of the seat against which your back reclines

back-seat: An air conditioning term which means to rotate a service valve counterclockwise all the way down until the valve is back-seated. When referring to a stem type service valve, the term has a more specific meaning-in the back-seated position, the valve outlet to the system is open and the service port in the valve is closed (its normal operating position)

back-step welding: Welding small sections of a joint in a direction opposite the direction that the weld as a whole is progressing.

back up: To go in reverse

back up alarm: An annoying loud beeping which is repeatedly sounded when a vehicle (usually a large truck) is placed in reverse. It is designed to warn pedestrians behind the vehicle. The British term is "reversing warning signal"

back up light: A light which is located at the rear of the vehicle and is illuminated when the transmission is placed in reverse. The British term is "reversing light"

back-voltage: Voltage which opposes the current when the current in an inductive circuit changes and the magnetic field cuts the conductors. Also see self-induction back-voltage backward welding: See backhand welding

BAC level: Blood Alcohol level

badge: An emblem with a manufacturer's name and/or logo on a plate to identify a model or component. Also see hood badge badge engineering: When a manufacturer sells two identical vehicles but the model names are different, he is badge engineering. For example, General Motors may sell a vehicle as a Chevrolet or a Pontiac where the only difference is the model name, logo, and more or less chrome or other minor alterations.

badging:

The tendency of a manufacturer to engage in badge engineering

baffle: An obstruction used to slow down or divert the flow of gases, liquids, sound, etc. They are found in the fuel tank, crankcase, muffler, and radiator. baffle plate: A metal plate that acts as a baffle.

bag: See air bag courier bag cruiser bag driver air bag passenger-side air bag shot bag side impact air bag tank bag bake: A process of drying or curing paint by using heat

Bakelite: The trademark for a synthetic thermosetting plastic resin used in electrical parts because it is a good insulator. The name comes from its inventor, L. H. Baekeland, 1863-1944.

baking finish: Paint that requires baking in order to dry

baking temperature: The temperature at which a varnish or paint must be baked to develop desired final properties of strength and hardness

balance: [1] The state in which weight is evenly distributed. [2] The action of applying weights or drilling holes in something to establish even weight distribution so that vibration is reduced.

Also see balance shaft counter balance crankshaft counter-balance dynamic balance harmonic balancer heat balance kinetic balance off-car balance on-car balance spool balance valve static balance steering wheel balance tire balance wheel balancer balance control: A switching device on a stereo radio which adjusts the amount of sound coming from the left and right speakers or from the front and rear speakers

balanced crankshaft: A crankshaft with extended reinforcements to form counterbalancing or act as a vibration damper

balance disc: A disc-shaped device in a centrifugal pump which is attached to the pump shaft. The disc lifts when a force is applied to the underside of the disc allowing pressure to leak past until the axial forces are balanced

balanced engine: An engine in which all the reciprocating parts such as pistons and connecting rods are adjusted to exactly the same weight

balance patch: A factory installed patch used to bring a new tire within quality control balance tolerances before distribution and sale. It is placed inside the tire casing and looks much like a nail hole repair patch.

balance pipe:

A tube which joins two or more carburetors to even out the flow difference.

balancer: See harmonic balancer wheel balancer balance shaft: An engine will normally vibrate because of the up-and-down motion of the pistons which turn a crankshaft in one direction. A balance shaft rotates (often in the opposite direction) so that its vibration cancels some of the vibration of the engine. Sometimes an engine will have two balance shafts turning in opposite directions located on either side of the crankshaft.

balance valve: See spool balance valve

balance weight: A lead weight attached to the rim of a wheel. See wheel weight.

balancing: [1] Dismantling engine and reassembling it to exact specifications and tolerances. This process may help to improve engine performance, smoothness, and reliability. Sometimes called "blueprinting." See balanced engine. [2] Keeping wheels in balance. Also see wheel balancing off-the-car balancing on-the-car balancing balancing machine: See wheel balancing machine

balancing weight: See wheel weight

bald tire: A tire on which the tread is all worn away. A slick also has no tread, but this is done deliberately for racing purposes

balk ring: A friction-regulated pawl or plunger used to make the engagement of gears easier. British spelling is "baulk ring" ball: A sphere usually made of metal when used in automotive applications. Also see ball and spring ball bearing ball joint ball joint rocker arm check ball detent ball and spring hitch ball impact swivel ball universal joint recirculating ball and nut steering recirculating ball steering recirculating ball worm and nut recirculating ball towing ball ball and nut: See recirculating ball and nut steering

ball-and-nut steering: See recirculating ball steering

ball and socket: See ball joint

ball and socket joint: See ball joint

ball and spring: See detent ball and spring.

ballast:

Any liquid or solid weight placed in a ship to change the trim, increase the draft, or to regulate the stability. Also see dry ballast lead ballast liquid ballast ballast ignition system: An ignition system which uses a ballast resistor connected in series with the coil primary winding and which is bypassed when the starter is engaged so that the spark is more efficient under cold weather starting

ballast tank: Tanks at the bottom or sides of a ship which are filled with seawater for ballasting purpose.

ballasting: The addition of liquid or dry weight inside the tire to act as a counterbalance, to increase traction, reduce wheel spin, and dampen out bounce.

ballast resistor: (BAL RES) A resistor constructed of a special type wire, the properties of which tend to increase or decrease the voltage in direct proportion to the heat of the wire.

ball bearing: An antifriction bearing consisting of an inner and outer hardened steel race (or cage) separated by a series of hardened steel balls.

ball bearing puller: A tool for removing a ball bearing from a shaft or from a housing

ball cage: A circular frame which holds the balls in place in a ball bearing

ball end hexagon screwdriver: A tool that looks like an Allen wrench except it has a small ball at the very end. This arrangement allows it to work at various angles.

ball joint: A flexible joint using a ball and socket type of construction, used in steering linkage setups, steering knuckle pivot supports, etc. Their flexibility helps to compensate for the changes in the wheel and steering when turning or hitting a bump on the road. There are usually upper and lower ball joints attached to the upper and lower A-arms. ball joint rocker arm: A rocker arm that instead of being mounted on a shaft, is mounted upon a ballshaped device on the end of a stud.

ball joint separator: A tool for forcing out ball or tapered joints. One style is shaped like a two-prong fork with a wedge-shaped jaw which is struck with a hammer to separate the joint. Another style uses direct pressure from a screw or screw-activated lever action to split the joint.

ball joint steering knuckle: A steering knuckle that pivots on ball joints instead of on a kingpin.

balloon tire: A type of low pressure tire which was first introduced in the 1920s. Its width and height were the same which gave it a rounded shape. This style was used on bicycles as well as automobiles.

Ballot: A vehicle brand of which the 1925-1948 model automobiles with required application are classic cars.

ball pien hammer: A hammer with two ends on the head. One is round and the other is flat. They are best used for hammering and shaping metal. Also spelled "ball peen"

ball peen hammer: A hammer with two ends on the head. One is round and the other is flat. They are best used for hammering and shaping metal. Also spelled "ball pien"

ball socket:

A recessed spherical well for receiving the ball in a ball joint

ball steering: See recirculating ball steering

ball universal: See impact swivel ball universal joint

ball universal joint: See impact swivel ball universal joint

ball valve: A check valve in which a ball in a tube is used to control the flow of liquid.

ball worm: See recirculating ball worm and nut

ball worm and nut: See recirculating ball worm and nut

BAL RES: Abbreviation for ballast resistor

band: Bands are like a metal belt which is in the shape of a circle where the two ends are close, but do not meet. They wrap around parts inside the transmission called "drums." The drums house the gears and clutches and freewheel until a certain gear needs to be applied. When first gear needs to be applied, the drum for first gear is locked up by the application of the band. By locking up the drum, the gears now drive the wheels rather than freewheel inside the drum. Also see brake band power band squish band band brake:

See brake band

band radio: See citizens band radio

bands: See band.

bandwidth: The range of audio frequencies that an audio component (radio) can handle

B & S: bore and stroke.

B & S gage: Abbreviation for "Brown and Sharpe." A standard measure of wire diameter.

B & S gauge: Abbreviation for "Brown and Sharpe." A standard measure of wire diameter.

banger: [1] A colloquial term used to express the cylinders in an engine. Often used with a number such as "six banger." Also see four banger [2] A British colloquial term for beater (an older, cheaper, well-worn car which is still usable). [3] One who fakes an accident. See car banger

banger racing: A competition of speed on small racing tracks where older cars are driven as fast as they can go and where bumping other racing cars is permitted (encouraged??)

banging: See car banging

banjo: [1] Besides being a musical instrument, this is a fitting which is shaped like a banjo. It has round end that is doughnut shaped with a tube coming out from one side. It is usually used to transfer fluid from the center hole of the round end and out the lateral tube. [2] A drum-shaped central part of an axle casing containing the differential. Also see rear axle housing, banjo type axle housing banjo bank: See cylinder bank

banking: The slope of a track from the wall to the apron, generally measured in the corners.

bar: [1] A unit of pressure. One bar equals 100 kilopascals or 14.5 psi. [2] A rod. Also see anti-roll bar anti-sway bar antiroll bar boring bar bull bar bumper bar busbar compensating bar compensator extension bar freeway bar gunwale bar header bar hi-way bar highway bar hood bar ladder bars landau bar landau bars levering bar locking bar clamp main bar nerf bar

nudge bar port bar push bar roo bar side impact bar sissy bar spring bar stabilizer bar stringer bar strut bar sway bar t-bar targa bar test bar tommy bar torsion bar track bar traction bar tread bar wear bars wheelie bar wheelie bars wobble extension bar Barach: The author and compiler of this dictionary at Motorera.com

bar clamp: A tool with a stationary head and a sliding foot for clamping purposes. Also see locking bar clamp

bare shell: The shell of a car body in which all parts have been removed including doors, hood, and trunk lid

barge: A flat-bottomed boat for carrying cargo or bunker oil, usually pulled by tugs. Also see tank-barge barge carriers:

Ships designed to carry barges.

BARO: [1] Acronym for barometric pressure sensor. [2] Acronym for barometric absolute pressure sensor

barometric absolute pressure sensor: (BARO or BP) sends a variable voltage signal to the computer which varies in accord with atmospheric pressure, allowing adjustment of the spark advance, EGR flow, and air/fuel ratio as a function of altitude. Also called a barometric pressure sensor

barometric and manifold absolute pressure sensor: (BMAP) a housing containing both BP and MAP sensors

barometric pressure sensor: (BARO or BP) A sensor found in the engine management system which detects the ambient barometric pressure so that precise fuel mixture can be maintained at different altitudes

barrel: [1] The air horn in the carburetor. In particular, it is that part where the throttle valve is located. If a carburetor has four openings with a throttle valve in each, it is called a "four-barrel carburetor." Also see carburetor barrel four barrel carburetor four barrel [2] Another name for the carburetor barrel cylinder, cylinder barrel, four barrel, polishing barrel, and single barrel. [3] To travel fast as in "We barrelled down the highway well above the speed limit."

barrel carburetor: See four barrel carburetor single barrel carburetor twin barrel carburetor barrel tappet:

A hollow rocker arm shaped like a barrel

barrier: See crash barrier

barrier cream: A special cream which is applied to your hands before working on a greasy engine. When the job is over, you can wash your hands and easily remove the grease stains. Also called "invisible glove" or "silicon glove"

barrier effect: The effect produced by coating metal to shield it from corrosion

barrier paint: A primer which is used on bare metal to prevent corrosion.

bar roof: See t bar roof

bars: See ladder bars landau bars wear bars wheelie bars bar suspension: See torsion bar suspension

base: [1] The lowest supporting part of an upright member. [2] The bottom layer or coating in a series of paint coats. Also see bead base edison base flat base rim taper flat base rim lithium base grease

load base negative load base rim well base base and clear system: Paint finish which is made up of a colored base coat (usually a metallic finish) and clear lacquer coat

base circle: As applied to the camshaft the lowest spot on the cam, the area of the cam directly opposite the lobe or nose. No lift is produced by the base circle. Also called cam heel

base coat: The first coat in a paint system. It is either the undercoat or primer or a colored coat which is covered by clear lacquer

base gasket: The gasket directly below the cylinder and between the cylinder and crankcase. Also called "cylinder gasket."

base grease: See lithium base grease

base idle: The idle speed determined by the throttle lever setting on the carburetor or throttle body while the idle speed control (ISC) motor, or any other computer-controlled idle speed control device, is fully retracted and disconnected.

base interest rate: The interest paid on the usage of the vehicle during a lease. It is the "cost" of a lease before factoring in discounts, fees, and penalties and is not directly comparable to the APR for a loan. Lowering the base interest rate is one of the methods manufacturers use to subsidize leases. The phrase "money factor" measures the same cost and can be converted into a base interest rate. For example, to convert a money factor of 0.00276 into an approximate base interest rate would multiply the money factor by 24. The result would be 0.0662 or 6.6%.

baseline:

A fore-and-aft reference line at the upper surface of the flat plate keel at the centerline for flush shell plated vessels. Vertical dimensions are measured from a horizontal plane through the baseline, often called the molded baseline.

base material: Any material (metal or plastic) which needs to be coated

base metal: [1] Metal that is under a coating or that needs to be coated. [2] Metal to be welded, cut, or brazed.

base model: The least expensive vehicle with the least amount of features as standard equipment. It has the smallest engine and often manual transmission as well as few power equipment. Base models constitute only a small percentage of the cars sold. Sometimes called a "stripper" or "stripped down" unit.

baseplate: A strong metal plate which is the main support for something. See distributor baseplate

base rim: See flat base rim flat base rim taper base rim taper: See flat base rim taper

basic ignition setting: The ignition setting on a non-running engine according to the specifications. After the engine is running, the timing can be set more accurately

basic ignition timing: The ignition timing on a non-running engine according to the specifications. After the engine is running, the timing can be set more accurately

basic price:

The price of a vehicle without including any optional accessories, taxes, delivery charges, etc.

basic timing: The ignition timing on a non-running engine according to the specifications. After the engine is running, the timing can be set more accurately

basin: See building basin

basket case: An old car which probably does not run. Often many engine and transmission parts have been removed and are either missing or stored in the trunk or a "basket"

bastard: A file (a tool) which has a coarse cut

bastard file: A file with a coarse cut

bat: A lump or collection of something. Also see fibreglass batch: [1] A number of things which are produced as a group. [2] A mixture of natural and synthetic rubber with other material such as fillers, chemicals, and vulcanizing agents in the production of tires

batch number: A number which may be added to a serial number to identify when the product was manufactured. In this way, when a problem occurs to some products of the same batch, action can be taken to correct or replace others from the same batch.

bath: A tub into which something is immersed.

Also see anodizing bath galvanizing bath oil bath air cleaner primer bath sealing bath zinc bath bath air: See oil bath air cleaner

bath air cleaner: See oil bath air cleaner

bathtub: Bodywork resembling an upside-down bathtub used on the rear of some Triumph motorcycles. It was introduced in 1957 and dropped in the early 1960s

battens: See cargo battens hatch battens battery: An electrochemical device for producing electricity by converting chemical energy. The typical automotive lead-acid battery supplies the source of power for cranking the engine and also provides the necessary electrical energy for the ignition system. In addition, it can (for a limited time) furnish current when the electrical demands of the vehicle exceed the alternator or generator output. Also called the "storage battery." Also see accumulator battery alkaline battery booster battery charged battery check the battery dead battery discharged battery disconnect the battery dry battery dry charged battery

flat battery gel cell battery high energy battery isolate the battery lead-acid battery low-maintenance battery low battery maintenance-free battery primary battery rechargeable battery secondary battery sodium-sulphur battery storage battery top up the battery battery acid: Electrolyte (usually sulphuric acid) in each of the battery cells

battery cap: Small caps which seal each battery cell

battery capacity: The amp-hour capacity

battery cell: Individual compartments in a battery which is filled with electrolyte. Six-volt batteries have three cells, 12-volt batteries have six cells

battery case: The box made of polypropylene holding several chambers (cells) which have lead plates and filled with electrolyte.

battery charge: The condition or state of the amount of electricity in a battery

battery charge indicator: An instrument which shows the state of charge in a battery

battery charger:

An electric device which is plugged into an electrical outlet (e.g., 110 volt AC) and connected to the two terminals of the battery to restore the state of charge in the battery. One of leads coming from the charger is red and the other is black. The red lead is clamped on the positive post of the battery while the other is clamped on the frame of the vehicle.

battery charging: The process of renewing the battery by passing an electric current through the battery in a reverse direction.

battery charging station: With the advent of electric cars, there needs to be places where their batteries can be recharged periodically -- thus is born the battery charging station. Also called a "charging point."

battery clamp: A hold down device which secures the battery from moving around

battery compartment: A place in the vehicle where the battery is located. In cars and trucks it may be found under the hood (usually toward the front), under one of the seats, or in the trunk. In motorcycles it is found in the middle of the bike, under the seat

battery condition: See battery charge

battery connector: A plug on battery-powered vehicles to connect the batteries to the charging station

Battery Council International: A group which makes decisions related to battery composition and disposal.

battery cover: The top of the battery case. It has several holes (covered with caps) for access to the battery cells.

battery discharge controller:

A device on a vehicle which is driven by an electrical motor. It triggers a warning indicator when the battery power drops below a certain level.

battery discharge indicator: An instrument on a vehicle which is driven by an electrical motor which indicates the percentage of the maximum charge of the battery

battery earth: British term for battery strap or ground strap

battery filler: A device with a long hollow tube with a rubber bulb at one end. It is used for inserting into a container of battery acid and sucking up the acid, then inserting into the battery cell to fill it. However, motorcycle batteries arrive from the manufacturer with no electrolyte (battery acid). Battery acid comes in a large plastic container with a rubber hose to which a metering clamp is attached. The container is usually placed on a higher shelf so that it is fed into the battery by gravity and regulated by the metering clamp

battery fill line: A horizontal line on the side of a translucent battery case which indicates the level to which you fill it with electrolyte. Usually there are two lines indicating a minimum level and maximum level.

battery fluid: See battery acid

battery hold down clamp: See battery clamp

battery ignition: Any system where the battery supplies the initial voltage to power the starter motor and fire the spark plugs

battery ignition system: See battery ignition

battery is flat:

The battery does not have enough electrical power to start the car

battery is flat: The battery does not have enough electrical power to start the car

battery master switch: A control which disconnects the battery power from all the electrical components

battery post: The terminal on a battery to which the cable is attached. Older automobile batteries used a round post which stood up from the top of the battery. To avoid confusion, the positive post has a larger diameter than the negative. On newer batteries the post may or may not be abandoned in favor of a terminal on the side of the battery. On motorcycle batteries, the posts are usually flat with a hole for bolting the cables to them.

battery state indicator: See battery charge indicator

battery strap: [1] A wire cable or braided wire strap to transfer electricity. It can be found between the engine block and the chassis because the engine is isolated from the chassis by rubber mounts. Also called ground strap. See ground wire. [2] A rubber strap with metal hooks at each end and is used to secure a battery in place, especially on motorcycles

battery terminal: [1] A battery post on the top of the battery or a lug with a hole on the side of the battery. [2] The clamp at the end of a battery cable

battery tester: [1] A voltage meter or hydrometer for checking the state of charge of a battery. [2] An instrument for checking the condition of the battery cells

battery tray: A metal or plastic on which the battery sits.

baulk ring: British spelling for balk ring

bay: See engine bay

bayonet bulb: See bayonet cap

bayonet cap: A cylindrical base of an electric bulb, usually with two pins projecting on either side, which engage in J-shaped slots to lock the bulb securely in its socket.

bayonet fitting: See bayonet socket

bayonet socket: A socket for receiving a bayonet cap. It has two slots on either side (usually Jshaped) to accommodate the bulb's pins.

BBDC: Acronym for "before bottom dead center."

bbl: Abbreviation for "barrel," as in 4-bbl carburetor.

BCDD: Acronym for boost-controlled deceleration device

BCI: Acronym for "Battery Council International."

BCM: Acronym for body computer module

BDC:

Acronym for "bottom dead center."

bead: [1] The portion of a tire which fits onto the rim of the wheel. On a tubeless tire, the contact of the bead with the rim seals the air into the tire. Bead heel, bead sole, and bead toe form a foot-like shape. Also see tire bead. [2] A small ball-like particle used in bead blasting or in some catalytic converters. [3] In welding, it is the appearance of the finished weld. It describes the neatness of the ripples formed by the metal while it was in a semi liquid state. Also see dual bead tire rim bead seat taper rim bead seat rolled bead single bead bead base: The part of the tire bead which is in contact with the rim bead seat

bead blaster: A cleaning device for removing paint and contaminants from an object. See bead blasting

bead blasting: A cleaning process which uses glass beads which are forced by air pressure against the object to be cleaned. This system removes paint and contaminants from objects which are awkwardly shaped.

bead breaker: A device used to remove a tire from its rim by releasing the tension the bead has upon the rim.

bead core: The ring of steel wires in the tire's bead. Also called bead wires

beaded edge: The edge of a body panel or upholstery panel wrapped around a wire or other stiffening item

beaded edge tire: An older form of high-pressure tire with projecting beads

beader: A power tool for forming beads on the edges of body panels

bead expander: A device used in the mounting of tubeless tires to prevent inflation air from escaping and bring the tire beads against the tapered bead seat area (rim).

bead heel: The portion of the tire bead in contact with the rim flange

beading: The action of forming a step in the middle of a panel (not at the edge) which creates a shallow indentation to reinforce the panel. Also see fender beading bead lock: See tire bead lock

bead movement: Movement of the bead on the rim caused by improper inflation, excessive loading, improper design, improper seating, or improper rim or tire size. Also called "bead rocking." See bead unseating

bead point: A feathered rubber extension of the bead toe used where a flap is not required; protects the tube from chafing between bead toes and rim base.

beads: See lubricate beads

bead seat: The portion of the wheel rim below the rim flange providing radial support to the bead of the tire.

See also rim bead seat taper rim bead seat safety bead seat bead seat mat: A seat cover made of a network of wood beads

bead seats: See contre pente on both bead seats

bead seat taper: See rim bead seat taper

bead seat diameter: The measurement of tire diameter, at the bead heel, where it seats on the rim. It is marked on the tire sidewall following section width.

bead separation: A situation where the bead comes off the wheel rim

bead tire: See dual bead tire

bead toe: The bottom portion of the tire bead in contact with the rim bead seat

bead unseating: Shifting of the tire bead from its seat on the wheel rim which often leads to the removal of the tire. See bead movement

bead wires: Steel wires wound around the circumference and placed in the beads. Their tension prevents the beads from lifting over the rim flanges. Also called bead core

beam: [1] A projection of light.

Also see dipped beam headlight beam setting high beam high beam indicator low beam main beam main beam indicator sealed beam [2] A supporting bar. Also see asymmetrical beam cant beam deck beam door beam hatch beam I-beam knee, beam molded beam pulling beam side impact intrusion beam transom beam [3] The width of a ship. Also called breadth.

beam axle: A rigid or dead axle which supports the non-driven wheels. See axle.

beam indicator: A light on the instrument panel which comes on when the high beams are activated. Also called high beam indicator

beam headlight: See sealed beam headlight

beam indicator: See high beam indicator main beam indicator beam knee:

Bracket between a deck beam and frame

beam setting: See headlight beam setting

beam unit: See sealed beam unit

bear: To turn as in the expression, When you get to the corner, bear right.

bearing: [1] The area of a unit in which the contacting surface of a revolving part rests in order to minimize wear and friction between two surfaces. [2] An antifriction reducing device that is usually found between two moving parts. The babbitt bearings found between the connecting rod and the crankshaft are lubricated and cushioned with oil, and the front wheel bearings must be repacked with grease at regular intervals. Bearings can be ball or roller type. Also see antifriction bearing ball bearing big-end bearing camshaft bearing carrier bearings clutch pilot bearing clutch release bearing clutch throwout bearing clutch thrust bearing connecting rod bearing con rod bearing friction bearing insert bearing jet bearing main bearing support main bearing needle bearing pilot bearing plain bearing precision insert bearing quill-type bearing quill bearing radial bearing

re-metalling the bearings release bearing rod bearing roller bearing rolling bearing sealed bearing shell bearing sleeve bearing small end bearing spigot bearing split bearing tapered roller bearing throw-out bearing throwout bearing thrust bearing timken bearing timken roller bearing wheel bearings bearing assembly: When more than one load needs to be supported, several bearings are used making up the bearing assembly. For instance, a crankshaft may have two bearings (one at each end) as well as a few more in the middle

bearing attachment: See split bearing attachment

bearing block: The two halves of metal which encase a bearing.

bearing cage: See ball cage

bearing cap: A rigid, semicircular part which encloses and holds the outer shell of a shell bearing

bearing clearance: The amount of space left between a shaft and the bearing surface, this space is for lubricating oil to enter.

bearing cone: [1] taper roller bearing. [2] The inner race in an adjustable axial or radial ball bearing

bearing crush: The additional height which is purposely manufactured into each bearing half to ensure complete contact of the bearing back with the housing bore when the engine is assembled

bearing cup: [1] Retainers, held in place by bolts and nuts, that hold the bearings in place. Also called bearing shell. [2] The bearing race that curves around the outside of a ring of ball bearings and works in conjunction with a cone.

bearing face: The bottom part of a nut or bolt head which clamps down on the surface of the part it is securing.

bearing housing: The cavity into which the bearing fits

bearing knock: The noise created by movement of a part in a loose or worn bearing

bearing material: The metal layer which forms the surface of the wear part of the bearing

bearing puller: A tool used to remove bearings from a shaft by pulling them off. It has two or more arms which circle around the back side of the bearing and a center post which butts up against the end of the shaft. As the center post is screwed down, the arms pull the bearing toward the end of the shaft. Also see ball bearing puller bearing race: In ball or roller bearings, it is one of the two steel rings on either side of the ball or roller

bearing scraper: A small, triangular tool that looks like a file without teeth. Used for deburring and chamfering the edges of camshaft bearings

bearing separator: A tool used to separate double bearings or close-fitting gears when a conventional bearing puller cannot be used

bearing shell: One of a pair of thin semicircular steel cups lined with an alloy such as coper-lead or lead-indium, which together enclose a shaft or other rotating member, and are held in a circular housing which can be divided into two halves.

bearing spin: A type of bearing failure in which a lack of lubrication overheats the bearing until it seizes on the shaft, shears its locking lip, and rotates in the housing or block

bearing spread: A purposely manufactured small extra distance across the parting faces of the bearing half, in excess of the actual diameter of the housing bore. Thus the diameter is slightly greater than the housing into which a shell bearing is being placed. Thus the bearing is forced into place to reduce its movement. See interference fit

bearing support: See main bearing support

bearing surface: The area of the bearing that is in actual contact with the shaft or other supporting member

bearing tang: A notch or lip on a bearing shell used to correctly locate the bearing during assembly

beast:

A vehicle which performs very well.

beater: [1] An old or collectible vehicle that is in drivable condition, but looks terrible inside and out, and probably is missing many original parts. Often used to describe a vehicle that is past the easy restoration stage but still contains many good driving miles. It is also a term for "urban combat car" and is usually used in conjunction with the word winter, as in winter beater, which is a vehicle that is so far gone, it is sacrificed to the salt covered roads of winter. It is a disposable collectible that is driven until it disintegrates. In other words, it looks as if someone had been beating it for quite a while. British term is banger. [2] Also see panel beater beating: See off-the-dolly panel beating on-the-dolly panel beating panel beating spring beating beating spoon: See spring beating spoon

bed: Any flat surface used as a support. Also see catalyst bed low bed test-bed bedding-in oil: British term for break-in oil

bed in: British term for break-in

beefed-up: [1] Colloquial term for making something stronger.

[2] Colloquial term for modifying or improving something so it will work faster or more efficiently. Similar to souped up

Beema: Colloquial term for BMW

Beemer: Colloquial term for BMW

Beetle: Colloquial term for the original rear-engined volkswagen. Also see split-window Beetle before bottom dead center: (BBDC) As the crankshaft rotates, it brings the piston down to a place just before it reaches bottom dead center.

before top dead center: (BTDC) As the crankshaft rotates, it pushes the piston up to a place just before the top of its movement.

before upper dead center: (BUDC) As the crankshaft rotates, it pushes the piston up to a place just before the top of its movement.

bell: See spray bell

bell housing: Sometimes called "clutch housing." The metal covering around the flywheel and clutch (of a manual transmission) or torque converter assembly (of an automatic transmission).

bell mouth: Bell-shaped air intake attached to some carburetors

bellows: See air bellows

belt: [1] A reinforcing band, normally textile, fiberglass, or steel, which runs around the circumference of a tire and strengthens the tread area. Also see cog belt [2] A circular band which is used to transfer power from one component to another. For instance, a fan belt is used to transfer power from the engine to the alternator, water pump, and air conditioner compressor. Also see cam belt camshaft drive belt cog belt cogged belt diagonal belt drive belt fan belt ring belt serpentine belt stabilizer belt static belt steel thrust belt timing belt toothed belt v-belt vee-belt [3] See automatic seat belt hip belt inertia reel seat belt integrated safety belts lap belt rear seat belt safety belt seat belt shoulder belt three-point seat belt Y-belt belt anchor:

The point where the end of the seat belt is attached

belt anchorage: The point where the end of the seat belt is attached. See seat belt anchorage

belt drive: In order to transmit power from a source to a destination, some kind of connection is needed. A bicycle, for instance, uses a chain drive to transmit the power from pedalling action to the rear wheel. A belt drive uses a leather or rubber belt to transfer power from one pulley to another thus increasing or decreasing the speed of rotation of the driven pulley through mechanical advantage. For instance the alternator is rotated by a belt (sometimes called the "fan belt") which is driven by a shaft which is directly attached to the crankshaft. Some motorcycle models (like Harley Davidson and Honda) have a belt drive to transmit power to the rear wheels. Since a belt drive requires no lubrication (in contrast with chain drive) it is one of the cleanest final drive systems.

belted bias tire: A tire which uses both cross-ply and radial-ply patterns with added belts (such as used on radial-ply tires) on diagonal body plies (as in cross-ply tires). As a result the tire has stiffer sidewalls than tires with just straight radial plies.

belted piston: A piston with a continuous steel band cast into the skirt below the rings for controlling skirt expansion.

belted radial tire: See steel belted radial tire

belted tire: A tire with a stabilizing belt of two or more plies of steel, fiberglass, etc., running circumferentially around the tire between the carcass and the tread rubber. The carcass can be either radial or bias ply. See bias belted tire.

belt end: The part of the seat belt which has the bracket which is attached to the floor pan. Some cars attach this end to the car seat itself.

belt line:

The horizontal line that runs around the body of the vehicle just below the bottom of the glass panels (greenhouse). The British term is "waistline"

belt mounting: See belt anchor

belt pulley: See timing belt pulley

belt retractor: A device which automatically pulls the seat belt back into its reel

belts: See integrated safety belts

belt sander: A power sanding tool with a rotating belt of sandpaper

belt slack: The looseness of a belt (either the drive type belt or a seat belt)

belt slip: When a drive belt is not as tight as it should be, it will slip on the pulley and thus will not transmit power. If a driven pulley is seized, the belt will also slip.

belt system: See seat-integrated belt system seat-integrated seat belt system belt tensioner: A device consisting of an idler pulley which is usually located between the drive and driven pulleys. It can be adjusted to increase the tension on the belt. See seat belt tensioner timing belt tensioner

belt transmission: See belt drive variable belt transmission belt up: A British term for buckle up

belt warning light: See seat belt warning light

belt webbing: Strong fabric material used for seat belts

bench: [1] A workbench. [2] A test bed for studying or repairing an engine. Also see bench test straightening bench bench grinder: A power tool mounted on a workbench with one or two grinding wheels

bench seat: A front seat which runs from the left door to the right door. The alternative is bucket seats. Also see split bench seat bench test: A determination of the power output of an engine when it is mounted on a test bed. Also it can be checked for oil leaks, fuel consumption, emission levels, etc.

bench vise: A vise which is mounted on a workbench

bend:

See free bend test

bender: See fender bender tube bender bending: See lower bending die

bending die: See lower bending die

bending pliers: Pliers with flat, smooth jaws used to hold sheet metal in place

bending strength: The ability of metal to resist bending

Bendix: See Bendix type starter drive pre-engaged Bendix starter Bendix drive: See Bendix type starter drive.

Bendix screw: A helical screw on the shaft of a starter motor

Bendix starter: A starter motor with a Bendix drive. Also see pre-engaged Bendix starter Bendix type starter drive:

A self-engaging starter drive gear, the gear moves into engagement when the starter starts spinning and automatically disengages when the starter stops. Also called inertia drive

bend test: See free bend test

benefits: See employee benefits

Bentley: A vehicle brand of which the 1925-1945 models are classic cars. The 1946-67 models are milestone cars.

Click here for books on Bentley

Benz: A vehicle brand of which the 1925-1948 models with required application are classic cars. Also see Mercedes-Benz benzene: (C6H6) A constituent of gasoline benzol: A by-product of manufacture of coke. Sometimes it is used as an engine fuel

berline: A term used during World War I which describes a closed luxury vehicle with small windows. The passengers were able to see out; but their privacy was maintained because it was difficult to see in.

between duals: See kissing between duals

between perpendiculars: See length between perpendiculars

between wheel spacer: An obsolete circular metal plate having a bolt hole circle and center bore and fitting between the faces of disc wheels to provide additional dual clearance.

bevel: The angle that one surface makes with another when they are not at right angles. Also see gutter bevel bevel differential: A differential which has bevel gears for its main elements. This allows the input and output shafts to be at right angles to one another. Also see spur differential bevel drive shaft: A shaft with a bevel gear at one end or both ends. It is used primarily for driving an overhead camshaft

bevel gear: A gear shaped like the wide end (frustum) of a cone, used to transmit motion through an angle. They are found in differentials. Also see spiral bevel gear. bevel gear drive: A transmission which is used to drive one or more shafts which do not line up with the output shaft. Also called bevel gear transmission

bevel gear transmission: A transmission which is used to drive one or more shafts which do not line up with the output shaft. Also called bevel gear drive

bevel joint: A piston ring gap in which the two ends of the ring are tapered.

beverage holder: A circular clip located on the center console, door panel, or dashboard which is designed to hold a cup or bottle. Also called cup holder

bezel: The crimped edge of metal that secures the glass face to an instrument. A bezel can be either decorative or functional. Some bezels are threaded and secure switches and control buttons to the dash, console, or steering column. B-flange: A type of passenger car wheel

bhp: Abbreviation for brake horsepower. Also see SAE gross bhp BHS: Acronym for bimetal heat sensor

bias: The acute angle at which the cords in the tire fabric intersect the circumferential centerline of the finished tire. Also see brake bias. bias belted tire: A type of tire construction in which there are bias plies as well as a belt of steel or synthetic (rayon, nylon, or fiberglass) cords between the carcass and the tread. The belt overlaps the bias plies and wraps around the circumference. The cords and belt cross each other at bias angles. biased: See spring-biased

bias ply tire: A tire having two or more carcass plies arranged in a criss-cross manner and diagonally to the beads and travels approximately 1/3 the distance around the circumference before attaching to the other bead. Each cord in the next ply is arranged in the same manner, but in the opposite direction. Also called a "conventional tire" or "cross-ply tire"

bias tire: A type of tire construction in which the tire cords or plies run diagonally from bead to bead. Generally in passenger cars, there are two plies of fabric. In a P185/80D13 tire, the "D" indicates a bias-ply tire. Sometimes called a "conventional" tire. Also see belted bias tire bib: A leather or vinyl covering for the front of a vehicle. See tank bib

bicycle: A two-wheel non-motorized vehicle in which the two wheels are not side-by-side but in line. Also called "bike." Also see all terrain bike coaster girl's bike loaded tourer mixte frame mountain bike penny-farthing quadricycle randonneuring sports tourer tandem tourist tricycle unicycle velocipede. bicycle carrier: A device which is attached to the rear bumper or to the roof of a vehicle to carry a bicycle

big-block: See big-block engine

big-block engine: A large V-8 engine produced in the '60s and '70s. It typically has a cast-iron block and head and is fed by a carburetor. Contrasts with small-block engine. Although both engines were of the same displacement, the big-block engine was larger in

overall size than the small-block engine. Thus, as vehicles grew smaller and more equipment was stuffed into the engine bay, the small-block engine was favored over its larger brother.

big end: The end of the connecting rod which fits around the crankpin

big-end bearing: See big-end bearing big-end bearing: The bearing in the end of the connecting rod that attaches to the crankshaft. big-end bolt: One of the bolts attaching the big-end cap to the connecting rod

big-end cap: The detachable end of the connecting rod which fits on the crankpin

Big Jim: A colloquial term for a device for opening door locks. It is a flexible metal strip about an inch wide and very thin and has a J-shaped end. It is inserted between the door window and the door frame to trigger the latch

big rig: A large truck -- usually a tractor-trailer unit

big three: General Motors, Ford, and Chrysler.

bihexagon: A twelve-sided figure. Some nuts and bolt heads have twelve sides.

bihexagonal: Having 12 sides

bihexagon socket:

A tool socket which fits 12-sided nuts and bolts

bike: A two-wheel vehicle -- either a bicycle or a motorcycle. Also see all-terrain bike girl's bike mountain bike street bike touring bike BIL: Acronym for "Bilimportorenes Landsforening" (Norway). Also Acronym for "Bilindustrief”reningen" (Sweden)

bilge: A recess area fitted at the curved section between the bottom and the side into which water drains from holds or other spaces.

bilge bracket: A vertical transverse flat plate welded to the tank top or margin plate and to the frame in the area of the bilge.

bilge keel: A long longitudinal fin fitted on the curved of a ship at the turn of the bilge to reduce rolling

bilge strake: Shell plates at the bilge area

billet: [1] A section of a log split lengthwise as you would make firewood. [2] A small bar of iron or steel

bill of lading: The cost or the paperwork describing the cost of a vehicle's load or freight.

bimetal:

Two types of metal bonded into a strip and formed into a coil. Each type of metal has different thermal expansion characteristics, so the coil straightens when heated and coils up when cold. Bimetals are used mainly to open and close choke plates on carbureted vehicle

bimetal heat sensor: (BHS) a strip (usually coiled) consisting of two metals with different expansion characteristics. Bimetal strips are used in thermostatically controlled devices because they move or bend toward the metal that expands least when heat is applied

bimetallic corrosion: When two different metals are attached to each other, some electrons tend to move from one metal to the other. This action happens especially when there is a little moisture between the two pieces. Also see galvanic corrosion bimetallic sensor: Consists of thermocouple, an arm made of two dissimilar metals with different rates of thermal expansion, that flexes in accordance with temperature changes. Used as a temperature sensor. Also called bimetal sensor

bimetal sensor: Consists of a thermocouple, an arm made of two dissimilar metals with different rates of thermal expansion, that flexes in accordance with temperature changes. Used as a temperature sensor. Also called bimetallic sensor

Bimmer: Colloquial term for BMW

binder: The ingredient in a paint that holds or suspends the pigment particles together. Also see binders. binder bolt: On a bicycle, the bolt used to fasten a stem inside a steerer tube or a seatpost inside a seat tube.

binders: Vehicle brakes.

binding: [1] The rubbing of brake shoes against the drum or of brake pads against the disc. [2] The strip material turned over along the edge of a carpet or mat. Also see edge binding binnacle: The cluster of instruments and switches mounted in a circular casing on or near the steering column

biocide: A product which kills any fungus or microbes that may have contaminated diesel fuel.

biodegradable: A product which is capable of being decomposed by bacteria into harmless elements without danger to the environment.

biodiesel: Diesel fuel made from animal or vegetable fats

bit: [1] A tool for boring or cutting which fits into a drill. See drill bit. [2] The tip of a screwdriver. Also see hexagon bit hex bit screwdriver bit socket bit twisty bits bit adapter: A tool (like a screwdriver) with a hollow socket (instead of the blade) to accept a variety of bits

bite:

[1] A vehicle's ability to adhere to the road (especially to a racing track). [2] The ability of a tool to secure itself to a fastener as in I want my wrench to get a good bite on that bolt.

bits: See twisty bits

bitter end: The inboard end of a ship's anchor chain that is secured in the chain locker

bituminous paint: Black or dark colored tarry paint which contains bitumen. Used for the protection of exposed metal parts.

BL: Acronym for "British Leyland"

black: See carbon black

black and white checkered flag: A flag which is waved at the finishing line in races to indicate the winner.

black box: [1] A recording device which reveals conditions just prior to a crash. [2] A control unit

black chromium plating: An electroplating deposit of a black chromium layer for decorative purposes

blackening: See bulb blackening lamp blackening black flag:

A flag which is colored black and is waved at a race. It indicates that the driver must return to his pit for consultation. It means that the driver has violated a serious racing rule such as spilling fluid on the track or was speeding on the pit road.

Blackhawk: A vehicle brand of which the 1925-1948 models are classic cars.

blacksmith hammer: A special hammer for hitting and shaping heated iron.

black smoke: Incompletely burned fuel in the exhaust indicating the fuel mixture is too rich

blackwall: Tires which do not have any white or red coloring. See whitewall red line bladder: A hollow bag which can be inflated. In some instances, fuel tanks will become rusty inside. A possible cure is to install a bladder. This is done by flushing out the rust chips, applying an acid solution to remove any oil/gas residue, and coating the inside with a plastic compound. When done correctly, this plastic coating does not dissolve when it comes in contact with gasoline.

blade: [1] A straight narrow flat part like the end of a screwdriver or knife. [2] The part of a windshield wiper (blade rubber) which contacts the windshield. [3] One of the vanes of a rotor or impeller. Also see bumper blade bumping blade fan blade feeler blade fork blade blade connector:

A plain metal tongue for forming electrical connections

bladed impeller: A rotating part of a centrifugal pump that has blades or vanes

blade rubber: The rubber strip that fits into the arm of a windshield wiper

blades: See fork blades

blank: See sheet metal blank

blanking piece: A flat piece of metal which closes off a tube. Also called a "blanking plate"

blanking plate: A flat piece of metal which closes off a tube. Also called a "blanking piece"

blanking plug: A rubber stopper for filling in the holes of sheetmetal such as drain holes in the floorpan

blast: See ocean liner blast horn sand blast blast cleaning: The removal of corrosion, dirt, paint, etc. by a blast of abrasive particles. Also see bead blasting sand blasting blaster:

See bead blaster

blast horn: See ocean liner blast horn

blasting: See bead blasting grit blasting shot blasting bleed: [1] To remove air bubbles from hydraulic lines and components of a system. Also see air bleed air bleed screw idle air bleed screw compensating jet . [2] To reduce the air pressure in tires that have been run, warmed up, and thus increased from their starting pressure -- an action which should be avoided.

bleed down: The collapse of a hydraulic lifter as oil drains out

bleeder: The valve or screw used to vent the air out of a liquid-filled system. See brake bleeder pressure bleeder bleeder nipple: See bleeder screw

bleeder screw: A screw used to release the air from a system like the brake system. Also see idle air bleed screw

bleeder valve: The device which vents air from the brake system.

bleeding: See brake bleeding

bleed screw: A screw used to release the air from a system like the brake system. Also see idle air bleed screw bleed valve: The device which vents air from the brake system.

bleeding: [1] A lower (older) color coming through a fresh coat of paint. [2] The action of venting air from a liquid-filled (hydraulic) system. [3] Reducing the air pressure in tires that have been run, warmed up, and thus increased from their starting pressure -- an action which should be avoided.

bleeding a system: Remove air bubbles from a brake system, a fuel injection system, or a cooling system so that they won't impede the flow of liquid through that system.

bleeding the brakes: This refers to the removal of air from the hydraulic system, bleeder screws are loosened at each wheel cylinder, (one at a time) and brake fluid is forced from the master cylinder through the lines until all air is expelled.

blem: An abbreviation for blemish.

blemish: A tire with a slight imperfection in appearance that will not affect tire life or safety. Also called a "blem."

blind:

See car blind

blind quarter: An unusually wide C-pillar enclosing the rear seat area

blind rivet: A pop rivet

blind spot: An area not visible from the driver's seat. It is usually the area behind the rear quarter and not visible in the mirrors. When approaching another vehicle in a lane beside you, avoid being in its blind spot. Also do a shoulder check before switching lanes to check for vehicles in the blind spot

blister: [1] A bubble on a paint surface. [2] A localized bubble on the surface of a tire, normally caused by a separation between plies or between surface rubber and a ply.

blistering: The formation of bubbles on the paint surface.

BLM: Acronym for the "Bureau of Land Management."

BLMC: Acronym for "British Leyland Motor Corporation"

block: That part of the engine containing the cylinders. Also see bearing block big-block block heater brake block brake pad cylinder block die

EN-block en block engine block heater engine block hollowing block hydraulic control block long block long block engine monoblock rubbing block sanding block short block tread block valve block keel blocks block coefficient: The ratio of the underwater volume of a ship to the volume of a rectangular block with the same effective lengths, draft and beam

block deck: The cylinder head gasket surface

block engine: See long block engine short block engine block heater: A devices which, during very cold weather, keeps the engine warm when the vehicle is not being used -- thus making cold starts easier. The free end is plugged into 110 volt AC wall socket. It is especially important for starting diesel engines at very low temperatures. Also see cylinder block heater engine block heater blocking ring: See balk ring

blocks:

See keel blocks

block sanding: The process of using a wooden block wrapped in sandpaper to sand the material.

blood alcohol content: The amount of alcohol in the bloodstream as a result of drinking liquor

blood alcohol level: The amount of alcohol in the bloodstream as a result of drinking liquor

bloom: A surface film on rubber, caused by the migration to the surface of sulphur, wax, or other unreacted ingredients of the compound. It may be protective to the tire and detrimental only if appearance is a major factor.

blooming: A formation of an undesired thin surface film or a milky white haze or mist on paintwork. It is caused when paint is applied during humid, cold conditions as moisture is trapped in the wet film

blow: To become defective either by leaking or burning through. Also see arc blow striking blow blow back: Because of a sticky valve or the intake valve closing late, some of the air-fuel mixture is blown back through the carburetor

blowby: The mixture of fuel-air which is lost past the piston rings and causes fumes that form acid and sludge in the crankcase and smoking from the oil filer hole. Generally there is a loss of engine power. Most are removed through the PCV system.

blow-by:

The mixture of fuel-air which is lost past the piston rings and causes fumes that form acid and sludge in the crankcase and smoking from the oil filer hole. Generally there is a loss of engine power. Most are removed through the PCV system.

blowdown: The escape of gases between the opening of the exhaust valve and the piston reaching bottom dead center, or in a two-stroke engine between exhaust port opening and transfer port opening.

blowdown period: In a two-stroke engine, it is the time between the exhaust port opening and the transfer port opening which should be sufficiently long enough to allow time for the cylinder pressure to drop below the crankcase pressure, so that the exhaust gases can be expelled more easily

blower: [1] Also called a "supercharger" or "turbocharger." This is a pump which forces air into the cylinders at higher than atmospheric pressure. The increased pressure forces more air into the cylinders than what would be drawn in normally. In this way the engine can burn more fuel and thus produce more power. There are two main types of blowers: the turbocharger, which uses some of the waste heat energy in the exhaust gases to drive a compressor and pump the air; and the belt-driven or shaftdriven supercharger which uses engine power to pump air. [2] A fan for an interior heating and ventilating system or even for an air-cooled engine. Also see heater blower blow gun: A paint spray gun with a wide nozzle which is fed by air pressure. It is used to blow out crevices in material that is otherwise hard to reach.

blowlamp: A British term for blow torch

blown: [1] An engine equipped with a turbocharger or supercharger. [2] An engine which is ruined. Usually the piston is seized. Also see blown head gasket.

blown head gasket: A gasket that has a break between the opening for the cylinder and an opening for the coolant. The coolant will leak into the combustion chamber. This condition can be diagnosed by a loss in coolant and white smoke out the exhaust.

blowoff valve: A one-way valve that opens to the atmosphere above a certain set pressure to relieve excessive internal pressure buildup; often used with a turbocharger installation to limit boost pressure to the engine. Also called pressure-relief valve. Also see wastegate blow-off valve: See blowoff valve

blow out: To clean a dirty or blocked pipe by blowing compressed air through it

blowout: A sudden rupturing of tire body, causing complete loss of air pressure which flattens the tire.

blow-out: A sudden rupturing of tire body, causing complete loss of air pressure which flattens the tire.

blow-over: A respray of doubtful quality, often poorly prepared and carelessly masked.

blowpipe: Another term applied to the oxyacetylene torch

blow through: A turbocharger system in which the turbocharger blows air through the carburetor(s) or fuel injector(s), i.e., the air and fuel mixing occurs downstream from the turbocharger

blow torch: A tool which is attached to a bottle of flammable gas. The gas is ignited to give an intense flame for brazing and soldering. The British term is "blowlamp"

blue book: A listing of the current prices for used cars, based on age, condition, and optional equipment. Available at banks, loan offices, libraries, and insurance companies.

blueing: The blue color that appears on chrome pipes when subject to intense heat. In some cases, it can be removed; but most often it is permanent.

blueprinting: Dismantling engine and reassembling it to exact specifications and tolerances. This process may help to improve engine performance, smoothness, and reliability. Sometimes called "balancing."

blue smoke: The color of the exhaust which indicates that oil is escaping into the combustion chamber and abeing burned. It is probably due to worn rings, valve seals, etc.

blushing: The formation of a whitish or misty appearance on the finish color of the paint surface.

BMAP: Acronym for barometric and manifold absolute pressure sensor

BMC: Acronym for "British Motor Corporation"

BMEP: Acronym for brake mean effective pressure

BMW:

Acronym for "Bayerische Motoren Werke." A vehicle brand of which the 1925-48 models 327, 328, 327/328, and 335 are classic cars. The 507 models for 1957-59 are milestone cars.

Click here for books on BMW

BMW roundel: The little black, blue, and white BMW checkerboard logo.

board: A printed circuit board. Also see circuit board dash board on board diagnostics printed circuit board running board shifting board board diagnostics: See on board diagnostics

board test: A test of a printed circuit board

boat chock: A cradle or support for a lifeboat.

boat trailer: A trailer for carrying a boat

BOB: Acronym for break-out box

bodge: A British term to describe work that is done poorly or with defective materials

bodily harm:

Physical injury to a person caused by an accident

bodily injury: Physical injury to a person caused by an accident

body: [1] The main portion of an automobile. Often it refers just to the outside shell. [2] The main part of a housing. [3] The shank of a bolt. [4] In welding, it refers to the main structural part of a regulator. Also see all-aluminum body all-enveloping body all-steel body aluminum body coachbuilt body distributor body dump body fabric body fibreglass body fully galvanized body half-round body file headlight body integral body and frame construction parallel middle body spark plug body special body stressed body throttle body tire body torpedo body unit body valve body body and frame: See integral body and frame construction

body and frame construction: See integral body and frame construction

body assembly:

The building up of the automobile body from its various components

body builder: A person who builds automobile bodies, i.e., coachbuilder.

body-colored: Something that is painted the same color as the body. Also see color-coded body component: Any structural part that makes up the body of a vehicle.

body computer module: (BCM) Key element of self-diagnostic system used to control vehicle functions based on monitored inputs

body construction: The manufacturer of a vehicle body

body file: When patching hole in a body panel and filling it with body putty, a body file which is a hand tool) is used for smoothing the putty to conform to the contour of the body. Also see half-round body file body filler: A substance (often with the name Bondo) which is a paste used to fill minor imperfections in a body panel. It hardens and is shaped to fit. It can also be painted to match the rest of the vehicle.

body flange: A point on the body where two panels overlap, forming a small step

body framing:

An assembly of the body components

body fuel injection: See throttle body fuel injection

body glass: The windshield, backlight (rear window), and side windows of a vehicle

body hammer: A hammer with a large flat pounding surface for removing dents

body housing: See valve body housing

body-in-white: In the process of building a vehicle, this is a body shell after everything is welded but before it is painted

body injection: See throttle body injection

body jack: A hydraulic tool for pushing or pulling body panels into shape

body lead: An alloy of lead and tin which is used to fill dents and seems in a body panel to establish a smooth surface. When heated it flows easily to fill the imperfections

body panel: The sheet metal that forms the outside body pieces.

body plan: A drawing showing the forms of the various cross sections, the curvature of the deck lines at the side, and the projections, as straight lines of the waterlines, the buttock lines, transverse elevations and the diagonal lines

body putty: A malleable material designed to smooth on dented body areas, upon hardening, the putty is dressed down and the area painted. Also called "bondo."

body rattle: A noise in the bodywork usually cased by loose parts, badly fitting doors, hood, or trunk lid

body repair: After a vehicle has suffered an accident or has corroded panels, the body needs to be repaired to bring it back to like-new condition

body roll: The rocking or tilting motion of a vehicle when it goes around the corner

body sealer: A tar-like substance which is used to seal body joints

body separator plate: See valve body separator plate

body shell: The bare skeleton of a vehicle with all the wheels, doors, hood, trunk lid, etc. removed

body shop: A service outlet specializing in vehicle body repair work.

body side molding: A protective stripe along each side of the vehicle running from the leading edge of the front fender, along the door panel(s) to the rear end of the back fender. It may be solid plastic or rubber attached directly to the panels while others are attached to a metal strip which in turn is attached to the panels.

body spoon: A tool with a flat contoured working surface like a spoon. It is used to slap out dents and is sometimes used in place of a dolly when it is too difficult to reach behind the panel

body stripe: A decorative stripe applied to a motorcycle fuel tank or the outside of a car to enhance the appearance. Sometimes model names are also part of the stripes.

body styling kit: An additional set of bolt-on parts (like spoilers, air dams, fender skirts, laker pipes, wings) which are intended to improve the looks, performance, and efficiency

body tub: The bare body shell (minus the doors, trunk lid, hood, fenders) which is lowered onto the chassis at the time of assembly

bodywork: The complete body structure mounted on the chassis of a vehicle with a separate chassis, and the complete sheet metal panel for unibody vehicles.

bog: A hesitation usually experienced when starting out.

bogie: An assembly of four wheels on two axles with common suspension, usually on heavy commercial vehicles, trailers, and older Ski-Doos

bogie wheel: One of the suspension wheels on an older Ski-Doo

boil: The process of change from a liquid to a gas through the application of heat.

boiling point: The exact temperature at which a liquid begins to boil or changes to a gas (i.e., vaporizes). The boiling point of a liquid decreases with increasing altitude, and increases with pressurization. The coolant in a modern radiator/coolant system can be as high as 260°F (127°C). Also see dry boiling point

wet boiling point bold-up: The application of retread or repair rubber.

bolster: [1] A supporting brace. [2] The act of supporting. Also see hexagonal bolster bolt: A securing device upon which a nut is threaded. It usually has a nut-type head. It is usually measured not so much by the size of the wrench required to secure the bolt; but by the diameter of the threads, the thread pitch, the length of the bolt under the head, and the strength of the bolt. Also see anchor bolt big-end bolt binder bolt carriage bolt coach bolt countersunk bolt crankarm fixing bolt cylinder head bolt eccentric bolt fixing bolt flange bolt four bolt mains hexagon bolt hex bolt locking lug bolt lug bolt mounting bolt octagonal bolt octagonal head bolt pivot bolt round head bolt shear bolt stirrup bolt through bolt u-bolt wheel bolt

wheel lug bolt bolt and nut: A pair of objects with matching screw threads. When either the bolt or the nut is turned, it moves with great force. Often used as fixing devices. The nut is the circular piece that looks like a ring with threads on the inside hole. The bolt is the shaft with threads. Also see pivot bolt. bolt hole: The hole in metal through which a bolt must be inserted or screwed in place. Also see wheel bolt hole. bolt hole circle: See wheel bolt hole circle.

bolt mains: See four bolt mains

bolt-on: Accessories which are easily secured to an automobile with just a few bolts rather than having to be welded in place. Usually done by the owner.

bolt-on fender: A fender which is secured with bolts rather than being welded in place

bolt-on goodies: Accessories which are easily secured to an automobile, but are often for show rather than function

bolt-on kit: A group of parts available in one package which the owner can attach himself.

bolt-on wing:

British term for bolt-on fender

bomb: A vehicle which is in very poor shape, "The car is a bomb and not worth a nickel." In contrast, it can mean a vehicle which has great acceleration, "The car flew down the track like a bomb."

bond: [1] A state of adhesion. [2] The act of connecting two components by means of a glue or adhesive [3] The junction of the weld metal and the base metal

bonded abrasive: A grinding part which is made of very hard particles which have been glued together to form a wheel, bar, rod, or cone used to wear down or smooth metal.

bonded brake lining: brake lining that is attached to the brake shoe by an adhesive rather than by rivets.

bonded lining: Brake lining cemented to shoes or bands which eliminates need for rivets

bonding: See adhesive bonding panel bonding bonding agent: A material which provides adhesion

bonding method: A procedure of joining two components with adhesive

bondo: See body putty.

bone:

See A bone T-Bone backbone frame herringbone gears wishbone. boned: See T-boned

bonnet: British term for vehicle hood. Also see auto bonnet bonnet badge: British term for hood badge

bonnet bump rubber: British term for hood bump rubber

bonnet bumper: British term for "hood bumper" or hood bump rubber

bonnet landing panel: British term for hood landing panel

bonnet liner: British term for hood liner

bonnet lock: British term for hood lock

Bonnet pin: British term for hood pin

bonnet pin kit:

British term for hood pin kit

bonnet release: British term for hood release

bonnet stay: British term for hood rod

bonnet support: British term for hood rod

bonnet tape: British term for hood tape

bonus: See no-claims bonus

book: See blue book paint chip book booming: [1] A noise caused by interruptions to the flow of air such as an open windows. [2] Low pitched resonance, especially in the exhaust. [3] Thumping sound coming from large stereo woofers

boost: [1] The amount of positive pressure created in an intake system above normal atmospheric pressure by a turbocharger or supercharger. Normal atmospheric pressure is 14.7 psi. A blower providing 10 psi boost increases the pressure to 24.7 psi. Boost is sometimes measured in atmospheres where one atmosphere equals 14.7 psi. Thus 24.7 psi is about 1.7 atmospheres. Also see on boost off-boost [2] The action of jump starting one battery from another.

[3] To increase power, charge, or pressure, etc.; or to amplify volume, audio sound, etc.

boost-activated ignition retard: On a turbocharged engine, a system which retards the ignition timing when the intake manifold is under pressure, in order to reduce the chance of detonation

boost-controlled deceleration device: (BCDD) a valve that, during deceleration, is triggered into action by high intake manifold vacuum the BCDD valve allows an additional source of air and fuel to enter the intake manifold during deceleration to obtain a more burnable mixture

boost control valve: See blowoff valve

booster: [1] A radio device which amplifies the signal or the audio output to the speakers. Because of its size it is mounted in the glovebox, under the dash, in the center console, under the seat, or in the trunk. [2] A device incorporated in vehicle system (such as brakes and steering), to increase the pressure output or decrease amount of effort required to operate, or both. Also see brake booster hydraulic brake booster power booster spring booster vacuum booster vacuum brake booster booster battery: A second battery used in commercial vehicles to give a little more power when starting.

booster cable: See jumper cables

booster coil:

A secondary ignition coil which increases the intensity of the spark

booster venturi: A small venturi located immediately above and concentric with the main venturi in a carburetor. Boosters are designed to amplify the weak venturi vacuum signal that occurs during low airflow conditions

boost gauge: An instrument or meter which indicates boost pressure

boosting: See start boosting

boost pressure: Pressure in the intake system of a supercharged engine when the supercharger operates. See the first definition of boost.

boost sensor: A sensing device in a supercharger. It is located in the choke tube which sends a signal to the ignition control unit according to pressure conditions. In turn, the control unit adjusts the ignition timing for the best performance.

boost valve: A valve in a hydraulic system which increases the pressure

boot: [1] British term for a trunk. [2] The rubber or plastic cover located at either end of the spark plug cable to insulate the connections between the cable ends and the spark plug and distributor terminal. Always grasp the cable by the boot when removing it. See spark plug boot. [3] The protective cover of the ball joint that holds the grease. Also see dust boot CV joint boot [4] The covering around the CV joint. [5] A simple protective device (sometimes a piece of tube, tire, etc., cut to size) placed between the casing and tube. It offers temporary protection for the tube

against pinching by an injury in the casing. It is not a repair of the injury and is unsafe to use. [6] A denver boot, which is a device which clamps on the wheels of a parked car to immobilize it. Also called a heavy yellow boot. [7] A colloquial term for the action of going very fast as in, We were booting along as fast as the snowmobile would go.

booted: A vehicle which has been disabled by a denver boot is said to be "booted."

booted version: British term for trunk model

booth: See low-bake booth paint booth spray booth boot handle: British term for trunk handle

bootlid: British term for trunk lid

boot puller: See spark plug boot puller

boots: See boot.

boot spoiler: British term for trunk spoiler

border shopping: See Canadian cross border shopping

bore: [1] The cylinder hole itself. Also see piston bore. [2] The diameter or width of the cylinder. [3] As a verb, it means to cut a circular hole. [4] With the word "full" it means to go fast. Also see full bore center bore cylinder bore wheel center bore bored: To increase the diameter of the cylinder. Also see stroked. bore diameter: The diameter of the cylinders. It is usually measured in either inches or millimetres. When a cylinder is bored out because of scored walls, it is increased by "ten thou" of an inch (0.01") or 0.25 mm.

bore-stroke ratio: The relation between the diameter of the cylinder bore and the length of the stroke of the piston. If the stroke is longer than the cylinder bore diameter then the engine is called a long stroke engine. If the stroke is shorter than the cylinder bore diameter then the engine is called a short stroke engine. If the stroke is the same as the distance of the cylinder bore diameter then the engine is called a square engine

Borgward: A German automobile manufacturer which began by Carl F. Click for books on W. Borgward in 1921. Borgward boring bar: A machine with a stiff bar that has multiple cutting bits used to cut engine cylinders to a specific size. As used in garages, to cut worn cylinders to a new diameter or bearing bores in proper alignment with each other.

boring:

Renewing the cylinders by cutting them out to a specified size, a boring bar is used to make the cut.

boss: An extension or strengthened section that holds the end of a pin or shaft. For example, the holes in the piston through which the piston pin is placed would easily break the thin walls of the piston when under pressure. The area around the hole (on the inner side of the piston) are strengthened to prevent breakage. This area is the piston boss. Also see gudgeon pin boss horn boss piston pin boss. bossing mallet: A hammer with a pear-shaped wooden head used for shaping and stretching metal over a sandbag or wooden block.

botch: [1] A repair job which is very poorly done. [2] To do a repair job poorly

botched-up job: A colloquial term for a poor repair which will not be permanent.

bottle: See acetylene bottle

bottled gas: (LPG) (liquefied petroleum gas or propane) gas compressed into strong metal portable tanks. The gas, when confined in the tank, under pressure, is in liquid form.

bottle jack: A hydraulic lifting device which is in the shape of a bottle

bottleneck: A traffic situation where the road narrows to the point where traffic is excessively slowed

bottom: [1] The lowest point. See door bottom. [2] To lower something. [3] To reach the end of its travel (i.e., bottom out). [4] To make contact with the road. Also see double bottom bottom bracket: The cylindrical part of a bicycle frame that holds the crank axle, two sets of ball bearing, a fixed cup, and an adjustable cup.

bottom dead center: (BDC) The lowest point of the piston and connecting rod travel in a cylinder. In a horizontally opposed engine, it is sometimes called the outer dead center. Opposite to top dead center. Also see after bottom dead center before bottom dead center bottom dumps: Trailers that unload through bottom grates.

bottom end: [1] All the moving parts in the crankcase and their bearings. [2] The lower range of engine revolutions

bottom end gasket kit: All the gaskets below the base gasket (crankcase gaskets and inspection cover gaskets) and all the O-rings and replaceable spacers in the bottom end of an engine. Also see top end gasket kit. bottom gear: The lowest gear in a transmission.

bottoming: [1] A situation where the suspension reaches the end of its travel.

[2] A situation where the lowest part of the chassis touches the ground, especially on a bump

bottom out: To reach the end of its travel.

bottom tank: In a thermosyphon water-cooling system, this is the bottom radiator tank. Also see header tank radiator tank bounce: [1] When referring to valves, it indicates a condition where the valve is not held tightly closed in the seat even though the camshaft has not opened it. Also called "flutter" or valve bounce [2] When referring to a distributor, it indicates a condition where the points make erratic contact when they should remain closed. See contact bounce. [3] When referring to suspension, it indicates an up-and-down motion called "jounce" and "rebound." You can test it by pushing down and releasing a corner of a vehicle

bound electron: See b.

bound electrons: Electrons in the inner orbits around the nucleus of the atom, they are difficult to move out of orbit.

bourdon tube: A circular, hollow piece of metal that is used in some instruments, pressure on the hollow section causes it to attempt to straighten, the free end then moves a needle on the gauge face.

bow: See header bow hinge bow hood bow

main bow spring bow bowed: A bent shape.

bowden cable: A wire control cable within a metal or rubber sheath and used for activating a valve, clutch, choke, or accelerator

bowl: See float bowl.

bowl vent: (BV) connects the float bowl to the carburetor's air inlet. Depressurizes the fuel being pumped into the float bowl by the fuel pump and acts as a vapor separator by allowing vapors in the float bowl to escape into the carburetor air inlet. Bowl vents are cut at a 45-deg angle and face incoming air so that reference pressure remains the same regardless of airflow

bowl vent port: (BVP) the port in the carburetor which vents fumes and excess pressure from the float bowl to maintain atmospheric pressure

bowser: A tanker used for refuelling military ground vehicles or airplanes

bow thrusters: A propeller at the bow of the ship, used during maneuvering to provide transverse thrust

bow wow: A vehicle in very bad shape. A dog.

bow-wow: A vehicle in very bad shape. A dog.

box: [1] Colloquial term for a transmission. Also see crash gearbox [2] A term for an electrical or electronic device. Also see E-box control box control unit crash recorder fuse box [3] A silencer. Also see black box cdi box crash box panhard rod mounting box rocker box roof box slush box squirt box steering box stuffing box tail light box transfer box trigger box boxed rod: connecting rod in which the I-beam section has been stiffened by welding plates on each side of the rod.

boxer engine: A horizontally opposed engine.

box member: A structural part made as a box section

box section: A closed panel structure of square cross section which is used to strengthen a vehicle's underbody

box spanner: A British term for a hollow tube with a socket at each end and two holes through which a bar can be inserted to turn the wrench. The bar is called a T-bar; but the British call it a tommy bar

box van: A British term for a cube van with a large cargo box behind the driver's cab.

box wrench: A tool designed to secure or remove a bolt or nut. Each end of the wrench fits around the bolt head or nut. British term for "ring spanner." In contrast, see open end wrench.

boxy: A derogatory description of a car that has square angles instead of smooth curved lines.

boy: See low boy

boy racer: A low-cost car without much sophistication or performance; but it does have a very sleek and sporty appearance.

BP: Acronym for barometric absolute pressure sensor or barometric pressure sensor

BPA: Acronym for bypass air solenoid

B-pillar: The center body pillar on sedans. It connect the sills and provides roof support. Sometimes referred to as simply post, as in 1957 Chevy two-door post. On a true hardtop design these pillars are missing, leaving uninterrupted glass area along the sides of the car. Also called "B-post."

B pillar: See B-post.

B post: B-post. B-post: The center body post on sedans. It connect the sills and provides roof support. Sometimes referred to as simply post, as in 1957 Chevy two-door post. On a true hardtop design these pillars are missing, leaving uninterrupted glass area along the sides of the car. Also called "B-pillar." BPS: Acronym for exhaust back pressure transducer valve

BPV: [1] Acronym for bypass valve. [2] Acronym for exhaust back pressure transducer valve

Bra: A protective cover, usually of leather or vinyl, which is mounted to the front of a vehicle to protect the finish from stones. Also see stealth Bra brace: A support beam to give reinforcement between two objects. Also see roof brace speed brace bracing: [1] To stiffen something by using a brace. [2] A brace. See cross bracing

bracket: a support device which is often a right-angled shape. Also see bilge bracket bottom bracket bumper bracket

drive end bracket end bracket fender support bracket margin bracket slip-ring end bracket spring bracket towing bracket tripping bracket wing support bracket bracket set: See chassis bracket set

braided hose: A rubber hose which is covered in a woven material or braided wire. Used for various hoses under the hood.

brake: [1] To slow down a vehicle. [2] The mechanism that converts motion (kinetic energy) into heat energy through friction. The most common instance is found in the wheels of cars where the brake shoes or disc pads are designed to press against the brake drum or brake disc. Also see air brake anti-lock brakes anti-lock brake system armature brake assisted brakes band brake bleeding the brakes bonded brake lining cable brake caliper disc brake cantilever brakes clutch brake coaster brake disc brake disc brake gauge disc brake rotor disc brakes double leading brake shoe drum brake dual brakes

duo-servo brake E-brake emergency brake engine brake fixed-caliper disc brake fixed-cam brake flexible brake pipe floating caliper disc brake flushing the brakes foot brake forward brake shoe four wheel disc brakes high-mounted brake light hinged-caliper disc brake hub brake hydraulically-activated brakes hydraulically-assisted brakes hydraulic assisted brakes hydraulic brake booster hydraulic brakes inboard brake jake brake jam on the brakes jam the brakes juice brake leading brake shoe low brake pedal master brake cylinder maximum brake power mechanical brakes non-servo brake park brake park brake extension parking brake console parking brake lever strut parking brake lever parking brake pedal parking brake pin slider caliper disc brake power assisted brakes power brake press brake primary brake shoe primary forward brake shoe prony brake pumping the gas brakes

pump the brakes reverse brake shoe rim brake riveted brake lining rollercam brake self-energizing brake shoe service brake servo action brake servo brake shooting brake single-anchor self-energizing brake sliding-caliper disc brake sprag brake spring brake U-brake uni-servo brake vacuum assisted brake ventilated brakes brake adjuster: A device which moves the drum shoes closer to or further apart from the drum.

brake adjusting spanner: A British term for brake wrench

brake adjusting wrench: A wrench which is used to adjust the brake shoes

brake anchor: A steel stud or pin upon which one end of the brake shoes is either attached to or rests against. The anchor is firmly affixed to the backing plate.

brake, anti-lock: See anti-lock brakes.

brake antiroll device: See brake anti-roll device.

brake anti-roll device:

A unit installed in the brake system to hold brake line pressure when the vehicle is stopped on an upgrade, when the vehicle is stopped on the upgrade and the brake pedal released, the anti-roll device will keep the brakes applied until either the clutch is released or as on some models, the accelerator is depressed.

brake backing plate: A rigid metal (steel) plate, located inside the brake drum, on which the wheel cylinder, brake shoes, and other brake parts are mounted. The braking force applied to the shoes is absorbed by the backing plate. brake band: A band, faced with brake lining, that encircles a brake drum, it is used on several parking brake installations. It differs from brake shoes in that brake shoes squeezes against the inside surface of a drum while a brake band squeezes against the outside surface of a drum.

brake bias: The front/rear distribution of a vehicle's braking power. For the shortest stopping distance, brake bias should match the vehicle's traction at each end during hard braking brake modulation -- the process of varying pedal pressure to hold a vehicle's brakes on the verge of lockup. Ideally, the brakes will unlock with only a slight reduction in the pressure needed to lock them. Typically, however, a considerable pressure reduction is required.

brake bleeder: A valve attached to each wheel brake. This valve can be opened and closed to allow air to be removed or bled from the brake lines.

brake bleeding: See bleeding the brakes.

brake block: See brake pad.

brake booster: A mechanical device which attaches to the brake system to multiply the force the driver applies with his foot (or hand as in the case of a motorcycle). The device uses air, vacuum, or hydraulic fluid to accomplish this purpose. Sometimes called "power assisted brakes," "vacuum assisted brakes," "hydraulically assisted brakes," or just "power brakes." In most cars, the boost

comes from engine intake vacuum. In motorcycles it comes from hydraulic fluid. Also See hydraulic brake booster vacuum brake booster brake cable: A wire cable which activates the brakes. Used on motorcycles, trailers, and for the parkbrake

brake caliper: See calipers.

brake console: See parking brake console computer brake control brake cylinder: A cylinder containing a movable piston actuated by hydraulic pressure to push fluid through the lines and wheel cylinders and force the brake lining or pads against a drum or disc. Also see wheel cylinder master brake cylinder brake disc: A British term for brake rotor.

brake disc type: A braking system that instead of using the conventional brake drum with internal brake shoes, uses a steel disc with caliper type lining application, when the brakes are applied, a section of lining on each side of the spinning disc is forced against the disc thus imparting a braking force. This type of brake is very resistant to brake fade. Also see disc brake. brake dive:

The action of the front end of a vehicle as it dips down when the brakes are applied. Opposite to squat. Also see anti-dive system anti-lift anti-squat system brake drum: A cast iron or aluminum housing bolted to the wheel, that rotates around the brake shoes. When the shoes are expanded, they rub against the machined inner surface of the brake drum and exert a braking effect upon the wheel to slow or stop the vehicle. brake drum lathe: A machine to refinish the inside of a brake drum.

brake dust: The dust created as the brake linings wear down in normal use. Brake dust usually contains dangerous amounts of asbestos

brake extension: See park brake extension

brake fade: Reduction or loss in braking force due to loss of friction between brake shoes and drum (or brake pads and disc). Caused by heat buildup through repeated or prolonged brake application.

brake failure: The total inability of the brakes to function. May be caused by worn out pads or shoes, broken hydraulic lines, broken cable or other linkage, non-functioning master cylinder, low or empty brake fluid reservoir, etc.

brake feel: A discernible, to the driver, relationship between the amount of brake pedal pressure and the actual braking force being exerted. A special device is incorporated in power brake installations to give the driver this feel.

brake fluid:

A special fluid used in hydraulic brake systems to stop or slow the vehicle. Never use something else in place of regular fluid. There are four types of brake fluid on the market. DOT 3, DOT 4, DOT 5, and DOT 5.1. Also see silicone brake fluid brake fluid reservoir: In an automobile, it is a translucent tank located in front of the master cylinder. It usually has two chambers containing brake fluid. In a motorcycle, it may be found on the handlebar (for the front brake) or near the back of the bike (for the rear brake).

brake flushing: Cleaning the brake system by flushing with alcohol or brake fluid. This is done to remove water, dirt, or any other contaminant, flushing fluid is placed in the master cylinder and forced through the lines and wheel cylinders where it exits at the cylinder bleed screws.

brake gauge: See disc brake gauge

brake horsepower: (bhp) A measurement of the actual usable power (not calculated power) measured at the output shaft (usually the crankshaft) rather than at the driveshaft or the wheels. Thus none of the auxiliaries (gearbox, generator, alternator, differential, water pump, etc.) are attached. It is called the brake horsepower because the shaft power is usually measured by an absorption dynamometer or "brake." This is not the brake on the vehicle's wheels but a testing device applied to the shaft. This instrument is applied to stop or absorb the rotation of the output shaft and returns a value. Compare SAE gross horsepower and SAE net horsepower. Also see horsepower brake hose: A flexible high-pressure hose that is reinforced. It connects between the brake pipes and the brake assembly. It needs to be flexible because of the constant movement of the suspension

brake lathe:

The machine used to resurface the friction surfaces of brake discs or drums

brake lever: [1] A blade attached to the right side of the handlebars of a motorcycle which usually activates the front brake. [2] A device for activating the park brake. Also see parking brake lever brake lever strut: See parking brake lever strut

brake light: A red light at the rear of the vehicle which is activated when the brakes are applied. Also called "stop light." Also see high-mounted brake light auxilliary brake lights brake line: See brake lines.

brake lines: A system of hoses and metal tubes through which the brake fluid flows from the master cylinder to the brake calipers at each wheel. Cracks or breaks in these lines will cause the fluid to leak out and result in loss of brakes.

brake lining: A heat-resistant friction material (usually asbestos) that is attached to the brake shoe. When the shoe is pressed against the brake drum, the lining grabs the inside of the drum, which stops the vehicle and also prevents the drum and the shoe from wearing each other away. Also see bonded brake lining riveted brake lining brake lock: See steering wheel and brake lock

brake master cylinder: The part of the hydraulic brake system which stores the brake fluid. As the brake pedal is applied pressure is forced against a small movable piston in the master cylinder to push hydraulic fluid through the lines to the wheel cylinders and force the brake linings against the drum (in the case of drum brakes) or force the brake pads against the disc (in the case of disc brakes). brake mean effective pressure: (BMEP) The average pressure in the cylinders of an engine divided by its mechanical efficiency, i.e., the ratio of the power actually delivered at an output shaft to the power developed in the cylinders. It is used as an indication of torque.

brake pad: The friction material or lining which is secured to metal plates. They press against the brake disc or rotor to enable the wheel to stop. They are to be distinguished from brake shoes which press against the inside of a drum. On a bicycle, brake pads are blocks of rubber-like material fastened to the end of the brake caliper; they press against the wheel rim when the brakes are applied. Also called "brake block." Sometimes the term "brake pad" refers to both the pad and the metal backing. Also see ceramic brake pad sintered metal brake pad brake pads: See brake pad.

brake pad wear indicator: A device which detects the thickness of the brake pad by using an L-shaped strap which will scrape against the disc when the pad thickness is below tolerance. Others use an electrical circuit in which a worn pad closes an electrical circuit that illuminates a light on the dash panel.

brake pedal: A foot operated device which engages the brakes to stop or slow the rotation of the wheels. Also see low brake pedal parking brake pedal spongy brake pedal

brake pipe: A steel pipe used to transmit the brake fluid. See flexible brake pipe

brake piston: On a motorcycle, pressure from the brake lever (when squeezed) forces the brake fluid to flow from the master cylinder down through the brake line and into the caliper. The pressure of the brake fluid causes the piston to push the brake pad to rub against the disc, thus stopping movement of the motorcycle.

brake, power: See power brakes maximum brake power brake puck: See brake pads.

brake pucks: See brake pads.

brake pulling: A situation where the vehicle moves to one side when the brakes are applied. It is usually due to uneven application of the brakes from side to side.

brake, parking: See parking brake emergency brake brake proportioning valve: A valve that limits braking force to the front or rear wheels, usually as a function of pedal effort or line pressure, loading of the vehicle or front-rear weight transfer, to prevent wheel locking and provide the most effective braking. brake rod: A long rod which connects between the brake pedal and the brake actuating lever.

brake rotor:

The brake disc which is attached to the wheel and is surrounded by a brake caliper. Also see disc brake rotor brakes, antilock: See anti-lock brakes.

brakes, anti-lock: See anti-lock brakes.

brake servo: A device which multiplies the driver's physical effort in applying the brakes by using manifold vacuum

brake servo unit: See brake servo

brake shoe: That part of the brake system, located at the wheels, upon which the brake lining is attached. There are usually two shoes (curved or arc-shaped pieces) in each wheel. When the wheel cylinders are actuated by hydraulic pressure they force the brake shoes apart and bring the lining into contact with the brake drum. In this way the vehicle is slowed or stopped. On a bicycle, it is the metal part that holds a brake pad and is bolted to the end of a brake caliper. Also see double leading brake shoe forward brake shoe leading brake shoe primary brake shoe primary forward brake shoe reverse brake shoe secondary brake shoe self-energizing brake shoe single leading brake shoe trailing brake shoe. brake shoe grinder: A grinder used to grind brake shoe lining so that it will be square to and concentric with the brake drum.

brake shoe heel: That end of the brake shoe closest to the anchor bolt or pin.

brake shoe return spring: A spring which is attached to the two brake shoes. After the brake is applied, this spring pulls the shoes away from the drum

brake shoe toe: The free end of the shoe, it is not attached to or resting against an anchor pin.

brakes, power: See power brakes.

brake system: A system that uses hydraulic pressure to enable your vehicle to slow and stop safely. Consists of the master cylinder, brake lines, and disc or drum brakes at each wheel. Also see anti-lock brake system brake system cleaner: A type of solvent designed exclusively for cleaning brake system components. It will not destroy plastic, rubber, or synthetic rubber components and it dries quickly, without leaving a residue

brake test: A testing procedure which determines the efficiency of a vehicle's brakes in order to pass safety tests

brake torquing: A procedure generally used in performance tests to improve the off-the-line acceleration of a vehicle equipped with an automatic transmission. It is executed by firmly depressing the brake with the left foot, applying the throttle with the vehicle in gear to increase engine rpm, then releasing the brakes. Brake torquing is particularly effective with turbocharged cars because it helps overcome turbo lag.

brake warning light: An indicator light on the dash which indicates problems such as low fluid level in the brake fluid reservoir, a malfunction in any of the hydraulic brake circuits, or

excessive wear of the brake pads or shoes. It also illuminates when the parkbrake is applied. When the ignition is first started, the light will illuminate momentarily to show that the light is working.

brake wrench: A wrench which is used to adjust the brake shoes. The British call it a "brake adjusting spanner."

braking: The action of operating the devices for slowing the motion of a vehicle. Also see active braking time all-out braking cadence braking diagonal split braking system dual-circuit braking system dual-line braking system dual braking system engine braking effect heavy braking hydraulic braking system late braking light braking regenerative braking stab braking trail braking braking distance: A measurement of the distance that a vehicle will travel from the time the brakes are first applied to the actual moment it stops. Also see stopping distance braking effect: See engine braking effect

braking efficiency: braking effort as a percentage of the weight of the vehicle

braking effort:

The amount of strength needed by the operator to bring a vehicle to a stop or the amount of resistance in the brake system

braking force: The amount of strength needed by the operator to bring a vehicle to a stop or the amount of resistance in the brake system

braking ratio: The distribution of braking effort between the front and rear wheels

braking system: All the components that contribute to stopping the vehicle. Also see anti-lock braking system diagonal split braking system dual-circuit braking system dual-line braking system dual braking system hydraulic braking system secondary braking system single-circuit braking system single-line braking system braking time: See active braking time

brand number: A series of identifying numbers and letters which some companies burn into the sidewall rubber of a truck tire to show their initials, mounting date, etc.

brass hammer: A hammer with a brass head. Because the head is softer than steel it is used for hitting a steel object without damaging that object

brass punch: A drift or punch made of brass which is used to remove bushings and bearing races because brass does not score or mark steel.

brass hammer:

A hammer with a brass head which is used to pound steel pins etc. into place without damaging them.

braze: To join two pieces of metal together by heating the edges to be joined and then melting drops of brass or bronze on the area. Unlike welding, this operation is similar to soldering, except a higher melting point material is used.

braze on: See braze-ons.

braze-on: See braze-ons.

braze-ons: Parts for mounting shift levers, derailleurs, water bottle cages, and racks, which are fastened to a bicycle frame through a type of soldering process known as brazing.

braze welding: Making an adhesion groove, fillet, or plug connection with a brazing alloy

brazing: Making an adhesion groove, fillet, or plug connection with a brazing alloy

breadth: See beam

break: [1] The action of an item when it no longer holds integrity -- usually resulting in unusable pieces. See impact break circumferential break [2] To dismantle a vehicle for parts. [3] To separate as when a switch breaks contact when it is shut off

break away:

See breakaway

breakaway: The action of a wheel when it turns very rapidly and loses traction so that there is no contact with the ground. Bias-belted tires and radial tires resist the breakaway action better than a bias ply tire. Also see spark breakaway

breakbulk vessel: A general, multipurpose, cargo ship that carriers cargoes of nonuniform sizes

break down: [1] To cease to operate as in our car broke down on the highway. [2] To lose its insulating effectiveness

breakdown: [1] A failure of a mechanism or vehicle as in we had a breakdown on the highway. [2] A loss of insulating effectiveness

breakdown recovery: Rescue of a vehicle that has suffered a breakdown by towing it to a service station, etc.

breakdown service: A service provided by a tow-truck in providing repairs at the place where the breakdown occurred

breakdown truck: A tow-truck

breaker: [1] A person who dismantles a vehicle for parts. Also called a dismantler. [2] A cushioning layer between the belt layers and the tread in radial tires. [3] A device for removing contact. Also see bead breaker chain breaker circuit breaker contact breaker

dual breaker points glaze breaker breaker arm: The movable part of a pair of contact points in a distributor or magneto.

breaker cam: The lobed cam rotating in the ignition system which interrupts the primary circuit to induce a high tension spark for ignition. breaker gap: See contact breaker gap

breaker plate: The movable plate inside the distributor to which the points and the condenser are attached. Also see contact breaker plate breaker point: See breaker points contact breaker point breaker points: A mechanical switch in the distributor with two metal contact points (usually made of silver, platinum, or tungsten) that open and close. When the points are closed, energy is stored in the primary windings of the coil. When the breaker points open, this energy is transferred to the secondary windings of the coil and stepped up, resulting in a high voltage to fire the plugs. The air gap between the breaker-point surfaces is critical. If the gap is too small, the timing is retarded, if too wide advanced. Also called "points," "contact points," and "ignition points." Also see dual breaker points contact breaker point. breakerless: A distributor or ignition system where the mechanical switching device (such as points or contacts) are replaced by an electronic switching device through the use of transistors. They are also called "contactless" or "all-electronic ignitions."

breaker's yard:

A British term for a salvage yard

breaker-triggered transistorized ignition: A transistorized ignition system whose distributor is the same as that of a coil ignition system, but whose contact breaker switches only the control current of the transistor, not the primary current. Usually not fitted as original equipment.

break in: See break-in.

break-in: Period of operation between the installation of new or rebuilt parts and the time in which the parts are worn to the correct fit, driving at a reduced and varying speed for a specified mileage to permit parts to wear to the correct fit. British term is "runin."

break-in oil: Special formulated oil used in a new engine for a specified amount of time so that all bearing surfaces, etc. are properly seated.

break-out box: (BOB) a service tool that tees-in between the computer and the multi-pin harness connector. Once connected in series with the computer and the harness, this test device permits measurements of computer inputs and outputs

breakover: The area of a dent in a panel where the sheet metal is actually buckled into the opposite direction of its normal shape

break time: The length of time the contact breaker points remain open. Opposite to dwell

break up: British term for dismantling a vehicle and selling the parts. Similar to part out

breakwater: Plates fitted on a forward weather deck to form a V-shaped shield against water that is shipped over the bow

breasthook: A triangular plate bracket joining port and starboard side stringers at the stem.

breathalyze: To administer a breathalyzer test

breathalyzer: A device into which a driver blows to determine the amount of alcohol in his breath (and thus in his blood)

breathalyzer test: A test given by the police to determine if a driver has exceeded the allowable alcohol content in his system.

breather: A vent in the crankcase for relieving internal pressure or admitting air. Also see crankcase breather oil breather pipe oil breather breather pipe: A pipe opening into the interior of the engine. It is used to assist ventilation the pipe usually extends downward to a point just below the engine so that the passing air stream will form a partial vacuum thus assisting in venting the engine. Also see oil breather pipe breather port: See replenishing port

breathing: The action of taking in air for combining with fuel for burning as energy and then exhausting it. See breathing capacity.

breathing capacity:

The volume of air that enters the cylinder during each intake stroke. Volumetric efficiency is determined by comparing the actual volume of air with the maximum possible amount. Also called "air capacity."

breath test: See breathalyzer test

brevet: Literally, the word means "certificate," "patent," or "diploma" in French. In randonneuring, it means two things: certification of having successfully done a randonné, and the long-distance bicycle event itself of at least 200 kilometers. Brevet and randonnée are often interchangeable terms, but a randonnée might be considered to be less structured or less formal than a brevet.

Brewster: A vehicle brand of which the 1925-1948 models with required application are classic cars.

BRG: Acronym for British Racing Green

bricklayer hammer: A special hammer for chipping cement blocks and bricks

bridge: A metal support which is installed in the valve slot of a wheel rim and prevents the flap and tube from bulging through the slot under high pressure and high heat conditions. Also called "lemna." Also see flying bridge house bridge navigating bridge port bridge bridge bolts: High-strength bolts used to fasten together the halves of a split brake caliper

bridged:

See diode.

bridge igniter: A device for detonating the air bag

bridge washer: A protective thin metal washer installed at the valve stem between the flap and rim base to prevent the tube and flap from protruding through the valve slot as a result of high pressure and high temperature.

bridging: A characteristic of undercoats that occurs when a scratch or other imperfection in the surface isn't completely filled. Usually due to under-reducing the primer or using a solvent that dries too fast. Also see gap bridging bright: A lustrous, shiny finish. Opposite to matt

brightening: See chemical brightening

Brinell hardness: A test of a metal's hardness by hydraulically pressing a hard ball into the metal

Bristol: See Arnolt Bristol.

British Association: (BA) A term used to describe a series of fine, small diameter threads for electrical and precision equipment

British Leyland: (BL) A former manufacturer of British automobiles, now called the Rover Group

British Motor Corporation:

(BMC) A former manufacturer of British automobiles which changed its name to British Leyland and then to the Rover Group

British Racing Green: (BRC) A dark green color which used to be the official racing color for British cars

British Standard Fine: (BSF) The fine screw thread used on most British vehicles before metrication. The coarse thread was British Standard Whitworth

British Standards Institution: (BSI) An organization which prepares and issues British standard specifications

British Standard Whitworth: A coarse screw thread used on British vehicles before metrication

British thermal unit: (BTU) A measurement of the amount of heat required to raise the temperature of one pound of water, one degree Fahrenheit.

brittle point: A low extreme temperature at which a substance (like rubber) fractures on sudden impact.

broach: Bringing a metal surface to the desired shape by forcing (pushing or pulling) a multiple-edged cutting tool across the surface.

broken-in: A condition in which a new engine has overcome any wear-in problems.

broken storage: The spaces between and around cargo packages, including dunnage, and spaces not usable because of structural interference.

broker:

an intermediary with legal authority to operate on behalf of the manufacturer.

bronze: An alloy of copper and tin. See phosphor-bronze sintered bronze bronze welding: See braze welding

Brough: A vehicle brand of which the 1925-1948 Superior with required application are classic cars.

Brougham: See Cadillac Eldorado Brougham

BROW: A small inclined ramp to allow passage of trucks over a hatch coaming or bulkhead door sills etc

bruise: Any tire injury which weakens, breaks, or separates the carcass cords without damaging the visible rubber surface.

brush: [1] A paintbrush. See airbrush. [2] The pieces of carbon, or copper, that rub against the commutator on the generator or starter motor or against the slip rings on an alternator. As they wear down, they need to be replaced. Also see carbon brush card brush cup-shaped wire brush file card brush spark plug brush third brush wire brush

brushes: See brush.

brush holder: A device which keeps the carbon brushes in an electric motor in contact with the commutator or slip ring

brush spring: A spring which pushes against the back end of a carbon brush in an electric motor to force it against the commutator or slip ring. Also see carbon brush spring BSF: Acronym for British Standard Fine

BSI: Acronym for British Standards Institution

BSW: Acronym for British Standard Whitworth

BTDC: before top dead center. Spark occurs on the compression stroke, before the piston reaches top dead center.

B thread: See internal thread class B thread BTU: Acronym for "British thermal unit." The amount of heat that must be added to one pound of water to raise its temperature one Fahrenheit degree.

bubble:

A small blister in the finish of paint

bubble car: A type of small car which was popular in the 1950s. It had a bulbous-shaped glass front to provide maximum interior room in spite of its small size. The door opened to the front of the driver. Examples are the BMW Isetta and Heinkel Trojan

Bucciali: A vehicle brand of which the 1925-1948 models with required application are classic cars.

bucket: See headlight bucket rust bucket shim under bucket bucket seat: An individual seat which is found in pairs in the front of a vehicle. Named because the curvature of the backrest and cushion resembles a cut-out bucket.

bucket tappet: valve lifters that are hollow, cylindrical, and closed at one end and used with some overhead camshafts. The flat, closed end of the tappet (bottom of the bucket) rests against the camshaft lobe with part of the valve spring and valve stem enclosed by the cylinder. Called "bucket tappets" because they are shaped like upside-down buckets. Buckland: See AC Buckland Open Tourer.

buckle: [1] A locking clasp usually found on seat belts and tie-down straps. [2] To crumple up, especially when metal bends in a vehicle accident

buckled plates: Battery plates that have been bent or warped out of a flat plane

buckler: A portable cover secured over the deck opening of the hawsepipes and the chain pipes to restrict the flow of water through the openings

buckle up: To put your seat belt on. British term is "belt up"

BUDC: before upper dead center. Same as BTDC.

budd mounting: See double cap nut.

buff: As a verb it means to polish. As a noun it indicates an expert in a field or a person greatly interested in the field as in Jim is a car buff. Also see nut buff contour: The specked shape of a buffed retread tire.

buffer: A machine used to rasp the old tread from the tire. Also see jounce buffer buffered radius: A dimension that ensures the proper contour of the buffed surface according to tire size and type and matrix dimensions.

buffeting: Severe, pulsating force of wind. When you drive in a convertible with the top down, you will often experience this buffeting action of the wind. It is also noticeable when a vehicle is driven quickly with the windows down.

buffing:

[1] Smoothing and polishing a surface by using a buffing wheel and polishing paste or liquid. [2] Grinding or rasping off remaining tread rubber to give the casing proper texture to accept new retread stock and proper dimensions to fit the matrix.

buffing template: A machined device of a specific shape used to obtain the required buffed contour.

buffing wheel: A disc which is covered in soft cloth or lambswool. It is powered by a tool like a drill which spins the disc to give a high gloss shine to the surface of a vehicle.

buff line: The dividing line in the cross section of a tire between the buffed surface of the original tire and the new retread rubber.

bug and tar remover: A solution which will dissolve bugs and tar residue. After application, it needs to be washed off or it will also remove the paint.

bug deflector: A length of clear plastic which is attached to the front of the hood to prevent bugs from hitting the windshield.

Bugatti: A vehicle brand of which the 1925-1948 models are classic cars. Click for books The 1951 Type 101 model is a milestone car. on Bugatti Buick: A vehicle brand of which the Riviera for 1949 and 1963-70 are milestone cars. The 1931-32 series 90 with required application are classic cars. The 1953-54 Skylark are milestone cars.

Click for books on Buick

Buick Century: A model of automobile manufactured by Buick Click for books on Buick Century

Buick Electra: A model of automobile manufactured by Buick

Click for books on Buick Electra

Buick Grand National: A model of automobile manufactured by Buick

Click for books on Buick Grand National

Buick Park Avenue: A model of automobile manufactured by Buick

Click for books on Buick Park Avenue

Buick Regal: A model of automobile manufactured by Buick

Click for books on Buick Regal

Buick Riviera: A model of automobile manufactured by Buick

Click for books on Buick Riviera

Buick Skylark: A model of automobile manufactured by Buick Click for books on Buick Skylark build: The thickness of the paint film deposited on the body during spraying (measured in mils). Also see heavy film build build date code: A code which tells you what day, month, and year the engine was made. Expressed alpha-numerically and stamped somewhere on the block

builder: In retreading a tire, a machine used to apply tread rubber to a casing. Also see body builder Builders and Repairers Association:

See vehicle Builders and Repairers Association

building basin: A structure in which one or more ships may be built and floated by flooding the basin.

build quality: The quality of workmanship and material composition in the construction of a vehicle.

build up: [1] To increase the surface level of metal by welding more material on it (and later grinding it to shape) or by adding filler to it. [2] To assemble or put something together. [3] To add material to something. See carbon build-up pressure buildup buildup: [1] The amount a weld face is extended above the surface of the metals being joined. [2] An excess of some material as in, "There was a buildup of carbon on the top of the piston." Also see carbon build-up built-up crankshaft: A crankshaft which is not cast or forged as one piece, but made of several different parts.

bulb: An electronic device which gives off light by the heating of an element contained with a glass enclosure. The metal base which conducts the electricity may be a barrel with locating pins, or it may have small filament wires protruding from the base. In some cases it is a tube with contacts at either end. When replacing bulbs, especially high intensity bulbs like halogen, be sure to avoid touching the glass. The oil from your fingers will cause the bulb to overheat and burn out quickly. If you do touch the glass, you need to clean it with air dry it. Also see

alcohol bayonet bulb double filament bulb festoon bulb halogen bulb light bulb outer bulb quartz-halogen bulb quartz halogen bulb tungsten-halogen bulb bulk cargo: Cargo such as oil, coal, ore, woodchips, etc. not shipped in bags or containers

bulk carrier: Ship designed to carry cargo such as grain, woodchips, ore, coal, etc. in bulk

bulk charging: Using large containers of refrigerant to charge the system. Commonly employed with charging stations to perform complete system charges

bulkhead: [1] A structural partition that separates compartments. This is generally a metal wall that extends from one side of a vehicle to the other. In the engine compartment, you would find a radiator bulkhead near the front and a firewall near the back. Another bulkhead separates the passengers from the trunk. The dashpanel is also a bulkhead. Also see rear bulkhead. [2] Vertical partition walls which separates the interior of a ship into compartments or rooms. Also see afterpeak bulkhead collision bulkhead forepeak bulkhead screen bulkhead swash bulkhead bulkhead connector: An OEM device used to connect wiring inside the vehicle body with wiring outside the body. Usually located at the bulkhead or firewall

bulkhead deck: The uppermost deck to which the transverse watertight bulkheads are carried

bulk refrigerant drum: A large (e.g., 10 lbs, 25 lbs, 30 lbs) container of refrigerant generally used in professional air conditioning service shops which employ charging stations to perform complete system charges

bull bar: The upward extension of a bumper to protect lights and the grille. Also see nerf bar bullet-point pick hammer: See pick hammer

bull horn: A warning horn that sounds like the bellow of a bull or the moo of a cow

bull low: The lowest gear in a transmission. Some older transmissions listed their gears as bull low (used for getting out of a stuck condition or climbing a very steep hill), low or first (used for starting out from a stop or for climbing a moderate hill), second (used for town driving or slight hills), third (used for highway cruising).

bulwark: Fore-and-aft vertical plating immediately above the upper edge of the sheer strake

bump: The upward movement of the wheels and suspension. Also called "jounce." Also see hood bump rubber bump and rebound: The two stages of suspension movement requiring damping. Also see

bump rebound bumper: Originally a bumper was a separate metal bar or blade at each end of a vehicle to prevent damaging the main part of the vehicle from damage occurred by a slight bump into an obstruction or another vehicle. Also see bumper system energy-absorbing bumper energy absorbing bumper front bumper hood bumper jounce bumper quarter bumper rear bumper skirt absorbing bumper bonnet bumper bumper to bumper wrapround bumper bumper bar: A tubular bar or series of bars which are designed to protect the front of a vehicle

bumper blade: A flat bar which is designed to protect the front or rear of a vehicle.

bumper bracket: A device to which the bumper is attached to the frame, body, or chassis

bumper filler: A small panel usually made of plastic which fits between the bumper and the body of the vehicle.

bumper horn: A short bumper extension which is mounted vertically (i.e., perpendicular to the main bumper), usually one on each side of the bumper. The British term is "overrider."

bumper insert:

A rubber or plastic strip fitted to the width of a bumper to prevent scoring of the bumper.

bumper iron: A bumper bracket

bumper jack: A device for lifting one corner of a vehicle to change a tire. Older cars used a long bar which fitted into a base. A device on the long bar had a hook which was placed in a strategic place on the vehicle. A lug wrench was inserted into the other end of the device and used to move the device up the long bar thus lifting the vehicle.

bumper panels: See side bumper panels

bumpers: See jounce bumpers

bumper skirt: See rear bumper skirt

bumper system: An energy-absorbing system with some type of deformable material including hydraulic cylinders which enable the bumpers to protect the vehicle from damage in low-speed impacts.

bumper to bumper: [1] A traffic condition in which a line of vehicles are stopped one after the other or are moving very slowly. [2] A way of expressing the entire vehicle from one bumper to the other.

bumping blade: An autobody tool used for slapping out slight dents (sometimes without a supporting dolly). It has slight serrations which hold the metal to avoid stretching. Also called a "bumping file."

bumping file:

An autobody tool used for slapping out slight dents (sometimes without a supporting dolly). It has slight serrations which hold the metal to avoid stretching. Also called a "bumping blade."

bumping hammer: An autobody hammer used with a dolly for restoring a panel's shape. Also see fender bumping hammer bumping out: An autobody term in which a damaged panel is hit with a hammer until it is nearly the correct shape.

bumping spoon: See spring beating spoon

bump rubber: See hood bump rubber

bump start: [1] A method of starting a manual transmission (not for automatics) vehicle by pushing it (especially down a hill) and letting in the clutch while in second gear and the ignition set to the "on" position. [2] To start a car using a bump start

bump steer: When an uneven road surface causes a vehicle to steer or lose directional stability, this is called "bump steer." At the front, bump steer is associated with the tie-rod and linkage-arm relationship. It is caused by the method of locating the rear suspension, the type of rear suspension, and the geometry of the various linkages. In race cars, bump steer is designed out of the suspension so that the handling is as precise as possible. In most cars it is present to some degree. In fact, it can be useful to allow engineers to design a small amount of understeer or oversteer into the chassis.

bump stop: A cushioning device, usually rubber, that limits the upward movement of the wheels and suspension to prevent metal-to-metal contact that could lead to suspension damage or failure. Also called "jounce bumpers."

bungee cord: A rubber tie down strap of various lengths (usually 10 mm diameter) with a metal hook on each end. Most are covered with fabric. The hooks are often plastic coated to minimize scratching. Some have an extra hook attached in the middle. Others are linked with a second cord to produce an X-shape. They are used to secure objects to a luggage rack. See bungee net.

bungee net: A specialized bungee cord shaped in the pattern of 25 squares with plastic covered hooks on two opposite sides of the net. It is used to secure objects to a luggage rack. See bungee cord and cargo net.

bunk: A built-in bed on a ship

bunkers: Fuel consumed by the engines of a ship

buoyancy: See center of buoyancy

Bureau of land management: (BLM) The United States government agency within the U.S. Department of the Interior which has divided trails into four classes: Type I is at least 7 feet (213 cm) wide (enough for a family vehicle), paved, easy to traverse. Type II is also at least 7 feet (213 cm) wide, not paved, but is usually improved. However it may be rough or rutted and contain washboards. It is best travelled by high-clearance 4WD vehicles. Type III is a narrow unimproved dirt road, often with rocks, steep hills, and mud over which only 4WD should use. Type IV trails are for mountain bikes, dirt bikes, and ATVs. 2WD or 4WD vehicles are not allowed.

burglar: See car burglar

burned metal: A term occasionally applied to the metal which has been combined with oxygen to the end that some of the carbon has been changed into carbon dioxide and some of the iron into iron oxide.

burned valves: Valves that have become pitted so that they do not close properly

burner: A device which tends to consume a lot of material. Also see fuel burner gas burner lead burning oil burner burning: [1] The violent combination of oxygen with any substance to produce heat. [2] The action of consuming something to produce heat, i.e., combustion. Also see lead burning. [3] The action of erosion or eating away. Electrical contacts are burning when they wear away; exhaust valves are burning when they pit and don't close properly. [4] flame cutting. Also see afterburning lead burning burnish: To bring a surface to a high shine by rubbing with a hard, smooth object.

burn rate: See cbr process controlled burn rate burn rubber: The action of rapid acceleration where the wheels make rapid rotation, but there is only very little momentum. As a result, the driving wheels leave some rubber behind on the pavement. Also see peel rubber.

burnt valves: See burned valves

burr: A roughness left on a cut or punched metal. A rough edge or ridge.

burred wheel: A wheel which has metal slivers or roughness around the edge of the rim.

burr walnut: A wood veneer used for dashboards and door trim on some cars. Also see zebrawood burst: To explode and suddenly lose all the air in a tire.

bury the needle: Going beyond the displayed maximum speed. For example, a digital speedometer may show speeds from zero to 137 kph (85 mph) on its display. When the needle goes beyond the maximum displayed point, it may go beyond the line of sight and is considered buried.

bus: [1] A large public or private passenger vehicle used for transporting many (at least 10) passengers. Also see articulated bus single-decker bus double-decker bus. [2] A busbar which is a heavy conductor used to carry or make a mutual connection between several circuits.

busbar: A heavy conductor used to carry or make a mutual connection between several circuits. Also called a "bus."

bush:

British term for bushing.

bushing: [1] A protective liner or sleeve that cushions noise, friction, or movement. Suspension bushings are often made from two pipes (one inside the other) with a sleeve of rubber in the space between the two pipes. [2] Rubber bushings on the suspension system should be lubricated regularly. [3] A bearing for a shaft, spring shackle, piston pin, etc., of one piece construction which may be removed from the part. Also see valve bushing buster: See lock buster

busy intersection: A road junction where there is a lot of traffic and may be controlled by signal lights or not. Usually a place where accidents are more likely to occur.

butane: A petroleum gas that is a liquid, when under pressure. Often used as engine fuel in trucks. Also see LPG. butt: [1] The end joint between two plates or other members which meet end to end. [2] The square ends of a piston ring

butt connector: A solderless wire connector used to permanently join two wire ends together

butted tubing: Tubing whose outside diameter remains constant but whose thickness is reduced in midsection where less strength is needed.

butterfly: See

butterfly valve throttle butterfly butterfly valve: A nut with wings to be turned by thumb and finger. Sometimes called a "wing nut."

butterfly valve: A small metal disc located in the carburetor that controls the flow of air into the carburetor. It is so named due to its resemblance to the insect of the same name.

butt joint: [1] A piston ring gap in which the two ends of the ring are squared off. [2] A weld where the two panels are not overlapped but fit against each other end to end.

button: A small disk or knob which activates something electrical when it is pressed such as a starter button. Also see abs override button eject button frequency scan button horn button memory button override button preset station button push button release button reset button scan button button head: A bolt with a round head

buttons: See button.

buttress: A thick rubber reinforcement in the shoulder of a tire. It provides support at the edge of the tread, limits shoulder area flexing, and protects the shoulder of off-road

tires. See fender strengthening buttress

buttressed thread: A screw thread with one vertical and one inclined flank

butt strap: A strap that overlaps the butt between two plates, serving as a connecting strength strap between the butted ends of the plating

butyl: A non-porous synthetic rubber used in making inner tubes and tubeless tire liners.

buy at end-of term interest rate: The effective net interest rate for the lease if, at the end of the lease, the car is purchased at the end-of-lease purchase price.

buying decisions: the act of determining whether or not a product purchase or repair, will be made, and/or which product or service will be purchased.

BV: Acronym for bowl vent

BVP: Acronym for bowl vent port

BVT: Acronym for backpressure variable transducer

B/W: Black and white, usually referring to photographs.

BW: Acronym for "blackwall," as in BW tires.

bypass:

[1] A road which avoids the congested area of a city traffic. [2] An alternate route for a flowing substance. [3] To go around something to avoid it. Also see oil cooler bypass valve oil filter oil filter bypass valve start bypass bypass air screw: A screw located on the airflow sensor of a fuel injection system. It adjusts the amount of air allowed into the air-fuel mixture.

bypass air solenoid: (BPA) a device used to control the idle speed on some fuel-injected vehicles

bypass filter: An oil filter that constantly filters a portion of the oil flowing through the engine.

bypass valve: (BPV) A valve that can open and allow fluid or gas to pass through in other than its normal channel. Also see oil cooler bypass valve oil filter oil filter bypass valve

2

DICTIONARY OF AUTOMOTIVE TERMS "C" [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [C] [Ca] [Cb] [Cc] [Cd] [Ce] [Cf] [Cg] [Ch] [Ci] [Ck] [Cl] [Cn] [Co] [Cp] [Cr] [Cs] [Ct] [Cu] [Cv] [Cw] [Cy]

C: [1] Abbreviation for Celsius or centigrade. [2] Abbreviation for coulomb. [3] Abbreviation for comfort.

C-3: Acronym for a computer command control system

C3I: Acronym for computer controlled coil ignition

C-4: Acronym for computer command control system

C-4 system: See computer-controlled catalytic converter

CA: API classification for diesel engine oil widely used in the late '40s and '50s.

CAAM: Acronym for "China Association of Automobile Manufacturers."

cab: [1] A taxi or car for hire. [2] The closed part of a truck (or even a car) where the driver sits. Also see

chassis cab cab chassis: A truck chassis which includes the driver compartment.

cab-forward design: A car design in which the front end is short and the footwells extended to the front axle. This design gave more passenger space and pushed the windshield further from the passengers

cabin: A passenger compartment. Also see rear cabin pillar cabin forward: See cab-forward design

cabin-forward design: See cab-forward design

cabin pillar: See rear cabin pillar

cable: A cord generally made of strands of thin wire. Electrical cables are covered with a protective non-conducting material. Control cables are housed within an outer sleeve. Also see booster cable bowden cable brake cable clutch cable control cable gearchange cables heavy cable ignition cable jumper cables light cable,

shift cables, spark plug cable, speedo cable, speedometer cable, speedometer drive cable, starter switch control cable, stirrup cable, straddle cable, transverse cable cable activated: A device which is controlled by a cable. As a lever or pedal is engaged, the device is correspondingly moved. The longer the cable the less efficient is the system. Cables tend to stretch and fray with use.

cable brake: A braking device which is activated by a cable

cable clamp: [1] A device for securing a cable end to the point where it connects. [2] A device which secures the outer sheath of a cable

cable cover strip: See spark plug cable cover strip

cable guide: A tube which is secured in place to channel the cable which runs through it

cable lock: A thick cable with a lock at one end and which can be wrapped around a bicycle frame and a post to protect the bike from being stolen.

cable loom: See spark plug cable loom

cable marker: See spark plug cable marker

cable operated: An item which is controlled by a cable

cables: See cable.

cable separator: See spark plug cable separator

cabriolet: Similar to the sport coupé, it has a provision for converting to an open-type body (i.e., convertible). A rumble seat is a common on older vehicles, but not mandatory feature. Mercedes-Benz distinguishes the cabriolet from the roadster in that the former has a soft-top which folds up while the roadster has a hard-top which is stored in the trunk. Also called a "drophead coupé."

CACIS: Acronym for "Continuous AC Ignition System"

CAD: Acronym for "computer aided design"

Caddy: An euphemistic name for Cadillac Also see plug caddy cadence braking: A braking method in which the driver rapidly depresses and releases the brake pedal to bring a vehicle to an emergency stop

Cadillac: The following Cadillacs are classic cars: • • • •

All 1925-35 models All 12-cylinder models All 16 cylinder models All 1938-41 60 Special models

Click for books on Cadillac

•

All 1936-48 series #67, #70, #72, #75, #80, #85, #90

For a history of Cadillac, see Cadillac History. Cadillac Eldorado: A vehicle brand of which the 1953-58, 67-70 Eldorado models are milestone cars. Also see the history of Cadillac Eldorado.

Click for books on Cadillac Eldorado

Cadillac Eldorado Brougham: A vehicle brand of which the 1957-58 models are milestone cars. Also see history of Cadillac Eldorado.

Cadillac 60 Special: A vehicle brand of which the 1948-49 models are milestone cars. Also see history of Cadillac.

Cadillac 61 Coupe Fastback: A vehicle brand of which the 1948-49 models are milestone cars. Also see history of Cadillac.

Cadillac 62: A vehicle brand of which the Sedanet and Convertible DeVille for 1948-49 are milestone cars. Also see history of Cadillac.

Cadillac 75: A vehicle brand of which the Sedan/Limo for 1946-70 are milestone cars. Also see history of Cadillac.

Cadillac Seville: A model of automobile manufactured by General Motors

Click for books on Cadillac Seville

cadmium-plated: Something that is covered with a coating of cadmium. It is usually used to protect aluminum and steel nuts and bolts

CAE:

Acronym for Computer Aided Engineering

CAFE: Acronym for "Corporate Average Fuel Economy."

cafe racer: An early sportbike motorcycle which originated in Europe. They had a low windshield and the rider was bent forward to optimize the flow of air. Its name came from those who raced from one restaurant (cafe) to another.

cage: [1] On a front derailleur of a bicycle, it is a pair of parallel plates that push the chain from side to side; on a rear derailleur, it is a set of plates in which pulleys are mounted to hold and guide the chain from cog to cog. [2] Any device for holding or securing something, e.g., a bottle cage on a bicycle. [3] When referring to bearings, it is the part which holds the balls or rollers in place. Usually called ball cage. Also see bearing cage needle cage roller cage [4] When referring to a vehicle, it is the safety enclosure called a "roll cage." [5] Any enclosure. See differential cage integrated roll cage multi-reed cage CAJAD: Acronym for "Canadian Association of Japanese Automobile Dealers"

CAL: Acronym for Computer Aided Lighting

calcium chloride: A chemical (salt) which is added to water in a liquid ballast.

calculation:

See load distribution calculation

calendering: A thin layer of rubber inside the tire casing which covers the carcass cords to protect them from moisture and to protect the tube from chafing by the cord body. In tubeless tires, calendering consists of a layer of air proof butyl rubber.

calibrate: As applied to test instruments it is the procedure of adjusting the dial needle to the correct zero or load setting.

calibration: Marking the measuring units on an instrument or checking their accuracy

calibration oil: Oil which is used in a tester for checking injection nozzles, meeting SAE J967D specifications

California wheel: A name given to a spoked wheel produced by particular manufacturer. Although the wheel is popular in the East and Midwest of United States, it is not common in California or other Western states.

caliper: [1] The apparatus on disc brakes which hold the disc pads and straddles the disc. When actuated the pads press against the disc to stop or slow the vehicle. Also see brake caliper floating caliper disc brake pin slider caliper disc brake swinging caliper [2] On bicycles, the brake arms that reach around the sides of a wheel to press brake pads against the wheel rim. [3] An adjustable measuring tool that is placed around (outside caliper) or within (inside caliper) an object and adjusted until it just contacts. It is then withdrawn and the distance measured between the contacting points. Also see dial caliper

digital caliper inside spring caliper machinists' caliper outside spring caliper pocket caliper pocket slide caliper vernier caliper caliper disc: See floating caliper disc brake pin slider caliper disc brake caliper disc brake: See floating caliper disc brake pin slider caliper disc brake caliper gauge: A caliper (definition #3)

calk: To fill seams in a wood deck with oakum or hammer the adjoining edges of metal together to stop leaks. Also spelled "caulk"

call: See close call

calliper: Alternate spelling for caliper

Cal-look: A style modification of small vehicles which first started in California. Most of the chrome is removed and the vehicle is painted a bright color like yellow, light blue, and red.

calorie: A metric measurement of the amount of heat required to raise 1 gram of water from 0° to 1° Celsius

calorific value: A measure of heating value of fuel

calorimeter: An instrument to measure amount of heat given off by a substance when burned

CAM: Acronym for "Computer Aided Manufacturing"

cam: [1] A designed bump on a shaft or disc which causes a rocking motion in an adjacent part. [2] A metal disc with irregularly shaped lobes used in the camshaft to activate the opening and closing of the valves and in the distributor, to force the points to open. [3] A colloquial name for the camshaft. [4] A name for the breaker cam. Also see adjuster cam closing cam distributor cam double overhead cam dual overhead cam engine exhaust cam fast idle cam floating cam inlet cam intake cam overhead cam single-overhead cam cam-and-lever steering: A steering system in which a conical peg mounted on a lever engages in a helically cut groove on a cylindrical drum. Also called "cam-and-peg steering"

cam-and-peg steering: See cam-and-lever steering

cam-and-roller steering:

A steering system in which a tapered disc or a set of discs or rollers engage with a helically cut, tapered groove on a cylindrical drum

cam angle: See dwell.

Camaro: A series of pony cars from the Chevrolet division of General Motors. It is often misspelled as "Camero" because of a mispronunciation. The Click for books on 1967-69 SS/RS V-8 and Z-28 models are milestone cars. Also see Camaro Chevrolet Camaro cam belt: See timing belt

camber: [1] A wheel alignment adjustment of the inward or outward tilt on the top of the wheel when viewed from the front of the vehicle. Tipping the top of the wheel center line outward produces positive camber. Tipping the wheel center line inward at the top produces negative camber. When the camber is positive, the tops of the tires are further apart than the bottom. Correct camber improves handling and cuts tire wear. Camber is measured in degrees. See wheel camber. [2] The rise of a deck of a ship, athwartship

cambered axle: An axle that has a slight arch which curves upward at the center so that the wheels can tilt outward at the top. In this way it is better than an axle which might sag under load.

camber thrust: The side force generated when a tire rolls with camber. Camber thrust can add to or subtract from the side force a tire generates.

cam chain: A timing chain which controls the overhead camshaft.

cam design:

See cam profile

camel: A padded fender to keep a vessel away from a pier or quay to prevent damage to the hull or pier

camelback: Uncured retread rubber in crescent shape, available in various widths and depths according to size and type of tire being retreaded. Also see die size Camel Grand Touring Prototype: (GTP) An International Motorsports Assocation's (IMSA) premier racing category until 1993 when it was replaced by the controlled cars World Sports Car Championship. GTP cars were the most powerful and the fastest on most road racing circuits in North America at that time. Over the years, many automakers fielded factory teams in this series including Ford, Toyota, Jaguar, Nissan, and Porsche.

cam engine: See dual overhead cam engine twin cam engine cam face: The surface of a cam lobe

cam follower: The unit that contacts the end of the valve stem and the camshaft. The follower rides on the camshaft and when the cam lobes move it upward, it opens the valve. Also called "valve lifter" or "tappet." cam ground piston: See cam-ground piston.

cam-ground piston: A piston with a skirt that is ground slightly egg-shaped or oval-shaped. The widest diameter of the skirt is at right angles to the piston-pin axis. When it is heated, it becomes round. The design allows for a closer fit in the cylinder so that there is a

reduction of blowby gas, cylinder scuffing, and piston slap.

cam heel: The lowest point of a cam opposite the lobe. Also called base circle

cam lobe: See cam lobes.

cam lobes: The bumps on a cam that contact and activate such devices as the lifters, which operate the valves, and the rubbing block, which causes the points to open and close, as the cam spins with the distributor shaft.

cam lubricator: A device, often in the form of a wick, for lubricating the contact breaker cam in the distributor

campaigning: Racing a particular vehicle for an entire season.

camper: A structure which fits into a truck bed for camping purposes. It usually has beds and possibly cooking and washing facilities. Also called a "truck camper." Also see van camper camping: See folding camping trailer

camping trailer: A trailer containing camping equipment. Also see folding camping trailer soft-top trailer hard-top trailer trailer

cam profile: The shape of each lobe on a camshaft. These shapes determine when the valves open or close.

cam/rocker: See opening cam/rocker

cam/rocker: See opening cam/rocker

cam roller: Rotating wheel acting as a cam follower

Camry: A model of automobile manufactured by Toyota

Click for books on Camry

camshaft: A shaft with cam lobes (bumps) which is driven by gears, a belt, or a chain from the crankshaft. The lobes push on the valve lifters to cause the valves to open and close. The camshaft turns at half the speed of the crankshaft. Also see double-overhead cam double overhead camshaft exhaust camshaft inlet camshaft intake camshaft overhead cam overhead camshaft race camshaft three-quarter race camshaft single-overhead camshaft twin camshaft twin overhead camshaft camshaft bearing: Usually a plain bearing which supports the camshaft

camshaft drive:

A connection between the crankshaft and camshaft by means of gears, chain, drive belt, shaft, or eccentric shaft to maintain the ratio of 1:2.

camshaft drive belt: A timing belt

camshaft drive sprocket: A sprocket attached to a crankshaft (either at one end or somewhere in the middle) which drives the camshaft with the use of a chain

camshaft end play: The amount of lateral movement of the camshaft once it is installed

camshaft engine: See twin camshaft engine

camshaft gear: A gear that is used to drive the camshaft.

camshaft housing: That part of the engine which encloses the camshaft and often other parts of the valve train.

camshaft journal: That part of the camshaft that runs in one of its bearings

camshaft pulley: The pulley on the end of the camshaft for the camshaft drive belt

camshaft sprocket: The sprocket on the camshaft which (through a chain) is driven by the camshaft drive sprocket

can: [1] A tube in a canned motor pump which insulates the motor winding. [2] A muffler. [3] A container for liquid or other substances.

Also see oil can Canada-U.S. Free Trade Agreement: (FTA) Implemented in January 1989 to eliminate all tariffs on U.S. and Canadian goods by January 1998 and to reduce or eliminate many non-tariff barriers.

Canadian Automotive Repair and Service Council: (CARS) A not-for-profit organization established to serve the human resource and training needs of the Canadian car and truck repair and service industry.

Canadian cross border shopping: cross border shopping describes the purchasing by Canadian consumers of products in the United States. Of particular interest is the decision by these buyers to obtain their products in the U.S., even though similar products are available in the Canadian market.

Canadian Environmental Protection Act: (CEPA) act where the goal is pollution prevention and protection of Canadians from toxic substances.

cancellation: See noise cancellation

candela: (cd) A basic unit of luminous intensity. If, in a given direction, a source emits monochromatic radiation of frequency 540 x 1012 Hz, and the radiant intensity in that direction is 1/683 watt per steradian, then the luminous intensity of the source is 1 candela.

candle: See candle power.

candle power: A measurement of the light producing ability of a light bulb.

candy apple paint:

A bright color (usually red) paint (often with metal flakes) with a transparent clear coat

candy paint: A bright color (usually red) paint (often with metal flakes) with a transparent clear coat

canibalize: The action of removing good parts from one vehicle in order to put them into another vehicle.

canister: A small metal box or can. Also see activated carbon canister adsorption canister charcoal canister vapor canister canister air filter: A centrifugal force air filter

canister purge shut-off valve: (CPSOV) a vacuum-operated valve that shuts off canister purge when the air injection diverter valve dumps air downstream

canister purge solenoid: An electrical solenoid that opens the canister purge valve between the fuel vapor canister line and the intake manifold when energized

canister purge valve: Valve used to regulate the flow of vapors from the evaporative canister to the engine

canned motor pump: A glandless pump with a special type of submersible or "canned" motor, whose stator winding is insulated from the fluid pumped by a tube, the so-called can

cannibalize: To take parts from a vehicle to fit to another vehicle

canning: The insertion of the catalyst element into the converter shell of a catalytic converter

cant beam: Beams supporting the deck plating in the overhanging portion of the stern.

cant frame: A frame connected at the upper end to the cant beams

cantilever: An arm that projects from a source and supports cables. Also see cantilever brake cantilever brake: rim brake on bicycles with pivoting arms mounted on fork blades or seatstays at or below rim level.

cantilever brakes: See cantilever brake.

cantilever spring: [1] A leaf spring which is mounted upside down and attached to the vehicle at its mid-point. This system is no longer in use in modern vehicles. [2] A quarter-elliptic leaf spring

cantrail: The roof rail

canvas top: The convertible top.

cap: [1] A protective round cover which is secured to something.

[2] The base of a light bulb which fits into a socket. [3] Cleaner air package system of reducing the amount of unburned hydrocarbons in the automobile exhaust. Also see air cap battery cap bayonet cap bearing cap big-end cap car cap cold cap distributor cap double cap nut dust cap end cap external mix air cap filler cap flip-top filler cap fuel cap full cap hot cap hubcap inner cap nut insulating cap internal mix air cap net cap cost oil filler cap outer cap nut plug cap pressure cap pressure radiator cap radiator cap radiator pressure cap roto cap safety pressure cap spark plug cap spindle cap top cap valve cap valve spring cap capacitance: The property which opposes any change in voltage in an electrical circuit. The property of a nonconductor by which it stores electrical energy when separated surfaces of the nonconductor are maintained at a difference of potential. Capacitance is measured by the ratio of the charge induced to the potential difference and is proportional to the area of the conducting plates and the dielectric

constant of the nonconducting material, and inversely proportional to the separation of the plates (mks unit: farad).

capacities: See fluid capacities

capacitive discharge: (CD) A type of ignition system. It can be either all-electronic or breaker point controlled. The primary power is drawn from the engine's battery and put into the CD power supply, where it is changed from 12 volts direct current to about 300 volts of pulsating direct current that is stored in a capacitor (condenser). The release of this energy through the coil is governed by a silicon-controlled rectifier (SCR). When the SCR switch is closed, the voltage stored in the capacitor is supplied to the coil, which acts as a voltage step-up transformer boosting firing voltage to around 30,000 volts to fire the plugs.

capacitor: A device which gives capacitance, usually consisting of conducting plates or foil separated by layers of a dielectric. A potential difference applied across the plates induces a separation of charge centers in the dielectric, thus storing electrical energy. Also see condenser ignition capacitor capacitor controlled electronic ignition: See electronic ignition system capacitive discharge capacitor discharge ignition: (CDI) See capacitive discharge

capacity: [1] The ability to contain or hold something. [2] Maximum production attainable under normal conditions. With regard to normal conditions, the company's operating practices are to be followed with respect to the use of production facilities, overtime, workshifts, holidays, etc. [3] The output of an electric motor or other electrical equipment. [4] The volume of fluid which a pump can handle.

Also see air capacity ampere hour capacity battery capacity breathing capacity carrying capacity cubic capacity energy engine capacity fuse fuse capacity load capacity net capacity nominal capacity passenger capacity ply rating rated capacity reserve capacity seating capacity top off work capacity capacity plan: A plan outlining the spaces available for fuel, cargo, ballast, fresh water, etc, with guides on weight and volume for spaces at various drafts and displacements

capacity rating: See rated capacity

cap cost: See capitalized cost net cap cost cap cost reduction: See capitalized cost reduction

cape chisel: A metal cutting chisel shaped to cut or work in channels or grooves

capillary:

A tube with a very small bore used for temperature gauges

capillary action: The property of a liquid to move into small spaces if it has the ability to "wet" these surfaces

capillary tube: A tube usually gas-filled, with a precisely calibrated length and inside diameter, used to connect the remote bulb or coil to the expansion valve or thermostat. A tube with a very small bore used for temperature gauges. Also called pressure sensing line

capitalized: See net capitalized cost

capitalized cost: The total price of the vehicle, in effect, its purchase price. In theory, the cap cost should equal the amount you would pay for the vehicle if you were purchasing the vehicle. When a lease is made, the dealer sells that vehicle to the leasing company (for the cap cost), which then leases the the vehicle to you. Also see net capitalized cost capitalized cost reduction: A fancy name for a cash down payment, money you pay up front that is applied to the final purchase price of a lease. A large cap cost reduction will, of course reduce the monthly payments, but it will also negate one of the big advantages of leasing. However, if you own your present car, you may be able to use it, as a trade-in, to satisfy the cap cost reduction to start the lease. Remember, you must pay sales tax on any cap cost reduction you make. Another source of capital cost reduction may be dealer or manufacturer participation. Dealers and manufacturers will sometimes lower the cap cost or offer a rebate that reduces the cap cost. A dealer or manufacturer cap cost reduction does lower your total out-of-pocket dollars, unlike a cap cost reduction that you must pay.

capital expenditures: expenditures to acquire or add to capital assets that will yield benefits over several accounting periods. Included are cost of procuring, construction, installing new durable plants, machinery and equipment where for replacement, addition or for lease or rent to other companies including subsidies.

cap nut: A nut that is closed at the threaded end often with a dome. Also see double cap nut inner cap nut outer cap nut capping: [1] Installing a new tread on a tire carcass. Also see retreading. [2] Door molding or capping

capstan: A stump with a vertical axis used for handling mooring and other lines

capstan screw: A screw or bolt with a round head and one or more holes through it into which a bar may be inserted for securing or removing it

capstat: A wax-type thermostat at the base of the jet of a SU carburetor, which expands and reduces fuel flow when the underhood temperature rises. Also see temperature compensator capsule: See advance capsule vacuum capsule captive: Something that is permanently located in the desired position

captive finance company: A leasing or finance company which is affiliated with an automobile manufacturer or distributor.

captive import: an imported motor vehicle or part manufactured by another automaker usually for sale under the brand name of the importer.

captive nut: A nut which fits into a cage and is welded in place. This is done where the nut is not easily accessible.

car: A wheeled vehicle such as an automobile, a section of a train, or a streetcar. The word is an abbreviation of "carriage" -- a device to carry people or goods. Also see 49-state car bubble car champ car city car classic car collector car compact car company car competition car concept car cult car cycle car donor car dream car edwardian car electric car estate car executive car family car fleet car forty-nine state car full-size car funny car hybrid car intermediate car kit car luxury car mass-produced car mid-size car milestone Car Society

milestone cars motor car multi-storey car park new car dealer open car pace car parts car passenger car wheel passenger car pony car production car program cars recycling car shopping car solar car spares car sports car stock car street car sun car super car touring car town car veteran car vintage car volume car car accident: A collision between two or more vehicles (or between a vehicle and a stationary object), whether the vehicles are cars or trucks. Some are minor like a fender bender while others are totalled. Also see written off caravan: [1] A group of vehicles (belonging to one organization) which follows after one another. [2] A British term for camping trailer or a mobile home.

caravanning: A British term for travelling with a camping trailer

carb:

An abbreviation for "carburetor."

car banger: A British term for a person or organization which fakes a car accident in order to defraud an insurance company

car banging: The act of faking a car accident in order to defraud an insurance company

carbide: See silicon carbide

car blind: A curtain or pull-down covering for the backlight (i.e., rear window) to obscure the bright headlights of a following vehicle. Some are also used for side windows for privacy. It is generally illegal to use them on the driver's side window or the windshield.

carbon: [1] The hard or soft, black deposits found in the combustion chamber, on the plugs, under the rings, on and under the valve heads, etc. Although it is not a metal, it is a good conductor of electricity. [2] An element which forms various kinds of steel when combined with iron. In steel, it is the changing carbon content which changes the physical properties of the steel. [3] Carbon is used in a solid form as an electrode for arc welding, as a mold to hold weld metal, or for motor brushes. Also see activated carbon high carbon steel low carbon steel medium carbon carbon black: A by-product of the petroleum industry used as a pigment and to give body in the manufacture of rubber products, both natural and synthetic. Carbon is the black residue from burning petroleum.

carbon brush:

A block of carbon to which a copper wire (or braided cable) is attached at one end and the other end rubs against a commutator, collector ring, or slip ring to transmit electricity

carbon brush spring: See brush spring

carbon build-up: A deposit of burned oil which collects in the combustion chamber on the top of the piston and the head. Too much carbon build-up can lead to an inefficient engine and sticky valves.

carbon canister: See activated carbon canister

carbon-core leads: High tension wire going from the distributor to the coil or the spark plugs. Each wire has a core of carbon or graphite rather than copper wire to conduct the electricity. Carbon-core wire is not recommended for most small engines such as motorcycle engines.

carbon dioxide: (CO2) A colorless, odorless, non-toxic gas which is a product of breathing and the combustion process.

carboned up: covered with a thick deposit of carbon. In Britain it is called "coked up"

carbon fiber: Threadlike strands of pure carbon that are strong and flexible. Carbon fiber can be bound in a plastic resin matrix to form a strong composite. It is light-weight and stronger than steel. Can also be spelled "carbon fibre."

carbon fibre: See carbon fiber.

carbon fouling:

The situation that occurs when the two electrical terminals of the spark plug are coated with carbon causing a reduction in efficiency leading to intermittent firing or complete failure.

carbonize: Building up of carbon on objects such as spark plugs, pistons, heads, etc.

carbonizing: Another term for carburizing or reducing

carbon knock: When there is a build-up of carbon in the combustion chamber, uncontrolled ignition will take place causing a knocking noise.

carbon monoxide: (CO) A deadly, colorless, odorless, and tasteless gas found in the engine exhaust. Toxic even in relatively small concentrations. Formed by incomplete burning of hydrocarbons. Thus at its greatest with a rich mixture.

carbon pin: A thin cylinder of carbon located in the distributor cap to transfer high tension electricity from the coil to the rotor to the high tension leads going to the spark plugs.

carbon steel: See high carbon steel low carbon steel carbon tetrachloride: A liquid often used in fire extinguishers. The fumes are toxic -- avoid inhaling.

carbon tracking: A trace of carbon found inside the distributor cap which leads away some electricity, thus causing the engine to misfire.

carbs: Abbreviation for carburetors.

Also see dual carbs carburation: British term for carburetion

carburetion: The mixture of vaporized fuel and air in the proper proportions for combustion in an engine

carburetor: Optionally spelled carburetter or carburettor. A device that vaporizes fuel and mixes it with air in proper quantities and proportions to suit the varying needs of the engine. A filter screens the air which is drawn into the carburetor. Here the gasoline mixes with the air and this fuel vapor enters the combustion chamber through the intake valve where it is compressed and burned. Also see air-valve carburetor air valve carburetor barrel carburetor compound carburetor cross-draft carburetor double-barrel carburetor downdraft carburetor dual carbs dual carburetors feedback carburetor fixed-choke carburetor fixed-jet carburetor flood the carburetor four-barrel carburetor four barrel carburetor hif carburetor horizontal draft carburetor progressive carburetor sidedraft carburetor single-barrel carburetor slide carburetor starting carburetor stromberg carburetor su carburetor tamperproof carburetor

twin-choke carburetor twin barrel carburetor twin carburetors two-stage carburetor updraft carburetor variable-choke carburetor variable-venturi carburetor vv carburetor carburetor adapter: An adapter that is used to fit or place one type of carburetor on an intake manifold that may not be originally designed for it. Also used to adapt four-barrel carburetors to two-barrel manifolds.

carburetor barrel: The tube-like part of the vehicle through which air flows and is mixed with vaporized fuel. The choke butterfly valve is located at the top of the carburetor barrel, and the throttle valve is located at the bottom. Midway through, the barrel narrows, and this part is called the "venturi." Carburetors can have one, two, or four barrels.

carburetor circuit: A series of passageways and units designed to perform a specific function idle circuit, full power circuit, etc.

carburetor circuits: See carburetor circuit.

carburetor engine: A combustion engine which uses a carburetor instead of fuel injection.

carburetor icing: The formation of ice on the throttle plate or valve during certain atmospheric conditions. As the fuel nozzles feed fuel into the air horn it turns to a vapor. This robs heat from the air and when weather conditions are just right (fairly cool and quite humid) ice may form. Also see icing carburetor throat:

See venturi

carburetor venturi: See venturi

carburetter: British spelling for carburetor.

carburettor: See carburetor.

car burglar: A person who steals object from a car, but does not steal the car itself. Also see car thief carburization: The process of creating carbon steel by increasing the carbon content of steel to reach the desired degree of hardness

carburizing: A carburizing flame in welding terms is an oxygen-fuel gas flame with a slight excess of the fuel gas

car cap: A waterproof cover which encloses just the greenhouse (i.e., the roof, windshield, side glass, and backlight)

car care product: One of several items for taking care of the outward finish of the car (i.e., cleaners, polish, wax, preservers) as well as the interior pieces (e.g., dash cleaners, upholstery cleaners and sealers)

carcass: The primary structure of a tire body with its cords, plies, rim wires, etc. apart from the tread itself. Structurally the carcass should hold air and provide strength to the tire, but would not wear well without the tread.

Car Club of America: See Classic Car Club of America

car cover: A cover which encloses the entire vehicle to protect the finish from the elements.

car crash: A car accident

card: See file card brush

cardan: See cardan joint.

cardan joint: A type of universal joint named after the Italian Cardan who developed the concept in the 16th century. In the 17th century, Robert Hooke of England developed and patented the conventional universal joint. Sometimes it is called the "Cardan universal" or the "Hooke universal." It has two yokes at right angles to each other. cardan shaft: A shaft with universal joints at each end

cardan universal: See cardan joint.

card brush: See file card brush

car dealer: See new car dealer

care product:

See car care product

cargo: See bulk cargo general cargo cargo area: The space within a station wagon or van for carrying goods or the bed of a pickup truck for carrying goods

cargo battens: Strips of wood fitted inside the frames to keep cargo away from hull steelwork. Also called sparring

cargo net: A type of bungee net usually found in the trunk of a car to secure packages from moving around.

cargo port: Opening in a ship's side for loading and unloading cargo.

cargo shifting: Movements or changing positions of cargo from one place to another which can easily endanger the seaworthiness of the ship

cargo ship: See dry cargo ship

Carina: A model of automobile manufactured by Toyota

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car insurance: An insurance policy (mandatory in most states and all of Canada) to cover possible damage to the vehicle or property or passengers, etc. Sometimes basic insurance is abbreviated PL&PD (public liability and property damage). Also called "motor insurance"

car jacker: A person who steals a car at gunpoint.

car jacking: A process of stealing a car while the driver is still in it. The car may be stopped at a traffic light when a car jacker appears with a gun and demands that the driver get out, then he drives away with the car. If it happens to you, give him the car -- your life is worth more than the vehicle.

car key: An unlocking device for the ignition switch, doors, trunk, gas cap, etc.

car lot: A place where vehicles are sold by an independent dealer

car mechanic: See mechanic

car park: A parking area usually located within a building. Also see multi-storey car park carpeting: The action of covering the passenger compartment floor (and sometimes the trunk floor) with a form-fitting rug or carpet.

car phone: A telephone that is installed in a vehicle, but has recently been replaced by personal cell phones. Also see cellular phone car polish: A product which enhances the shine of the paintwork of a vehicle

car radio: A radio receiver which is installed (usually in the dash) in a vehicle

carriage: [1] A horse-drawn vehicle for people to ride in. [2] A railroad vehicle for passengers.

carriage bolt: A bolt that has a smooth dome head (like a mushroom) so that no screwdriver or wrench can remove it from the dome-side.

carriageway: See dual carriageway

carrier: See barge carriers bicycle carrier bulk carrier carrier bearing contract carrier differential carrier hub carrier jet carrier lng carrier luggage carrier ore-bulk-oil carrier ore carrier pinion carrier planet carrier product carrier spare tire carrier carrier bearing: The bearings upon which the differential case is mounted.

carrier bearings: See carrier bearing.

carrier, pinion:

See pinion carrier.

carrier, planet: See planet carrier.

carriers: See barge carriers top carriers carrosserie: French term for coachwork.

carrozzeria: Italian term for coachwork.

carrying capacity: The maximum load that a tire is allowed to carry with a particular wheel and rim. Also called "load capacity."

CARS: Acronym for "Canadian Automotive Repair and Service Council"

car society: See milestone Car Society

car sponge: A large sponge for washing the exterior of a vehicle

car stereo: A listening device in an automobile which usually has an AM/FM radio and often a cassette player, CD player, and/or CD changer. It also includes at least a pair of speakers.

car tax: A government imposed tax which is added to the price of a new car. Some governments charge a road-use tax and call it a car tax.

car test: A test of a vehicle's roadworthiness, reliability, and performance.

car theft: Unauthorized removal (i.e., stealing) of a car or the items in or on a car. Also see car jacking car thief: A person who steals a car. If someone steals just the objects from a car, he is a car burglar. Also see car jacker car tire: An automotive tire which is used exclusively on a passenger car, not a light truck, etc.

cartridge: See filter cartridge oil filter cartridge cart spring: A leaf spring used in small trailers.

carvac: A small, hand-held vacuum cleaner which is either battery-operated or which is plugged into the accessory outlet or cigarette lighter socket.

car wash: [1] A place where you can get your car cleaned. Some are automatic (you drive through and large brushes clean the car) while others provide a bay with spray wands and brushes for you to do the labor. Also see automatic car wash

[2] A product like soap which is added to water for the purpose of cleaning a vehicle.

car wax: A polish which may be in a paste or a cream and used in protecting the finish of a car.

car wheel: See passenger car wheel

CAS: Acronym for "cleaner air system"

case: See basket case battery case chain case converter case differential case top case transfer case

case harden: The action of hardening the surface of steel.

case-hardened: A piece of steel that has had the outer surface hardened while the inner portion remains relatively soft.

casehardening: The action of adding carbon to the surface of a mild steel object and heat treating to produce a hard surface.

cash value: See actual cash value

casing: [1] The outside shell of something such as the shell of an alternator or starter motor. Also see axle casing differential casing spiral casing turbine casing volute casing [2] The tire casing.

casing factor: That portion of the load supported by tire casing stiffness instead of air pressure.

casing head gasoline: A term used to describe the lighter parts of petroleum products, which were obtained from natural gasoline by condensing natural gas from an oil well

cassette compartment: A storage place for cassettes

cassette player: A unit which plays (but does not record) cassettes and is often linked with a stereo unit in an automobile

cast: [1] To shape molten metal by pouring it into a mold. [2] A model or result made by pouring metal into a mold. See cast iron casting die cast castellate: Formed to resemble a castle battlement: e.g., a castellated nut

castellated: See castellated nut.

castellated nut: A nut with several lugs protruding from one end making it look like the turrets on the top of the wall of a castle. This nut is used on a shaft with a hole drilled in it. It is secured to the shaft by passing a cotter pin through an opening in the nut and through the shaft hole.

caster: A wheel alignment adjustment that positions the wheels like the casters on a chair or shopping cart, so the tires follow naturally in a forward straight line. In a truck or older car, the top of the kingpin is either forward (negative) or toward the rear of the vehicle (positive). On a turn, the wheels will tend to straighten out when the steering wheel is released. If the car has independent front suspension, the upper ball joint is set forward or rearward in relation to the lower ball joint. Caster is measured in degrees. Also see trail distance caster action: The self-centering action which causes a caster wheel to move into a straight-ahead position.

caster angle: The inclination or angle that a wheel makes when measuring the distance between the vertical post and the offset of the wheel placement.

caster offset: The distance on the ground between where the vertical post would touch the ground if it were extended and the point where the wheel touches the ground. Also called caster trail

caster trail: The distance on the ground between where the vertical post would touch the ground if it were extended and the point where the wheel touches the ground. Also called caster offset

caster wobble: A condition generally produced in the front wheels when they are attached to the ends of a beam axle. It is particularly noticeable on rough roads and the shimmy at the steering wheel makes it difficult to control the vehicle. You have probably seen

this condition in a shopping cart that has caster wheels that wiggle or fluctuate back and forth and will not roll in a straight line.

casting: [1] A process technology that delivers a liquid molten metal into a purpose-built mold. After cooling, the solid metal surface has the shape of the mold cavity. [2] Pouring metal into a mold to form an object. Also see die casting lost-foam casting process malleable castings monobloc casting sand casting thin-wall casting casting number: The number cast into a block, head, or other component when the part is cast. Casting numbers can be helpful when identifying an engine or its parts, but they are not completely accurate, because castings are sometimes machined differently

casting process: See lost-foam casting process

castings: Metallic forms which are produced by pouring molten metal into a shaped container or mold. Also see malleable castings cast iron: An alloy of iron and more than 2% carbon. It is used for engine blocks and transmission and differential cases because it is relatively cheap and easy to mold into complex shapes.

castle: See castellated nut.

castle nut:

British term for castellated nut.

castle section: A panel with humps or ribs which strengthen the panel. They are called "castle" because from the end they look like the turrets of a castle

castor: British spelling of caster.

cast spoke assembly: That part of the vehicle consisting of the brake drum and wheel spider, having 3, 5 or 6 spokes.

cast spoke type: A type of dual mounting wheels where two demountable rims are mounted directly on the spoke wheel and drum assembly held apart by a spacer band and locked in place by clamps and nuts which attach to studs in the spoke face.

cat: An abbreviation for catalytic converter

catalog: See parts catalog

catalyst: [1] A substance that changes the rate of a chemical reaction without itself being used up. [2] A special agent which is added to a plastic body filler or resin or paint to speed up the hardening process. Also see aged catalyst fresh catalyst metal catalyst oxidizing catalyst particulate catalyst pellet catalyst reducing catalyst three-way catalyst two-way catalyst

catalyst bed: A layer of catalyst-coated material such as pellets or ceramic in a catalytic converter through which the gases pass.

catalyst charge: A catalyst-coated material such as pellets or ceramic in a catalytic converter.

catalyst coating: A catalytic layer

catalyst container: A housing of a catalytic converter. Also called a "converter shell"

catalyst contamination: A reduction of efficiency because of impurity deposits

catalyst degradation: A reduction of efficiency because of impurities or overheating. Also called catalyst deterioration

catalyst deterioration: A reduction of efficiency because of impurities or overheating. Also called catalyst degradation

catalyst efficiency: See catalytic efficiency

catalyst indicator: A light on the instrument panel which glows when a prescribed distance has passed in order to remind the driver to have the catalytic converter replaced.

catalyst substrate: A base material which carries the catalytic layer or coating. Also called catalyst support

catalyst support:

A base material which carries the catalytic layer or coating. Also called catalyst substrate

catalytic: See catalytic converter dual-bed catalytic converter mini catalytic converter open-loop catalytic converter pellet-type catalytic converter primary catalytic converter three-way catalytic converter catalytic activity: The rate a catalytic converter purifies the exhaust system

catalytic converter: A pollution-control device found on the exhaust system of all cars since its introduction in 1974 which acts like an afterburner to reburn unburned gas in the tail pipe. It looks like a small muffler and is usually made of stainless steel. It contains platinum, rhodium, or palladium which is a catalyst for the chemical reaction needed to burn off any unburned hydrocarbons and carbon monoxide by turning them into water vapor, carbon dioxide and other less toxic gases. Also see dual-bed catalytic converter mini catalytic converter open-loop catalytic converter pellet-type catalytic converter primary catalytic converter single-bed 3-way catalytic converter three-way catalytic converter two-way catalytic converter catalytic efficiency: The effectiveness of a catalyst in purifying exhaust gases

catalytic layer: A thin layer of catalyst such as platinum and supported by a ceramic or metal carrier material

catamaran:

A double hulled vessel

cataphoretic painting: A process of applying the first coat of paint to the body of a car by positively charging the paint particles and then dunking the metal into the paint. A current is turned on so that the positively charged paint is attracted to the negative metal panel. Also called cathodic electropainting

catback: A performance exhaust system upgrade which consists of new pipes from the catalytic converter to the tail pipe which increases horsepower. These new pipes are larger, thus, more exhaust can exit the system. The faster the exhaust can exit, the more horsepower you gain.

catch: See safety catch

category: See speed category

cathode: In an electric circuit, the negative terminal.

cathode ray tube: A sealed tube on which graphs or pictures are displayed like a TV screen

cathodic electropainting: A process of applying the first coat of paint to the body of a car by positively charging the paint particles and then dunking the metal into the paint. A current is turned on so that the positively charged paint is attracted to the negative metal panel. Also called cataphoretic painting

cathodic protection: The action of protecting metal from electrochemical corrosion by using it as the cathode of a cell with a sacrificial anode

catwalk: [1] A raised walkway running fore and aft from the midship.

[2] An obsolete term for the section between the fender and the hood. On modern cars, this section does not exist at all. But on older cars (like the 1939 Cadillac), the fender was spaced a little way apart from the hood. The headlights were mounted toward the front of the catwalk.

caulk: To fill seams in a wood deck with oakum or hammer the adjoining edges of metal together to stop leaks. Also spelled "calk"

caustic etching: The removal of metal by dipping aluminum parts in caustic soda

caution: A period in racing in which track conditions are too hazardous for racing due to an accident or debris on the racing surface. The cars remain in their racing positions behind the pace car until it is determined that it is safe to resume the race.

caved: Dented inward as in When the car hit me, it caved in the door.

cavitation: A condition in which a partial vacuum forms around the blades or impeller wheels of a pump, reducing the pump's output because part of the pump blades lose contact with the liquid. It can be a problem in fuel and water pump, fluid couplings, torque converters. When severe, it can result in the erosion of the pump blades and other internal surfaces.

cavity: [1] An empty space in a body structure, either in a box section or a double-skinned area. [2] A holder and contact for fuses

cavity sealant: A product made of oil, wax, and rust inhibitors which is painted or sprayed into a cavity to prevent rust and corrosion.

CB: [1] diesel engine oil introduced in 1949. [2] An acronym for Contact Breaker.

[3] An acronym for Citizens' Band. Also see CB radio CB radio: A two-way radio which is limited to specific frequencies. Initially used by truck drivers and later by both mobile vehicles and stationary sites; but more recently it has declined in use with the advent of cell phones.

CBR process: Acronym for Controlled Burn Rate process. It is a method of improving fuel economy by increasing or decreasing the rate which the fuel burns

CBU: Acronym for "Completely Built-Up."

CC: [1] Cruise control. [2] A type of diesel engine oil introduced in 1961. [3] (cc) Cubic centimeter.

CCC: Acronym for computer command control

CCCA: Acronym for "Classic Car Club of America."

CCEC: Acronym for "constant current electronic circuit"

CCEGR: Acronym for coolant controlled exhaust gas recirculation

CCFA: Acronym for "Comité Des Constructeurs Français d'Automobiles"

C-clamp:

A tool which is in the shape of the letter "C". A screw at one end of the clamp forces the end of the screw against the object to be secured. Also see long-reach C-clamp CCOT: Acronym for "cycling clutch orifice tube system" or "Cycling clutch orifice tube air conditioning system"

CCP: Acronym for controlled canister purge

CCS: Acronym for "controlled combustion system" of reducing unburned hydrocarbon emission from the engine exhaust.

CCT: Acronym for computer controlled timing

Cd: Abbreviation for "Drag Coeffient," a measurement of air resistance (drag). The lower the number, the less drag that a vehicle or shape has.

CD: [1] Diesel engine oil introduced in 1955. [2] See capacitive discharge. [3] (Cd) A measurement of drag coefficient.

CD changer: A device which is connected to a stereo system and allows several music CDs to be played.

CDI: Acronym for "Capacitor discharge ignition"; Also see CDI box CDI box:

Acronym for "capacitive discharge Ignition" device sometimes controlled by a computer. It is designed to help the spark plug fire at a rate consistent with the rpms of the engine.

CD player: A device which plays music compact discs. Usually combined with a stereo radio receiver and sometimes with a CD changer.

CDR: Acronym for crankcase depression regulator

CDV: Acronym for "Car-Derived Van" (e.g., Renault Kangoo).

Cd value: a number representing the coefficient of drag which is the amount of resistance that a moving vehicle makes in a wind tunnel

CEC: Acronym for "combination emission control"

ceiling: See hold ceiling joiner work ceiling Celebrity: A model of small car produced by Chevrolet

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Celica: A model of automobile manufactured by Toyota

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cell: [1] A compartment or chamber in a battery which contain positive and negative plates suspended in electrolyte. A six-volt battery has three cells, a twelve-volt battery six cells. [2] The combustion chamber in a rotary engine.

Also see battery cell: Seedry cell electrolytic cell fuel cell galvanic cell local cell microgalvanic cell passenger cell primary cell roller cell pump seam sealing cell secondary cell storage cell cell battery: See gel cell battery

cell connector: The lead bar or strap connecting battery cell groups.

cell phone: See cellular phone

cell pump: See roller cell pump

cellular phone: A portable, wireless telephone which was first introduced in 1983 in the US. Currently it is used both as a car phone and a personal phone. Commonly called "cell phone."

cellular telephone: A portable, wireless telephone which was first introduced in 1983 in the US. Currently it is used both as a car phone and a personal phone. Commonly called "cell phone."

cellulose: A popular term for nitrocellulose -- a universal automotive finish, which is thin and therefore suitable for spraying, fast drying, and gives a hard and brilliant finish

cellulose putty: A filler used to cover minor body imperfections.

Celsius: Thermometer on which the boiling point of water is 100 deg and the freezing point is 0 deg. The term replaces the word "centigrade." To convert from Fahrenheit to Celsius, subtract 32 then multiply the result by 5 and divide by 9. To convert from Celsius to Fahrenheit, multiply by 9, then divide by 5. Now add 32 to the result.

CEMA: Acronym for "Consumer Electronics Manufacturers Association."

cement: An adhesive rubber compound dissolved in solvent used to provide building tack and cured adhesion for tires. May be brushed or sprayed on the buffed surface. Also called contact cement

cementite: FE3C Iron carbide. A hard substance found in cast iron. census value added: residual representing the difference between the value of goods and industrial services produced and the direct material costs associated with the production of goods.

center: To place something in a central place in relation to other items. Also see after bottom dead center after top dead center before bottom dead center before top dead center before upper dead center bottom dead center dead center diagnostic center Driver and Vehicle Licensing Center drop center rim taper

drop center rim gravity, center high center rim inner dead center lower dead center message center outer dead center roll center top dead center upper dead center center bore: See wheel center bore.

center console: A section of the dash which is mounted between the driver and passenger sections. It often houses the shifter, cup holders, storage space, and possibly the stereo.

center differential: A differential which is used in a four-wheel-drive vehicle to distribute the power to both the front and rear differentials. Also see variable limited-slip axle/center differential center drive: Most engines have the power take-off at the end of the crankshaft. A center drive has the power take-off between the cylinders.

center drive plate: The disc between the driven plates in a twin plate clutch.

centered: See high-centered

center electrode: [1] Electrode which protrudes out of the insulator nose of a spark plug. [2] A center terminal. Also see compound center electrode

center gear: The sun gear of a planetary gearset.

center girder: A vertical plate on the ship's centerline between the flat keel and inner bottom extending the length of the ship. Also called center vertical keel.

center-hung float: This type of carburetor float pivots on an axis that's parallel with the vehicle axles. It's a better float design than a side-hung float during high speed cornering because the float isn't affected by centrifugal force, so it won't pull the inlet valve open in the middle of a corner

centering: See self-centering steering wheel centering center keelson: See center girder

centerline: [1] An imaginary line which passes from the front to the rear of a vehicle, half way between the distance between the left and right side of the vehicle. [2] The middle line of the ship, extending from stem to stern at any level.

center locking disc: A hub cap which is secured in place with a bolt or other locking device.

center lock nut: A spinner which secures the wheel to the hub.

center median: On a divided highway, the area between the two directions of traffic. The British call it the "central reserve."

center of buoyancy:

The position in a floating object where the upthrust appears to act.

center of gravity: (CG) That point in an object, if through which an imaginary pivot line were drawn, would leave the object in balance. In the vehicle, the closer the weight to the ground, the lower the center of gravity. Cornering, acceleration, and other forces act upon the vehicle's center of gravity, thus affecting body roll and other handling characteristics.

center of pressure: An aerodynamically determined point at which wind force on the side of a vehicle is assumed to be concentrated for analytical purposes. It is a function of the shape and aerodynamic drag (resistance) of an automobile's body shell, determines the effect of side winds on a vehicle's direction of travel, and is a concept similar to the center of gravity.

center pillar: The supporting post which is located in the middle of the car and holds up the roof. It is also called the "B-post" or "B-pillar"

center point steering: A steering geometry where the steering axis cuts the wheel axis in the wheel center plane, with no offset at the road surface.

center punch: A metal tool that is shaped like a pencil where you can hit the blunt end with a hammer so that the sharp point makes an indentation in some metal. In this way the drill-bit can fit into the indentation when you want to make a hole.

center rim: See drop center rim taper drop center rim high center rim semi-drop center rim center rim taper: See drop center rim taper

semi-drop center rim taper center section damage: A description of a vehicle after it is involved in an accident when it has been hit on the side somewhere between the front and rear wheels. The frame and body are bashed in at the center, but the front and rear of the vehicle may not have sustained any damage.

center steering linkage: A steering system using two tie rods connected to the steering arms and to a central idler arm, the idler arm is operated by a drag link that connects the idler arm to the pitman arm.

center terminal: A high tension distributor has a rotor which spins around a center post and transfers electrical energy from the center post or terminal to each of the surrounding terminals located in the distributor cap. In this way the energy from the coil is transferred to the high tension leads going to each spark plug.

center the clutch: To align the center holes in the clutch plates so that they fit easily on the splines of the crankshaft.

center tunnel: The hump which runs from front to rear between the left and right passenger (i.e., driver and passenger). It often accommodates the transmission and/or drive shaft. In front wheel drive vehicles it covers the wiring leading to the rear of the vehicle. Also see transmission tunnel center vertical keel: See center girder

centigrade: Thermometer on which the boiling point of water is 100° and the freezing point is 0°. The term is no longer in use and is replaced by the word Celsius.

centimeter:

See cubic centimeter

central fuel injection: (CFI) a computer-controlled fuel metering system which sprays atomized fuel into a throttle body mounted on the intake manifold

central gearchange: The usual arrangement with the gear lever in the center of the floor.

central chassis lubrication: A configuration of the engine and chassis where an oil change and the greasing of grease (zerk) fittings can be made from one spot -- generally underneath the vehicle.

central locking: The locking or unlocking of all the doors by locking from one location. This may be done by turning a key in a door lock or using an electronic device. Also see central locking hub central locking hub: A wheel with splines in the center which match up with the splines on the outside of the hub. This system is usually found on wheels that are attached to the hub with a center attaching nut on older cars -- especially sports cars -- rather than the type that is attached with several studs or bolts in a circular pattern.

central reservation: A British term for the median which divides the north and southbound lanes (or east and westbound lanes) of a divided highway.

central reserve: A British term for the median which divides the north and southbound lanes (or east and westbound lanes) of a divided highway.

centre: See center.

centrifugal advance:

A device found on the distributor which, through the action of centrifugal force on two weights, advances or retards the ignition spark to correspond with changes in engine speed and load. Also see vacuum advance centrifugal clutch: A clutch that uses centrifugal force to expand a friction device on the driving shaft until it is locked to a drum on the driven shaft.

centrifugal force: That force which tends to keep moving objects travelling in a straight line, when a moving vehicle is forced to make a turn, centrifugal force attempts to keep it moving in a straight line, if the vehicle is turning at too high a speed, centrifugal force will be greater than the frictional force between the tires and the road and the vehicle will slide off the road.

centrifugal force air filter: A type of canister air filter used on the engines of semi-tractor-trailer units which removes the dust before it reaches the filter element.

centrifugal governor: A device which controls the speed by using centrifugal force. As the speed of a shaft increases, weights are moved outward. When the weights reach a predetermined place, the shaft can no longer increase in speed. This governor may be found in automatic transmissions

centrifugal oil filter: A filter in the lubrication system which pushes any impurities to the outside of the filter as it rapidly rotates.

centrifugal pump: A pump which forces liquid from one location to another by the rotation of an impeller.

centrifugal weight: The movable part in a centrifugal clutch or centrifugal advance. The weight (sometimes called a "finger") moves outward as a result of centrifugal force.

Changing the mass of the weight will cause the weight to move outward sooner or later. The heavier the weight the later the movement.

centrifuge brake drums: To combine the strength of steel with the desirable friction characteristics of cast iron, a lining of cast iron is sprayed on the inside of a steel drum. Both metals are handled while hot to encourage the fusion of the two metals

centripetal force: A force which acts towards a central point, such as Earth's gravity. In a sense it is the opposite of centrifugal force.

century: A bicycle ride of 100 miles (160.9 km). Also see metric century Buick Century CEPA: Acronym for "Canadian Environmental Protection Act."

ceramic: A product made from clay or glass. Currently some manufacturers are trying to develop ceramic cylinders because of its ability to retain its shape when heated in contrast with metal which expands when heated. Also see ceramic filter ceramic brake pad: A brake pad constructed with ceramics to reduce wear and heat.

ceramic filter: A filtering device using a porous ceramic as the filtering agent.

ceramic honeycomb: The interior of a monolithic converter which supports the catalyst.

ceramics:

See ceramic.

certificate: See international load line certificate international tonnage certificate mot certificate seaworthiness certificate type approval certificate certificate of registry: A document specifying the country the vessel is registered.

Certification Label: See safety Compliance Certification Label

cetane number: A method of rating diesel oil or fuel by measuring the time lapse between fuel injection and ignition to determine how easy it is to ignite and how fast it will burn. The lower the cetane number, the higher the temperature required to burn the oil.

cetane rating: A method of rating diesel oil or fuel by measuring the time lapse between fuel injection and ignition to determine how easy it is to ignite and how fast it will burn. The lower the cetane number, the higher the temperature required to burn the oil.

ceton filter: A sock-type filter in the fuel tank capable of wicking diesel fuel, but not water; keeps water from the rest of the fuel system until the sock is 90% submerged in water

CFC: Acronym for chlorofluorocarbon.

CFC gases: Chlorofluorocarbon gases.

CFI:

Acronym for central fuel injection. A Ford fuel injection system that uses an injector mounted throttle body assembly

CFM: Acronym for "Cubic Feet per Minute." This is the rating of the volume of air moved.

CG: Acronym for center of gravity.

chafer: The area between the bead and sidewall of a tire.

chafer strip: The area between the bead and sidewall of a tire.

chafing plate: A bent plate for minimizing chafing of ropes

chain: Linked, flexible metal "rope" that connects two sprockets (e.g., the chainwheel to the back wheel, sized differently for different types of bikes.) The teeth of the sprockets fit inside the spaces between the links. Also called a roller chain. Also see cam chain derailleur chain, narrow width derailleur chains double roller chain drive chain duplex chain O-ring chains primary chain safety chains silent chain simplex chain single roller chain snow chains timing chain tire chains triplex chain

chain breaker: A tool for removing the pins in a roller chain so that the links can be removed.

chaincase: An enclosed metal covering which encircles the drive and driven sprockets as well as the chain.

chain case: See chaincase.

chain drive: A system of transferring power from one shaft to another by means of sprockets and an endless chain. This is the system used on a bicycle; but it is also used on an engine to control the timing of valve opening (called "timing chain" or "cam chain").

chain filter wrench: A chain wrench which encircles the oil filter to assist in its removal.

chain guard: A metal or plastic covering for the top run of a chain. It is most often found on bicycle chains where the guard keeps your clothing from being caught in the chain or even from getting greasy.

chain hoist: A lifting device which uses a chain and block and tackle to lift large objects like engines.

chain locker: A compartment for the stowage of anchor chain

chain pipe: A pipe for passage of chain from windlass to chain locker

chain pipe wrench: A chain wrench which circles around a pipe and grips it so that the pipe can be tightened or removed.

chainring: A sprocket attached to the right crankarm of a bicycle to drive the chain. Also called "chainwheel."

chainring nut spanner: A special bicycle tool used to loosen the slotted nuts that fasten a chainring to a crankarm.

chain run: The distance between the front and rear sprockets.

chains: See chain

chain scrubber: A device attached to a chain which rubs away the grime while the chain is moving.

chainstay: One of the two tubes of a bicycle frame that run from the bottom bracket back to the rear dropouts.

chainstays: The two tubes of a bicycle frame that run from the bottom bracket back to the rear dropouts.

chain stopper: A device used to secure the chain cable when riding at anchor, thereby relieving the strain on the windlass

chain switch: See snow chain switch

chain tensioner: A device which takes up the slack in a chain. Some use an idler wheel which can be adjusted (manually or automatically), others use a flat slide which pushes against the chain to keep it from bouncing around. Most modern units are spring loaded so

that the tensioner automatically takes up the slack. Some require that you need to undo a locking nut to allow the spring to push against the chain. Afterward the lock nut needs to be secured again.

chainwheel: A sprocket attached to the right crankarm of a bicycle to drive the chain. Also called "chainring."

chain whip: A tool consisting of a metal bar and two sections of chain, used in changing cogs on a freewheel. Sometimes called "chain wrench."

chain wrench: A locking pliers which employs a chain to wrap around an object such as a pipe to secure or remove it. Also see chain whip chair: Motorcycle sidecar

chalking: The appearance of a white powder on a paint surface as it weathers and ages.

chamber: [1] A pressure chamber used to vulcanize pre-cured tread stock to the buffed casing. [2] A compartment which is basically empty or hollow. Also see climatic chamber combustion chamber exhaust chamber fireball combustion chamber float chamber gas chamber hemispherical combustion chamber humidity chamber main combustion chamber mixing chamber pent-roof combustion chamber plenum chamber

pre-chamber pre-combustion chamber pre-compression chamber pumping chamber salt spray chamber spherical combustion chamber suction chamber swirl chamber twin swirl combustion chamber vacuum chamber wedge combustion chamber chamber recess: See combustion chamber recess

chamber volume: See combustion chamber volume

chamfer: To bevel or taper the edge of an object especially the sides of a hole or a sharp corner

chamfered: a chamfered object is one that has a symmetrically bevelled edge.

chamois: Pronounced SHAM-mee. A soft piece of animal skin (from a deer, sheep, goat, etc.) used to absorb water after washing the surface of a vehicle. Also called a chamois leather or shammy leather.

chamois leather: See chamois.

champ car: When Championship Auto Racing Teams (CART) was co-sponsored by FedEx, the series became known as the FedEx Championship Series for the PPG Cup. The cars in this series, previously known as Indy Cars, are called Champ Cars.

change:

To remove something and replace it with something else. Also see climate change downward change floor change oil change range-change upward change change down: A British expression meaning to shift to a lower gear.

change gear: The action of selecting a different gear. This expression is used more in Britain than in North America where the expression is "shift gear."

change into: A British term for the action of shifting into another gear, such as "change into second" (shift into second gear) or "change into top" (shift into high gear)

change of state: Rearrangement of the molecular structure of matter as it changes between any two of the three physical states: solid, liquid, or gas

changeover: [1] The refitting of equipment to either neutralize the effects of the just completed production or to prepare equipment for production of the next scheduled item, or both. [2] The removing of new original equipment tires in exchange for a different make, size, or type.

changer: See CD changer column changer column gear changer change-speed gearbox: A transmission which houses a set of gears which move into various configurations of engagement in order to produce different output ratios.

change the oil: The act of draining out the old or dirty oil from an engine and replacing it with fresh oil.

change up: A British term meaning to shift up to another gear

change valve: A British term for a valve in an automatic transmission which raises the oil pressure as the vehicle speed increases. In North America it is called the shift valve.

changing: See charge changing wheel changing channel: [1] To lower the vehicle body around the frame. [2] A route or groove through which anything passes. Also see chassis channel distribution channel glass channel grip channel runabout run channel run channel window channel channelled: Vehicle body lowered down around the frame.

channel section: A long metal U-shaped member used in the chassis.

chap: See tank chap

Chapman: Anthony Colin Bruce Chapman (1928-1982), the founder of Lotus. One of the most innovative engineer in automotive racing history.

Chapman strut: A type of rear suspension using a lower lateral link and a long spring-shock strut to determine wheel geometry. The basic principle is the same as that of the front MacPherson strut and it is so named because Colin Chapman first used it on the original Elite; it is also used on the Elan models, the new Elite, and the Datsun (Nissan) Z-car. characteristic map: A three-dimensional picture showing the relationship between various components of a vehicle. With the help of a computer, engineers can modify one component to see the effect it has on the whole operation of the vehicle.

characteristics of materials: See performance characteristics of materials

character line: The design line or bend in the side of the vehicle that separates the upper and lower sections of the fenders and doors

charcoal: The amorphous form of carbon obtained by the destructive distillation of animal or vegetable matter in a limited supply of air. In automotive use, it is used to purify air or exhaust gases. Also see activated carbon activated charcoal charcoal canister: Another name for activated carbon canister

charcoal filter: A filtration system using activated carbon to remove impurities.

charcoal trap:

See activated charcoal trap

charge: [1] The action of passing an electric current through a battery to restore it to the active (charged) state. Normally the vehicle's generator or alternator takes care of this. If the vehicle is not used much, an external charger is needed to charge the battery. [2] The definite quantity of electricity usually found in a storage battery. [3] Refers to the mass of air and fuel that enters a cylinder during the intake stroke. [4] A refund amount of money. See core charge. Also see air charge temperature battery charge catalyst charge core charge cylinder charge electric charge fuel charge intake charge state of charge stratified charge trickle charge charge air: The air/fuel mixture.

charge air cooling: An intercooler

charge-air recycling: A device on a turbocharger which maintains the speed of the compressor when there is no boost so that the boost is more instantly available on demand.

charge changing: In a two-stroke engine, the removal of exhaust gases through the exhaust port in order to introduce a new load of fuel-air into the transfer port. Also called "charge exchange process."

chargecooler: A radiator that cools and therefore recondenses the intake air that has been compressed and heated by the turbocharger thus allowing a greater amount of air

into the engine. With more air in the combustion chamber, the ECM can deliver more fuel and make more power. This radiator can be either cooled by air or by water. Also called intercooler

charged: See dry charged battery

charged battery: See dry charged battery

charge engine: See stratified charge engine

charge exchange process: Another name for charge changing

charge indicator: See battery charge indicator

charge losses: In a two-stroke engine, the exhaust gases are expelled out the exhaust port and the fresh charge is brought in through the transfer port. Sometimes some of the fresh charge is also forced out with the exhaust gases. There is therefore a loss of some of the fresh air-fuel charge. Also see scavenging losses charger: Common name for a battery charger. Also see fast charger trickle charger turbo charger charges: See on-the-road charges

charge temperature:

See air charge temperature

charging: See battery charging piston charging pump slow charging charging characteristic: When a battery is being charged, the charger will reveal how much voltage and/or amperage is being required to bring the battery up to full charge.

charging circuit: See charging system.

charging current: The amount of electric current being supplied to the battery from the alternator or from a battery charger.

charging efficiency: [1] In a vehicle's electrical charging system, its efficiency is the ratio of energy output to energy input, i.e., how well does the alternator work to supply voltage to the electrical components and still charge the battery. [2] In a two-stroke engine, it is the ratio of the amount of the fresh charge that remains in the cylinder after the two ports are closed and the actual volume.

charging hose: A small diameter hose constructed to withstand high pressures. It is connected between the air conditioning system and the manifold set

charging piston: In a two-stroke engine, this is a secondary piston which precompresses the fresh charge and sends it into the cylinders

charging point: A place where a battery can be charged -- especially for battery-powered electrical vehicles. Also called battery charging station

charging pressure: See boost pressure.

charging pump: See piston charging pump

charging rate: The amount of electrical current which is delivered by the charging system. It is usually measured in amperes.

charging station: See battery charging station

charging stroke: See induction stroke.

charging system: A system that, using a fan belt driven by the engine, enables the alternator (or generator) to generate electrical current, which is stored in the battery and delivered to the electrically operated pars of the vehicle chassis: The parts of the vehicle which are left when the body and fenders are removed.

Charpy test: An impact resistance test in which the specimen is supported as a horizontal beam and broken by a single swing of a pendulum with the impact line midway between the supports and directly opposite the notch for notched specimens.

chart: See color chart

chase: To repair damaged threads on a bolt or nut with a tap or die

chassis: Generally, chassis refers to the frame, engine, front and rear axles, springs, steering system, fuel tank. In short, everything but the body or cab and fenders. Because most modern automobiles (apart from trucks) do not have a separate chassis, the body is sometimes called the chassis.

Also see backbone chassis cab chassis cowl chassis ladder chassis mid-engine chassis configuration punt chassis separate chassis chassis bracket set: when the sill panel does not have a jointing flange, a set of securing pieces are welded under the sill before straightening a bent or damaged sill.

chassis cab: A truck with a cab but no bed. To this system various bodies (ambulance, moving van, flat beds, etc.) can be added by aftermarket suppliers.

chassis channel: A channel section which makes up a member of the chassis.

chassis configuration: See mid-engine chassis configuration

chassis dynamometer: A test stand for a vehicle to determine its power output or emission levels, etc. when the vehicle is placed under a variety of driving conditions. Also see dynamometer chassis frame: A frame (found on large trucks) which is made up of two long side members which are joined by several crossmembers. The suspension and axles are attached to this frame.

chassis leg: The short channel or box section which runs along the vehicle's main axle. It is an auxiliary member, not the main side member.

chassis lubrication:

See central chassis lubrication

chassis number: The serial number of an older vehicle which was originally stamped on a chassis member. Later it became known as a vehicle identification number (VIN)

chassis section: One of the chassis channels or boxes, whether bolted or welded to the whole.

chatter: [1] A noise which is caused by an irregular movement of rattling parts. [2] The jerky movement of two components which may have moved in a systematic way under low speed; but as the speed increases, the components make irregular contact. Also see contact bounce contact chatter check: [1] An inspection to determine if everything is functional. [2] A slight slash or marking which may appear in a tire or upholstery. Also see checking compression check door check arm door check strap optical check check arm: See door check arm

check ball: A small ball (like a ball bearing) often made of metal or plastic, found in a check valve to halt the progress of fluid in a certain direction.

check engine light: A light on the instrument panel that lets the driver know of any detectable engine management system malfunctions. Also used as an emission maintenance reminder light on some vehicles. Often when this light is on, a trouble code is stored in the computer

check engine warning light: An light on the dash which is illuminated when one of the engine sensors or components does not function properly.

checkered flag: The black and white flag to signal the end of the race.

checking: [1] Short, very fine crack lines that appear in the paint film. [2] Small cracks in the surface of rubber (e.g., tires) caused by aging and oxidation. Also see ozone checking check point: [1] A designated spot on a component where it is possible to determine if there is a malfunction. [2] A place on the road where vehicles are stopped during a rally.

check routine: A series items in an inspection which traces a fault or problem or which determines if all the components of a new vehicle meets the required specifications.

check stop: An action taken by the police to stop vehicles in order to determine if the drivers have been drinking, wearing seat belts, and conforming to the other requirements of operating a vehicle.

check strap: See door check strap

check the battery: Determine if the electrolyte is at the correct level and add distilled water to bring it up if necessary

check the oil:

Using a dipstick, determine if there is sufficient oil in the crankcase

checkup: The process of discovering the reliability of a vehicle or its components. "Give my engine a checkup." Sometimes it means "tune-up."

check valve: A one-way valve that opens to permit the passage of fluid or air in one direction and closes to prevent passage in the opposite direction. Also see residual check valve cheese head: A cylindrical head for a screw with a straight slot and straight sides.

chemical brightening: The improvement of the smoothness of the surface of metal by immersing it into a solution designed to remove any roughness. Also called "chemical polishing."

chemical cure: Vulcanization at room temperature or above, activated by chemical agents without the application of heat from an outside source.

chemical polishing: See chemical brightening.

chemical staining: Spotty discoloration of the paint caused by air pollution in industrial areas

chemical toilet: A portable toilet which is used in campers and motorhomes. They contain chemicals to deal with the feces and its smell until the contents are dumped.

Chenard-Walcker: A vehicle brand of which the 1925-1948 models with required application are classic cars.

cherry: A colloquial term for a vehicle that has been kept in, or restored to, perfect condition. Also called "mint" or "like new."

cherry condition: A colloquial term for a vehicle that has been kept in, or restored to, perfect condition. Also called "mint condition."

chest: See sea chest

Chevelle: An intermediate model automobile produced by Chevrolet

Click for books on Chevelle

Chevrolet: A vehicle brand of which the 1955-57 Bel Air V-8 Hardtop and Convertible are milestone cars.

Chevrolet Camaro: A vehicle brand of which the 1967-69 SS/RS V-8 and Z-28 models are milestone cars.

Click for books on Chevrolet

Click for books on Chevrolet Camaro

Chevrolet Celebrity: See Celebrity

Chevrolet Chevelle: See Chevelle

Chevrolet Corvair: A vehicle brand of which the 1960-64 Monza models are milestone cars. The 1962-64 Monza Spyder models are milestone cars. The 1965-69 Monza/Corsa models are milestone cars. Chevrolet Corvette: A vehicle brand of which the 1953-70 models are milestone cars. See also a history of the Corvette

Click for books on Corvair

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Corvette Chevrolet Monte Carlo: See Monte Carlo

Chevrolet Nomad: A vehicle brand of which the 1955-57 models are milestone cars.

Chevrolet Nova: See Nova

Chevrolet type: A dual mounting wheel type consists of one cone locking nut on each stud that holds both wheels in place against the hub.

childproof lock: On the rear doors of a car, a specially designed locking device can be set to normal or to childproof. When set to childproof, the door cannot be opened from the inside.

child restraint system: A term for a number of items which are designed to protect children from injury during an accident (such as child seats).

child safety: See integrated child safety seat

child safety seat: See integrated child safety seat

child seat: A small safety seat which is mounted on a regular car seat and is held in place by the seat belt. Also see integrated child seat chilled iron:

cast iron possessing a hardened outer skin.

chimney: See coil tower coil chimney chip: [1] Small pits in the glass (windshield or headlight) or in the paint caused by small flying stones. [2] To cut with a chisel. [3] A collection of sample paint. Also see paint chip book chip book: See paint chip book

chip damage: See stone chip damage

chipping: The action of tearing away small bits or flakes of paint or of rubber from the tread of a tire. When larger pieces of rubber tear away, it is called chunking.

chipping hammer: A hammer used to remove the slag from weld seams.

chisel: A thick pencil shaped tool with a sharp flat end like a blade screwdriver. When you hit the blunt end with a hammer, it forces the blade end into metal to mark it or even cut through it. Also see splitting chisel chloride: See calcium chloride

polyvinyl chloride chlorofluorocarbons: (CFCs) A gas compound which was used as a propellant in aerosol cans and in refrigerants.

chock: [1] A wedge used to prevent a wheel from rolling -- especially when replacing a tire/wheel. Also called a "wheel chock." [2] A heavy smooth-surfaced fitting usually located near the edge of the weather deck through which wire ropes or fiber hawsers may be led, usually to piers. Also see boat chock choke: A butterfly valve or plate located near the top of the carburetor that limits or restricts the amount of air allowed to enter the carburetor, thus enriching the fuel-air mixture and enabling the vehicle to start and run more easily when cold. Automatic chokes have a thermostatic coil or thermostatic spring that activates a butterfly valve at the top of the carburetor barrel. Older cars have manually operated chokes. Some vehicles use an enrichner instead of a choke. Also see manual choke radio choke choke stove: A flapper near the top of the carburetor which regulates the amount of air entering the carburetor. Also see choke choke control: A device or system for operating a non-automatic choke. It is usually a cable attached at one end to the choke butterfly and a knob on the dash at the other end.

choke index: Automatic chokes have index marks. The factory setting closes the choke when the bimetal is about 70° F. If you want less or more choke at this temperature, move the choke index one mark in the direction indicated by the arrows designating a leaner or richer mixture. You will seldom need to move the choke more than one mark

choke kick: A preset position for the choke valve set by manifold vacuum that is routed through a carburetor body passage to the choke diaphragm

choke knob: A knob on the dash fascia which is part of the choke control system.

choke stove: A heating compartment in or on the exhaust manifold from which hot air is drawn to the automatic choke device.

choke thermal vacuum switch: (CTVS) a switch used on some GM vehicle to deny vacuum to either the front or the auxiliary choke vacuum breaks. Its purpose is to slow the opening of the choke and to provide better driveability when the engine is cold

choke tube: The part of the carburetor air horn where the choke butterfly is positioned. Also called a carburetor venturi.

choke valve: In a carburetor, it is the choke butterfly.

chop: Lowering the height of some area of the vehicle roof, hood, top, etc.

chopped wheel: Lightened flywheel.

chopper: [1] A motorcycle which has been modified so that it has lengthened and raked front forks and a lowered seat. Often the original fuel tank is changed to a smaller size. The handlebars are also lengthened. [2] To travel by motorcycle.

chop shop: [1] A garage which specializes in turning a two-door car into a convertible by removing the steel top.

[2] An illegal garage which processes stolen cars by removing valued parts and selling them privately or by changing the serial numbers for illegal resale.

Christmas tree: A device, using a series of lights, to start cars on the timed 1/4 mile drag run.

chromate: [1] A salt or ester of chromic acid which is often used as a paint pigment. [2] The action of treating metal with a solution of chromium compound to produce a protective metal chromate coating. Also called "chromatize."

chromate coating: A conversion coating produced by chromating.

chromate treatment: A solution of chromium compound is applied to metal to produce a protective coating of metal chromate.

chromatize: The action of treating metal with a solution of chromium compound to produce a protective metal chromate coating. Also called "chromate."

chrome: [1] A short form for chromium. [2] The chromium plating of metal on a vehicle. [3] To plate with chromium. Also see piston ring, chrome ring, chrome chrome-hardened: Steel that has been made harder by adding chromium.

chrome-plated: In order to prevent iron from rusting and showing bright and shiny, the iron is coated with a layer of chromium by process of electroplating (or electrodeposition).

chrome ring:

A piston ring with a chrome face. Also see piston ring, chrome chrome steel: in order to improve rust resistance and increase hardness, chrome is added to steel. Also called "chromium steel."

chrome work: All the metal on a vehicle which has been plated with chrome.

chromic acid: electrolyte which is used in anodizing processes for producing non-transparent, nonmetallic oxide layers.

chromium: A very hard grey metal used in electroplating and the production of very hard steel compounds that are also resistant to rust. Also see hard chromium plating chromium-plated: A coating of metal with chromium to protect the metal from rust.

chromium plating: The process of coating metal with a layer of chromium to prevent rust. Also see black chromium plating hard chromium plating chromium steel: In order to improve rust resistance and increase hardness, chrome is added to steel. Also called "chrome steel."

Chrysler: A vehicle brand of which the 1926-30 Imperial 80, 1931 Imperial 8 Click for Series CG, 1932 CG and CH, 1933 CL, 1934-6 CW with required books on application are classic cars. The 1970 300 Hurst is a milestone car. The 1955-65 300 Letter Series are milestone cars. The 1946-50 Town Chrysler

and Country models are milestone cars. chubby screwdriver: A British term for a screwdriver with a short handle and blade for reaching into confined spaces. In North America it is called a "stubby screwdriver."

chug: [1] The short explosive sound of an engine going steadily and rather slowly. [2] To make the sound of chug. [3] To drive slowly and steadily.

chunking: The action which occurs when large pieces of rubber from the tread of tire breaks away. When small pieces break away, it is called chipping.

CI: [1] Acronym for "compression ignition." [2] Acronym for "coil ignition."

Ciera: A model of automobile manufactured by General Motors Click for books on Ciera CIH: Acronym for "camshaft in head"

CIH engine: A type of overhead valve engine (OHV) where the camshaft is enclosed within the cylinder head not placed on top of it. It is not the same as an overhead camshaft (OHC).

CID: Acronym for "cubic inch displacement."

cigar lighter: A device which heats up an element when engaged. In turn, the lighter can ignite something flammable like a cigarette. The socket can also be used to power other electrical components requiring 12 volts.

cigar lighter: A device which heats up an element when engaged. In turn, the lighter can ignite something flammable like a cigarette. The socket can also be used to power other electrical components requiring 12 volts.

CIM: Acronym for "computer-integrated manufacturing."

circle: See base circle bolt hole circle cam heel hole circle pitch circle diameter pitch circle traffic circle turning circle wheel bolt hole circle circle diameter: See pitch circle diameter

circlip: A flat retaining ring in the shape of an incomplete circle where the ends at the gap may have small holes for inserting special pliers to spread the circlip apart. Also called a snap ring. Also see internal circlip pliers piston pin circlip wrist pin circlip circlip pliers: See internal circlip pliers

circuit: [1] A source of electricity (battery), a resistance unit (headlight, etc.) and wires that form a path for the flow of electricity from the source through the unit and back to

the source. The path of electrical current through an electrical system. See starting system. [2] The path of the fuel in the carburetor. See carburetor circuits. [3] The course over which vehicles are raced particularly if it is somewhat circular. Also see carburetor circuit charging circuit cranking circuit high-tension circuit HT circuit idle circuit idling circuit ignition circuits low-speed circuit low speed circuit low voltage circuit LT circuit open circuit parallel circuit primary circuit printed circuit board printed circuit secondary circuit series-parallel circuit series circuit series parallel circuit short circuit circuit board: See printed circuit board

circuit breaker: A protective device that will make and break the flow of current when current draw becomes excessive. Unlike the fuse, it does not blow out but vibrates on and off thus giving the driver some light to stop by. Also see cutout circuit diagram: A wiring diagram showing the path of the electrical connections and the various colors of the wires. circuiting:

See short circuiting

circuitry: See phase-locked loop circuitry pll circuitry circuit tester: A tool which looks like a screwdriver with a light at the end of the handle as well as a long wire with an allegator clip. The pointed end touches the hot wire while the allegator end touches or clips to the ground. If there is continuity and power, the light in the handle will glow.

circular headlamp: The older type of headlight which may be the larger one (7 inch) with both high and low beam or the smaller one (5.75 inch) dedicated to either low or high beam.

circular mil: Unit of area equal to the area of a circle one mil in diameter

circulating pump: A centrifugal pump, like an automotive water pump, which moves the liquid in a closed system.

circulation: See forced circulation oil circulation circumference: See rolling circumference

circumferential break: An injury to the tread or sidewall of a tire which encircles the tire.

circumferential crack:

A crack in the grooves of the tread which may be evident around the whole tire.

CIS: Acronym for "continuous injection system." A Bosch fuel injection system which injects a steady stream of pressurized fuel into each intake port. CIS was once widely used throughout the industry

CIS-E: A CIS system with electronic controls

CIS-Lambda: A CIS system with an oxygen sensor

CIS with Lambda: See K-Jetronic with Lambda

Cisitalia: A vehicle brand of which the 1946-49 GT (Pininfarina) models are milestone cars.

citizens band radio: A CB radio which is used to communicate over a specified frequency. It was particular the domain of truck drivers.

Citroen: A vehicle brand of which the 1955-64 models D8 and ID 19 Click for books on are milestone cars. Citroen city car: A compact vehicle used for driving within a city rather than on the highway. It is usually only 10 to 12 feet (300 to 360 cm) long.

city cycle: An adult bicycle or tricycle used for riding within the city. Also called an urban cycle.

Civic: A model of automobile manufactured by Honda

Click for books on Honda Civic

CKD: Acronym for "Completely-Knocked Down."

CL: Acronym for "Comfort Luxe" as a designation for a vehicle which is more luxurious than an "L" but not quite as luxurious as a "GL"

cladding: [1] a process of covering one material with another and gluing them together under high pressure and temperature. [2] The outer body panels which are attached to the vehicle's frame. [3] Excessive decorative elements applied to a vehicle.

Claire: See wills Sainte Claire

clamp: A fastening device which secures something within its jaws without constant human pressure. Also see bar clamp battery clamp battery hold down clamp C-clamp cable clamp distributor clamp distributor hold-down clamp G-clamp hold-down clamp hose clamp hose clamp installer hose clamp pliers hose clamps locking bar clamp locking clamp long-reach C-clamp piston ring clamp sheet metal clamp

triple clamp v-band clamp welding clamp wheel clamp clamping load: In a clutch, the amount of pressure on the plates.

clamp installer: See hose clamp installer

clamp pliers: See hose clamp pliers

clamshell: A shape which has a bottom and top but is hinged at one end so that it can be opened to expose its interior.

clapboard: A narrow board which is thicker at one edge than the other edge and used to protect from the weather.

Clark: Clark, Jim -- Winner of 3 Formula One Championships, 25 Grand Prix races and of the 1965 Indianapolis 500

class A thread: A British term for external thread.

class B thread: A British term for internal thread.

classic car: A vehicle that is generally considered to be one of the finest models ever built. Unlike antique cars, classic cars do not have to be extremely old. Mustangs and VW bugs built in the late 1960s are considered to be classics by many people; however, they are really milestone cars. Classic cars are defined by the Classic Car Club of

America and are considered to be certain models during the years 1925-1948. They include the following built during those years: • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

A.C.; Adler* Alfa-Romeo Alvis Speed 20, 25, and 4.3 litre Amilcar* Armstrong-Siddeley* Aston-Martin* Auburn Austro-Daimler Ballot* Bentley Benz* Blackhawk BMW (327, 328, 327/328, 335) Brewster* Brough Superior* Bucciali* Bugatti Buick (1931-32 series 90)* Cadillac (1925-35, all 12-cyl and 16-cyl, 1938-41 60 Special, 1936-48 all series 67, 70, 72, 75, 80, 85, 90) Chenard-Walcker* Chrysler (1926-30 Imperial 80, 1931 Imperial 8 Series CG, 1932 CG and CH, 1933 CL, 1934-6 CW)* Cord Cunningham Dagmar (25-70 model only) Daimler* Darracq (8-cyl. cars and 4-litre, 6-cyl. cars only) Delage (Model D-8, not 4-cyl.)* Delahaye (Series 135, 145, 165 not 4-cyl.)* Delaunay Belleville (6-cyl. cars only) Doble Dorris Duesenberg DuPont Excelsior* Farman* Fiat* FN* Franklin (All models except 1933-34 Olympic Six) Frazer Nash* Graham-Paige (Custom body only)* Hispano Suiza Horch

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

• • • • • • • •

Hotchkiss* Hudson (1929 Series L) Humber* Invicta Isotta-Fraschini Itala Jaguar (1946-48 2.5 Litre, 3.5 Litre Mark IV, not 4-cyl.) Jensen* Jordan (Speedway Series 'Z' only) Julian* Kissel (1925-26 all models, 1927 8-75, 1928 8-90 and 8-90 White Eagle, 1929 8-125 and 8-90 White Eagle, 1930 8-125) Lagonda (all except Rapier) Lanchester* Lancia* LaSalle (1927-1933) Lincoln (All L, K, KA, and KB, 1941 168H, 1942 268H) Lincoln Continental Locomobile (All models 48 and 90; 1927 8-80; 1928 8-80; 1929 8-80) Marmon (All 16-cyl.; 1925 74; 1926 74; 1927 75; 1928 E75; 1930 Big 8; 1931 88 and Big 8) Maserati* Maybach McFarlan Mercedes* Mercedes-Benz (All 230 and up, and K, S, SS, SSK, SSKL, Grosser and Mannheim)* Mercer MG (1935-39 SA, 1938-39 WA)* Minerva (All except 4-cyl) Moon (Custom bodies only)* N.A.G.* Nash (1930 Twin Ignition 8, 1931 Series 900, 1932 Series 990, Advanced 8, Ambassador 8)* Packard (All sixes and eights 1925-34, all 12-cyl. models, 1935 Models 1200-1208, 1936 Models 1400-1408, 1937 Models 1500-1508, 1938 Models 1603-1608, 1939 Models 1703-1708, 1940 Models 1803-1808, 1941 Models 1903-1908, 1942 Models 2004-2008 plus 2023, 1946-47 Models 2106 and 2126, all Darrin-bodied)* Peerless (1926-28 Series 69 1930-31 Custom 8 1932 Deluxe Custom 8) Peugeot* Pierce-Arrow Railton* Raymond-Mays* Renault (45 HP)*

• • • • • • • • • • • • • • • • • • • • • • • •

Reo (1931-33 Royale 8-31, Royale 8-35, Royale 8-52, and Royale Custom 8 and 1934 N1, N2, and 8-52) ReVere Riley* Roamer (1925 8-88, 6-54e, 4-75; 1926 4-75e and 8-88; 1927; 1928; 1929 888; 1929 8-125; 1930 8:125) Rochet-Schneider* Rohr Rolls-Royce Ruxton Squire SS and SS Jaguar (1932-1940 except 4-cyl.) Stearns-Knight Stevens Duryea Steyr* Studebaker (1929-33 President) Stutz Sunbeam (8-cyl. and 3-litre twin-cam only) Talbot (all 105C and 110C) Talbot Lago (all 150C) Tatra* Triumph (Dolomite 8 and Gloria 6 models only) Vauxhall (25/70 and 30/98 only) Voisin Wills Sainte Claire Willys-Knight (Series 66)*.

The items marked with an asterisk (*) indicate that these models require application to be a classic car.

Classic Car Club of America: P.O. Box 443, Madison, NJ 07940. Organization which defines which cars are true classics.

Classification: See American Industrial Classification

classification society: Independent and reputable organizations which verifies and inspects vessels for seaworthiness. As technical experts, they serve to provide the necessary basis for adjusting insurance rates for the vessel.

Classification System:

See North American Industrial Classification System

claw hammer: a hammer with a forked end on the head which is used for removing nails.

Claxton horn: A horn which makes a particular sound "Ah-oo-gah." Also see horn clay model: When the design department is creating a new model, it will be built in clay to full size to determine its looks etc.

clean: See steam clean

cleaner: A product to purify or remove unwanted substances. Also see abrasive cleaner air cleaner horn air cleaner air filter bath air cleaner low-profile air cleaner oil bath air cleaner paper air cleaner piston ring groove cleaner thermostatic air cleaner cleaner element: See air cleaner element

cleaner horn: See air cleaner horn

cleaning:

See blast cleaning self-cleaning cleaning unit: See spray gun nozzle cleaning unit

clean oil: Fresh oil that has not been used in a vehicle before.

clean oil lubrication: A lubrication system where fresh oil is supplied to the engine as needed -- such as in a two-stroke engine.

clearance: A given amount of space between two parts such as between piston and cylinder, bearing and journal , etc. Also see bearing clearance front wheel tire clearance ground clearance control ground clearance lateral clearance lateral tire clearance longitudinal tire clearance pedal clearance piston clearance piston ring side clearance radial clearance ring side clearance tire clearance valve clearance vertical tire clearance clearance control: See ground clearance control

clearance depression: See valve clearance depression

clearance fit: Parts that are assembled so that there is clearance between them so that one part can slide in or on the other. Also called "sliding fit"

clearance height: [1] The distance between the ground and the lowest portion of the bottom of a vehicle (not counting the wheels). Also called ground clearance. [2] The distance between the top of a vehicle and the bottom of a bridge or tunnel which determines whether the vehicle can pass under it.

clearance lamp: A light which is mounted on the extreme edges of the roof of a truck to show the maximum height and width of a vehicle. Also called "marker lamp."

clearance sensor: See ground clearance sensor

clearance volume: The space above a piston when it is at the top dead center.

clear coat: A clear paint covering used on modern vehicle bodies. It is the top coat.

clear system: See base and clear system

clearwater stern: A stern with a "shoeless" stern frame

cleat: Clips at intervals on the horizontal stiffeners of hatch coamings to secure the hatch covers

CLEPA: Acronym for "Comité de Liaison de la Construction d'Equipements et de Pièces d'Automobiles" (i.e., European Association of Automotive Suppliers).

clevis: A U-shaped metal piece with holes in each end through which a pin or bolt is run, used for attaching the brake pedal to the power brake booster pushrod, the clutch pedal to the clutch cable or master cylinder pushrod and for various other connections on an automobile

click: See kilometer

click-type torque wrench: A torque wrench which gives out an audible click when the preset torque is reached.

climate change: the international concern that increasing concentrations of greenhouse gases (GHGs) in the atmosphere are changing the climate in ways detrimental to our social and economic well-being.

climate control: A lever or button which you can move to change the temperature in the passenger compartment of a vehicle. It controls the heater, vent, and/or air conditioner.

climatic chamber: A test area into which an automobile can be placed to see if it will meet the extremes of temperature and humidity.

climbing ability: While some vehicles may have a high top end speed on a road with no incline, the real test of a vehicle in mountainous terrain is its ability to go up a hill at an adequate speed (i.e., its climbing ability).

clincher: A tire whose edges hook under the curved-in hooked edge of a special rim, not commonly found anymore on bicycles and often confused with the common wiredon tire.

clincher rims: Type of wheel rim used with early beaded-edge tires

clincher tire: A tire whose edges hook under the curved-in hooked edge of a special rim, not commonly found anymore on bicycles and often confused with the common wiredon tire.

clinometer: An instrument which measures the steepness of a hill.

clip: See alligator clip crocodile clip hose clip hose clip installer hose clip pliers jubilee clip rebound clip spring clip clip installer: See hose clip installer

clipless pedal: See clipless pedals.

clipless pedals: Road bike pedals that use a releasable mechanism like that of a ski binding to lock onto cleated shoes and do not use toe clips or straps.

clip-on engine: An engine that is attached to a conventional bicycle frame

clip-ons: Low racing handlebars that clamp directly onto the fork legs

clip-on weight: A wheel weight that is clipped on the rim between the rim and the tire. It is used to balance a wheel.

clip pliers: See hose clip pliers

clock: [1] An instrument showing the time. [2] An odometer as in the statement I want to buy this car, but it has too many miles on the clock. [3] To record the speed or time that vehicle makes.

clocking: [1] The action of recording the speed of a vehicle. [2] In Britain, it is the action of turning the odometer back.

C/locking: Abbreviation for "central locking."

clockwise: Rotation to the right like the direction of clock hands. In most cases it is the direction to secure a nut to a bolt. It is the opposite to counterclockwise.

clog: To obstruct a passageway or track so that the normal flow or operation of something is hindered.

close call: In driving it is the near possibility of an accident.

close coils: The coils or loops of a spring which are tightly together.

close coupled sedan: See close-coupled sedan.

close-coupled sedan: Similar to the sedan, this body style is shorter and thus usually accommodates only five passengers. The rear quarter windows were eliminated.

closed cooling system: See coolant recovery system.

closed crankcase ventilation: A system in which crankcase vapors are discharged into the engine intake system (usually through the intake manifold) and pass through the engine cylinders rather than being discharged into the atmosphere.

closed-end connector: Solderless connector shaped like a hat. Used to join two, three, or more wires together. Similar to wire connectors used in home wiring, but installed by crimping instead of twisting

closed end lease: Most leases offered today are close-end leases, meaning that the residual value is fixed and stated in the lease contract. The lessee's financial obligations are unaffected by what the vehicle is actually worth when the lease ends. In other words, the lessee assumes no risk for the depreciation of the vehicle.

closed loop: An operating condition or mode which enables modification of programmed instructions based on a feedback system

closed loop system: A self-adjusting system which keeps conditions stable and is controlled by negative feedback from a sensor.

close-ratio gearbox: A transmission in which there is very little difference between one gear ratio and the next. This kind of transmission makes it easy for fast shifting.

closes: See exhaust valve closes intake valve closes closing:

See power closing

closing cam: A cam or rocker which closes a valve in a mechanically operated valve system. Other types close the valve through the operation of the valve spring. Also called "closing rocker."

closing force: The force needed for the spring to close a valve.

closing panel: A panel which covers a hole in the body, interior panels, or frame.

closing rocker: A cam or rocker which closes a valve in a mechanically operated valve system. Other types close the valve through the operation of the valve spring. Also called "closing cam."

closing system: See automatic closing system

closure: See road closure

cloth: See emery cloth tack cloth cloth upholstery: The fabric of the seats made of cloth rather than leather or vinyl.

cloud point: The temperature at which diesel oil tends to thicken and cloud up (i.e., become cloudy).

cloverleaf:

A highway overpass system which has four basic loops for getting on the highway or leaving it.

club: See automobile club Royal Automobile Club club coupe: The club coupe designation seems to come from club car, describing the lounge (or parlor car) in a railroad train. The early postwar club coupe combined a shorter-than-sedan body structure with the convenience of a full back seat, unlike the single-seat business coupe. That name has been used less frequently in the 1976-86 period, as most notchback two-door models (with trunk rather than hatch) have been referred to as just "coupes." Moreover, the distinction between two-door coupes and two-door sedans has grown fuzzy. Also see two-door club coupe club hammer: A hammer with a short handle but a large, heavy head. It is used to hit the back end of a chisel or drift.

clunker: A vehicle which might run but is rusty and in need of a lot of repair work.

cluster: See analog cluster analogue cluster electronic cluster footpedal cluster instrument cluster lamp cluster rear lamp cluster seat cluster cluster gear: The cluster of gears that are all cut on one long gear blank. The cluster gears ride in the bottom of the transmission. The cluster provides a connection between the

transmission input shaft and the output shaft. Also called "counter gear."

cluster panel: The reverse side of the instrument panel or dash where all the wiring or circuit board is located.

clutch: A device that disconnects the engine from the transmission, to allow the vehicle to change gears, and then allows the engine and transmission to resume contact and turn together at a new speed. Also see center the clutch centrifugal clutch clutch diaphragm spring clutch disc clutch explosion clutch housing clutch lever clutch pedal free travel clutch pedal clutch pilot bearing clutch pressure plate clutch release bearing clutch semi-centrifugal release fingers clutch shaft clutch solenoid clutch throwout fork coil spring clutch cone clutch diaphragm spring clutch diaphram clutch disengage the clutch dog clutch double clutch double clutching dry clutch electromagnetic clutch fan clutch fluid clutch freewheeling friction clutch heavy clutch

hydraulically-activated clutch hydraulically-assisted clutch hydrodynamic clutch light clutch lock-up clutch magnetic clutch multi-plate clutch multiple-plate clutch multiple disc clutch oil-immersed clutch one-way clutch one way clutch overrunning clutch starter drive overrunning clutch starter overrunning clutch positive clutch pull-type clutch push-type clutch reactor one-way clutch reverse clutch riding the clutch roller clutch self-operating clutch single-plate clutch slip the clutch sprag clutch stator roller clutch sticky clutch torque converter lock-up clutch twin-plate clutch wet clutch clutch aligning set: A group of tools used to align the clutch plates with the flywheel. Usually there is a shaft, pilot bearing adapters, and tapered universal sleeves clutch aligning tool: A tool which looks like a bar or a disc which can be used to line up the clutch plates with the flywheel.

clutch brake: A device for slowing down the clutch discs (and thus the gears themselves) so that shifting is smoother and quieter.

clutch cable:

A cable (usually a cluster of thin strands within a plastic sheath) which operates the movement of the clutch plates. At the other end is a pedal (in automobiles) or a handlebar lever (left side).

clutch cover: A metal cover which encases the clutch plates.

clutch diaphragm spring: A round dish-shaped piece of flat spring steel. It is used to force the pressure plate against the clutch disc in some clutches.

clutch disc: A spinning plate located at the end of the driveshaft facing the engine flywheel and covered with a friction material such as asbestos. When the clutch is engaged, the disc is squeezed between the flywheel and the clutch pressure plate, causing the engine and the transmission to turn at the same speed. British term is called "clutch plate."

clutch drag: When the clutch discs do not disengage completely after the clutch pedal is depressed or the clutch lever is pulled in, there is excessive friction so that it is difficult to shift gears because both the driven discs and the input shaft are both rotating.

clutch explosion: clutches have literally flown apart (exploded) when subjected to high rpm, a scatter shield is used on competition cars to protect the driver and spectators from flying parts in the event the clutch explodes.

clutch facing: The asbestos-type lining on a clutch plate.

clutch field: A clutch part on an air condition compressor, consisting of hundreds of windings of wire, that creates a magnetic field when current is applied, pulling in the armature to engage the clutch

clutch fork:

When the clutch pedal (or lever) is depressed, it pulls on a cable which moves the clutch fork which in turn pushes on the release bearing and disengages the clutch discs.

clutch housing: A cast iron or aluminum housing that surrounds the flywheel and clutch mechanism. Also called "bell housing."

clutching: See double clutching

clutch interlock switch: A switch that prevents the vehicle from starting unless the clutch pedal/lever is pressed.

clutch judder: A British term for "clutch shudder."

clutch lever: A hand-operated blade located on the left side of the handlebar of a motorcycle. When the clutch lever is pulled in, it disengages the clutch so the engine and the crankshaft can turn independently of the transmission and the rider can change gears. Also see clutch release finger clutch lining: The friction material on the face of the clutch discs.

clutch pedal: A foot-operated pedal located on the floor of the vehicle to the left of the brake pedal on cars with manual transmission. When the clutch pedal is depressed, it disengages the clutch so the engine and the crankshaft can turn independently of the transmission and the driver can change gears.

clutch pedal free travel: The specified distance that the clutch pedal may be depressed before the throwout bearing actually contacts the clutch release fingers.

clutch pilot bearing: A small bronze bushing, or in some cases a ball bearing, placed in the end of the crankshaft or in the center of the flywheel depending on the vehicle, that is used to support the outboard end of the transmission input shaft.

clutch plate: The clutch discs.

clutch pressure plate: That part of a clutch assembly that through spring pressure, squeezes the clutch disc against the flywheel thereby transmitting a driving force through the assembly. To disengage the clutch, the pressure plate is drawn away from the flywheel via linkage. clutch release bearing: See throwout bearing.

clutch release finger: A flat piece of metal shaped like a curved finger. Through the movement of the throwout fork, the throwout bearing pushes against the clutch release fingers or levers to release pressure against the pressure plate. Also called "clutch release lever."

clutch release lever: See clutch release finger.

clutch semi-centrifugal release finger: See clutch semi-centrifugal release fingers.

clutch semi-centrifugal release fingers: Clutch release fingers that have a weight attached to them so that at high rpm the release fingers place additional pressure on the clutch pressure plate.

clutch shaft: The shaft that takes power from the clutch into the gearbox. Also called the "drive pinion."

clutch shudder: When the clutch tries to engage (when the pedal or lever is released), but the discs do not mate securely, the discs engage intermittently and slip past each other making a noise like a shudder. In Britain, it is called "clutch judder."

clutch slip: Clutch slip occurs when the clutch tries to engage (when the pedal or lever is released), but the discs do not mate securely.

clutch solenoid: In some automotive air conditioners, a solenoid that operates a clutch on the compressor drive pulley. When the clutch is engaged, the compressor is driven and cooling takes place.

clutch spring: The clutch cover will have several posts over which the clutch spring (shaped like a cylinder) fits and pushes the pressure discs against the driven clutch discs to transmit power.

clutch starter: See overrunning clutch starter overrunning clutch starter drive clutch starter drive: See overrunning clutch starter drive

clutch starter interlock: A device which disengages the starter once the engine has started.

clutch stop: A clutch brake

clutch throwout bearing: The clutch release bearing.

clutch throwout fork: The device or fork that straddles the throwout bearing and that is used to force the throwout bearing against the clutch release fingers.

clutch thrust bearing: The clutch release bearing.

cluttered engine compartment: An engine compartment or bay in which all the available space around the engine is occupied by other objects (alternator, pumps, air intake system, battery, wiper motor, heater motor, windshield washer motor, starter, radiator, air conditioner, hoses, pipes, wiring, electronic boxes, etc.)

C-matic transmission: Citroen's name for a semi-automatic transmission

C motorhome: See type C motorhome

CNG: Acronym for "Compressed Natural Gas"

CO: Acronym for "carbon monoxide." A deadly, colorless, odorless, and tasteless gas found in the engine exhaust. Toxic even in relatively small concentrations. Formed by incomplete burning of hydrocarbons. Thus at its greatest with a rich mixture.

coach: [1] An enclosed two-door type body with permanent back panels and top, it is similar to the coupe, but the seating is different. A full width cross seat in the rear accommodates three passengers. Two separate seats in the front fold out of the way to admit rear passengers. There is no trunk, but trunk racks are frequently provided. [2] A luxurious bus, a tour bus.

coach bolt: A bolt with a mushroom head, but just below the head there is a square neck and then the threads. The square neck fits into a matching square hole to keep the bolt from moving.

coachbuilder: A person or company which manufactures special bodies for automobiles.

coachbuilt body: A separate body which is not integral with the chassis.

coachbuilt construction: The process of building an automobile so that the body is separate from the chassis. Often the bodies are built to customer specifications and may differ from one another even though they are built upon the same chassis design. Also see skeleton construction unitary construction coachlining: Pinstriping along the side of a vehicle or along the side of the fuel tank of a motorcycle.

coach paint: A slow-drying, high-gloss paint used on cars in the early 1900s. It was painted on car bodies with a brush.

coachwork: Although it is strictly the body of an automobile, it is particularly the comfort and luxury appointments as distinguished from the operational chassis thus it would include the interior, seats, upholstery, dashes, fenders, etc. -- everything but the mechanicals and the chassis. The French call it Carrosserie, the Germans call it Karosserie, and the Italians call it Carrozzeria. Also called "bodywork."

coalescing action: The process of smaller water droplets merging together into larger droplets which takes place in a water separator

coaming: See hatch coaming

coarse:

See national coarse thread

coarse-cut file: A file with deep grooves for removing a lot of metal quickly. It leaves rough edges which will need to be cleaned up with a smooth-cut file

coarse file: A file with deep grooves for removing a lot of metal quickly. It leaves rough edges which will need to be cleaned up with a smooth-cut file

coarsening: See grain coarsening

coarse pitch: Gears or screw threads which have wide gaps between each tooth or thread.

coarse thread: The threads of a screw are wider apart. Opposite to fine thread. Also see national coarse thread coast: [1] To proceed, usually downhill, on a bicycle without pedalling; or in a motor vehicle without the aid of the engine. Also see freewheel. [2] A designation on a cruise control switch which (when activated) will cause the vehicle to slow down to a lower cruise controlled speed.

coastal: Domestic shipping routes along the coast.

coaster: A vehicle, usually a bicycle, which has no means of propulsion (you can't pedal it and it is without any engine).

coaster brake:

A braking system on a bicycle in which the rider stops pedalling forward (thus coasting) and pedals backward to engage the brake within the hub of the rear wheel.

coat: [1] A covering of paint or similar substance. Also see anodize base coat clear coat color coat cross-hatch coat cross coat finish coat fog coat gel coat guide coat intermediate coat mist coat prime coat protective coat single coat tack coat top coat undercoat [2] To apply a covering of paint, etc.

coat drier: See top coat drier

coated abrasive: Sandpaper or grinding wheel where an abrasive material such as sand or diamond grit is glued to a backing material and used to reduce or smooth a surface.

coated electrode: See covered electrode

coating: A protective covering usually of paint. Also see anodic coating

anti-chip coating catalytic layer chromate coating coil-coating conversion coating electrostatic powder coating galvanized coating hard anodic coating manganese phosphate coating phosphate coating polymer coating protective coating pvc underseal coating roll coating spray coating underbody coating undercoating zinc phosphate coating coat oven: See top coat oven

cobble: To put something together in a rough or clumsy manner. This is usually done as a temporary measure until more permanent repairs can be made.

cobbled: The action of putting something together in a rough or clumsy manner. This is usually done as a temporary measure until more permanent repairs can be made.

Cobra: See AC Shelby Cobra

COC: Acronym for conventional oxidation catalyst

cock: A tap or shut-off valve which controls the flow of liquid. Also see fuel cock

radiator drain cock cockpit: The area, usually in racing cars, in which the driver sits and the instruments in front of him.

code: A system of symbols (as letters, numbers, or words) used to represent meaning of information. Also see highway Code Nordic Anti-Corrosion Code coded: See color-coded

code hopping: A technology which prevents thieves with scanners from either picking up your encoded remote-control signal or from randomly firing numerous codes at your vehicle in order to stumble upon the one that will disarm your security system.

coefficient: See block coefficient drag coefficient coefficient of drag: See drag coefficient.

coefficient of friction: A measurement of the amount of friction developed between two objects or surfaces in physical contact when one of the objects is drawn across the other. If a book were placed on a table and a measuring scale used to pull the book, the amount of weight or pull registered on the scale would be the coefficient of friction. This coefficient of friction is dependent upon both surfaces in contact. It is large if the surfaces are rough and small if they are smooth.

cofferdam:

Narrow void space between two bulkheads or floors

cog: Any toothed gear. A sprocket attached directly to the rear wheel hub on a singlespeed bike and mounted on a freewheel on a multi-speed bike.

cog belt: A toothed belt normally of fibreglass-reinforced rubber for driving the camshaft from the crankshaft. In cars, cog belts are primarily used with overhead camshafts but are sometimes used to drive pumps. cogged belt: See cog belt

coil: [1] Metal bands or strands of wire wrapped in a circular fashion. [2] A pulse-type transformer for increasing the voltage to fire the spark plugs. Also see booster coil close coils exciter coil field coil four-spark ignition coil glow coil high energy coil hold-in coil holding coil ignition coil resistor ignition coil induction coil multi-spark coil multi-spark ignition coil multiple-spark coil multiple-spark ignition coil open coil glow plug pick-up coil pickup coil pulser coil single-spark ignition coil thermostatic coil choke

coil binding: Compressing a valve spring to the point at which each coil touches the adjacent coil coil chimney: The top of the ignition coil where the high tension leads are attached.

coil choke: See thermostatic coil choke

coil glow plug: See open coil glow plug

coil ignition: The standard ignition system which uses an ignition coil which stores the power from the battery and steps it up. Then the high voltage is sent to the spark plugs. Also see transistorized coil ignition coil ignition with Hall sensor: See transistorized coil ignition with Hall sensor

coil lead: A British term for the high tension wire going from the coil to the distributor. In America, it is called the "coil wire."

coil resistor: See ignition coil resistor

coils: See close coils

coil spring: A section of spring steel rod wound in a spiral pattern or shape. Widely used in both front and rear suspension systems. Like large metal bed springs, these coils cushion and absorb the shocks and bumps as the vehicle is driven. They are usually found near the front wheels, but some cars have them in the rear as well. Often the shock absorbers run up the center of the coil springs. coil spring clutch:

A clutch which has a ring of coil springs which hold the pressure plate in position.

coil spring compressor: See spring compressor

coil tester: See spark gap coil tester

coil tower: The top of the ignition coil where the high tension leads are attached.

coil wire: The high tension wire going from the coil to the distributor or spark plug.

coin holder: A device which retains coins for easy access.

coked up: A British term for "carboned up" to indicate something covered in carbon.

cold: The relative absence of heat

cold air: Air that is below the prevailing ambient temperature.

cold air induction: The induction system forces cold air into the combustion chamber. Because cold air is more dense than warm air, it contains more oxygen molecules. With more oxygen, fuel will burn more effectively and thus increase horsepower.

cold air intake: The induction system forces cold air into the combustion chamber. Because cold air is more dense than warm air, it contains more oxygen molecules. With more oxygen, fuel will burn more effectively and thus increase horsepower.

cold cap: A process in retreading a tire where the tire is placed in a pressure chamber in a temperature range of 195°-212° until bonding of the pre-cured tread rubber is achieved. Also see hot cap cold-condensate corrosion: The corrosion of the inside of an exhaust system by direct chemical attack resulting from an acidic, aqueous solution that condenses from the exhaust gas at relatively low temperatures and collects at the cooler rear portions of the exhaust system.

cold cranking ability: A measurement in amps of a battery's ability to start a vehicle under cold temperatures. A higher number is better than a lower one. Basic automobile batteries begin around 400 cold-cranking amps (which is only marginally acceptable in most vehicles). The best batteries are around 1000 cold-cranking amps.

cold cranking amps: See cold cranking ability

cold-cranking rating: The minimum number of amperes a fully charged 12-volt battery can deliver for 30 seconds at 0° F without falling below 7.2 battery volts

cold galvanizing: The application of zinc to prevent rusting. It can be applied by a paint with lots of zinc or by electroplating with zinc.

cold lash: The valve lash clearance, measured between the rocker arm and valve tip, when the engine is cold

cold manifold: An intake manifold not heated by exhaust gas

cold plug: A spark plug which has a short insulator nose which absorbs less heat and dissipates heat quickly. A colder plug is used in a hot engine while a hot plug is used in a cold

engine. Thus if the plugs are fouling too much, try a hotter plug. If the plugs are coming out white, try a colder plug. The ideal color of the center insulator nose should be a light chocolate brown.

cold solder joint: A poor soldering technique where the solder has not quite melted enough to produce a good electrical contact.

cold spark plug: See cold plug

cold spraying: A method of paint spraying where the paint is excessively diluted with solvent. This process makes spraying easy, but the coats are very light.

cold start: Getting a vehicle started which has been sitting for some time and cooled down to ambient temperature. When temperatures reach -40°, a vehicle may require three or four times as much battery power as it would during the summer. As well, the carburetor or fuel injection system needs to be much richer (more gasoline than air). Because condensation has a tendency to build up in the gas tank during the winter, the liquid going to the carburetor or fuel injectors may be diluted with water -- thus making starting more difficult. The application of isopropyl alcohol (marketed as "gasline antifreeze") removes the water from the tank.

cold starting: See cold start

cold start enrichment: A method of providing a higher ratio of fuel to air for starting a cold engine. In some cases, more fuel is fed into the engine with a cold start injector; in other cases, the amount of air is restricted through the use of a choke.

cold start injector: A device in a fuel injection system which shoots an extra amount of fuel into the cylinder to increase the ratio of fuel to air.

cold weather modulator:

(CWM) a vacuum modulator located in the air cleaner on some models. The modulator prevents the air cleaner duct door from opening to non-heated intake air when outside air is below 55° F. Similar to a temperature vacuum switch

collapse: See piston collapse

collapsed piston: A piston whose skirt diameter has been reduced due to heat and the forces imposed upon it during service in the engine. Also see piston collapse collapsible spare tire: A space-saver spare wheel.

collapsible steering column: When a vehicle is involved in an accident, the driver's chest is forced into the steering wheel. In older cars, the immovable steering column meant that the driver could sustain chest damage. The collapsible steering column telescopes or folds (articulate) so that chest damage is reduced.

collar: A sleeve that fits over a shaft. Also see hexagonal collar split collar underhead collar valve spring collar collector: See solar collector

collector car: An older car which may not fit into the category of a classic car or a milestone car, but it has nostalgic appeal.

collet:

A removable ring or collar which fits into a groove to hold something in place.

collier: Vessel used for transporting coal.

collision: See head-on collision

collision avoidance system: Electronic system used to prevent collisions in inland navigable waterways.

collision bulkhead: The foremost main transverse watertight bulkhead designed to keep water out of the forward hold in case of bow collision damage. Also called forepeak bulkhead

collision insurance: Insurance coverage that pays to repair damages to your vehicle when it is involved in an accident.

colonnade hardtop: In architecture, the term colonnade describes a series of columns, set at regular intervals, usually supporting an entablature, roof, or series of arches. To meet US federal rollover standards in 1974 (standards that never emerged), General Motors introduced two-door and four-door pillared body types with arch-like quarter windows and sandwich type roof construction. They looked like a cross between true hardtops and miniature limousines. Both styles proved popular (especially the coupe with louvered coach windows and canopy top) and the term colonnade was applied. As their "true" hardtops disappeared, other manufacturers produced similar bodies with a variety of quarter-window shapes and sizes. These were known by such terms as hardtop coupe, pillard hardtop, or opera-window coupe.

color: See four color identification color integral color anodizing off color paint color matching

color anodizing: See integral color anodizing

color chart: A listing of paint samples of available exterior paint for a vehicle.

color coat: A coat of paint with the final color. Sometimes a clear coat is applied over it.

color-coded: [1] Something that is colored the same as the main part of the bodywork. Also called "color-keyed" or "color-matched." [2] A series of similar things in which each one is a different color to distinguish one from the other, such as the wiring (e.g., the red wire goes from the battery to the fuse box, the blue wire goes from ... to the ...).

colored: See body-colored

color-keyed: See color-coded.

color-matched: See color-coded.

color matching: See paint color matching

color scheme: The combination of exterior colors which harmonize, e.g., A maroon body and a white roof.

column: See absorbing steering column adjustable steering column collapsible steering column

energy absorbing steering column height adjustable steering column safety steering column steering column telescopic steering column tilt column column changer: See column shifter

column controls: See steering column controls

column gearchange: See steering column gearchange

column gear changer: See column shifter

column shifter: A gear changer lever and mechanism which is located on the steering column below the steering wheel. In Britain it is called a "column changer" or "column gear changer."

combi: Vessel designed for a combination of passengers, and different types of cargo.

combination: A vehicle like a motorcycle and sidecar or a tractor and trailer.

combination lamp: A light or group of lights which serves two or more purposes. For example, the rear combination lamp illumines the running lights (i.e., the ones that are turned on when the headlight is turned on) and brake light and/or the signal light

combination pliers:

A British term for a Lineman's pliers or slip-joint pliers

combination spanner: A British term for combination wrench

combination valve: A brake system hydraulic control device includes a pressure differential valve, metering valve, and proportioning valve

combination weight: See gross combination weight

combination wrench: A flat wrench with a hex ring at one end and an open end at the other.

combination valve: A pressure-regulating valve in braking systems incorporating a failure warning switch and comprising two or more of the following valves: pressure-differential valve, metering valve, and proportioning valve.

combined weight rating: See gross Combined Weight Rating

combiner: See holographic combiner

combustion: The intense burning of the fuel-air mixture in the combustion chamber. Some used to think that the fuel-air mixture exploded; but further investigation has shown that it rapidly burns. Also see combustion chamber volume combustion chamber combustion space compression ignition controlled combustion system external combustion engine fireball combustion chamber

hemispherical combustion chamber internal combustion engine main combustion chamber pent-roof combustion chamber pre-combustion chamber wedge combustion chamber combustion chamber: The volume of the space in the cylinder above the piston with the piston at top dead center (TDC) in the compression stroke. The head of the piston, the cylinder walls, and the head form the chamber. Combustion of the fuel-air mixture begins here when ignited by a spark plug. The design and shape of the combustion chamber can affect power, fuel efficiency, and emissions of an engine. Also see fireball combustion chamber hemispherical combustion chamber main combustion chamber pent-roof combustion chamber spherical combustion chamber twin swirl combustion chamber wedge combustion chamber combustion chamber recess: The area where combustion occurs in a rotary piston engine combustion chamber volume: volume of combustion chamber (space above piston with piston on TDC) measured in cc (cubic centimetres).

combustion engine: See external combustion engine internal combustion engine combustion pressure: The pressure created during the combustion of the air/fuel mixture in the cylinder, measured in pounds per square inch.

combustion residue:

Carbon and other deposits resulting from combustion.

combustion space: See combustion chamber.

combustion system: See controlled combustion system

CO meter: A device for checking exhaust gases for carbon monoxide, a high level indicates an over-rich mixture as well as causing pollution.

Comet head: A cylinder head with a swirl chamber for indirect injection diesel engines.

Comfort: A designation of some automobiles as a basic or standard line usually abbreviated as "C"

Comfort Luxe: An automobile designation (abbreviated as CL) which has more luxury appointments than a "Comfort" but less than a Grand Luxe (GL).

commercial tire: A tire which is designed for truck and industrial use.

commercial vehicle: A vehicle (like a truck or bus) used for carrying goods or large numbers of passengers for money.

commutator: A series or ring of copper bars that are connected to the armature windings. The bars are insulated from each other and from the armature. The brushes (as in the generator or starter) rub against the whirling commutator.

compact:

See compact car sub-compact compact car: A designation no longer used because even "full-size cars" are now about the size of what was the compact car. In 1970, for instance, a Chevrolet Impala was a full-size car, a Chevelle was an intermediate, a Nova was a compact. When cars smaller than the Nova came out (i.e., Chevette), they were called sub-compacts.

companionway: An access way in a deck, with a ladder leading below, for the use of the crew

company logo: An emblem which represents all or part of a company's trademark.

comparison and identification: See program comparison and identification

compartment: See battery compartment cassette compartment cluttered engine compartment crowded engine compartment engine compartment glove compartment passenger compartment compartmentation: The subdividing of the hull by transverse watertight bulkheads so that the ship may remain afloat under certain flooding conditions

compass: An instrument with a magnetic needle which is mounted on the dash to give the driver an idea of where magnetic north might be.

compensating bar:

See compensator

compensating jet: A fuel tube or pipe in the carburetor, into which air is admitted through one or more holes to compensate for a tendency of the main nozzle to deliver too rich a mixture as the air velocity through the carburetor increases. Also called "air bleed." compensating port: A small hole in a brake master cylinder to permit fluid to return to the reservoir.

compensator: A horizontal bar which is pulled forward when the parkbrake is applied at its central point, which is pivoted, while it is connected at each end to the parkbrake cable, enabling equal force to be exerted on each rear brake. Also see temperature compensator compensator valve: A valve in automatic transmissions designed to increase the pressure on the brake band during heavy acceleration.

competition: See interchannel competition

competition car: A vehicle which is designed to compete in races, hill climbs, and rallies.

compliance: A slight resiliency, or "give," designed into suspension bushings to help absorb bumps. Good compliance allows the wheels to move toward the rear a little as they hit bumps but does not allow them to move laterally (sideways) during cornering.

Compliance Certification Label: See safety Compliance Certification Label

component:

[1] One of the parts that make up the whole system or device, as in The brake pad is a component of the brake system. [2] A raw material, ingredient, part or subassembly that goes into a higher level assembly, compound, or other item. Also see body component primary structure component shared component component assembly: A combination of two or more parts or sub-components to form an assembly.

component design: the activity for the design of specific components including responsibility for material, cost, weight, reliability, durability, function, appearance, and serviceability.

components: The various parts that make up the whole system or device.

component sharing: The use of the same basic parts used in different models -- even in models from different manufacturers.

composite: Any material that consists of two or more substances where one or more of them are high strength fibers and another is an adhesive binder. The most common composite is fiberglass, which consists of thin glass fibers bonded together in a plastic matrix. The structural properties of composites can be altered by controlling the orientation and configuration of the high-strength components.

composite headlamps: Reflector and lens system designed for specific vehicle model

composite headlight: A headlight system which is unlike the sealed beam headlight. When the bulb fails, you can replace just the bulb, not the whole unit. Because the lens is contoured to the shape of the vehicle, there are many different shapes. Thus each lens is low production and can be very costly to replace.

composite propeller shaft: A single-piece propeller shaft made of fibre-reinforced epoxy in which the fibres are usually glass and/or carbon.

compound: [1] Two or more ingredients mixed together. [2] An abrasive paste or liquid that smooths and polishes the painted surface. Also see anti-drum compound anti-ozone compound cutting compound intermetallic compound ozone compound rubbing compound sealing compound sheet molding compound underbody sealing compound valve grinding compound valve lapping compound compound carburetor: A carburetor with more than one choke. Usually there are two: one for the large throttle opening and one for the small throttle opening, but they fit to a single port

compound center electrode: Also called compound electrode

compound electrode: A spark plug with a copper core and a jacket of a nickel-based alloy.

compound gauge: A gauge that can indicate both pressure and vacuum. Also called a low side gauge

compound glass: See laminated glass

compounding:

See pre-compounding

compound motor: A direct current electric motor with two separate field windings, one in parallel and the other in series with the armature circuit; used as a starter motor

comprehensive insurance: Insurance coverage that pays for damages to your car, its accessories, spare parts against loss or damage caused by an accidental collision, fire, theft, vandalism, typhoon, earthquake, and flooding. It will also pay expenses to have the disabled vehicle towed to the repair shop and expenses to return the vehicle back to you when the repairs are completed. It also covers for the death and bodily injury of the insured or driver; loss or damage to someone else's property as a result of the accident; legal liabilities to the death or bodily injury of the third party arising from the accident; legal liabilities to the damage to property of the third party arising from the accident; loss or damage to the property of the spouse(s) or the child(ren) of the insured or driver; and medical expenses of the insured or driver's injury caused by the accident.

compress: To place under pressure or to squeeze into a small space. Also see pre-compress compressed-air spray gun: A paint gun which makes a fine spray of paint for coating the surface.

compressed natural gas: Abbreviated CNG. See natural gas

compression: [1] Applying pressure to a spring, or any springy substance, thus causing it to reduce its length in the direction of the compressing force. [2] Applying pressure to a gas, thus causing a reduction in volume. [3] One of the essential factors in a internal combustion engine (fuel, air, proper proportion of mixture, compression, timing, spark). It is the squeezing of the fuelair mixture in the cylinder of a spark-ignition engine or the squeezing of the air in a diesel engine. Compression makes the process of combustion more effective and increases engine efficiency. Also see

crankcase compression grooved compression ring high compression head piston ring, compression primary compression ratio primary compression ring, compression secondary compression compression check: Testing the compression in all the cylinders at cranking speed. All plugs are removed, the compression gauge placed in one plug hole, the throttle cracked wide open and the engine cranked until the gauge no longer climbs. The compression check is a good way in which to determine the condition of the valves, rings, and cylinders.

compression gage: See compression gauge.

compression gauge: A gauge used to test the compression in the cylinders. A poor compression reading can indicate that there is leakage through the valves or the piston rings. In two stroke engines, it could indicate that there is poor primary compression because of a leak in the crankshaft seals.

compression head: See high compression head

compression ignition: combustion of a fuel-air mixture without spark. In the diesel engine, air is drawn into the cylinder and compressed to a temperature sufficiently high that fuel oil injected at the end of the compression stroke burns in the cylinder without a spark to initiate combustion. A prank played on new employees is to send them on a search for the spark plugs for a diesel engine -- they don't exist.

compression leakage: In an engine, when some gases escape past the piston because the rings or cylinder walls are worn, the compression is reduced so that there is less efficiency.

compression molding:

The shaping of molding material by softening it under pressure and the action of heat, and forcing it through a hole into a hollow space which it completely fills. Also see molding compression moulding: British term for compression molding

compression ratio: When the piston is at the bottom of its travel (BDC), the volume of cylinder is measured (suppose the volume is X). Then the piston is placed at the top of its travel (TDC) and the volume of the cylinder is measured (suppose this volume is Y). The compression ratio is a comparison of these two values expressed as X:Y. Then the values are mathematically changed so that the second number is always 1. Thus you hear of ratios like 10.5:1 or 9.5:1 or 8:1. The higher the compression ratio, the more mechanical energy an engine can squeeze from its air-fuel mixture. Higher compression ratios, however, also make detonation more likely. Also see primary compression ratio compression ring: A ring which surrounds the piston and fits in a grove in the piston. It is designed to seal the burning fuel charge above the piston. Generally there are two compression rings per piston and they are located in the two top ring grooves. They also help to transfer heat from the piston into the cylinder walls and subsequently to the water jacket surrounding the cylinder. Also see grooved compression ring stepped compression ring tapered compression ring compression spring: An open-coil, helical spring that offers resistance to a compressive form.

compression stroke: The second stroke of the four-stroke cycle, in which the piston moves upward from bottom dead center to top dead center, compressing the fuel-air mixture. compression tester: A device which is screwed or pushed into the spark plug hole so that when the engine is turned over, it measures the amount of compression in that cylinder.

compressor: [1] A mechanism in a refrigerator or air conditioner that pumps vaporized refrigerant out of the evaporator, compresses it to a relatively high pressure and then delivers it to the condenser. [2] A tool for compressing a coil spring, such as a valve spring. Also see air compressor coil spring compressor piston-type compressor piston compressor positive displacement compressor reciprocating compressor roots compressor spring compressor valve spring compressor compressor cut-off switch: A device used by some manufacturers to prevent compressor operation. Such as the wide open throttle (WOT) cut-off switch, low pressure switch, and high pressure switch

compressor discharge switch: A device that shuts off the compressor when refrigerant pressure is low. The switch is wired in series between the compressor clutch and the control panel switch

compressor impeller: An impeller of a turbocharger driven by the turbine at speeds up to 160,000 rpm, which accelerates by centrifugal force the charge air which enter axially and leaves radially at a very high velocity.

compressor pressure ratio: In a turbocharger system, the ratio between the absolute pressure at the compressor outlet and the compressor inlet

compressor ratio: In a turbocharger system, the ratio between the volume in the cylinder when the piston is at the bottom of its stroke and the volume in the cylinder when the piston is at the top of its stroke

compressor shaft seal: A seal in an air conditioner compressor, surrounding the compressor shaft, that permits the shaft to turn without the loss of refrigerant or oil

Comprex supercharger: A supercharger using the pressure waves created by the expanding exhaust gases to compress the inlet charge. Also called "pressure wave supercharger."

computer: A device which calculates information and sends the results to a specific destination. In automobiles, computers are used to regulate fuel flow, control the air conditioner, display speed, time, ETA, etc. Also see diagnostic computer fuel computer on-board computer spark control computer trip computer computer-aided: Something which has been helped or designed by a computer.

computer brake control: See anti-skid.

computer command control: (CCC) an electronically-controlled fuel metering system used on GM vehicle. Uses an oxygen sensor, a throttle position sensor and other information sensors to provide a computer with the data it needs to alter the air/fuel ratio via mixture control solenoid in the carburetor

computer command control system: (C-3) an earlier engine management system used on GM vehicles. (C-4) A later engine management system used on GM vehicles

computer-controlled: Something which is monitored by a computer

computer controlled coil ignition:

(C3I) GM's computerized ignition coil system, used on many different engine applications

computer controlled timing: (CCT) a system that feeds input from various engine sensors into a computer. The computer then matches spark timing exactly to engine requirements throughout its full range of operations

con: See forked con rod master con rod concave weld face: A weld having the center of its face below the weld edges

concealed headlamps: Headlamp doors close to resent a flush fitting sheet metal to reduce air resistance in headlamp area

concealed headlights: Headlight which (when not lit) are hidden behind a panel. When the headlight switch is turned on vacuum is applied to a controller which opens the panel exposing the light. Also called "hide-away headlights" or "pop-up headlights."

concentration: See stress concentration

concentric: Two or more circles so placed as to share a common center but different diameters.

concept car: A vehicle that is not currently in production, but is still in the design stage. Some are merely paper drawings, but others are clay mock-ups. The ideas in the concept cars sometimes appears in production models. Also see prototype

concept vehicle: a current production vehicle modified for installation of new design concepts for evaluation of environmental functional feasibility.

concho: A chrome trim disk for saddlebags and leathers.

concours: Also called "concours d'elegance." This is the term used to describe a show where cars in superb condition are judged against a standard of excellence established by the sponsors, with awards given to winners. Show cars compete in a concours.

concours d'elegance: See concours.

cond: Abbreviation for "condition," as in excellent cond.

condensate: See cold-condensate corrosion

condensate corrosion: See cold-condensate corrosion

condensation: Moisture, from the air, deposited on a cool surface. The reverse of evaporation.

condense: Turning a vapor back into a liquid.

condenser: [1] A small metal cylinder which is usually located in the distributor. It is installed between the breaker points and coil to prevent arcing at the breaker points by absorbing or storing the excess current. A condenser (also called a "capacitor") has the ability to absorb and retain surges of electricity. It is constructed of two metal plates separated by an insulator. [2] The unit in an air conditioning system that cools the hot compressed refrigerant and turns it from a vapor into a liquid. It is the opposite of an evaporator.

Also see steam engine condition: See air conditioner battery charge battery condition cherry condition conditioner mint condition original condition spark plug condition conditioned: See air-conditioned

conditioner: See air conditioner.

conditioning: See air-conditioning

conditions: See driving conditions

conductance: A measure of the ease with which a conductor allows electron flow. In DC circuits, conductance is the reciprocal of resistance

conduction: The transfer of heat from one object to another by having the objects in physical contact. Also see thermal conduction conductive:

The ability of something to conduct electricity.

conductivity: The ability of something to conduct electricity. Opposite of resistivity. Also see electrical conductivity heat conductivity conductor: A material forming a path for the flow of current, such as silver, copper, and carbon. Also see semiconductor cone: [1] A bearing race that curves to the inside of a circle of ball bearings and works in conjunction with a cup. [2] In welding, it is the inner visible flame shape of a neutral or near neutral flame. Also see bearing cone inner cone cone clutch: A clutch using a cone-shaped member that is forced into a cone-shaped depression in the flywheel, or other driving unit, thus locking the two together, although no longer used on cars, the cone clutch finds some applications in small riding tractors, heavy power mowers, etc.

configuration: The particular arrangement of the parts in relation to each other. Also see chassis configuration delta configuration mid-engine chassis configuration Y-configuration conformation: The ability of a precision insert bearing to match the shape and contour of a shaft surface even after it has been in use for some time.

conical:

something in the shape of a cone. It is usually tapered.

conical seat: A circular, tapered place that something rests. For instance, a spark plug may fit into a tapered hole.

connecting rod: The connecting link or arm between the piston and the crankshaft. It converts the up-and-down (reciprocating) motion of the piston into the circular (rotary) motion of the spinning crankshaft. Often called "con rod." Also see big-end bearing boxed rod forked con rod master con rod slave con rod throwing a rod connecting rod bearing: A precision insert bearing. Also called "big end bearing"

connecting rod shank: A longitudinal part of the connecting rod

connection: the joining of two or more parts which generally conduct electricity. Also see axle connection earth connection ground connection rigid axle connection negative connections positive connections connections: See negative connections positive connections connector:

A device which joins two items. Also see adapter battery connector blade connector cell connector engine diagnostic connector eyelet connector helmet connector multicon connector system T-connector Y-connector connector system: See multicon connector system

con rod: See connecting rod.

con rod bearing: See connecting rod bearing.

conscious: See environment-conscious

console: A small storage space or fascia between the two front seats in a car with bucket seats. Often it houses the shifter, some instruments, coffee holders, coin holders, etc. Also see brake console center console parking brake console seat rail console constantan: An alloy made of nickel and copper which is used in resistance wire and in thermocouplers.

constant depression:

See air-valve carburetor.

constant-depression: See air-valve carburetor.

constant idle system: An electronically-controlled air bypass around the throttle. Also called idle speed actuator or idle-speed stabilizer

constant mesh gearbox: A type of transmission in which all or most of the gears are always in mesh with one another, as opposed to a sliding-gear transmission, in which engagement is obtained by sliding some of the gears along a shaft into mesh. In a constant-mesh manual gearbox, gear ratios are selected by small clutches that connect the various gearsets to their shafts so that power is transmitted through them. Also see sliding mesh gearbox constant mesh gear: One of the gears that is always in mesh with another -- whether it is driving or not (i.e., just idling).

constant mesh gears: Gears that are always in mesh with each other -- whether it is driving or not (i.e., just idling).

constant vacuum: See air-valve carburetor.

constant-vacuum: See air-valve carburetor.

constant velocity joint: (CV joint) A type of universal joint so designed as to create a smooth transfer of torque from the driven shaft to the driving shaft without any fluctuations in the speed of the driven shaft. constant velocity universal joint:

See constant velocity joint.

constant voltage regulator: (CVR) a device used to maintain a constant voltage level in a circuit, despite fluctuations in system voltage. CVRs are wired into some gauge circuits so voltage fluctuations won't affect accuracy of the gauge readings

constant volume sampling: See constant-volume sampling.

constant-volume sampling: An exhaust-emissions measuring technique in which the exhaust gases produced by a vehicle's engine are collected as it is driven through a test sequence of accelerations, decelerations, and cruise modes on a chassis dynamometer. A quantity of air is added to the exhaust gases until a specific volume (the same for all cars) is obtained. Concentrations of pollutants in the total sample are then analyzed for determination of their actual mass.

construction: See body and frame construction body construction coachbuilt construction frameless construction integral body and frame construction monobloc construction palletized construction sandwich construction skeleton construction unibody construction unitary construction unitized construction consumer factors: demographic characteristics of consumers including age, gender, income and geographic location, affordability.

consumption: The act of using up an amount of fuel. Actually the fuel is joined with air and merely changed into other substances (Carbon Dioxide, Carbon Monoxide, etc. and energy).

Also see fuel consumption indicator fuel consumption oil consumption specific fuel consumption consumption indicator: See fuel consumption indicator

contact: [1] The touching of two or more parts. [2] The parts that actually touch each other when making electrical connection whether permanently or intermittently. Also see fixed contact ground contact area moving contact sliding contacts contact area: The part of the tire that actually touches the ground at any particular moment. Also see ground contact area tire contact area contact arm: The movable segment of the points which is moved by the lobe of the distributor.

contact bounce: The rapid movement of the breaker arm as it opens and closes

contact breaker: See breaker points.

contact breaker gap: The distance between the contact points at their furthest opening.

contact breaker plate:

The plate on which the breaker points are mounted. When adjusting the points, the plate and the points are moved apart in relation to each other.

contact breaker point: The individual contact of the breaker points.

contact cement: See cement.

contact chatter: The rapid movement of the breaker arm as it opens and closes

contact controlled electronic ignition: See electronic ignition system.

contact gap: See point gap.

contactless electronic ignition: See breakerless transistorized ignition

contactless ignition: See breakerless.

contact patch: The area of a tire's tread that touches the ground.

contact pattern: The visible wear pattern created by two parts which touch each other

contact point: See contact points.

contact points: Two movable points or areas that when pressed together, complete a circuit. These points are usually made of tungsten, platinum, or silver.

Also see breaker points contact set: Replacement parts consisting of breaker points and possibly breaker plate and condenser.

contact spring: A spring which pushes on a contact which holds something in place and maintains contact.

contact zone: See tire contact zone

container: A strong steel box of standard dimensions of 8 feet square and length of 20 feet or 40 feet, in which cargo is preloaded. Also see catalyst container reefer container containerization: A shipping system where cargo is loaded into a large container at the factory and shipped from truck to train to ship, etc. without rehandling of contents within the container.

container ship: A ship designed to carry containers as cargo.

contamination: See catalyst contamination

contaminant: Some impurity in gasoline or oil or anything else.

content:

See blood alcohol content

Continental: A vehicle brand of Ford cars of which the 1956-57 Mark II Click for books on models are milestone cars. Continental Also see Lincoln Continental continental tire: The bulge in the rear portion of the trunk which resembles a tire or a rear mounted tire Continental-type fuse: A ceramic fuse with conical end caps. They are color coded for different values.

Continuous AC Ignition System: Abbreviated CACIS. An ignition system where a high-energy alternating current arc burns for the entire power stroke. In this system, the spark plugs don't erode as quickly and the air/fuel mixture is more completely burned. Thus there is no need for a catalytic converter.

continuous injection system: (CIS) A mechanical fuel injection system designed and manufactured by Bosch, used on many German vehicles. In a CIS system, the fuel injectors are always open (i.e., they emit a continuous spray of fuel into the intake ports). The amount of fuel sprayed is determined by the fuel pressure in the system, which in turn is determined by the position of the throttle. Also see K-jetronic continuously variable transmission: Abbreviated CVT. See infinitely variable transmission.

continuous weld: Completing a weld in one operation

Conti tire system: Abbreviated CTS. A run flat tire and wheel combination which allows the tire to be run for up to 400 km (250 miles) at a speed of up to 80 kph (50 mph)

contour: See buff contour panel contour

contract carrier: A shipping company which is transporting goods because of a contract with another shipping company.

contracting-band brake: A brake in which a band is tightened around a rotating drum

contraction: A thermal action where the size (mass or dimension) of an object is reduced when cooled; the opposite of expansion.

contre: See outboard contre pente

contre pente: Abbreviated CP. A French designed wheel where the raised portion of one of the rim bead seat is designed to hold the tire bead of a nearly flat tire without breaking the bead (i.e., becoming unseated). Also see outboard contre pente contre pente on both bead seats: Abbreviated CP2. A safety rim contour with a contre pente on both rim bead seats

control: [1] A device or mechanism for adjusting a component. See cruise control. [2] The ability of the driver to make a vehicle perform as required. [3] To regulate. Also see air control

automatic frequency control automatic level control automatic speed control automatic temperature control automatic volume control balance control choke control clearance control climate control computer brake control corrosion control cruise control digital frequency control dimmer control dwell-angle control electric air control valve electronic control module electronic control unit electronic engine control electronic ride control electronic spark control electronic traction control electronic transmission control emission control engine control system evaporation control system evaporative emission control system exhaust emission control feedback control finance and control flow control ground clearance control headlight leveling control heat control valve height hamper pitch control hydraulic control block ignition control unit illumination control inflation control seam infrared remote control intermittent wiper control IR remote control knock control level control limit cycle control low-speed traction control

low speed traction control manifold heat control valve mirror control mixture control knob mixture control screw mixture control unit multi-function control stalk oil control ring overrun control valve piston ring, oil control remote control running-on control valve speed control temperature control vacuum control vacuum ignition-timing control vacuum timing control control arm: A metal strut on the suspension which is located at the top and bottom of the wheel spindle. The upper and lower control arms allow the front wheels to change direction. Also called a "wishbone" or "A-arm." Also see suspension system track control arm control arms: See control arm.

control block: See hydraulic control block

control box: A container which houses electrical components which regulate the action of something.

control cable: A wire cable which runs from a knob or lever to a device which operates or regulates. Also called a "control wire." Also see starter switch control cable

control computer: See spark control computer

contrôle: A checkpoint where randonneur bicycle riders must stop to have their route cards signed and stamped to prove they have kept to the course within the time limits.

control element: See temperature control element

control head: The dashboard mounted assembly which houses the mode selector, the blower switch and the temperature control lever of the heating, air conditioner, and ventilation system

Control Information: See Vehicle Emission Control Information

control knob: See mixture control knob

controlled burn rate: See CBR process

controlled canister purge: (CCP) ECM-controlled solenoid valve that permits manifold vacuum to purge the evaporative emissions from the charcoal canister

controlled combustion system: An emission control term used by General Motors to include the following: • • • • • • •

modified combustion chamber design high-temperature coolant systems thermostatically controlled air cleaners very lean air/fuel mixtures high idle speeds severely retarded ignition timing TCS (transmission controlled spark) and TVS (thermal vacuum switch)

controlled electronic: See magnetically controlled electronic ignition

controlled electronic ignition: See contact controlled electronic ignition magnetically controlled electronic ignition capacitor controlled electronic ignition controlled intersection: A road junction which is controlled by traffic lights (signal lights)

controlled spark: See transmission controlled spark

controlled vehicle: A vehicle with a reduced emission system consisting of a catalytic converter, EGR, air injection, fuel evaporative emission control, etc. Also called a "detoxed vehicle."

controller: See battery discharge controller solid state controller control link: See toe control link

control module: See electronic control module transmission control module control orifice valve: See oil control orifice valve

control plunger: [1] A device in a fuel injection system which moves up and down to provide the correct amount of fuel to each cylinder. [2] One of several names for a solid state device which monitors engine conditions and controls certain engine functions, i.e., fuel injection, ignition timing, glow plug system in a diesels engine, etc

control pressure: [1] The pressure in a fuel injection system. [2] the pressure coming from line pressure or throttle pressure in the automatic transmission which pushes on the command valves. [3] In a Bosch CIS, the pressurized fuel used as a hydraulic control fluid to apply a counterforce to the control plunger in Bosch CIS. Control pressure alters the air-fuel ratio through the operation of the control-pressure regulator

control ring: See oil control ring.

controls: See dual controls emission controls exhaust emission controls instruments and controls steering column controls control screw: See mixture control screw volume control screw control seam: See inflation control seam

control stalk: A shaft which projects from the steering column just below the steering wheel. It may control lights, cruise control, wipers, windshield washer, signal lights, horn, etc. Also see multi-function control stalk

control switch: See vacuum control switch

control system: See active noise control system anti-spin regulation traction control system engine control system evaporation control system evaporative emission control system exhaust emission control system traction control system transmission control system control unit: See electronic control unit ignition control unit mixture control unit vacuum control unit warm-up control unit control vacuum advance: See speed control vacuum advance

control valve: A valve which regulates or operates a system, especially a hydraulic or vacuum control system. Also see air control valve boost control valve electric air control valve heat control valve manifold heat control valve oil control orifice valve overrun control valve running-on control valve control valve assembly: A casting located in the sump of the automatic transmission. It contains most of the valves for the hydraulic control system.

control wire: A wire cable which runs from a knob or lever to a device which operates or regulates. Also called a "control cable."

controlled combustion system: (CCS) A system of reducing unburned hydrocarbon emission from the engine exhaust.

conv: Abbreviation for "convertible."

convection: The transfer of heat from one object to another when the hotter object heats the surrounding air and the air in turn heats the other object. Also see thermal convection conventional oxidation catalyst: (COC) a catalyst which acts on the two major pollutants: HC and CO

convenience: See flags of convenience

conventional cross ply: A tire having two or more carcass plies arranged in a criss-cross manner and diagonally to the beads and travels approximately 1/3 the distance around the circumference before attaching to the other bead. Each cord in the next ply is arranged in the same manner, but in the opposite direction.

conventional ignition: The transfer of heat from one object to another when the hotter object heats the surrounding air and the air in turn heats the other object.

conventional ignition system: An ignition system consisting of the battery, ignition switch, ballast resistor, ignition coil, distributor, contact breaker points, condenser, centrifugal or vacuum advance unit, spark plugs, and high tension wires.

conventional spare tire: A spare tire & rim which is the same size as the other four wheels. Most cars do not have them because they take up too much space in the trunk.

conventional theory: The direction of current flow was arbitrarily chosen to be from the positive terminal of the voltage source, through the external circuit, then back to the negative terminal of the source

conventional tire: A bias ply tire.

conversion: [1] The change from one state to another, e.g., harmful gases into harmless gases. [2] altered state of a particular system, or set of parts needed to achieve it. Also see manual choke conversion energy conversion tractive conversion conversion coating: A coating of some metal which uses the same kind of metal in the coating compound and improves paint adhesion and corrosion resistance

conversion rate: The rate at which a given catalytic converter purifies the exhaust gas stream, governed by various parameters such as operating conditions and converter design

converter: [1] When used with LPG (propane), it is a device which turns LPG (propane) from liquid to vapor for use in the engine. [2] Referring to a transmission it is the device that transfers engine torque to the transmission. Also see catalytic converter dual-bed catalytic converter hydrodynamic torque converter lock-up torque converter

lockup torque converter mini catalytic converter monolithic converter open-loop catalytic converter oxidizing converter pellet-type catalytic converter primary catalytic converter rust converter single-bed 3-way catalytic converter single-bed oxidizing converter three-way catalytic converter three way catalytic converter torque converter two-way catalytic converter converter case: An assembly in the automatic transmission encasing the impeller with the converter cover welded to it. It contains the converter fluid and vane wheels and connected to the crankshaft by means of the drive plate and revolving at engine speed.

converter, catalytic: See catalytic converter three-way catalytic converter converter cover: A part in the automatic transmission that is welded to the pump and makes up the converter case

converter drive plate: See torque converter drive plate

converter housing: [1] A stationary outer part of the automatic transmission which encloses the converter case. Also see torque converter housing [2] The housing of a catalytic converter. Also called "converter shell."

converter lock-up clutch:

See torque converter lock-up clutch

converter preheating: An emission control device which increases catalytic action in cold starts when HC and CO are their highest. Although not in use in current cars, it may become necessary in the future. Thus it may mean the following: Take longer to start a vehicle in the morning, require a larger battery, necessitate plugging a vehicle into household circuit, need for frequent replacement of the catalytic converter. Also see preheating converter shell: See the second definition of converter housing

convertible: Generally this is a two-door automobile without a fixed roof. Instead, the roof folds up or is removed in some way so that the passenger compartment is exposed to the open air. Some roofs are made of flexible fabric or plastic which folds up behind the passenger compartment. Other roofs are not flexible and retract into the trunk. Some retract automatically while others must be manually removed and placed in the trunk. The term was introduced in the 1930s. In the 1950s, a hardtop convertible was introduced to look like a convertible with its top up; but its fixed roof did not fold or retract. It was also called a "drophead coupé" or "open car." Also see hardtop convertible convertible sedan: This is similar to the sedan body type, but with provisions of lowering both the allweather side windows and the fabric top to create a four-door convertible.

convertible top: The soft foldable canvas or vinyl top of a convertible. It usually has a clear plastic rear window.

convex weld: A weld with the face above the eld edges

coolant: Liquid in the cooling system. Usually a mixture of water and antifreeze (ethylene glycol). This mixture lowers the freezing point of the water in the cooling system,

prevents rust and corrosion, lubricates the water pump, and picks up heat from the engine and transfers it to the air passing through the radiator. Also see engine coolant coolant controlled exhaust gas recirculation: (CCEGR) a system that prevents exhaust gas recirculation until engine coolant temperature reaches a specific value

coolant level warning light: A small light on the dash which is illuminated when the radiator is low on coolant

coolant pump: See water pump

coolant recovery system: A small bottle that acts as a reservoir for liquid expelled from the cooling system through the overflow pipe and returns the liquid to the system when it cools down. A special radiator pressure cap is also part of the kit. It is also called a "Closed Cooling System" when it is part of the original equipment.

coolant temperature override switch: CTO A switch that prevents vacuum from reaching a component until coolant temperature reaches a certain value

coolant temperature sensor: A sensor located at the bottom of the radiator which is connected to the temperature gauge.

cooled: See air-cooled air cooled liquid-cooled water-cooled cooled engine:

See air cooled engine

cooled valve: See sodium cooled valve

cooler: A device for cooling hot liquid or air by passing air through the vanes of a heat sink. Also see aftercooler oil cooler cooler bypass: See oil cooler bypass valve

cooler bypass valve: See oil cooler bypass valve

cooling: See charge air cooling fan cooling flushing the cooling system intercooling thermosyphon cooling cooling fan: [1] A large fan designed to suck relatively cool air and force it onto a warm object like an engine. [2] A large fan designed to pull away the radiant warm air surrounding a hot object.

cooling fins: The greater the surface area that needs to be cooled, the better you will be able to cool off a hot object, like an engine. By putting a number of fins on a surface, you increase the overall area. On air cooled engines, for instance, you will see a series of closely formed ridges or fins in parallel. As the air passes by them, the engine heat is dissipated.

cooling jacket:

See water jacket

cooling system: The system that removes heat from the engine. In a water-cooled engine it includes radiator, pressure cap, fan, water pump, thermostat, water jackets; in an air-cooled engine it consists of a fan, cooling fins, and ducting. Also see closed cooling system flushing the cooling system water cooling system copolymer: A polymer produced from two different monomers. Also see graft copolymer copper core: The center electrode of a spark plug or the center wires of a high tension wire which is made of copper.

copper-faced hammer: A hammer with a round head made of copper or brass. It is used to hit objects without damaging them where hitting them with a steel hammer might.

copper plating: The application of a thin layer of copper by a process of electrolysis. Primarily it is done to electrical contacts and terminals to give excellent conduction of electricity.

Cord: [1] A vehicle brand of which the 1925-1948 model cars are classic cars. [2] A strand of fabric or steel cable used in the ply of a tire. [3] A rope. Also see bungee cord cordura: The brand name for a heavy-duty, synthetic material made by DuPont that feels like canvas. It is often used in the manufacture of lightweight clothing, backpacks, and camping gear.

core: [1] When referring to casting -- a sand unit placed inside of a mold so that when the metal is poured, the core will leave a hollow shape. [2] The magnetic center of a coil usually made of iron. [3] The primary part (engine block, alternator, starter, radiator, etc.) which has malfunctioned, but is still suitable for rebuilding or remanufacturing. You can exchange it for a new or rebuilt part. Thus, instead of paying full price for a new alternator, you can submit your old alternator as a core and pay a lower amount for the new alternator. "CORE" is an acronym for "cash on return." Also see bead core copper core laminated iron core timer core valve core core charge: The word "core" is short for "cash on return." When you purchase a part which is rebuildable, you can return your old part and receive a core charge. Generally a core charge is collected for engines, crankshafts, alternators, radiators, brake shoes. If the part is beyond repair, there may be no core charge.

core hole plug: See core plug freeze plug core hole plugs: See core plug.

core/insulator: See projected core/insulator nose

core/insulator nose: See projected core/insulator nose

core leads:

See carbon-core leads

core plug: A metal plug located in the sides of the engine block which can pop out because of excessive pressure or freezing and prevent the engine block from cracking. These plugs are located in the water jacket and can sometimes leak and should then be replaced. Block heaters are installed by removing a core plug and inserting a heating element. Core plugs are also called "freeze plugs" or "expansion plugs."

core plugs: See core plug.

core support: The framework that supports the radiator and air conditioner condenser assembly and also serves as the attaching point for the front fenders, grille assembly, hood latch, etc.

corncob: A bicycle term used to describe a cluster of cogs on a racing freewheel because of the small variation in number of teeth on adjacent cogs.

corner: See inside corner weld outside corner weld rear corner valance rear corner panel cornering: The negotiation of a curve, bend, or corner of a road. Good cornering ability allows the vehicle to go around a curve at a reasonable speed without body roll and breakaway.

cornering force: The forces exerted on a tire by the slip angle when moving around a curve. Also see ultimate cornering force cornering limit:

The maximum speed that a vehicle can travel around a particular curve.

cornering speed: The speed that a vehicle makes when turning. It is relative to the sharpness of the curve and the ability of the vehicle to stay on the road under control.

corner joint: A junction formed by edges of two pieces of metal touching each other at an angle of about 90°

corner panel: A panel used to fill a gap between larger panels or frame members meeting at an angle and to serve as a stiffener, such as those at the intersection of sidemembers and crossmembers and the rear corner panels of rear fenders. Also see rear corner panel windshield corner panel corners: See across corners

corner steady: A British term for a jack stand used to support and level the corner of a parked travel trailer.

corner valance: See rear corner valance

corner weld: See inside corner weld outside corner weld Corolla: A model of automobile manufactured by Toyota

Corona:

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A model of automobile manufactured by Toyota

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corporate Average Fuel Economy: (CAFE) Regulation enacted in 1975 which requires a motor vehicle manufacturer to classify its U.S. vehicle fleet sales as either domestic or import for the purpose of fuel economy averaging.

corporation: Business association endowed by law with the rights and liabilities of an individual

correction jet: See air correction jet

corrector: See height corrector

corrode: To eat away, gradually, the surface material from an object by chemical action, such as rust.

corrosion: The chemical process in which a metal is eaten away (i.e., rusting). Also see anti-corrosion atmospheric corrosion bimetallic corrosion cold-condensate corrosion electrochemical corrosion electrolytic corrosion fretting corrosion galvanic corrosion general corrosion graphitic corrosion intercrystalline corrosion intergranular corrosion localized corrosion microbial corrosion oxygen corrosion pitting corrosion scab corrosion

selective corrosion underfilm corrosion uniform corrosion corrosion control: The minimizing of corrosion by coating with a protective metal, an oxide, or similar substance, or with protective paint, or by making the metal passive.

corrosion cracking: See stress corrosion cracking

corrosion inhibitor: A substance which reduces or prevents corrosion in oils, anti-freeze, paints, etc.

corrosion prevention: The minimizing of corrosion by coating with a protective metal, an oxide, or similar substance, or with protective paint, or by making the metal passive.

corrosion product: A substance formed as a result of corrosion (i.e., the rust itself)

corrosion protection: The minimizing of corrosion by coating with a protective metal, an oxide, or similar substance, or with protective paint, or by making the metal passive.

corrosion resistance: The ability of metal not to corrode. For example, nickel has a high corrosion resistance while iron does not.

corrosion warranty: See anti-corrosion warranty

corrosive: Causing corrosion, e.g., acid is corrosive because it eats away the substance on which it is applied. That's why acid rain is so harmful to the surface of automobiles. Also see anti-corrosive

Ford Cortina: A model of automobile manufactured by Ford of England

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Corvair: A vehicle brand of which the 1960-64 Monza models are milestone cars. The 1962-64 Monza Spyder models are milestone cars. The 1965-69 Monza/Corsa models are milestone cars.

Corvette: A vehicle brand of which the 1953-70 models are milestone cars. See also a history of the Corvette

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cost: The price that a shop charges for a vehicle or one of its components. To the shop, it is the price they pay for the component (i.e., the net price) to which they add an amount or percentage to arrive at the selling price. Also see cap cost capitalized cost net cap cost net capitalized cost opportunity cost total Out-Of-Pocket Cost operating costs cost-effective: worthwhile. Usually a determination of whether repairing a vehicle is worth the expense in comparison with junking or selling it in favor of purchasing a newer vehicle. If you spend a $1000 to repair a vehicle worth $20,000, that is cost effective. If you spend a $1000 to repair a vehicle worth $200, it probably is not. The exception would be a vehicle which has nostalgic or historic value.

cost of production: actual cost to the manufacturer of producing a vehicle (does not include mark-up).

cost option: An optional item for a new vehicle for which extra money must be paid to obtain it.

cost per kilometer: A ratio which is obtained by dividing the total cost of the tire by the distance the tire has gone. The total cost involves adding up the initial price of the tire, price of retreading, repairs, rotation of tires, balancing tires, and other services. From this total any credits such as warranty, rebates, and trade-in value is subtracted. It must be remembered that when calculating the cost per kilometer of summer tires if winter tires were installed for a few months that only the number of kilometers that the summer tires were actually in use should be determined for this ratio. When purchasing tires, it may be helpful to divide the retail cost by the number of expected kilometers in order to compare one brand or one series against another.

cost per mile: A ratio which is obtained by dividing the total cost of the tire by the distance the tire has gone. The total cost involves adding up the initial price of the tire, price of retreading, repairs, rotation of tires, balancing tires, and other services. From this total any credits such as warranty, rebates, and trade-in value is subtracted. It must be remembered that when calculating the cost per mile of summer tires if winter tires were installed for a few months that only the number of miles that the summer tires were actually in use should be determined for this ratio. When purchasing tires, it may be helpful to divide the retail cost by the number of expected miles in order to compare one brand or one series against another.

cost reduction: See cap cost reduction capitalized cost reduction cost reduction effort: See supplier cost reduction effort

Cotal gearbox: A semi-automatic electrically controlled transmission made in France just after WWII

cotter: A tapered pin or wedge which is inserted into holes in two parts to secure them. Older bicycles used a cotter to secure the crank arm to the crank spindle. Also see cottered crank cotter pin:

A fastener shaped like a pin, but split up the center. After it is inserted, the legs are bent around the item containing the hole. A length of wire which is folded almost in half and the bend forms an eye. Also called a "split pin."

cottered crank: A bicycle crankset in which the crankarms are fastened to the axle by means of threaded cotter pins and nuts.

cotterless crank: A bicycle crankset in which the crankarms are fastened to the axle by means of nuts or bolts instead of cotter pins.

cotterless crankset: A bicycle crankset in which the crankarms are fastened to the axle by means of nuts or bolts instead of cotter pins.

coulomb: Abbreviated: C. A unit of electric charge. It is the amount of electricity conveyed in one second by a current of one ampere.

Council for Automotive Research: See United States Council for Automotive Research

counter: See rev counter revolution counter trip mileage counter counter balance: A weight attached to some moving part so that the part will be in balance. Also see crankshaft counter-balance counterbore: Enlarging a hole to a certain depth.

counterclockwise:

Rotation to the left as if the hands of a clock were going backwards. In most cases it is the direction to remove a nut from a bolt. It is the opposite to clockwise.

counterforce: In Bosch CIS, the force of the fuel-pressure applied to the top of the control plunger to balance the force of the airflow pushing against the sensor plate

counter gear: See cluster gear.

countershaft: The shaft in a manual gearbox that carries power by means of gears from the clutch shaft to the driveshaft, turning opposite to them. The British term is "layshaft"

countersink: To make a counterbore so that the head of a screw may set flush, or below the surface.

countersunk bolt: A bolt with a special head. The underside of the head is tapered to fit into a hole that has tapered sides (countersunk hole) so that when the bolt is screwed in all the way, the top of the bolt is flush with the surface

countersunk hole: A hole with sloping sides where the top of the hole is larger than the bottom of the hole as in the shape of the letter "V"

countersunk screw: A screw with a special head. The underside of the head is tapered to fit into a hole that has tapered sides (countersunk hole) so that when the screw is screwed in all the way, the top of the screw is flush with the surface

counterweight: [1] Weight added to a rotating shaft or wheel to balance normal loads on the part and offset vibration. Counterweights are used on the crankshaft and are often found on the flywheel and driveshaft. [2] A balance weight

coupe: An enclosed single-compartment body with two doors and varying passenger capacity depending on seat arrangements. The SAE standard J1100 defines it as having less than 33 cubic feet (934 liters) of interior volume. Larger coupes have rear quarter windows. Coupes have fixed permanent back panels and top, as well as a luggage compartment in the rear deck. Originally it meant a vehicle which was "cut" (thus the French "coupé") by a glass partition behind the front seats so that the driver was exposed to the air while those in the back were enclosed. Also see club coupe drophead coupé hatchback coupe sport coupe three-door hatchback coupe two-door club coupe two-door coupe two-door hatchback coupe coupé: See coupe

coupled sedan: See close coupled sedan

coupler: A device which links two other components.

coupling: A connecting device used between two objects so motion of one will be imparted to the other; it may be mechanical, hydraulic, or electrical. Also see doughnut coupling föttinger coupling flexible coupling fluid coupling foettinger coupling guibo coupling layrub coupling rotoflex coupling rubber coupling rubber doughnut coupling

shaft-to-cage coupling shaft-to-shaft coupling viscous coupling coupling differential: See viscous coupling differential

coupling point: This refers to the point at which both the pump and the turbine in a torque converter are travelling at the same speed, the drive is almost direct at this point.

coupling sleeve: A collar or sleeve which is moved along the main shaft of a transmission by a selector fork engaging in a groove on its center and having dog clutches at either end.

courier bag: A flat rectangular-shaped bag with a long strap. They are slung over the head and one shoulder. Called a courier bag because they were originally made for motorcycle and bicycle couriers.

course: See road course

courtesy light: A light in the cab of a vehicle which is illuminated when the door is opened.

cover: [1] A protective panel designed to protect or hide components. Also see arm cover battery cover car cover clutch cover converter cover dust cover end cover end cover plate engine cover

headlight cover nut cover rocker arm cover rocker cover gasket rocker cover sill cover tonneau cover transfer port cover transmission cover valve cover wheel cover [2] The tire itself as opposed to the inner tube.

coverage: The surface area that a given quantity of paint will cover adequately

covered electrode: A metal rod used in arc welding which has a covering of materials to aid in the arc welding process

cover gasket: See rocker cover gasket valve cover gasket cover plate: See end cover plate

cowl: [1] The part of the vehicle body between the engine firewall and the front of the dash panel. It usually houses the instruments and the plenum chamber for the heater-ventilation system. The British term is "scuttle." [2] The part of the bodywork which protects and/or provides streamlining for a usually projecting component.

cowl chassis: A truck chassis with front fenders and hood as well as the instrument panel. It is used for companies want their own custom body and cab.

cowling: The part of the bodywork which protects and/or provides streamlining for a usually projecting component.

cowl panel: A British term for cowl

cowl section: A subassembly of the body shell that includes the bulkhead, cowl, and windscreen pillars; it is preassembled in the factory and spot-welded with the other subassemblies to form the body shell

cowl shake: This is a vibration or shake of a vehicle, usually a convertible type, in the cowl area due to lack of torsional rigidity of the frame and body. A certain amount is almost unavoidable in convertibles unless frame-strengthening weight penalties are of no concern.

cowl side panel: A vertical panel at either end of the cowl

CP: Acronym for contre pente

CP2: Acronym for contre pente on both bead seats

cpe: Abbreviation for "coupe."

C pillar: See C-post.

C-pillar: The body post that supports the rear of the roof and to which the left and right sides of the back glass are attached. Also called "C-post."

C post: See C-post.

C-post: The body post that supports the rear of the roof and to which the left and right sides of the back glass are attached. Also called "C-pillar."

CPSOV: Acronym for canister purge shut-off valve

CR: Acronym for "compression ratio."

crab: The action of a vehicle where the rear wheels are offset from the track of the front wheels.

crab-tracked: A situation where the front wheels are wider apart than the rear.

crack: [1] To open something just a little. [2] A fracture in something which does not split it open. A hairline crack is a very narrow fracture which is often barely visible with the naked eye. Also see circumferential crack groove cracks incipient crack cracker: A non-American colloquial term for something that is very enjoyable, e.g., "My car's a cracker." Also see nut cracker cracking: [1] The action of opening a valve slightly and then closing the valve immediately. [2] forming of cracks for instance in the sidewalls of a tire because of the hardening of the rubber or in paintwork because of weathering.

Also see heat cracking radial cracking stress corrosion cracking stress cracking weather cracking cracking groove: A split in the grooves of the tread caused by excessive strain.

cracking tread: A split in the grooves of the tread caused by excessive strain.

cradle frame: A motorcycle frame with two tubes passing under the engine. Also see open cradle frame crank: [1] An arm set at right angles to a shaft or axle, used for converting reciprocal (toand-fro) motion into circular motion. Also see cottered crank cotterless crank flat crank hand crank [2] The action of trying to start a vehicle engine or an electrical motor by means of a crank handle or by an electrical starter.

crankarm: [1] A part, one end of which is attached to the bottom bracket axle and the other holds a pedal, whose forward rotation provides the leverage needed to power the bicycle. [2] An arm set at right angles to a shaft or axle, used for converting reciprocal (toand-fro) motion into circular motion.

crankarm fixing bolt: The bolt that holds a crankarm on the end of the axle in a cotterless crankset of a bicycle.

crankcase: The lower part of the engine that surrounds the crankshaft. It contains the crankshaft, piston cylinders, connecting rods and other moving parts of the engine. As well, in non-air-cooled engines, it has a number of internal passages for the coolant and oil transfer. In air-cooled engines, it has internal passages for oil transfer; but usually it has fins on the exterior to dissipate the heat. The crankcase is not to be confused with the pan which is a thin steel cover that is bolted to the bottom of the crankcase. Also see positive crankcase ventilation system positive crankcase ventilation crankcase breather: A vent which allows fumes and blow-by gases to escape. It reduces condensation. This breather is usually connected to the air intake of the carburetor so that the fumes can be burned in the combustion chamber

crankcase compression: The primary compression in a two-stroke engine located below the pistons and enables a more fresh charge to be fed into the cylinder. Also called "crankcase precompression."

crankcase depression regulator: (CDR) a device which aids in the control of crankcase gases by maintaining a specific amount of vacuum in the crankcase

crankcase dilution: An accumulation of unburned gasoline in the crankcase, an excessively rich fuel mixture or poor combustion will allow a certain amount of gasoline to pass down between the pistons and cylinder walls and dilute the engine oil.

crankcase emissions: Pollutants allowed to escape into the atmosphere from the crankcase

crankcase half: One side of a crankcase usually split down the middle. Usually found in motorcycle engine.

crankcase pre-compression: See crankcase compression

crankcase scavenging: A system in a two-stroke engine where the fresh charge is induced into the cylinder by way of the crankcase and the transfer ports

crankcase ventilation: circulation of air through the crankcase of a running engine to remove water, blowby, and other gases in order to prevent oil dilution and contamination, sludge formation, and pressure build-up. Also see closed crankcase ventilation positive crankcase ventilation positive crankcase ventilation system crankcase ventilation system: See positive crankcase ventilation system

cranked: something which has an elbow or right-angle shape.

cranking: The act of engaging the starter by turning the key in the ignition switch which makes the engine turn over. In the old days, a hand crank was used to do this, thus the term "cranking." Also see cold cranking ability cranking ability: See cold cranking ability

cranking amps: See cold cranking amps

cranking circuit: See starting system.

cranking motor: See starter.

cranking On The Throttle: The action of moving a twist grip so that more fuel enters the engine and thus increases the speed of the vehicle.

cranking speed: The speed at which the starter turns the engine.

crank kit: A reground or reconditioned crankshaft and new main and connecting rod bearings

crankpin: The bearing surface on a crank of the crankshaft to which the connecting rod is attached. Also called the "journal" or "crank throw." Also see splayed crankpins crankset: A group of components on a bicycle that includes the bottom bracket removable parts, two crankarms, and one or more chainrings. Also see cotterless crankset crankshaft: A main rotating shaft running the length of the engine. The crankshaft is supported by main bearings. Portions of the shaft are offset to form throws to which the connecting rods are attached. As the pistons move up and down, the connecting rods move the crankshaft around. The turning motion of the crankshaft is transmitted to the transmission and eventually to the driving wheels. Also see assembled crankshaft balanced crankshaft built-up crankshaft offset crankshaft stroked crankshaft

crankshaft counter-balance: A series of weights attached to or forged integrally with the crankshaft so placed as to offset the reciprocating weight of each piston and rod assembly crankshaft counterbalance: Series of weights attached to or forged integrally with crankshaft & placed to offset reciprocating weight of each piston and rod assembly

crankshaft gear: A gear mounted on the front of the crankshaft. It is used to drive the camshaft gear.

crankshaft journal: The journals running in the main bearings as opposed to those for the big-end bearings.

crankshaft position sensor: A sensor which sends information concerning the precise position of the crankshaft so that accurate ignition timing can be achieved.

crankshaft pulley: A wheel attached to the front end of the crankshaft which is connected by fan belts to the fan, the alternator, and other devices so that the rotating crankshaft can drive these other parts as well. The crankshaft pulley usually has timing marks located on it, and these are necessary for checking and adjusting timing with a timing light. Also called a "harmonic balance wheel."

crankshaft runout: A term used to describe how much a crankshaft is bent

crankshaft sprocket: A chain-sprocket mounted on the nose of the crankshaft which drives the camshaft by means of a timing chain

crank throw: [1] The part of the crankshaft that the connecting rod fastens to. See crankpin. [2] The distance between the crankpin and the axis of rotation or centerline of the crankshaft, which is equal to half the stroke

crank web:

One of the pair of arms which carry the big-end journal

crash: A vehicle collision with another vehicle or a stationary object. Also see car crash frontal crash head-on crash oblique crash test crash barrier: A longitudinal railing usually found on the edge of the road especially around a curve to help prevent vehicles from leaving the road.

crash box: An informal term for a non-synchromesh transmission. Short term for "crash gearbox."

crash gearbox: An informal term for a non-synchromesh transmission.

crash recorder: An electronic device which measures and records a number of characteristics of a vehicle for 60 seconds before a crash: the speed, direction, braking, etc. so that the cause of a crash can be determined.

crash sensor: A sensor which deploys an air bag when a crash is determined -- usually because of excessive deceleration

crash test: A controlled test of a vehicle in which it is propelled into a wall or another vehicle at a given speed in order to determine the effect on its structure and the effectiveness of its safety devices. Also see oblique crash test crash test dummy:

A specially designed manikin which records the effects in the event of a crash

crate: [1] A framework of wooden boards for protecting something during transport. [2] A vehicle which appears to be unreliable and ready to fall apart.

crater: A depression in the face of a weld, usually at the termination of an arc weld

cratering: The formation of holes in the paint coat due to surface contaminants.

crawler: A British term for a slow-moving vehicle

crawler gear: A British term for a very low gear used especially in off-road application

crawler lane: A British term for a truck lane for slow moving trucks, especially going up a hill.

crazing: Many fine cracks in the paint surface, resembling crow's feet. It is similar to checking, but more sever, where fine lines or cracks appear in the paint

cream: [1] To hit another vehicle. [2] A soft paste. Also see barrier cream crease: A wrinkle or ridge in metal as a result of design or accident damage.

creep:

[1] The tendency of a vehicle with automatic transmission to edge forward when idling when the transmission is in Drive and the brake is not engaged. Also called "idling drag." [2] When a crankshaft has slightly excessive runout (is slightly bent), it can sometimes be corrected by laying the crank in its saddles, installing the center main bearing cap (with its bearing insert) and leaving it for a day or two. Sometimes the crank will creep or bend enough to put it within the specified runout range

creepage: The slow spreading of rust under the paint which usually first appears as a blister and then flaking

creeper: A platform on four small caster wheels that allows you to move around easily while lying on your back under your vehicle. Also see mechanic's creeper crescent: The part between the inner and outer gears of an internal gear pump

crescent wrench: An adjustable wrench with smooth jaws.

Cressida: A model of automobile manufactured by Toyota

Click for books on Cressida

crest: The highest point of a screw thread. The opposite is called a "root." Also see thread crest crew cab: A pickup truck with a larger passenger compartment usually with four doors.

crimper tool: See wire stripper/crimper tool

crimping: The creation of corrugations in two thin metal parts as they are pressed tightly together in order to join them. This is often the method used to attach fittings to the end of an electrical wire -- thus avoiding the necessity of soldering

crimping pliers: A tool which looks like pliers with serrated jaws which are used to attach fittings to the end of an electrical wire.

crimping tool: A tool which looks like pliers with serrated jaws which are used to attach fittings to the end of an electrical wire.

critical speed: The top speed of an engine or shaft at which unwanted vibration begins.

crocodile clip: British term for alligator clip

Crosley: A vehicle brand of which the 1950-52 Hotshot/SS models are milestone cars.

crossbar: [1] any transverse bar, especially a tie rod across the chassis. [2] The top tube of a bicycle or motorcycle frame. [3] A short bar used to assist a combination wrench in providing extra torque. The British term is "Tommy bar"

cross-bolt: A system of securing the main bearing caps with four bolts per cap by which two bolts support the bearing cap from below, in the conventional manner, and two other bolts enter the bearing from the side, passing through the sides of the engine block. The cross-bolts are visible from the outside of the engine. This system of securing the main bearing caps ensures good side-to-side, as well as up-and-down rigidity

cross border shopping:

See Canadian cross border shopping

cross bracing: strengthening ribs or other members which connect two sides of a frame

cross coat: Paint spraying technique in which consecutive coats are sprayed at right angles to one another

cross-country vehicle: An off road vehicle

cross-draft carburetor: A sidedraft carburetor

cross-draught carburetor: A sidedraft carburetor

crossflow cylinder head: A cylinder head design (especially in an OHC engine) with the inlet manifold on one side and the exhaust manifold on the other side of the head, so that inlet and exhaust valves are arranged on opposite sides of the combustion chamber, giving a wider engine but better gas flow.

crossflow head: A cylinder head with the intake valves) on one side of the combustion chamber and the exhaust valve(s) on the other. Also called T-head

crossflow radiator: A radiator in which the water flows sideways instead of vertically, and which is therefore wider than it is high, permitting a lower hood line

cross hatch: See cross-hatch.

cross-hatch:

The desired checkerboard design of the inner surface of cylinder after it is honed.

cross-hatch coat: Checkerboard application of paint to be sure of a continuous paint film. One medium coat is usually followed by a second medium coat in a perpendicular direction.

cross-head screw: A screw with a slot which looks like an X or + into which the tip of the blade of a Phillips or Reed and Prince screwdriver can be inserted

cross-head screwdriver: A Phillips or Reed and Prince screwdriver where the tip forms an X or +

cross-jetting: Rejetting the carburetor jets from left-to-right to compensate for a left-to right variation in performance. These tests are usually conducted using an engine dynamometer

cross member: A brace or strut which provides structural stability for the sides of a frame -- often in the shape of an "X". Also see axle crossmember rear axle crossmember rubber-isolated crossmember crossover: See heat crossover.

crossover gearing: A bicycle gearing system whose shift sequence involves moving from the lowest to the midrange of gears on the smaller chainring, then crossing over to the larger chainring for the remainder of the gears.

cross ply: See conventional cross ply

cross-ply tire: See bias ply tire

cross-point screwdriver: A Phillips or Reed and Prince screwdriver where the tip forms an X or +

cross scavenging: Scavenging in a two-stroke engine with flow across the cylinder assisted by a wedge-shaped piston crown

cross section: A view of an object when cut transversely at right angles across its center. Also see section width cross-shaft: [1] Any transverse shaft. [2] The outgoing shaft of the steering gearbox, to which the pitman arm is connected. The British term is "rocker shaft"

cross-shaft lug wrench: See lug wrench.

cross-shaft lug wrench: See lug wrench.

cross shaft: The shaft in the steering gearbox that engages the steering shaft worm, the cross shaft is splined to the pitman arm.

cross-spoke wheel: Modern design of alloy wheel which imitates the appearance of the classical wire wheel

cross-threaded: The characteristic of a bolt or nut in which the bolt is inserted at an angle so that the original threads are damaged

cross three: A spoking pattern in which a spoke passes over two and under a third spoke before being attached to the rim.

crosswind: Wind blowing at the side of a vehicle

crotch rocket: See sportbike.

crowbar: A iron bar tool with a crook at one end with a forking device for removing nails, etc. The other end has a wedge shape.

crowded engine compartment: An engine compartment or bay in which all the available space around the engine is occupied by other objects (alternator, pumps, air intake system, battery, wiper motor, heater motor, windshield washer motor, starter, radiator, air conditioner, hoses, pipes, wiring, electronic boxes, etc.)

crown: [1] The tread area of a tire. [2] The top part of the head of a piston. [3] The outward curvature of an apparently flat sheet metal Click for books on panel. Crown [4] The curve or convex surface of a properly finished weld. [5] A model of automobile manufactured by Toyota Also see fork crown high crown spoon low crown panel pent crown piston piston crown valve crown crown panel: See

high crown panel low crown panel crown piston: See pent crown piston

crown radius: The measurement of the curvature of a tire tread between the shoulders of the tire. Expressed as a percentage, it indicates the relative flatness of the tire tread area.

crown spoon: See high crown spoon

Crown Victoria: A model of automobile manufactured by Ford

Click for books on Ford Crown Victoria

crown wheel: The larger of two gears in a bevel gear drive with teeth around its periphery facing sideways

crown wheel and pinion: A pair of gears in the final drive of a vehicle, always found in the back axle of a rear-wheel drive layout where the pinion is on the end of the propeller shaft driving the crown wheel mounted on the differential at right angles to it, and also in frontwheel drives where the engine is not transversely mounted

crown width: The distance of a tire tread shoulder to shoulder measured along the buffed contour.

CRT: Acronym for cathode ray tube

cruciform frame: A frame with an X-shaped bracing either as a chassis frame, or in a monocoque as strengthening for the floor

crude oil: Unrefined petroleum as it comes out of the ground. It forms the basis of gasoline, engine oil, diesel oil, kerosene, etc.

cruise: To drive at a constant speed, often at highway speed.

cruise control: A feature that keeps your vehicle moving at a set speed. Old cruise controls were mere throttle control units which kept the engine speed the same. When the vehicle approached a hill, the vehicle slowed down noticeable going up and speeded up going down. Later models used vacuum controls to push or pull on the accelerator rod. Newer models use electronic controls to accomplish this task. It can be turned off by hitting the off button or touching the brake pedal. The resume switch allows you to return to the pre-set speed after brake disengagement. The coast switch slows the speed down and the accelerate switch increases it.

cruiser: [1] Any motorcycle designed to be ridden long distances. [2] Motorcycle riders who ride long distances.

cruiser bag: A leather bag which is mounted on the top surface of the fuel tank or possibly other parts of a motorcycle. Although it can be filled with anything for a trip, usually it contains items that you want to access quickly (e.g., camera, road map).

cruiser stern: A spoon-shaped stern used on most merchant ships designed to give maximum immersed length

cruising circuit: The main carburetor metering system

cruising speed: constant speed at which a vehicle can be driven on the highway

crumple zone: An area of a vehicle that is designed to compress during an accident to absorb the energy from the impact.

crush: A slight distortion of the bearing shell that holds it in place as the engine operates

crusher: A machine which crushes scrapped cars into small blocks.

crush height: The precision insert bearing must fit the bottom end of the connecting rod in order to transfer friction heat to the connecting rod. The insert will protrude a small amount above the rod bore parting surface. This distance is called the crush height. When the rod halves are drawn together, the inserts touch before the halves, thus forcing the inserts tightly into place.

crush washer: A disc with a hole in the center. It is placed around the threads of a bolt and secured with a nut or screwed into a hole. When the head of the bolt is forced against it, the washer is squashed. Crush washers are used on some spark plugs to provide a better seal when installed.

CRX: A model of automobile manufactured by Honda

Click for books on Honda CRX

cryogenics: The study of physical phenomena at a temperature below -50°F (46°C)

c spanner: See C-spanner.

c-spanner: A wrench whose end is shaped like a C, used to loosen the lockring on a bottom bracket of a bicycle.

CSSA: Acronym for "Chambre Syndicale Suisse de L'Automobile et Branches Annexes" (Switzerland).

CTC: Acronym for "Chrysler Technology Centre."

CTO: Acronym for coolant temperature override switch

CTS: Acronym for Conti Tire System

CTVS: Acronym for choke thermal vacuum switch

cubby hole: A glove compartment on older cars, often without a lid.

cubes: A colloquial term for cubic inches, or cubic inch displacement of an engine.

cube van: A truck with a large compartment behind the driver's cab and used for moving various products.

cubic capacity: See displacement.

cubic centimeter: (cc) Metric measurement of engine displacement. 1000 cc = 1 liter (litre) which is about 61 cubic inches (61.02374409). Thus a 428 cubic inch engine is 7 liters (428/61) and a 2 liter engine is 122 cubic inches (2 x 61).

cubic inch: a measurement of volume equal to 16.387 cc

cubic inch displacement: See displacement.

cubic inch engine: An engine which is measured in cubic inches rather than cubic centimeters.

cu. ft.: Abbreviation for "cubic feet."

cu. in.: Abbreviation for "cubic inch" (also C.I.).

cult car: A car which has many enthusiastic owners, but may not necessarily be a classic or milestone car.

Cunningham: A vehicle brand of which the 1925-1948 models are classic cars. The 1951-55 models are milestone cars.

cuno filter: A filter made up of a series of fine discs or plates pressed together in a manner that leaves a very minute space between the discs. Liquid is forced through these openings to produce a straining action.

cup: A type of lip seal used on hydraulic pistons. Also see adjustable cup agitation cup bearing cup bearing shell cup washer fixed cup vacuum suction cup viscosity cup cup dent puller: See suction cup dent puller

cup holder:

A device to hold a coffee cup or pop bottle. Also called beverage holder

cup seal: Synthetic rubber seal with a single lip used for sealing hydraulic and pneumatic pistons

cup-shaped wire brush: circular wire brush on an arbor for use with an electric drill

cup washer: A washer that is dished.

curb: A stone or cement ridge between the road and the sidewalk. In Britain it is called "kerb"

curber: [1] A person who buys cars needing a lot of work and fixes them, then sells them privately from his own residence. [2] A person who steals a car, falsifies the registration information, and sells it from a place not near his own home. You need to contact him on his cell phone where he informs you that you need to meet him at some parking lot or on the curb of a residential area.

curb idle: Normal idle rpm. Computer controlled on many modern vehicle

curb-idle port: See idle discharge hole

curb-idle stop screw: A screw which provides an adjustable stop for the throttle lever

curb weight: The weight of a vehicle without passengers or payload, but including all fluids (oil, gas, coolant, etc.) and other equipment specified as standard.

cure: A process of vulcanizing raw rubber through the application of heat, pressure, and time to permanently shape and set the rubber at the degree of hardness desired to protect it from the effects of normal operating temperatures and wear. Also see chemical cure cure time: The time required at a reference temperature for a compound to reach optimum physical properties.

curing: [1] Process of heating or otherwise treating a rubber or plastic compound to convert it from a thermoplastic or fluid material into the solid, relatively heat-sensitive state desired in the commercial product. When heating is employed, the process is called vulcanization. [2] The final drying stage where the paint reaches maximum strength.

curing gum: A soft, tacky rubber compound used in retreading and repair to facilitate bonding between different rubber compounds and between plies, etc. Also see cushion gum curing rim: When retreading a tire, a special rim that supports the inflated tire during the curing process.

curing time: The length of time required for paint or plastic to harden.

curing tube: In retreading a tire, a heavy tube within the tire that provides pressure to force the casing against the matrix during the curing process.

current: [1] The movement of free electrons through a conductor. Also see alternating current

charging current direct current discharging current electric current spark current [2] The most recent model vehicle (i.e., made in the same year as the present calendar).

current for low temperatures: See test current for low temperatures

current regulator: A device for controlling the current output of a generator (which increases with engine speed) by opening a switch when the current exceeds a certain value, thus protecting the generator from damage due to excess current.

curtain: See side curtain

curve: [1] A gradual bend in the road. A sharp bend is a corner. Also see advance curve and torque curve cush drive: A motorcycle transmission shock absorber, usually a rubber cushion in the rear hub

cushion: See air bag air cushion impact cushion seat cushion

cushion gum: A soft, tacky rubber compound used in retreading and repair to facilitate bonding between different rubber compounds and between plies, etc.

custom: [1] A restyled or modified vehicle. [2] A new body mounted on an existing chassis.

customer: A person who is at least potentially able to purchase something. Good customer service involves providing the customer with the best answers to his questions and the best choices to meet his needs or wants.

customize: [1] To restyle or modify a vehicle. [2] To mount a new body on an existing chassis.

customs duties: Customs duties levied on imported goods under the Customs Tariff.

custom wheel: A special wheel with attractive styling, usually alloy, available as an aftermarket accessory, designed to make a car look more sporty

cut: See T-cut

cut-and-shut: A British term for a process of shortening a vehicle by cutting out a section of the chassis and/or bodywork.

cutaway: A drawing which shows some of the exterior part and at the cutaway the interior parts and their workings are shown.

cut gears: See straight cut gears

cut in front:

The action of an overtaking (passing) vehicle which pulls back into the lane of the overtaken (passed) vehicle. Usually it is a derogatory expression of a vehicle's action which does not allow for much distance between the two vehicles. Also called, "cut off" as in "He cut me off so I had to jam on the brakes to avoid hitting him." Proper driving etiquette states that you should not pull in until you see the front of the overtaken vehicle in your rear-view mirror.

cut-in speed: The speed at which the generator has to rotate to produce a voltage which is greater than that across the battery terminals

cut off: See cut in front deceleration fuel cut-off fuel cut-off switch inertia fuel cut-off switch power cut-off switch power cut-off cut-off/shut-off: See overrun cut-off/shut-off

cut-off switch: See fuel cut-off switch power cut-off switch inertia fuel cut-off switch power cut-off switch fuel cut-off switch inertia fuel cut-off switch cutout: [1] A form of bypass valve, located in the exhaust line, that can be used to divert the flow of exhaust from one pipe to another. Often used to bypass the muffler into a straight pipe. See exhaust cutout. [2] A device to connect or disconnect the generator from the battery circuit. When the generator is charging, cutout makes circuit, when generator stops, cutout breaks circuit. Also referred to as "cutout relay," and "circuit breaker." [3] A portion of a panel which has been removed so that a cover can be inserted.

[4] A circuit-breaker, especially one in the charging circuit of a generator output is less than the battery voltage, so that the battery does not drain into the generator. Also called a "cutout relay." Also see exhaust cutout low-pressure cut-out valve cut-out wheel cutout cutout relay: A device to connect or disconnect the generator from the battery circuit. When the generator is charging, cutout makes circuit, when generator stops, cutout breaks circuit. Also referred to as "circuit breaker." Also see cutout cutter: A small pincer with sharp jaws for cuning and stripping wires, etc. The British term is "end cutters" or "end cutting pliers." Also see end cutters manual panel cutter metal cutter milling cutter mini tube cutter monodex-type cutter panel cutter sheet metal cutter side cutters taper cutter tube cutter valve seat cutter variable hole cutter cutters: See end cutters side cutters cut thread: A thread produced by removing material from the surface with a form cutting tool. This method keeps the unthreaded portion of the shank equal to the major diameter of the thread.

cutting: See acetylene cutting arc cutting end cutting pliers flame cutting heavy-duty diagonal cutting pliers heavy-duty end cutting pliers high leverage diagonal cutting pliers high leverage end cutting pliers hole cutting snips oxygen acetylene cutting cutting compound: An abrasive paste which is used to remove oxidation in the surface of paint in order to bring back the shine.

cutting disc: An abrasive wheel of an angle grinder

cutting flame: A process in welding where cutting takes place by a rapid oxidation at a high temperature produced by a gas flame accompanied by a jet action which blows the oxides away from the cut.

cutting line: A line established by the factory along which welded-up assemblies must be cut when replacing a sheet metal part, in order to maintain structural strength in the finished repair

cutting pliers: See end cutting pliers heavy-duty diagonal cutting pliers heavy-duty end cutting pliers high leverage diagonal cutting pliers high leverage end cutting pliers cutting snips:

See hole cutting snips

cutting torch: An oxyacetylene torch for cutting through metal, used by welders.

CV joint: Abbreviation for "constant velocity joint."

CV joint boot: A rubber cover over the CV joint. It usually has accordian folds.

CVK: Acronym for center vertical keel. Also see center girder CVMA: Acronym for "Canadian Vehicle Manufacturer's Association"

CVR: Acronym for constant voltage regulator

CVT: Acronym for "Continuously Variable Transmission." See infinitely variable transmission.

CWM: Acronym for cold weather modulator

cwt: Abbreviation for "hundredweight."

cycle: [1] A vehicle with one or more wheels (usually spoked) where the rider/driver straddles the vehicle as a bicycle, motorcycle, tricycle, etc. It also includes other vehicles adapted from a traditional cycle where the rider/driver no longer straddles

the vehicle (recumbent cycle, four-wheel side-by-side pedal powered vehicle). Obviously the distinction blurs with automobiles -- are they a cycle? [2] A sequence of changes of state after which the system is in its original state again. Also see city cycle diesel cycle ece test cycle four-stroke cycle engine four-stroke power cycle four cycle engine four stroke power cycle four stroke cycle engine ftp test cycle limit cycle control miller cycle otto cycle refrigeration cycle two-stroke cycle two stroke cycle urban test cycle working cycle cycle car: A term used to describe the very light production automobile made prior to 1922. It was usually made from motorcycle parts and generally powered by single-cylinder or twin-cylinder engine. They disappeared when genuine light cars appeared.

cycle control: See limit cycle control

cycle engine: See four-stroke cycle engine four cycle engine four stroke cycle engine two-stroke cycle engine two stroke cycle engine cycling clutch orifice tube system: (CCOT) the GM system that utilizes an accumulator (instead of a receiver-drier). The system uses a fixed orifice tube located at the evaporator outlet, instead of an expansion valve. A thermostatic switch or a pressure sensing switch cycles

compressor operation off and on in accordance with system status.

cycling clutch system: Any system that controls compressor clutch operation as a means of temperature control

cyl: Abbreviation for "cylinder," as in 12-cyl. engine.

cylinder: [1] The round chamber or hole in the cylinder block that houses the pistons and where combustion takes place. Also called "bore" or "barrel." [2] Any tube-like device. Also see acetylene cylinder brake cylinder brake master cylinder cylinder bore cylinder head cylinder sequence cylinder sleeve dual-piston master cylinder inner cylinder lock cylinder master brake cylinder master cylinder oxygen cylinder slave cylinder split-system master cylinder tandem master cylinder wheel cylinder working cylinder cylinder bank: One half of a V-6, V-8, V-12, and V-16 engines along one side. cylinder barrel: An external casing of a cylinder forming a separate unit, especially of an air-cooled engine

cylinder block: The basic framework of the engine to which other engine parts are attached. It is usually a casting and includes the engine cylinders and the upper part of the crankcase. Also see engine block cylinder block heater: An electric heater element in the water jacket connected at the other end to house current. The element warms the coolant so that in very cold weather the block will not crack and the car will start easier. Often just called "block heater."

cylinder bore: The cylinder holes.

cylinder charge: A quantity of fresh mixture fed into the combustion chamber prior to combustion

cylinder head: The detachable metal (aluminum or iron) section that is bolted to the top of the cylinder block. It is used to cover the tops of the cylinders, in many cases the cylinder head contains the valves, it also forms part of the combustion chamber. It has water and oil passages for cooling and lubrication. It also holds the spark plugs. On most engines a valve cover or rocker arm cover is located on top of the cylinder head. Some engines have just one cylinder head covering several cylinders, while others have separate heads for each cylinder. In some motorcycle engines and small engines, the cylinder head is not detachable -- it is cast with the cylinder which forms a blind hole. Also see crossflow cylinder head x-flow cylinder head cylinder head bolt: One of several bolts which hold the cylinder head in place

cylinder head gasket:

See head gasket

cylinder head nut: One of several nuts which hold the cylinder head in place.

cylinder head tester: A device used to detect cylinder head leakages which cause combustion gases to appear in the cooling system

cylinder hone: A tool that uses an abrasive to smooth out (hone) and bring to exact measurements such things as engine cylinders, wheel cylinders, bushings, etc.

cylinder liner: [1] A cylinder sleeve. [2] A hard metal block forming the cylinder wall and in which the piston runs

cylinder sequence: The order in which the cylinders are located on a vehicle. It is important to locate the number one cylinder to check and adjust timing. In some cars it may be at the front of an engine on U.S. built cars and at the rear of some foreign cars. Also see firing order cylinder sleeve: A replaceable cylinder liner or tube, it is made of a pipe-like section that is either pressed or pushed into the block. If the cylinder cannot be re-bored to an oversize or if the liner has been damaged beyond repair, the cylinder may be re-sleeved.

cylinder surfacing hone: Puts a cross-hatch pattern on the cylinder walls, after they have been bored, to help seat the new rings properly

cylinder wall: The inner surface of a cylinder.

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [D] [Da] [Db] [Dc] [De] [Df] [Dg] [Di] [Dl] [Dn] [Do] [Dr] [Ds] [Du] [Dv] [Dw] [Dy]

D: [1] Abbreviation for "diesel." [2] Abbreviation for "drive." [3] A mark on the output (live) terminal on a generator (contrasts with "F")

DAB: Acronym for "Digital Audio Broadcast."

dagmar: [1] Large bullet-shaped protrusion on bumpers of cars in the 1950s. It was named after the nickname of a buxom television star, Virginia Ruth Egnor (1921-2001). [2] Dagmar is an automobile of which only the 25-70 models of 1925-1948 are classic cars.

Daimler: Also called Austro-Daimler. A vehicle brand of which the 1925-1948 models with required application are classic cars. The 1949-53 DE-36 Custom Built models are milestone cars. The 1949-53 2.5 Special Sport Convertible models are milestone cars.

dam: See air dam heat dam damage: See accident damage center section damage direct damage ecological damage

engine damage frame damage impact damage indirect damage internal damage secondary damage stone chip damage damp: [1] To reduce the oscillations of spring, carburetor piston, etc. [2] To reduce the vibration in a crankshaft

damper: [1] A friction device sometimes called a "shock absorber." Used for controlling and damping spring oscillations. The springs actually absorb road shocks; the dampers convert the energy imparted to the springs into thermal energy (by friction), which is dissipated to the atmosphere or the vehicle's chassis. Dampers are distinguishable by the type of friction involved, mechanical or hydraulic but most modern cars used tubular-shaped hydraulic shock absorbers. Because they affect up and down wheel motions, dampers are an important link in tuning a vehicle's ride and handling. [2] A moveable plate which permits or restricts the flow of liquids or gasses. Also see friction damper gas damper harmonic balancer mass damper monotube damper piston damper pulsation damper steering damper steering wheel damper torsional vibration damper torsion damper twin-tube damper vibration damper damper piston: A piston in a cylinder whose movement is restricted by a liquid or gas, which thus also restricts the movement of another member to which it is connected.

damper settings:

See spring and damper settings

damper springs: Springs in a clutch plate providing a cushion against sudden loads due to abrupt engagement

damper strut: A suspension strut whose hub carrier is attached to the spring element rather than to the damper tube. Compare Macpherson strut

damping: Cushioning of force.

damping force: The amount of cushioning applied by a shock absorber

damping rate: The amount of cushioning applied by a shock absorber

Darracq: A vehicle manufacturer in which only the 8-cyl. cars and 4-litre, 6-cyl. cars of 19251948 are classic cars.

dash: See dashboard.

dash board: See dashboard

dashboard: That part of the body containing the driving instruments, switches, etc. Also called the "instrument panel" or "dash panel" or just "dash."

dashboard gearchange: British term for dash shifter

dashboard plaque: [1] A metal or plastic plate which is mounted to the dash to indicate the brand, model, or series of vehicle. [2] A metal plate which is mounted to the dash to indicate an award for attending or winning a rally or other automotive event.

dash design: See wrapround dash design

dash panel: [1] A structural panel with bracing across the width of the car on the inside of the bulkhead below the windshield that provides the mounting locations of the dashboard. [2] The bulkhead

dash plaque: [1] A metal or plastic plate which is mounted to the dash to indicate the brand, model, or series of vehicle. [2] A metal plate which is mounted to the dash to indicate an award for attending or winning a rally or other automotive event.

dashpot: A unit using a cylinder and piston or a cylinder and diaphragm with a small vent hole, to retard or slow down the movement of some part.

dash-pot: (DP) a diaphragm that controls the rate at which the throttle closes

dash shifter: A shift lever and indicator which is located on the instrument panel either as a short lever or push buttons

Data: See radio Data System

Data System: See radio Data System

Datsun: A model of automobile manufactured by Nissan

Datsun Truck: A model of truck manufactured by Nissan

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Click for books on Datsun Trucks

Datsun Z: A model of automobile manufactured by Nissan

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davit: A crane arm for handling lifeboats, stores, etc.

day-night mirror: A mirror which adjusts to prevent the glare from the headlights of following cars. The British term is "dipping mirror."

days' supply: number of days needed to sell all vehicles in inventory, based on the previous month's sales rate.

daytime running lights: A safety-oriented lighting system in which the headlights or other front lights are constantly on even during the day. They help to prevent possible accidents because oncoming traffic can be seen.

dazzle: The glare from the headlights of oncoming traffic which can momentarily blind a driver.

dazzle mirror: See dimming mirror

dBA: A unit of measure for decibels, the measure of sound intensity or pressure named after Alexander Graham Bell. It is a logarithmic measurement; every 3dB increase represents a doubling of the sound pressure. The "A" in dBA indicates that the measurement was taken with an A-weighted scale; sound pressure varies across the

audible spectrum, and the A-weighted scale approximates the human ear's sensitivity to various frequencies.

DBI: Acronym for "De Danske Bilimport rer" (Denmark)

dbl: Abbreviation for "double," as in dbl.-wide rear wheels.

DC: [1] As an electrical term, it is an acronym for "direct current." [2] As a piston position, DC is an acronym for "dead center" where the piston at the extreme top or bottom of its stroke.

DC generator: See generator

DC rim: Abbreviation for Drop-Center rim

dead: See inner dead center lower dead center outer dead center dead axle: An axle that does not rotate nor is driven but merely forms a base upon which to attach the wheels. Also see beam axle. It contrasts with a live axle. dead battery: A battery that registers almost no electrical charge. Sometimes it can be brought back to life with a charger. The British call it a "flat battery"

dead center: The point at which the piston reaches its uppermost or lowermost position in the cylinder the rod crank journal would be at 11 o'clock UDC or 6 o'clock LDC. Also see

after bottom dead center after top dead center before bottom dead center before top dead center before upper dead center bottom dead center inner dead center lower dead center outer dead center top dead center upper dead center deadfreight factor: The amount of a ship's carrying capacity that is not utilized.

dead-head pressure: A fuel pressure reading taken directly at the fuel pump outlet. Many systems use a fuel pressure regulator; dead-head pressure is an unregulated measurement

dead pedal: A footrest located to the far left of the driver so that he can brace his left leg during hard cornering or to balance the position of the right foot on the throttle pedal during normal driving.

dead rear axle: A rear axle that does not turn. E.g., rear axle of front wheel drive car

dead rise: Athwartship vertical rise between the keel and the bilge

dead space: The space below the piston availaable for pre-compression of the incoming fresh charge of the two-stroke engine.

deadweight: The total weight in tons (2240 lb.) that a ship carries on a specified draft including fuel, water in tanks, cargo, stores, passengers, baggage, crew and their effects, but excluding the water in the boilers. It is the difference in weight between a vessel when it is fully loaded and when it is empty measured by the water it displaces. Also see

tonnage deadweight dealer: [1] a firm that buys and sells, adding some value for the consumer in the process. Dealer often means a firm which operates closer in the distribution channel to the consumer than a distributor or wholesaler and may add more value for consumers than either of the above-mentioned terms. Also called "dealership." [2] A person whose business is buying and selling cars and trucks or motorcycles. Also see authorized dealer auto dealer car dealer franchised dealer new car dealer scrap dealer used car dealer dealer invoice: The price the dealer pays for a vehicle.

dealer participation: The amount contributed by the dealer to reduce the final purchase price in the lease contract. Dealer participation can take the form of a rebate or simply a discount. The dealer participation is reflected in the lease contract as a capitalized cost reduction.

dealer principal: The individual or corporation that owns and controls one or a number of auto dealerships.

dealership: A firm that buys and sells, adding some value for the consumer in the process. A dealership often means a firm which operates closer in the distribution channel to the consumer than a distributor or wholesaler and may add more value for consumers than either of the above-mentioned terms.

death rattle: An informal term for a noise from an engine which indicates that it is likely to break down at any moment

debugging:

The process of locating and correcting faults in a system

deburr: To remove burrs from a metal surface

deburring: Removing burrs from a metal surface or bearing

decal: A sticker or transfer which is applied to a smooth surface to identify a particular product. Pronounced dee-KALL in the United States, but DECK-ull in Canada.

decarbon: The action of removing carbon buildup from the surface of the cylinder head and the dome of the piston. The accumulation of carbon indicates poor combustion and will result in loss of performance.

decarbonize: See decarbon

decelerate: The action of slowing down. The opposite of accelerate

deceleration: Negative acceleration; the rate of change in velocity as a vehicle slows down during braking.

deceleration fuel cut-off: A device which stops the flow of fuel to the carburetor or injectors when the vehicle rapidly decelerates in the event of a crash thus preventing the possibility of a fire or explosion.

decelerometer: An instrument for measuring deceleration.

deck: [1] The bed of a half-ton truck.

[2] The floor of a commercial vehicle like a bus. [3] The trunk lid of a car. Also called "rear deck." [4] In an engine, top face of the cylinder block on which the cylinder head mounts. [5] A platform in a ship corresponding to a floor in a building. Also see bulkhead deck freeboard deck main deck radio/cassette deck rear deck rear deck panel shelter deck strength deck tween deck weather deck deck beam: An athwartship horizontal structural member supporting a flat or deck

decker: See double-decker

deck house: Small superstructure on the top deck which contains the steering wheel and other navigational instruments.

decking: See shaving

deck lid: The panel which covers the engine in a vehicle with the engine in the rear of the car. Also see hood deck panel: The sheet metal panel extending from the bottom of the rear window to the rear panel and enclosing the cutout for the trunk lid, extending sideways to the top of both rear fenders. In some cases, this panel covers only the area between the bottom of the rear window and the front edge of the trunk lid. Also see

rear deck panel deck ship: See flush deck ship

deck stringer: The strake of deck plating that runs along the outboard edge of a deck

declutch: The action of disengaging the clutch (i.e. releasing the clutch pedal or lever). Also see double-declutch decoke: To decarbon

decompressor: A valve which is manually operated to release compression in a cylinder by allowing air to escape in order to facilitate manual starting of an old engine or a diesel engine. Some motorcycles also used a decompressor to assist in kick-starting.

dedicated: Something that is designed for a specific use or for a specific vehicle.

de Dion axle: A rear axle setup developed by Count de Dion in the 19th century in which the driving wheels are attached to curved dead axle that is attached to the frame by a central pivot, the differential unit is bolted to the frame and is connected to the driving wheels by drive axles using universal joints. The De Dion system keeps the wheels upright (the same as a live axle does), but unsprung weight is reduced because the differential is out of the axle. De Dion suspension also leaves room around the differential for inboard brakes, which can further reduce unsprung weight. deep cycling: The process of discharging a battery almost completely before recharging

deep tank:

Tanks extending from the bottom or inner bottom up to or higher than the lowest deck of a ship

deer alert: A device which is mounted on the outside of a vehicle and which makes a highpitched sound to warn deer and other animals away. Whether it really works or not is debatable.

defect: A fault in a system or a flaw in materials or a finish

defective: A description of a component which is faulty or flawed.

defensive driving: A driving technique in which the driver prepares for and watches for the mistakes of other drivers around him so that he can avoid an accident.

deflated: An air chamber (like a tire or lumbar support chamber) which has lost all its air.

deflation: The loss of air from a tire or other air chamber

deflation warning system: (DWS) developed by Dunlop for on-line detection of tire pressure loss. When tire pressure is reduced, the tire circumference is also reduced resulting in increased wheel rpm. The system uses the wheel speed sensors of an existing ABS system to continuously monitor wheel speed and tire condition, and triggers a warning signal upon detecting a problem.

deflection: The movement of a suspension piece when subjected to a load. Also see effective deflection deflection rate:

The distance that a spring squeezes together (deflects) in relation to the pressure applied. E.g., 5 inches per 1000 lb load.

deflection under load: See temperature of deflection under load

deflector: [1] A device which causes bugs, tar, and grime from hitting other components. [2] A special piston profile used to achieve cross scavenging in earlier two-stroke engines. Also see air deflector air shield bug deflector stone deflector wind deflector deflector piston: A piston design which had a crown designed to direct the incoming fresh mixture upwards to expel the burnt exhaust gas from the cylinder. This design is no longer used today.

deflector shield: See sunroof deflector shield

defog: The action of removing mist or condensation from the inside of a window or the outside of a mirror by means of blowing air or heated wires imbedded in the glass. The British term is "demist." See defogger.

defogger: An electric or hot air device to remove the fog or ice from both the inside and outside of the windshield, backlight (i.e., rear window) or even mirrors. Some are designed to remove fog from the side windows.

defogging system: See backlight defogging system

deformation:

An alteration of shape or dimension which is caused by stress, expansion, or contraction because of temperature, humidity, or metallurgical changes. Also see plastic deformation deformation zone: A crumple zone

defrost: The action of removing frost from the inside of a window or the outside of a mirror by means of blowing air or heated wires imbedded in the glass.

defroster: The apparatus (either a fan connected to the heating system or electrical wires imbedded in the glass) which removes frost or fog from a window. Also called a "demister."

deglaze: The action of removing the smooth finish on cylinder walls so that a new set of rings will seat.

deglazer: An abrasive tool used to remove the glaze from cylinder walls so that a new set of rings will seat. Also see glaze breaker degradable: See bio-degradable

degradation: The deterioration in the condition of something. Also see catalyst degradation degrease: [1] To remove oil and grease from the surface of a parat. [2] Wiping the surface to be painted with a clean cloth saturated in a solvent. This is essential to good paint adhesion.

degreaser: A substance which removes dirt and grease from a mechanic's hands. Also called "hand cleaner."

degreasing: The removing of grease or oil from a surface. Also see alkaline degreasing and vapor degreasing degreasing agent: A solvent or alkaline solution which is used for removing oil and grease

degree: 1/360 part of a circle.

degree wheel: A wheel-like disc divided into 360 equal parts that is attached to the engine crankshaft it is used to time the valves to a high degree of accuracy.

dehumidifier: A device which absorbs moisture from the atmosphere. It can be a unit dedicated for this purpose, or even an air conditioner.

de-ice: To remove the ice from the outside of the windshield.

de-icer: A liquid or spray which is applied to the windshield to assist in removing ice. Also see door lock de-icer lock de-icer de-ionized water: Water from which impurities have been removed by a special process and used for topping up batteries.

Delage: An old brand of automobile of which the 1925-1948 Model D-8 (but not the 4-cyl.) with required application is a classic car. The 1946-49 D-6 Sedans are milestone cars.

Delahaye: An old brand of automobile of which the 1925-1948 Series 135, 145, 165 (but not the 4-cyl.) with required application are classic car. The Type 135, 175, 180 (194651) are milestone cars.

Delaunay: An old brand of automobile of which the 1925-1948 6-cyl Belleville are classic cars.

delay: See headlight on/off delay system ignition delay delay relay: See time delay relay

delay system: See headlight on/off delay system

delay vacuum bypass system: (DVB) an optional system used by Ford that bypasses the spark delay valve during cold operation to improve driveability

delay valve: A valve used in a vacuum or hydraulic system in which the valve's opening or closing is delayed. Also called vacuum delay valve

delay wiper: A windshield scraper which can be set to activate at various times and pauses between each swipe. It is useful when there is a mist or light rain. Also called "intermittent wiper."

d'elegance: See concours.

d'elegance: See concours d'elegance

deliver: [1] To pump or discharge a liquid. [2] To drive a new car from the factory to the distributor or dealer. Or to drive it to the customer.

delivery: [1] The discharging of a liquid from a pump. [2] Driving a new car from the factory to the distributor or dealer

delivery lines: Fuel lines used to carry fuel from the fuel injection pump to the injector nozzles

delivery mileage only: The odometer reading reflects only the distance from the factory to the selling dealer.

delivery valve: [1] The valve on the outlet side of a pump. [2] A fuel injection pump valve that rapidly decreases injection line pressure to achieve an abrupt fuel cutoff at the injector

Delorean: A model of automobile manufactured by John Z. DeLorean

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Del Sol: A model of automobile manufactured by Honda Click for books on Honda Del Sol delta configuration: A triangular connection of the three stator windings of an alternator. Also see

Y-configuration deluxe: Abbreviated (DL). A term used to indicate a series of vehicle which is just above the basic version.

delugger: A machine used to cut the lugs from tires prior to buffing.

demagnetize: Removing residual magnetism from an object which had been previously magnetized

demist: A British term to clear fog or frost from the windshield or rear window. In the US and Canada, the term is defog.

demister: A British term for a defogger or defroster

demonstrator: A vehicle used by a dealer for test drives and sold later at a reduced price. Also see ex-demonstrator demountable flange: A side ring or side and lock ring combination that retains the tire on the rim. It is removable to permit tire mounting or removal.

demountable rim: A two piece rim found on trucks. The main part of the rim remains on the axle while a side piece and a locking ring is removable. In this way the whole rim is not removed from the vehicle like a passenger car's rim and wheel. Also called a "detachable rim"

denatured alcohol:

Ethyl alcohol to which a denaturant has been added

Denovo tire: A special tire (fitted to a special rim) which used to be made by Dunlop, and which can be run flat for up to 160 km (100 miles) at up to 80 kph (50 mph)

density: Compactness; relative mass of matter in a given volume.

dent: [1] A hollow or dip in a body panel caused by a sharp blow or impact. [2] To cause a dent in a body panel

dent puller: A tool with a strong suction cup to pull out dents in body panels. Also see panel puller suction cup dent puller Denver boot: A locking device which wraps around the wheel of a vehicle to immobilize its movement

départ: The starting line of a randonnée or brevet

departure angle: The most sharply angled incline the vehicle can leave without its rear hitting the ground. As with approach angles, it's formed on one side by the horizontal axis, and on the other by a straight line connecting the rear edge of the rear tire and the most prominent point at the rear of the vehicle, usually the bumper or exhaust pipe.

depolarize: Removal of residual magnetism thereby destroying or removing the magnetic. To remove polarity

deposit: A coating of unwanted mineral or layer of sediment at the bottom of a tank.

[2] To apply a coating of something (often metal by electrolysis). Also see gum deposit lead deposit refundable deposit deposition: See electrolytic deposition vapor deposition zinc vapor deposition depreciation: The loss of value of a vehicle because of age or deterioration

depression: [1] An indentation or dent in the surface of a sheet of metal whether through deliberate design or accident. [2] A restriction of airflow which causes low pressure and a partial vacuum. Also see constant-depression constant depression engine depression valve clearance depression depressor: See valve spring depressor

depress the accelerator: The action of pressing down on the gas pedal (accelerator) to cause more fuel to enter the engine thus making the vehicle go faster. Opposite to "ease up on the accelerator."

depress the gas pedal: The action of pressing down on the gas pedal (accelerator) to cause more fuel to enter the engine thus making the vehicle go faster. Opposite to "ease up on the gas pedal."

depress the throttle pedal:

The action of pressing down on the throttle pedal (accelerator) to cause more fuel to enter the engine thus making the vehicle go faster. Opposite to "ease up on the throttle pedal."

depth: See molded depth profile depth skid depth throat depth tread depth well depth depth gauge: A measuring tool for determining the depth of something. Also see tread depth gauge depth micrometer: A measuring device (micrometer) used for precise measurement of a hole depth, recesses, keyways, etc.

depth of thread: The distance from the thread crest to root measured perpendicular to the axis of the thread

derailleur: A lever-activated mechanism that pushes the chain off one sprocket of a bicycle and onto another, thus changing the gear ratio.

derailleur chain, narrow width: A bicycle chain made especially for use on an "ultra" or narrow freewheel often recognized by bulging inner link plates and flush chain pins.

derailleur chain, standard width: A bicycle chain designed to fit a freewheel of standard width, usually characterized by straight-edged plates and chain pins that protrude slightly beyond the outer link plates.

derrick: A device for hoisting and lowering heavy weights, cargo, stores, etc

derust: To remove rust from a metal part

derv: Diesel oil when used as a fuel for road vehicles. Acronym for "diesel-engined road vehicle"

descaling: The removal of scale or metallic oxide from metallic surfaces by pickling

desiccant: A drying agent (silica gel or a similar substance) used in refrigeration or air conditioning systems to remove excess moisture from refrigerant vapour

design: [1] The arrangement of parts or the form of construction. [2] To arrange parts or construction of a vehicle or major component. Also see cab-forward design cabin-forward design cam design cam profile component design open-deck design product design wrapround dash design designation: See model designation one-piece rim designation rim designation type designation desmodromic: something (like valves) which is opened and closed by a mechanical device. In most 4-stroke engines the valves are opened by the cam, but closed by the action of the

valve springs. In a desmodromic system, the valves are opened by a cam and closed by a cam or a cable. A desmodromic system is more costly and more difficult to manufacture, but the advantage is more precise control of the valves and less valve bounce which is seen in a normal engine at high speed.

desorption: The removal of material which has been adsorbed. It is the opposite of adsorption.

DeSoto: A vehicle brand of which the 1956-58 Adventurer models are milestone cars.

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detachable rim: A wheel rim which is bolted to the wheel center or spider and can be disassembled for replacing the rubber tire. It is found on trucks and some quads. It is also called a demountable rim

detachment: See flow detachment

detail: The action of correcting all appearance flaws in a vehicle.

detailitis: A term coined by Art Treta to indicate a compulsive disorder which compels a vehicle owner to correct its every flaw to the extent that he searches for even the most hidden flaw. Also see restorationitis detector: See glass tampering detector radar detector detent ball and spring: A spring loaded ball that snaps into a groove or notch to hold some sliding object in position.

detergent: A soap-like chemical added to the engine oil (particularly MS oil) or gasoline to improve its characteristics and keep the engine clean by controlling the formation of sludge and gum as well as controlling foaming.

detergent oil: An MS oil which keeps the engine clean by preventing the formation of sludge and gum.

deterioration: See catalyst deterioration thermal deterioration DeTomasoPantera: A model of automobile manufactured in Italy

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detonation: The action of the fuel charge firing or burning too violently, almost exploding. It sometimes results in a noise called "pinging." Detonation is caused by autoignition of the "end gas" i.e., that part of the charge not yet consumed in the normal flamefront reaction. Detonation occurs because piston motion and compression of the end gas raise its temperature and pressure to the point where the end gas autoignites. The pinging or knocking noise is the result of intense pressure waves in the charge which cause the cylinder walls to vibrate. Also called "fuel knock."

detonation-activated ignition retard: A system which retards the ignition timing when the detonation sensor picks up vibration at frequencies typical of denotation

detonation sensor: A sensor, , usually piezoelectric, mounted near the cylinders which can detect engine knocking or frequencies of detonation so that it will send a message to retard the ignition timing to prevent damage to the engine.

detour: An alternative route which traffic has to follow due to closure of a stretch of road for repairs, etc. A diversion.

detoxed vehicle: A vehicle with a reduced emission system consisting of a catalytic converter, EGR, air injection, fuel evaporative emission control, etc. Also called a "controlled vehicle"

detuned: The intentional adjustment of an engine to reduce its power in an attempt to reduce emissions, reduce top-end speed, increase fuel economy, or meet specific governmental standards.

deuce: Hot rod built around a 1932 Ford coupe body.

deutsche Industrie Normen: See DIN.

development: See research & development

deviation angle: See tire deviation angle

device: A piece of equipment or a mechanism designed for a specific purpose or function. See anti-roll device antiroll device economy device electronic sensing device enrichment device sensing device triggering device Devon: A vehicle brand of which the 1958-62 S/S models are milestone cars.

dewax:

To remove a coating of wax from the body of a vehicle usually in preparation for painting.

dew point: The temperature at which vapor begins to condense.

DFC: Acronym for digital frequency control

dhc: Acronym for drophead coupe

DG: Acronym for "Diesel General" oil for use under ordinary conditions in diesel engines.

diagnosis: Refers to use of instruments to determine cause of improper function of parts or system of a vehicle See fault diagnosis self-diagnosis diagnostic: See engine diagnostic connector on-board diagnostic system diagnostic center: A garage or part of a garage where problems with a vehicle or part of a vehicle are determined.

diagnostic code: [1] Code displayed on instrument panel which can be used to determine area in system where malfunction may be located. [2] Code numbers obtained by accessing the diagnostic mode of the engine management computer. This code can be used to determine the area in the system where a malfunction may be located

diagnostic computer: A computer terminal or engine analyzer which is hooked up to the car's electronic box and reveals the condition of the engine and various sensors.

diagnostic connector: See engine diagnostic connector

diagnostic link: The electric cord which connects the computer terminal to the socket on the vehicle.

diagnostics: The process of identifying the cause or nature of a condition, situation, or problem to determine the appropriate corrective action to take in the repair of an automotive system. See on board diagnostics

diagnostic socket: A socket on the vehicle (usually found in the engine compartment) which is part of the onboard electronic sensor system.

diagnostic system: The various sensors and electronic devices which record the operation of a number of functions within the vehicle. Also see on-board diagnostic system diagnostic testing: The analysis of the various functions of the components of a vehicle to determine if they are operating properly or have recorded faults which need to be corrected.

diagonal: See heavy-duty diagonal cutting pliers high leverage diagonal cutting pliers diagonal belt:

Another term for shoulder belt

diagonal cutting: See heavy-duty diagonal cutting pliers high leverage diagonal cutting pliers diagonal cutting pliers: See high leverage diagonal cutting pliers heavy-duty diagonal cutting pliers high leverage diagonal cutting pliers heavy-duty diagonal cutting pliers diagonal split braking system: A dual-circuit braking system in which each circuit brakes one front wheel and the diagonally opposite rear wheel, so that in the case of failure of one circuit reasonably balanced braking can be achieved. See dual brakes -- especially the picture.

diagonally split system: A dual-circuit braking system in which each circuit brakes one front wheel and the diagonally opposite rear wheel, so that in the case of failure of one circuit reasonably balanced braking can be achieved. See dual brakes -- especially the picture.

diagram: See circuit diagram indicator diagram timing diagram wiring diagram dial: The face (usually circular) of an instrument like a speedometer, tachometer, vacuum gauge, etc.

dial caliper:

A slide-type caliper which registers on a dial the distance between two points

dialed in: The action of fine tuning an engine or component to its peak capacity.

dial gage: See dial gauge.

dial gauge: A precision micrometer type instrument that indicates the reading via a needle moving across a dial face.

dial indicator: A precision measuring instrument that indicates movement to a thousandth of an inch with a needle sweeping around a dial face. See dial gauge.

dial torque wrench: A wrench usually with a socket end and which measures the torque of a nut-bolt fastener. It registers the value on a dial.

diameter: The distance between one edge of a circular object to the other edge and passing through the center. Also see bead seat diameter bore diameter circle diameter external diameter inside diameter internal diameter major diameter minor diameter nominal diameter nominal rim diameter nominal thread diameter outer diameter outside diameter overall rim diameter pitch circle diameter pitch diameter

rim diameter thread diameter valve diameter diamond frame: [1] The traditional men's bicycle frame the principal parts of which form a diamond shape. [2] Tubular-frame design for motorcycles common until WW II and derived from the bicycle layout. The engine cases often form part of the structure. In profile it resembles a diamond shape

diamond star: The name of Chrysler Corporation which comes from the pattern of its emblem.

diaphragm: [1] A flexible cloth-rubber sheet that is stretched across an area thereby separating two different compartments. A diaphragm is used in pumps to create a pressure differential that causes a fluid to be pushed or pulled from one point to another. Some carburetors have no float bowl (i.e., Tillotsen), but use a series of diaphragms to pump gasoline into the engine. [2] A flexible partition used to separate two chambers or elements. [3] In air-conditioning system, a rubber-like piston or bellows assembly which divides the inner and outer chambers of backpressure regulated air conditioning devices. [4] In fuel system, a thin dividing sheet or partition which separates a housing into two chambers, one of which is usually vented to vacuum while the other is not; used in vacuum-controlled secondaries, anti-stall dashpots, and other carburetor control devices. Also see piston diaphragm

diaphram clutch: Another term for a diaphragm spring clutch

diaphram link: The arm which transmits the movement of the diaphram and the distributor baseplate in a vacuum advance mechanism.

diaphragm pump: A device which has a flexible diaphragm which moves forward and backward by a solenoid or other mechanical device to transfer fluid. Also see

twin diaphragm pump diaphragm spring: A type of spring shaped like a disc with tapering fingers pointed inward or like a wavy disc, used in some clutches. In an automotive clutch the diaphragm spring is part of the clutch pressure plate. When the clutch is engaged, this spring forces the pressure plate against the clutch disc; driver effort through the clutch linkage overcomes the spring pressure to disengage it. A type of spring, shaped like a disc with tapering fingers pointed inward or like a wavy disc, used in some clutches. In auto application, the diaphragm spring is part of the clutch pressure plate. When the clutch is engaged this spring forces the pressure plate against the clutch disc. Also see clutch diaphragm spring diaphragm spring clutch: A common clutch used in most vehicles with manual transmission where a diaphragm spring keeps the pressure plate in contact with the friction plate dickey: British term for rumble seat.

die: [1] One of a matched pair of hardened steel blocks that are used to form (by stamping, pressing, extruding, drawing or threading) metal into a desired shape. Also see bending die lower bending die [2] A tool for cutting threads. See tap and die set.

die back: See die-back.

die-back: In a lacquer finish the loss of gloss after compounding, caused by continued evaporation of thinner.

die cast: Manufactured by forcing molten metal into a die. Especially used of aluminum or an alloy.

die casting: Formation of an accurate and smooth object by forcing molten metal, plastic, etc., into a die under pressure. See cast.

dielectric: A material which is an electrical insulator or in which an electric field can be sustained with a minimum loss of power.

dielectric grease: A special grease which is applied to the ends of electric terminals to inhibit corrosion between the terminals or to be sure that there is good electrical contact between the terminals.

diesel: A type of engine or fuel or oil used for that engine. Also see diesel engine dieselFuel diesel oil turbo-diesel diesel cycle: A four-stroke cycle where the air is sucked into the cylinder and compressed at a ratio of up to 24:1. At the end of the compression stroke the fuel is injected. Because of the high compression and resulting increase in temperature, the fuel is ignited leading to the power stroke and followed by the exhaust stroke where the combustion products are removed.

diesel engine: An internal combustion engine that uses diesel oil for fuel. The true diesel does not use a carburetor or an ignition system (i.e., spark plugs) but injects diesel oil into the cylinders when the piston has compressed the air so tightly that it is hot enough to ignite the diesel fuel without a spark. Because a cold engine cannot ignite the diesel fuel, glow plugs are used to heat the mixture, but they do not provide a spark. Named after Rudolf Diesel (1858-1913), the inventor. Also see compression ignition diesel fuel:

A light oil fuel which has a relatively low ignition temperature

dieseling: A form of autoignition in which a gasoline engine continues to fire after the ignition has been shut off. In late-model emission-controlled engines, dieseling or run-on is caused by heat and the unusually high manifold pressure that result from retarding the spark at idle.

diesel knock: The noise caused by the rapid rise in pressure in a diesel engine especially when the engine is cold or running at a low speed. Also called "diesel rattle."

dieselling: See dieseling

diesel oil: Fuel for cars with diesel engines. This is not a form of lubricating oil. See cetane rating.

diesel particulate filter: A filter which removes small particles from a diesel exhaust. It looks like a honeycomb catalytic converter but acts as a mechanical separator.

diesel rattle: Another term for diesel knock

die set: See tap and die set

die stock: A tool used to hold and operate dies when cutting outside threads.

die size: Retread rubber is designated by its crescent shaped dimensions in inches and eighths, and its thickness in 32nds of an inch; (e.g., 66-72-16; the crown would measure 6 and 6 eighths, the base 7 and 2 eighths wide; and the thickness 16/32 of an inch, or gauge of the stock rubber.)

diff: A colloquial term for a differential

differential: A unit that takes the power of the rotating driveshaft at right angles to the rear axle and passes it to the axle. It will not only drive both rear axles at the same time, but will also allow them to turn at different speeds when negotiating turns. In this way the tires do not scuff or skid. Also see automatic slip-control differential axle differential bevel differential center differential front differential helical differential inter-axle differential limited-slip differential limited slip differential lockable differential locking differential lockup differential multiple-disc limited-slip differential no-spin differential open differential planetary gear differential pressure differential switch rear axle differential rear differential spur differential torque sensitive limited slip differential torsen differential traction differential variable limited-slip axle/center differential visco-differential differential cage: The rotating metal fram which encloses the differential side gears and pinion gears inside the axle casing. Also called the "differential carrier"

differential carrier:

See differential cage

differential case: The steel unit to which the ring gear is attached. The case drives the spider gears and forms an inner bearing surface for the axle and gears.

differential casing: The differential housing

differential gear: See differential gears.

differential gears: The gears that transmit engine power to the driving axles and are arranged so as to permit the rear wheels to turn at different speeds as required when the vehicle is negotiating a turn.

differential grease: See gear grease.

differential housing: The enclosure which contains the differential gears.

differential lock: A mechanism which eliminates the action of the differential so that both wheels can be driven for better adhesion on slippery surfaces.

differentially: See galvanize differentially

differential pinion: The bevel pinion in the differential.

differential pressure: The pressure difference between two regions, such as between the intake manifold and the atmospheric pressures. In Bosch KE-Jetronic systems, the difference

between actuator fuel pressure in the lower chambers of the differential-pressure valves and the system pressure entering the pressure actuator. Also see pressure drop differential-pressure regulator: A pressure actuator

differential-pressure valve: Inside the Bosch CIS fuel distributor, these valves (there is one for each cylinder) maintain a constant pressure drop at each of the control-plunger slits, regardless of changes in the quantity of fuel flow

differential side gear: The bevel gear on either side of the differential into the center of which the axle shaft fits

differential switch: See pressure differential switch

diffusing lens: The lens in the headlight glass which helps to focus the beam

diffusion: [1] The way in which innovations spread through market or non-market channels. [2] Mixing the molecules of two gases by thermal agitation

digifant: VW collaborated with Bosch to develop this electronic injection system. Digifant is similar to a Motronic system, except that its timing control map is less complicated than the Motronic map. And it does not have a knock sensor

digifant II: A refined version of VW 's digifant. This system has some control improvements and uses a knock sensor for improved timing control

digital caliper:

A slide-type caliper which gives a digital readout.

digital frequency control: (DFC) A system which automatically stabilizes or tunes the frequency of a selected radio station.

digital fuel injection: (DFI) a GM system, similar to earlier electronic fuel injection system, but with digital microprocessors. Analog inputs from various engine sensors are converted to digital signals before processing. The system is self-monitoring and self-diagnosing. It also has the capabilities of compensating for failed components and remembering intermittent failures

digital speedometer: A speedometer which shows the speed in digital numbers rather than a needle on a dial gauge (which is called an analog speedometer).

digital volt-ohm multimeter: (DVOM) a digital electronic meter that displays voltage and resistance

dig out: To accelerate at top power.

diluent: A fluid which thins or weakens another fluid.

dilution: See crankcase dilution.

dimmer: A switch used to lower or dip the headlights from high beam to low beam and back again. Also see headlight dimmer switch dimmer control: A rotary control switch which will increase or decrease the intensity of the instrument lights. Also called interior dimmer light switch.

dimmer switch: A device used to lower or increase the brightness and focus of the headlights (i.e., from high-beam to low-beam). The British term is "dipswitch." Also called headlight dimmer switch

DIN: Acronym for "Deutsche Industrie Normen" (German industrial standards). DIN horsepower is similar to the SAE net horsepower. It is measured at the output shaft of an engine fully equipped with normal accessories.

dinging: The action of straightening a damaged panel by using a hammer and dolly to bring it back into shape.

DIN mounting: The standard hole in the dash through which a DIN radio can be installed

Dino: A model of automobile manufactured by Ferrari

Click for books on Ferrari Dino

DIN radio: An aftermarket radio which fits into a thinner hole than most American radios. When installing a repacement radio, special faceplates are necessary

diode: An electrical component having the ability to pass electric current readily in one direction but resisting current flow in the other. When four diodes are connected in a certain way (i.e., "bridged") they will convert AC to DC, thus becoming a rectifier. Also see rectifier diode zener diode Dion axle: See de Dion axle

dioxide:

See carbon dioxide

dip: [1] A British term for dimming the headlights. [2] A low horizontal indentation of the pavement which may cause a speeding vehicle to lose control. [3] To immerse. See full dip treatment hot dip dipped beam: A British term for low beam

dipper: A British term for the dimmer switch

dipper switch: A British term for the dimmer switch

dipping mirror: A British term for day-night mirror

dipstick: The metal rod that passes into the oil sump it is used to determine the quantity of oil in the engine. The oil level is marked on the rod and matches level indicators on the rod. Dipsticks are used to check engine oil and transmission fluid. In most instances, the dipstick is inserted as far as it will go and then removed to check the level. In motorcycle engines, the dipstick is placed on the top of the threads (i.e., not screwed down) to check the level. oil dipstick

dipswitch: A British term for the dimmer switch

dip treatment: See full dip treatment

direct-acting shock absorber:

A telescopic shock absorber.

direct current: (DC) An electric current that flows steadily in one direction only. This is the type of current found in a battery and throughout the lighting and accessory system of a vehicle. Contrasts with alternating current (AC).

direct damage: A vehicle damage caused directly by an impact with an object. In contrast with an indirect damage.

direct drive: When the gearing is such that the crankshaft and driveshaft revolve at the same speed, the vehicle is in direct drive. Usually this occurs in high gear (except for those with overdrive). It is represented as 1.00:1 ratio.

direct drive powertrain: A system of propulsion where the speed of the engine, transmission, and propeller shaft rotate the same.

direct ignition system: (DIS) An ignition system which does not used a distributor but carries high voltage from the ignition coils directly to the spark plugs. Also see integrated Direct Ignition System direct injection: A fuel injection system which is generally used in diesel engines and forces fuel directly into the combustion chamber. It requires very high injection system pressure to overcome the pressure within the combustion chamber. Also see high speed direct injection directional baffle plate: Installed in a Quadrajet carburetor's secondary bores to help direct the airflow for improved distribution in the intake manifold

directional stability:

Ability of a vehicle to move forward in a straight line with a minimum of driver control. A vehicle with good directional stability will not be unduly affected by side wind, road irregularities, etc.

directional tire: Directional designs are recognized by the grooves in the tread that swipe away in a backward angle from the center of the tread face and rotate in only one direction. A direction of rotation arrow is located on both sidewalls of the tire. Directional tires enhance straight-line acceleration, provide maximum dry traction, better wet performance which helps to reduce rolling resistance as well as providing shorter stopping distances. See asymmetrical tread directional tread Symmetrical directional tread: An arrangement of bars, grooves, and ribs on a tire's tread in any manner that gives most effective traction when the tire revolves in only one direction. Also see directional tire direction indicator: The signal lights which blink on either side of the front of the vehicle and either side of the rear of the vehicle. Some early cars (like the Austin and Flying Standard) had small illuminated arms that flipped out from the B-post instead. The purpose of signal lights is to warn other drivers of a change in direction when turning a corner or changing lanes.

direction indicator warning light: A light on the instrument panel which flashes when the signal lights are operating. Usually this light is in the shape of a green arrow. On some cars, like Cadillac, a secondary light is mounted in a pod on the upper edge of each front fender and in a pod inside the cab above the backlight (i.e., back window)

direction of rotation: The direction in which a wheel or shaft turns or is supposed to turn.

direction of travel:

The direction in which an object (e.g., a vehicle) is moving.

direct polarity: Direct current flowing from anode (base metal) to cathode (electrode). The electrode is negative and the base metal is positive.

DIS: An acronym for direct ignition system or a distributorless ignition system similar to the C3I system, using two coils on four-cylinder engines

disabled: [1] the condition of a vehicle which is not able to be driven because of a failure of some component (e.g., bad battery, flat tire, engine seized) or because of an accident. [2] A driver who lacks the use of a limb.

disabler: See ignition disabler

disassemble: To take a vehicle or major component (e.g., the engine) apart in order to repair or restore the vehicle or component or to sell or recycle them. Also called "dismantle."

disc: May be spelled "disk." A flat dish-shaped item which may or may not have a center hole. Also see abrasive disc balance disc brake disc brake disc type caliper disc center locking disc clutch disc cutting disc disc brake fixed-caliper disc brake floating caliper disc brake four wheel disc brakes friction disc

grinding disc hardy disc hinged-caliper disc brake multi-disc multiple disc clutch multiple disc padding disc parking disc pin slider caliper disc brake plain disc wheel rotary disc valve tax disc ventilated discs wheel disc discard diameter: The diameter at which a worn brake drum should be replaced

discard thickness: The thickness at which a brake disc should be replaced

disc brake: A type of brake that has two basic components: a flat rotor (disc) that turns with the wheel and a caliper that is stationary. When the brake pedal is depressed, linkage (mechanical or hydraulic) causes the caliper to force its heat-resistant brake pads against both sides of the rotating disc thus slowing or stopping the wheel. Almost all new cars have disc brakes on the front wheels with drum brakes on the rear. More expensive cars have four wheel disc brakes. Because of the need for greater pressure to activate disc brakes, most cars so equipped also have a power booster. Wear takes place in the pads and the rotors. The pads are usually replaced while the rotors can sometimes be reground else they too must be replaced. If the rotors are not tightened correctly when installed, they can warp and cause a jerking motion when stopping. Also see brake, disc type caliper disc brake fixed-caliper disc brake floating caliper disc brake four wheel disc brakes hinged-caliper disc brake pin slider caliper disc brake sliding-caliper disc brake

disc brake gauge: A tool for measuring the thickness, wear, and score depth on brake discs

disc brake rotor: See brake rotor

disc brakes: See disc brake.

disc clutch: See multiple disc clutch

discharge: [1] The action of drawing electric current from the battery. The opposite action to charging. [2] to pour out liquid from a pump. [3] the product (e.g., the liquid) that is poured out of a pump. Also see battery discharge controller capacitive discharge gas discharge headlight gas discharge lamp gas discharge light gaseous discharge headlight gaseous discharge lamp main mixture discharge nozzle discharge air: Air conditioning air forced through the vents (ducts) into the passenger compartment

discharge check ball: In a carburetor, a small check ball that lifts off its seat when the pump well is pressurized by the accelerator pump, which allows fuel to be discharged into the venturi through the shooter nozzle

discharge controller: See battery discharge controller

discharged battery: A battery that cannot produce sufficient power.

discharge headlight: See gas discharge headlight gaseous discharge headlight discharge ignition: See capacitor discharge ignition system

discharge indicator: See battery discharge indicator

discharge lamp: See gas discharge lamp gaseous discharge lamp discharge light: See gas discharge light

discharge line: In an air conditioning system, the line which connects the compressor outlet to the condenser inlet

discharge nozzle: In a carburetor, the end of the main delivery tube that discharges fuel into the venturi area. See main mixture discharge nozzle

discharge pipe: The outlet pipe from a pump

discharge plug: See surface discharge plug

discharge pressure:

[1] The pressure exerted in a liquid pumped, expressed in psi. [2] The (high side) pressure of the refrigerant being discharged from the air conditioner compressor

discharge rate: Amount of current discharged from a battery, expressed in amps

discharge side: [1] Outlet side. [2] The part of the air conditioner system under high pressure, extending from the compressor outlet to the thermostatic expansion valve/tube inlet

discharge valve: [1] Valve on the outlet side of a reciprocating pump. The opposite is suction valve. [2] In an air conditioner system, a device used to check high side pressures, usually referred to as the high side service valve

discharge voltage: See spark discharge voltage

discharging current: Current supplied by a storage cell or battery, whose direction is opposite to that of the charging current

discolor: To alter the color of (a finish, metal, etc.) to a color which is not wanted. This fading may be caused by sitting in the sun, drops of contaminants (tree sap, bird dropping, spilled gasoline), poor paintwork, etc.

disconnect: To remove the terminal from a mechanical or electrical device or from the other side of the terminal. While some may be simply pulled apart, others have catches which must first be released.

disconnect terminal: Solderless connectors in male and female forms, intended to be easily disconnected and connected. Typically, a blade or pin (male connector) fits into a matching receptacle or socket (female connector). Many components have built-in (blade) terminals that require a specialized female connector

disconnect the battery: The action of removing the high tension electrical cables from the battery terminals. Also called "isolate the battery"

discount: See residual discount manufacturer discounts disc sander: A round, rubber disc powered by an electric drill and covered with abrasive paper for rough sanding work. also see orbital sander disc type: See brake disc type

disc valve: A type of rotary valve that allows the passage of fluid through an arc-shaped slot. Also see rotary disc valve disc wheel: [1] A wheel constructed of stamped steel. [2] A rim and metal disc that have been welded together. The disc is usually offset from the centerline of the rim to allow for dual tire mounting and to provide sufficient clearance between the duals. Disc wheels are attached to the hub with either single nuts or double cap nuts. Also see plain disc wheel solid disc wheel disc wheel type: A type of dual mounting wheels where the discs are offset from the centerline of the rim to provide clearance between the tires. They are held in place by double cap nuts, inner cap nuts, and outer cap nuts.

disengage: To move (a gear, dog clutch, etc.) so that it no longer meshes with another matching part

disengage the clutch: During normal driving, the power of the engine is being transferred to the gears of a manual transmission because the clutch plates are pressed together. When you press down on the clutch pedal (or pull in the clutch lever on a motorcycle), you are releasing that contact (i.e., disengaging the clutch) so that there is no connection between the engine and the transmission. You engage the clutch when you release the pedal or lever.

dish: [1] A depression in the top of a piston. [2] Offsetting of the hub on a rear wheel on a derailleur bike to make room for the freewheel and still allow the wheel to be centered within the frame. Also see negative wheel dish offset dish dished: A plate, washer, or disc is dished when the center is recessed from the rim like a shallow bowl.

dished brake disc: A disc that has worn thinner at the inner part of its friction surface. This is an abnormal form of wear

dishing: See negative wheel dishing

dish washer: A washer is a flat disc with a hole in the center. The disc in a dish washer is dished or bent in a concave fashion.

disk: More commonly spelled "disc."

dismantle:

To take a vehicle or major component (e.g., the engine) apart in order to repair or restore the vehicle or component or to sell or recycle them. Also called "disassemble."

dispersant: Dispersing or scattering in various directions; a state of matter in which finely divided particles of one substance (disperse phase) are suspended in another (dispersion medium) substance

displacement: The total volume of air displaced by all the pistons in travelling from BDC to TDC, i.e., the total volume of air and fuel the cylinder can hold before compression occurs. Also called "piston displacement." Also see cubic inch displacement engine displacement light displacement loaded displacement piston displacement positive displacement compressor displacement compressor: See positive displacement compressor

displacement taxes: A vehicle taxation system which determines the amount of taxes based on the engine displacement of the vehicle.

displacement volume: That part of the cylinder capacity that is swept by the pistons on their up and down strokes (i.e., the volume through which a piston moves in one stroke) formed by the bore diameter and the piston stroke. Also called "swept volume."

display: Any device that conveys information. In a vehicle, displays are either lights, gauges, or buzzers. Gauges may be analog or digita also l. See compass display graphic display unit heads up display

display unit: See graphic display unit

disposition fee: A fee you pay at the end of the lease, to the lessor, that covers the lessor's cost of getting the vehicle ready for sale after you have returned the vehicle. It is often applied against any deposit you made at lease inception.

dissipate: Scattered in various directions

distance: See braking distance reaction distance stopping distance trail distance distance piece: A collar or spacer which is placed between two parts to keep them the correct distance apart.

distance to the sun: See mean distance to the sun

distillation: Heating a liquid and then catching and condensing the vapors given off by the heating process.

distilled water: Pure water that through distillation has had all other chemicals (salts, suspended solids, and organisms) removed. It is recommended for topping up batteries and radiators.

distortion: A warpage, bendng, twisting, or change in form from the original shape.

distribution: See asymmetic power distribution asymmetrical power distribution constant power distribution equal power distribution load-controlled power distribution load distribution calculation load distribution power distribution static high-voltage distribution distribution calculation: See load distribution calculation

distribution channel: The path goods take as their title transfers from producer to consumer. The title transfer for consumer goods is usually accompanied by transfer of the physical goods, as well.

distribution tube: See distribution tubes.

distribution tubes: Tubes used in the engine cooling area to guide and direct the flow of coolant to vital areas.

distributor: [1] A unit in the ignition system designed to make and break the ignition primary circuit and to distribute the resultant high voltage to the proper cylinder at the correct time. The high voltage comes from the coil to the center terminal of the distributor cap and passes down the rotor. As the rotor turns, contact is made with each successive terminal on the circumference of the distributor cap. From there, the voltage goes into the spark plug wires and to the spark plug. Generally when your vehicle has its timing adjusted, it is the distributor that is adjusted. Also called "ignition distributor." [2] A distributor performs many of the same functions as wholesalers such as selling, physical distribution, credit, etc.; but is between the dealer and the wholesaler. Some industries use the term distributor instead of wholesaler. Also see breakerless distributor

fuel distributor high-tension distributor HT distributor ignition distributor shaft distributor short-type distributor distributor baseplate: The fixed plate in the body of the distributor on which the contact breaker or triggering device is mounted, and through the centre of which the distributor shaft passes distributor body: The bowl-like part containing the distributor shaft with the rotor arm at its top end, and, in the conventional version, the centrifugal advance mechanism and the contact breaker

distributor cam: The cam at the top of the distributor shaft with as many lobes as there are cylinders, acting on the heel of the contact breaker arm

distributor cap: An insulated cover containing a central terminal or tower with a series (one per cylinder) of terminals or towers that are evenly spaced in a circular pattern around the central terminal or tower, the secondary voltage travels to the central terminal or tower where it is then channelled to one of the outer terminals or towers by the rotor. The cap also keeps dirt and moisture out of the distributor.

distributor clamp: See distributor hold-down clamp

distributor hold-down clamp: A metal bracket at the base of the distributor that has a nut or bolt which can be loosened to allow the distributor to be moved on its shaft to readjust ignition timing or to open the points for gapping.

distributor injection pump: A fuel injection pump using pistons which pressurizes fuel for injection in the proper cylinder based on the relative port position of the rotating shaft in the hydraulic head

distributorless ignition system: (DIS or DLS) An electronic ignition system that does not have a conventional rotating distributor. Instead, it uses multi-spark ignition coils or one ignition coil for each spark plug.

distributor pipe: A pipe or tube through which the fuel travels from the fuel distributor to the injection nozzle

distributor rotor: A rotating part of the distributor which transfers high voltage to each spark plug. In a distributors with points, it is oblong-shaped; but in a distributors without points, it is usually a disc. Also called a "rotor" or "rotor arm."

distributor shaft: The metal shaft inside the distributor that has a cam wheel which revolves with the shaft and forces the points to open. A spring causes the points to close. The distributor rotor is mounted on the top of this shaft.

distributor tower: The terminals at the top of the distributor cap into which the spark plug wires fit. Also called "terminal tower"

distributor weight: One of two flat pieces of metal found inside the distributor's centrifugal advance mechanism on the baseplate. They swing out as speed increases and consequently advances the timing of the spark.

distributor wrench: A special tool used to tighten or loosen the distributor hold down clamp when installing or removing a distributor

dive: The action of the front of the vehicle to point downward (or dip) during braking. The opposite is squat. Also see anti-dive system anti-lift anti-squat system

anti-dive brake dive nose dive diversification: In today's market, especially in smaller centers, a dealership cannot make a profit on just one brand of vehicle -- especially foreign imports. Thus the dealership will diversify by having several brands (e.g., Mercedes-Benz, BMW, and Mazda). A car manufacturer diversifies by making several different kinds of vehicles (trucks, vans, luxury cars, family-size cars, commuter cars, compacts, convertibles, sports cars, etc.) in an attempt to reach every segment of the population. Some dealers or manufacturers may diversify by offering lawnmowers, boat motors, and motorcycles as well as automobiles (e.g., Honda) or even musical instruments (e.g., Yamaha).

diversion: An alternative route which traffic has to follow due to closure of a stretch of road for repairs, etc. A detour.

divert: To cause (air, a liquid, traffic, etc.) to follow a different course. For example, air is diverted to the air cleaner; traffic has been diverted around the accident site.

diverter valve: [1] A valve which adds an amount of air to the rich air-fuel mixture entering the intake manifold during deceleration. [2] Used in air injection system to channel airflow to either the exhaust manifold or oxidation catalyst under different operating conditions. See air gulp valve air bypass valve divided propeller shaft: A propeller shaft, usually in long chassis rear-wheel drive vehicles, which is divided into two sections with a bearing and CV joint mounted on a chassis crossmember at the central point. Also called "divided propshaft"

divided propshaft: A propeller shaft, usually in long chassis rear-wheel drive vehicles, which is divided into two sections with a bearing and CV joint mounted on a chassis crossmember at the central point. Also called "divided propeller shaft"

divider: A measuring tool with two straight pointed arms used to mark off and transfer measurements, e.g., on sheet metal or other metal components. Also see spring divider divorced choke: Vacuum diaphragm is mounted on the carburetor, but the bimetal spring is mounted either on a pad on the intake manifold or in a heat well in the exhaust man. Choke lever is operated by a mechanical linkage rod from the bimetal spring. Also called a remote choke

DIY: An acronym for "Do-it-yourself." Also see do-it-yourself market DIY mechanic: A person, whether qualified or not, who does his own repairs on his own vehicle.

D-Jetronic: Term used by Bosch to describe a fuel injection system controlled by manifold pressure. The D is short for "druck," the German word for "pressure." Manifold pressure is measured to indicate engine load (how much air the engine is using.) This pressure is an input signal to the control unit (ECU) for calculation of the correct amount of fuel delivery

DKW: In 1904 Jörgen Skafte Rasmussen set up on his own as a manufacturer of boiler fittings. In 1906 he purchased a textile mill in Zschopau, Saxony. Production started there in 1907. During the First World War Rasmussen worked on a steam-driven vehicle (Dampfkraftwagen), from which the three letters DKW were derived. In 1922 the company Zschopauer Motorenwerke started manufacturing its own motorcycles. The sporting successes of the lightweight motorcycles with 2.25 hp two-stroke engine were remarkable. Victories in the Berlin Avus race in 1922 and the triple victory by the DKW team in the ADAC Reichsfahrt the same year made people sit up and take notice. The first DKW motorcycle was consequently called the Reichsfahrt. Over the next six years Zschopauer Motorenwerke/DKW established itself as the world's biggest motorcycle manufacturer. Rasmussen finally had access to a powerful engine for the DKW car (600 cc, 15 hp) in the form of the

two-cylinder motorcycle unit (1927). The vehicle, which had a load-bearing body covered in imitation leather, had rear-wheel drive. It was produced in the Spandau district of Berlin from 1928.

DL: An abbreviation for deluxe which is usually applied to a series of vehicles which is one step up from "custom"

DLI: Acronym for "distributorless ignition"

dlr: Abbreviation for "dealer"

dnf: A racing term for "Did not finish"

Doble: A vehicle brand of which the 1925-1948 models are classic cars.

DOC: Acronym for "double overhead camshafts"

dock: See dry dock

document: See registration document vehicle registration document Dodge: A vehicle brand of which the 1967-70 Coronet R/T models are milestone dog: [1] Man's best friend.

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[2] A vehicle in very bad shape, which may not be man's best friend. [3] A lug or protrusion on an object.

dog clutch: [1] A simple coupling with two halves called "dogs," with square projections in one that engage in square slots in the other to transmit drive, but can also be disengaged to break the drive. [2] Mating collars, flanges, or lugs which can be moved as desired to engage or disengage similar collars, flanges, or lugs in order to transmit rotary motion

dog guard: A grid made of tubular bars or wire mesh to keep a dog in the back part of a vehicle

dogleg pillar: The C-post or C-pillar.

dogleg section: An irregular shaped part of the leading edge of the rear quarter panel of a four-door sedan along the wheel cutout and up to the waistline

DOHC: Acronym for "double-overhead camshaft." Refers to an engine with two overhead camshafts. Also see double overhead cam engine type do-it-yourself market: (DIY) The vehicle maintenance and repairs conducted by the vehicle owner or friend/relative who purchase auto parts from a retail outlet.

do-it-yourself mechanic: A person, whether qualified or not, who does his own repairs on his own vehicle.

dolly: [1] A metalworking tool, available in a variety of shapes and sizes, comprising a curved polished block of cast iron or forged steel, used to assist in forming three-

dimensional shapes and in straightening dented panels, usually by holding the dolly behind the metal to be shaped and hammering the metal. See heel dolly. [2] A small two-wheeled trolley for moving heavy objects. [3] A trolley that supports the front wheels or back wheels of a disabled vehicle for towing it. Also see grid dolly heel dolly kidney dolly mushroom-shaped dolly shrinking dolly toe dolly wheel dolly domains: Groups of atoms that have same magnetic polarity

dome: See pop-up piston dome dome lamp: A dome-shaped interior light. Also called a "dome light."

dome light: A dome-shaped interior light. Also called a "dome light."

domestic: A vehicle produced in Canada, United States, or Mexico. The opposite is "foreign."

donor car: A car from which parts are used to repair another one of the same type or to build a special or kit car

door: The hinged side panels of a vehicle which permit the occupants to enter or leave the passenger compartment. In most cases the doors open so that the hinge is toward the front of the vehicle. When the hinge is toward the back of the vehicle, they are called "suicide doors."

Also see filler door five-door four-door gull-wing door pull-out door handle rear-hinged door sagging door suicide door three-door two-door door alignment: Accuracy or fitting of the door in the door aperture

door aperture: opening into which the door fits

door beam: A longitudinal reinforcing bar which fits between the inner and outer shell of the door. It is designed to withstand side impacts. Also called a side impact bar.

door bottom: The lower door area, both of the door skin and of the door frame, also the narrow horizontal lower panel of the door frame that has the drain holes

door capping: the molding between the door trim panel and the window glass

door check arm: A metal part near the hinge which has several notches which allows the door to remain partially or fully open

door check strap: A leather strap near the hinge which prevents the door from opening too far.

door face: The edges of a door which are not visible from the outside or inside when the door is shut. Also called "door shut."

door frame: [1] the bare skeleton of the door to which the door skin and door trim are added. [2] the door aperture.

door gap: The distance around the door between the edge of the door and the aperture

door glass: The glass pane filling the top half of a door, which can usually be lowered or raised

door handle: The interior or exterior handle for opening a door. Also see pull-out door handle door hinge: The pivoting part which is attached to the door fram and the door pillar. It allows the door to swing open or shut.

door hold-open spring: A spring attached to the door hinge to provide a spring load to keep the door in an open position

door latch: That part of the door lock which contacts the striker plate as the door is closed, and springs back when the door is fully shut to hold it in the closed position

door lock: A mechanism for allowing a door to be opened either by the operation of a key on the outside of the door or by releasing a mechanical switch on the inside of the door.

door lock de-icer: A fluid which is inserted into the key-hole to melt the ice which has bound the tumblers in a door lock.

door mirror:

An exterior, door mounted, rear-view mirror. On trucks and older vehicles the mirror is manually adjusted; but on many cars they are adjuste either by a cable inside the cab or by an electric motor with the switch inside the cab. The control device is located on the door, on the dash, or on the console between the driver and passenger.

door pad: The door inner trim panel

door panel: A panel covered in vinyl or other material and mounted to the inside of the door

door pillar: One of the vertical members of the body shell ahead of and behind the doors, which also support the roof structure and reinforce the body as a whole

door pillar switch: A small switch, typically in the lower portion of the A-pillar, whose main function is to turn on the courtesy lights when the door is opened and to indicate that the door is open especially if the key is left in the door.

door pocket: A container or pouch located on the lower inside portion of the door. It can be used to store maps and other small items

door post: One of the vertical members of the body shell ahead of and behind the doors, which also support the roof structure and reinforce the body as a whole

door protector: A strip of rubber, plastic, or chrome which fits over the edge of the door to protect it from damage when opened carelessly

door pull: A handle on the inside of a vehicle door which allows the driver/passenger to pull his door shut

door rates:

The hourly rates charged by dealers on standardized units of service work. Hourly rates may or may not correspond to an actual hour of work.

door seal: A weatherstrip surrounding the door to form a seal when the door is closed

door shut: The edges of a door which are not visible from the outside or inside when the door is shut. Also called "door face."

door sill: The bottom part of the door frame (i.e., the pat under the door when it is closed).

door skin: The large sheet metal panel of the door visible from the outside. Available to body shops as a replacement panel for most cars

door speaker: Radio/stereo speakers mounted in the door panel

door stay: A device incorporated in door hinges that keeps the door in an open position and prevents it from closing under its own weight

door step: Top part of the outer sill, visible when the door is opened

door surround: The faces of the door step, door pillars, and roof section which makes up the door aperture

door trim: A panel covered in vinyl or other material and mounted to the inside of the door

door well: A cavity enclosed by the door frame, door skin, and trim panel containing the window winding mechanism and into which the window glass is lowered

doosy: See Duesy.

dope: Highly combustible alcohol/methanol-based fuel mixture

Dorris: A vehicle brand of which the 1925-1948 models are classic cars.

dos-a-dos: Back to back seating on older cars where the driver and front passenger faced forward; but the two rear passengers faced rearward.

DOT: Acronym for "Department of Transportation" -- an American federal agency or "Department of Transport" -- a British agency

DOT 3: This brake fluid has a glycol base. It is clear or light amber in color. Its dry boiling point is 401° minimum and wet boiling point of 284° minimum. It will absorb 1 to 2 percent of water per year depending on climate and operating conditions. It is used in most domestic cars and light trucks in normal driving. It does not require cleaning the system and it can be mixed with DOT 4 and DOT 5.1 without damage to the system. The problem with it is that it absorbs moisture out of the air and thereby reduces its boiling point. It can also damage the paint on a vehicle.

DOT 4: This brake fluid has a borate ester base. It is clear or light amber in color. Its dry boiling point is 446° minimum and wet boiling point of 311° minimum. It is used in many European cars; also for vehicles in high-altitude, towing, or high-speed braking situations, or ABS systems. It does not require cleaning the system and it can be mixed with DOT 3 without damage to the system. The problem with it is that it absorbs moisture out of the air and thereby reduces its boiling point. It can also damage the paint on a vehicle.

DOT 5: This brake fluid generally has a silicone base. It is violet in color. Its dry boiling point is 500° minimum and has no wet boiling point in federal DOT 5

specifications. It is used in heavy brake applications, and good for weekend, antique, or collector cars that sit for long periods and are never driven far. It does not mix with DOT 3, DOT 4, or DOT 5.1. It will not absorb water and will not damage the paint on a vehicle. It is also compatible with most rubber formulations. The problem with it is that it may easily get air bubbles into the system which are nearly impossible to remove, giving poor pedal feel. It is unsuitable for racing due to compressibility under high temperatures. If as little as one drop of water enters the fluid, severe localized corrosion, freezing, or gassing may occur. This can happen because water is heavier and not mixable with silicone fluids. It is unsuitable for ABS.

DOT 5.1: This brake fluid has a borate ester base. It is clear or light amber in color. Its dry boiling point is 500° minimum and wet boiling point of 356° minimum. It is used in severe-duty vehicles such as fleets and delivery trucks; towing vehicles, and race cars. It can be mixed with DOT 3 or DOT 4 without damage to the system. It maintains higher boiling point than DOT 3 or DOT 4 fluids due to its higher borate ester content. It is excellent for severe duty applications. The problem with it is that it costs more than other fluids and there is limited availability. It also absorbs moisture out of the air and thereby reduces its boiling point. It can also damage the paint on a vehicle.

DOT number: The symbol DOT on a tire means it meets or exceeds Department of Transportation safety standards. Following DOT are a maximum of eleven numbers. E.g., "DOT FT TW A2NX 092." ("DOT" = meets or exceeds federal standards; "FT" = identifies manufacturing plant; "TW" = the code for tire size; "A2N" or "A2NX-3" or optional 4 digits = manufacturer's code to identify the characteristics of the tire; "092" = Week of mfg., in this case, 9th week of 1972. Prior to May 22, 1971 the manufacturer's plant was identified by only three numbers (Example DOT 129). Retreaded tires must also have a new serial number and can be determined by the letter "R" following DOT letters.

double-acting: (of a shock absorber or pump) having a piston with fluid on both sides so that in a pump one piston end performs the suction stroke while the other discharges the liquid, and in a shock absorber both upward and downward movements are damped

double-barrel carburetor: Two throttle openings or barrels from the carburetor to the intake manifold. Also called "twin-choke carburetor." Also see

four-barrel carburetor single-barrel carburetor double bottom: Compartments at the bottom of a ship between inner bottom and the shell plating, used for fresh water, ballast water, fuel oil, etc

double cap nut: (Budd mounting) A type of securing device which consists of an inner cap nut (sleeve nut) and an outer cap nut. It is the most common method for mounting disc wheels in dual.

double century: A bicycle ride of 200 miles.

double clutch: See double clutching.

double clutching: Vehicles with manual transmission and no synchromesh have difficulty shifting from one gear to another. With synchromesh, shifting is accomplished by depressing the clutch pedal and moving the gearshift selector from one gear to the next. Without synchromesh, shifting is not smooth unless you double clutch. Here you depress the clutch pedal shift to neutral lift up on the clutch pedal blip the throttle (accelerator), then depress the clutch pedal again and shift to the next gear. While this action seems complicated, you can get used to doing it to avoid the grinding noise heard in non-synchromesh transmissions.

double coat: Two single coats of primer or paint applied with little or no flash time between them. Also see single coat double-decker: A passenger bus with a set of seats on a floor above a lower set.

double-decker bus:

A passenger bus with a set of seats on a floor above a lower set.

double-declutch: A British term for double clutch

double-ended spanner: British term for double-ended wrench

double-ended wrench: A tool which has a hexagon ring at each end.

double filament bulb: A light bulb with two filaments. For example a headlamp bulb with one for the high beam and another for the low beam; or a bulb with one filament for the stop light and another for the taillight.

double flare: The end of the tubing, especially brake tubing, has a flare made so that the flare area uses two wall thicknesses. This makes a much stronger and safer joint in bicycle tubing.

double helical gear: A gear with two rows of inclined teeth, each forming an open "V" or chevron. Also called "herringbone gear"

double hexagon socket: A socket with 12 points rather than the normal 6 points.

double leading brake shoe: A system of braking where two hydraulic plungers and separate pivots create better braking when the vehicle is going forward; however it is not very effective when the vehicle goes in reverse. Also see single leading brake shoe double overhead cam: (DOHC) An engine with two camshafts located above the cylinders. One

drives the intake valves and the other operates the exhaust valve. In a single overhead cam engine (SOHC), one cam has enough lobes to drive both the intake and exhaust valves. The DOHC engine is considered to be a very sophisticated and more efficient engine; but is sometimes more difficult to adjust the valves. Also called "twin overhead camshaft." See engine type. double overhead camshaft: See double overhead cam

double-pivot steering: Steering in which the steered wheels are pivoted on kingpins, which is the usual arrangement on motor vehicles. Also see ackermann steering single-pivot steering double reduction axle: A drive axle construction in which two sets of reduction gears are used for extreme reduction of gear ratio

double reduction gearing: Gearing in which the ratio is reduced in two stages, used especially in heavy trucks

double roller chain: See duplex chain

double-tube shock absorber: An older design of hydraulic shock absorber using two concentric tubes, one serving as the working cylinder, the other as the reservoir. Also see single-tube shock absorber double wishbone: A form of independent suspension used on the front of a vehicle where both the upper and lower wishbones are of equal length.

double wishbone suspension: See double wishbone

doughnut: See rubber doughnut coupling

doughnut coupling: A flexible joint made of rubber and shaped like a ring doughnut. It is used, for example, between the front of the propeller shaft and the gearbox. Also called "doughnut joint." Also see rubber doughnut coupling doughnut joint: A flexible coupling made of rubber and shaped like a ring doughnut. It is used, for example, between the front of the propeller shaft and the gearbox. Also called "doughnut coupling."

dowel: A pin projecting from one of two mating surfaces which fits into a correspondng hole in the other thus lining up the two pieces accurately during assembly. Also see locating dowel dowel pin: A pin (steel or wood), passed through or partly through, two parts to provide proper alignment and to prevent movement between them. Sometimes called "locating pin."

downdraft carburetor: A carburetor in which the air passes downward through the carburetor into the intake manifold. Contrasts with sidedraft carburetor.

downdraught carburetor: British spelling for downdraft carburetor

downflow radiator: A traditional type of vertical radiator, with header tank and bottom tank and a system of small tubes and cooling fins in-between, the hot water entering at the top and exiting at the bottom. This type of radiator has been replaced by a crossflow radiator.

downforce: A vertical force directed downward, produced by airflow around an object such as the body of a vehicle.

downgearing: See downshifting.

downhand welding: See flat position welding

downpipe: The pipe that joins the entire exhaust system to the exhaust manifold.

downshift: The act of selecting a lower gear. In Britain it is called "downward change." Also see forced downshift downshifting: Manually shifting to a lower gear in order to use the engine compression to assist in reducing the vehicle's speed. Also called "downgearing."

downstroke: The downward movement of the piston, either the intake stroke or the power stroke in a four-cycle engine.

downtime: Downtime occurs when a vehicle is being repaired (esp. a commercial vehicle), it cannot fulfil its function. There is a loss in both potential proceeds from its use as well as the salary of its operators.

down tube: The tube running from the headset to the bottom bracket one part of the main triangle on a bicycle frame.

downward change: A British expression of shifting the transmission to a lower gear. The North American term is downshift.

dozer: A portable frame straightening machine

DP: Acronym for "dash-pot"

D-pillar: The fourth vertical post in a van or station wagon. Also called D-post

D-post: The fourth vertical pillar in a van or station wagon. Also called D-pillar

dr: Abbreviation for "door," as in 2-dr. Sedan."

draft: [1] An unpleasant current of air intruding into the interior of a car. [2] The depth of the ship below the waterline measured vertically to the lowest part of the hull. Also see horizontal draft carburetor drafting: The action of following closely behind a faster vehicle so as to take advantage of the aerodynamic effect which causes both the vehicles behind and the one in front to move faster. See slip stream.

draft marks: The numbers which are placed on each side of a ship at the bow and stern from the lower edge of the number to the bottom of the keel

drag: [1] To accelerate a vehicle from a standing start, over a course one-fourth mile in length. Also called "drag racing." [2] Used by some drivers when referring to challenging another driver to an acceleration race. [3] Air resistance. See aerodynamic drag.

[4] The condition of a clutch when it fails to fully disengage. The plates still rub against each other and causes intermittent contact between the engine output and the transmission gears. Called "clutch drag." [5] The condition of brakes when the pads or shoes still rub the disc or drum. Called "brake drag." Also see aerodynamic drag clutch drag coefficient of drag idling drag wind drag drag coefficient: (Cd) A number used in calculating the aerodynamic drag acting on a vehicle. The drag coefficient is a function of factors like the shape of the vehicle, airflow through the vehicle for ventilation and cooling. The number is determined in a wind-tunnel or by coasting tests performed on the vehicle. The lower the drag coefficient the less drag on the vehicle and the more aerodynamic is the vehicle. A sleek vehicle has a drag coefficient, or "Cd," of about 0.30; a square, flat plate's is 1.98. Also signified by Cx.

drag link: A steel rod connecting the pitman arm to one of the steering knuckles. On some installations the drag link connects the pitman arm to a center idler arm.

drag race: A competitive match between two vehicles in which they race over a 1/4 mile course.

dragster: A specially constructed car for drag racing, typically with a huge supercharged V-8 engine mounted well back in the chassis and extremely wide rear tires

dragstrip: A quarter-mile stretch of track for drag racing

drag wheel: Special steering wheel used on some dragsters. Often consists of a crossbar spoke and a portion of rim on each end.

drain: [1] To empty a container usually from the bottom. [2] A tube or channel which allows water to run to another place. Also see magnetic drain plug oil drain plug oil drain valve radiator drain cock radiator drain plug draincock: A petcock or drain tap. Also see radiator drain cock drain hole: A hole drilled in the bottom of a box section or a door, to allow water that has accumulated to escape so as to prevent or delay rusting

draining tray: A container used to catch oil when draining the sump, transmission, etc.

drain plug: Usually a threaded plug at the lowest point of the sump, gearbox, cooling system, etc., which is removed in order to drain the oil or coolant, and typically has a recessed hexagon head. Also see magnetic drain plug oil drain plug oil pan drain plug radiator drain plug sump drain plug drain plug key: A tool for removing and tightening drain plugs, e.g., on transmissions and engine sumps, either as a multi-purpose tool with a number of different drives in the form of hexagonal or square projections at either end for different drain plugs, or as a special tool for one specific size of drain plug. Also called a "drain plug wrench."

drain plug spanner:

A British term for a drain plug wrench

drain tap: A device which controls the flow of fluid (oil or coolant) out of the bottom of the cylinder block or the bottom of the radiator.

drain plug wrench: A tool for removing and tightening drain plugs, e.g., on transmissions and engine sumps, either as a multi-purpose tool with a number of different drives in the form of hexagonal or square projections at either end for different drain plugs, or as a special tool for one specific size of drain plug. Also called a "drain plug key."

drain valve: See oil drain valve

draught: British spelling for "draft"

draught excluder: A British term for "weatherstrip"

draw: [1] To form wires by pulling the wire stock through a series of hardened dies. [2] The process of removing the hardness from a piece of metal. [3] The amount of electrical load or electrical requirement.

drawback: See duty drawback

drawbar: Two converging bars forming a V-frame or an A-frame at the front of a trailer or motorhome, which carry the coupling for attaching to the towing vehicle

draw filing: A file is drawn across work at right angles. See draw-filing.

draw-filing:

Filing by passing the file, at right angles, up and down the length of the work.

draw-through: A tubocharger system in which the turbocharger sucks the air/fuel mixture through the carburetor or fuel in, i.e., the air and fuel mixing occurs upstream from the turbocharger

dream car: A one-of-a-kind futuristic, experimental automobile usually appearing at auto shows to stimulate interest in the manufacturer's products. Much design benefit spurs from dream cars and many reach the production stage.

dress: [1] to give (a rough surface, flanges, etc.) the right shape by grinding or a similar process. [2] To prepare ore for smelting by removing impurities.

dressing: See tire dressing

dribble: Insufficiently atomized fuel issuing from the fuel injection nozzle at or immediately following the end of the main injection phase

drier: [1] A dehumidifier. [2] A drying oven. Also see A-drier accumulator-drier accumulator drier gelling drier infrared radiant drier receiver-drier top coat drier tunnel drier drift: [1] A short bar or punch used with a hammer to drive a component in or out of place for removal or installation.

[2] To deviate from the normal direction. See four-wheel Drift tire deviation angle drift punch: A tapered tool which is hit with a hammer and used to remove or install pins, shafts, rivets, etc. or to align holes when inserting screws and bolts.

drill: [1] A tool used to bore holes. [2] The action of using a drill to make a hole. Also see hammer drill hand drill letter drills number drills press, drill spot-weld drill twist drill drill bit: A piece of rod with spiral recesses cut in it and a hardened steel tip, made in different sizes for drilling different sized holes, and inserted in the chuck of a drill

drilled: An expression used to describe a hole which has been cut into a crankshaft to allow oil to be fed to the main bearings on the connecting rod throws.

drill press: A nonportable machine used for drilling.

d ring: See D-ring.

d-ring: A D-shaped ring found on many models of bicycle shift levers, used to adjust the level of tension on the inner parts of the lever.

drip molding: The curved metal molding around the edge of the roof that directs water away from the side windows. Also called "drip rail"

drip moulding: British term for "drip rail"

drip rail: A gutter running along either side of the roof to take water to the front or rear of the car, and prevent it from dripping into the car when the door is opened. The British term is "drip moulding"

drivable: The condition of a vehicle which may have many mechanical and appearance problems, but it has an engine which runs and wheels that turn, etc. so that it can be operated and driven.

drivability: The general qualitative evaluation of a powertrain's operating qualities, including idle smoothness, cold and hot starting, throttle response, power delivery, and tolerance for altitude changes.

drive: [1] to travel in a car as in the expression, "We drove to Chicago." [2] to operate a vehicle as in the expression, "Martha drove to New York by herself." [3] to cause a wheel, shaft, etc. to turn or rotate. [4] to propel a vehicle. [5] a journey in a car as in "The drive to Chicago was uneventful." [6] to go for a drive as in, "We went for a drive last Sunday." [7] A stretch of private road leading to a house (i.e., driveway). [8] A means of transmitting power or motion as in "The drive is controlled by a servo switch." [9] A tool which has a square end (1/4 inch, 3/8 inch, or 1/2 inch) which fits into a recess in a corresponding socket for the installation or removal of nuts and bolts. [10] a die position. [11] One of the forward gears marked on the gear selector of an automatic transmission. Also see all-wheel drive all wheel drive

automatic four-wheel drive axle drive belt drive bendix drive bendix type starter drive bevel gear drive camshaft drive sprocket camshaft drive center drive chain drive clutch starter drive direct drive powertrain direct drive dual drive eccentric drive Ferguson four-wheel drive final drive gear final drive ratio final drive fixed drive flexible drive handle flexible drive four-wheel drive friction drive front-wheel drive front wheel drive full-time four-wheel drive hotchkiss drive hydrostatic drive inertia drive intermediate drive plate left-hand drive meshing drive metallic drive screw overrunning clutch starter drive part-time four-wheel drive permanent four-wheel drive real-time four-wheel drive rear-wheel drive rear-wheel drive transaxle right-hand drive shaft drive starter drive strap drive tandem drive test-drive

test drive torque tube drive torsen four-wheel drive tri-drive two-wheel drive v-belt drive drive belt: A flat belt which connects two or more pulleys so as to transmit motion from one pulley to the other. Also see camshaft drive belt drive cable: See speedometer drive cable

drive chain: An endless chain which encircles two or more sprockets so as to transmit motion from one sprocket to the other

drive end: The end of an alternator, generator, etc., where the drive pulley or gear is located.

drive end bracket: The cover which houses the drive end of an alternator or generator

drive fit: A condition of fit (contact) between two parts that requires pressure to force the parts together. Usually the shaft is slightly larger than the hole so that they must be pounded or forced or driven together. Also called "force fit," "press fit," or "interference fit."

drive gear: The gear which transmits the power to a driven gear. Also see final drive gear drive handle:

A tool, typically in the form of a bar, for turning sockets to loosen and tighten nuts and bolts, with a male square drive to be inserted into the female square drive of sockets for the turning operation. They include ratchets, jointed handles, speed brace, T-handles, torque wrenches, speeeder handle, and breaker bar. Also see flexible drive handle drive layout: The arrangement of the order of the engine, transmission, and driven axles, e.g., Front-wheel drive, rear-wheel drive, mid-engine drive, four-wheel drive, two-wheel drive

drive line: See driveline

driveline: All the individual components beyond the engine up to the wheels (e.g., clutch, drive shaft, differential, driven axles); but not the engine or transmission. Also called "drivetrain" or "powertrain"

drive module: interchangeable unit providing motive power, either in the form of an electric motor and ancillaries, or an internal combustion engine with all necessary components, for alternative use in the same vehicle according to needs and conditions

drive motor: electric motor providing motive power in an electric vehicle

driven: Something made to rotate by the engine or some other source of motive power. Also see two-wheel driven driven axle: The axle to which power is transmitted to drive the vehicle

driven gear: An engine needs to transmit power to the wheels by the use of sprockets and chain (as in a motorcycle) or by a drive gear which meshes with a driven gear to propel

the vehicle.

driven plate: The central clutch plate carrying clutch linings and held under pressure between the flywheel and the pressure plate when the clutch pedal is released, and transmitting power to the gearbox input shaft via splines

driven pulley: A pulley which is surrounded by a belt to receive power from the drive pulley

driven sprocket: On a vehicle which uses a chain (like a bicycle and some motorcycles), there are two important sprockets: the drive sprocket is connected to the power source (the engine or your pedals) and the driven sprocket is usually connected to your rear wheel.

driven wheel: The wheel (or wheels) to which power is transmitted to drive the vehicle

drive pinion: The shaft that takes power from the clutch into the gearbox. Also see clutch shaft hypoid gear drive plate: A light plate bolted to the crankshaft to which the torque converter is attached in a vehicle with automatic transmission. Also see center drive plate intermediate drive plate torque converter drive plate drive powertrain: See direct drive powertrain

drive pulley:

A pulley which is surrounded by a belt to transmit power to the driven pulley

driver: [1] A collectible vehicle which is too good to treat as a beater and not quite good enough to show. It is a presentable old car or truck that is used for everyday purposes. It is maintained as though it were a late-model vehicle. With care, it could be easily restored to show car condition. [2] A person who operates the controls of a vehicle to regulate its speed and direction. [3] A tool used to insert something like a fastening device (e.g., screwdriver). [4] Also see drivers impact driver nut driver rim drivers socket driver tubular nut driver valve guide driver driver air bag: original type of air bag, designed to protect the driver from being hurled into the steering wheel and instrument panel

Driver and Vehicle Licensing Agency: (DVLA) A section of the British Department of Transport which is responsible for keeping records of all registered vehicles and issuing registrations and licences for vehicles as well as licences for drivers. The center is located in Swansea.

Driver and Vehicle Licensing Center: The location for the British Driver and Vehicle Licensing Agency located in Swansea.

drive ratio: See final drive ratio

driver error: A mistake made by the operator of a vehicle particularly when there is an accident. An accident may be caused by a vehicle failure (e.g., a tire blowout), unsafe road conditions (e.g., snow, ice, fallen rock or tree), the inattention of a pedestrian, or the fault of a driver (e.g., drunkenness, inattention, intentional damage, disobedience to

rules of the road).

driver evaluation: A test of a driver's ability to handle a vehicle. May be used to grant a driver's licence for a particular type of vehicle (i.e., motorcycle, passenger car, truck, bus, taxi)

drivers: Colloquial term for "drive axle tires." Also see rim drivers drive screw: See metallic drive screw

driveshaft: The shaft connecting the transmission output shaft to the differential pinion shaft. It transmits power from the transmission to the differential. It is found primarily on rear-drive vehicles. There is usually a universal joint on either end. Also called "propeller shaft." Also see auxilliar drive shaft bevel drive shaft drive shaft: See driveshaft driveshaft safety strap: A metal strap or straps, surrounding the driveshaft to prevent the shaft from falling to the ground in the event of a universal joint or shaft failure.

drive sprocket: On a vehicle which uses a chain (like a bicycle and some motorcycles), there are two important sprockets: the drive sprocket is connected to the power source (the engine or your pedals) and the driven sprocket is usually connected to your rear wheel. Also see camshaft drive sprocket drive tool:

Any accessory for use with a socket wrench, including the drive handle

drive train: [1] This term refers to the entire moving part of the car: Engine, clutch, transmission, driveshaft, differential, axles, and sometimes the wheels. Also see strain in the drive train [2] The derailleurs, chain, freewheel, and crankset of a bicycle.

drivetrain: [1] This term refers to the entire moving part of the car: Engine, clutch, transmission, driveshaft, differential, axles, and sometimes the wheels. [2] The derailleurs, chain, freewheel, and crankset of a bicycle.

drive transaxle: See rear-wheel drive transaxle

driveway: A short drive, often leading to a garage

driving: [1] providing motive power, making a gear, shaft, etc. rotate. [2] Controlling the movement and direction of a vehicle. Also see al fresco driving defensive driving metro driving urban driving driving axle: The axle which is driven by the engine through the drivetrain. Used to hold, align, and drive rear wheels and support weight of vehicle on rear wheel drive cars, or half shafts on front wheel drive cars that provide torque force to front wheels. Also called the "drive axle" or "driven axle"

driving conditions: The situation created by the amount of traffic, the weather, and state of the roads

driving gear: The gear which is driven by the engine. Also called the "driven gear"

driving habits: The personal behaviour of the driver when controlling the vehicle, including the speeds he travels, how and when he shifts gears, how he uses the brakes, when and if he uses his signal lights, how he changes lanes, how he turns corners, etc.

driving lamp: A British term for "driving light" or "spot light." Also see auxilliar driving lamp driving licence: A British term for "driver's licence" or "operator's licence." A document which allows the holder to drive a certain type or types of vehicle, and is the only document required to be carried by the driver in Britain

driving light: An auxiliary light used at night to illuminate the side of the road and increase the viewing distance. Also see auxiliary driving light driving mirror: A British term for either the interior rear-view mirror or the mirrors mounted on the outside of the front doors or the front fenders

driving position: The position in which the driver grasps the steering wheel and adjusts the location of the seat in relation to the pedals.

driving style: The manner in which the driver handles a vehicle. See sporty driving style

driving wheel: The wheel(s) which is driven by the engine through the drivetrain. Also called the "driven wheel"

drop: [1] A sudden reduction of pressure or voltage, etc. See voltage drop. [2] The vertical distance from the horizontal line connecting the two wheel axles and the bottom bracket, one way of determining the location of the bottom bracket in relation to the rest of the bicycle frame. Also see drops drop arm: A British term for the pitman arm

drop-center axle: A beam axle in which the main central portion of the beam is lower than the wheel centers, which was the usual layout for front axles until independent front suspension became almost universal

drop-center rim: See drop center rim

drop center rim: A one-piece rim with a deep center section which is lower than the two outer edges, this allows the bead of the tire to be pushed into the low area on one side while the other side is pulled over and off the flange. The British term is "well-base rim"

drop center rim taper: A passenger rim where both bead seats are tapered 5° or a tubeless truck rim where both bead seats are tapered 15°.

drop-centre rim: See drop center rim

drop centre rim: See drop center rim

drop forged: A part that has been formed by heating the steel blank red hot and pounding it into shape with a powerful drop hammer.

drop forging: A piece of steel shaped between dies while hot

drophead: [1] A British term for a convertible. The word "head" refers to the roof. [2] Having a folding top which can be raised or lowered over the passenger compartment. See drophead coupé Jaguar Drophead Lagonda Drophead drophead coupe: (DHC) This is a two-door automobile which has the appearance of a convertible, but the roof is fixed in place. Abbreviated: dhc. In Europe, it is called a "cabriolet."

drophead coupé: This is a two-door automobile which has the appearance of a convertible, but the roof is fixed in place. Abbreviated: dhc. In Europe, it is called a "cabriolet."

dropout: A slot in the frame into which the rear wheel axle fits. Also see fork tips dropout hanger: A threaded metal piece that extends below the right rear dropout of a bicycle used as a mount for the rear derailleur.

dropped axle: A front axle that has been altered so as to lower the frame of the vehicle, consists of bending the axle downward at the outer ends.

dropped valve: A situation where the rising piston hits a valve which has become dislodged or open at the wrong time.

drops: The lower, straight portion of a turned-down-type handlebar set.

droptop: A colloquial term for "convertible."

Druid forks: Side-sprung girder forks on a motorcycle. Druid was the original maker

drum: [1] A cylindrical container. [2] A housing for transmission gears where the bands are located. [3] To make a "whump, whump" sound. Also see brake drum brake drum lathe drum brake drum brake: A type of brake using a shallow drum-shaped metal cylinder that attaches to the inner surface of the wheel and rotates with it. When you press down on the brake pedal, curved brake shoes with friction linings press against the inner circumference of the drum to slow or stop the vehicle. Also see brake drum drum brakes: See drum brake.

drum compound: See anti-drum compound

drum lathe: See brake drum lathe

dry: [1] For paint, to lose its wetness often to the place where the surface is not even tacky. [2] For bearings, to lack grease or other lubricant.

Also see air-dry air dry hard-dry surface dry touch-dry dry ballast: A form of ballasting where a fine powder of barium sulphate is inserted inside the tire. It is sometimes referred to incorrectly as "Lead" ballast because of one brand name, "Ledballast."

dry battery: See dry cell.

dry boiling point: The temperature at which fresh brake fluid from a new container will boil. See wet boiling point, and DOT 3.

dry cargo ship: Vessel which carries all dry cargo

dry cell: A battery (like a flashlight battery) that uses no liquid electrolyte.

dry charged battery: A battery with the plates charged but lacking electrolyte when ready to be placed in service, the electrolyte is added.

dry clutch: A clutch with only one plate.

dry dock: An enclosed basin used to place a ship on dry land so that all the submerged parts and fittings can be repaired.

dryer:

See a-dryer

dry friction: Dry friction exists when the rubbing parts have no other substance between them and are clean of other materials (i.e., no grease or oil). Opposite to wet friction.

dry galvanizing: A hot-dip galvanizing method in which the metal components are first immersed in a solution of flux and then dried, so that they become pre-coated with a thin film of flux, which melts in the zinc bath, to which certain metals, such as tin and aluminum, may be added to give fluidity, and in the case of tin, brightness. The opposite is wet galvanizing

drying oven: An enclosure where painted vehicle bodies are subjected to heat in order to dry and/or bake on the paint

dry joint: A faulty electrical joint which does not give proper contact

dry liner: When a cylinder sleeve is pressed into a bore and the cooling fluid does not contact the outside of the sleeve, the engine has a dry liner. Also see liner dry manifold: An intake manifold with no integral coolant passages cast into it

dry setting: The adjustment of the float with a graduated rule or drill bit while the carburetor is disassembled on the bench. Usually consists of setting a prescribed clearance between the top of the float and the air horn

dry sleeve: A cylinder sleeve application in which the sleeve is supported in the block metal over its entire length, the coolant does not touch the sleeve itself. Also see

wet sleeve dry spray: See dry-spray.

dry-spray: A paint fault where the paint pigment is not being held properly by the binder, or where the binder evaporates before the paint reaches the surface. Atomized paint that does not dissolve into the material being sprayed. It is caused by holding the gun too far from the work, too much air pressure or a solvent that evaporates too fast.

dry sump: A lubrication system in which the engine's supply of oil is not contained in the crankcase (sump) but is pumped to the engine from an external container. This system allows the crankcase to be reduced in size and the engine to be installed lower in the chassis, and eliminates the oil starvation most conventional oiling systems suffer when subjected to the accelerative, braking, and cornering forces generated by a racing car.

dry sump lubrication: See dry sump

dry weight: The weight of a vehicle without any fuel, oil, or coolant. Also see curb weight gross vehicle weight DS: Acronym for "Diesel Severe" oil for use in under adverse conditions in diesel engines.

dual: [1] a combination of two nearly identical parts (e.g., a truck with dual tires has two tires at each end of the axle). [2] In Britain, dual is a verb meaning to twin a highway or railroad.

dual-acting:

See double-acting

dual axles: See tandem axles.

dual bead tire: Heavy service and large truck tires using two or more sets of bead wires in each bead rather than one.

dual-bed catalytic converter: A catalytic converter which combines two converters (with different catalysts) in a single housing

dual brake: See dual brakes.

dual brakes: A brake system that uses a tandem or dual master cylinder to provide separate brake system for both front and rear of vehicle. In the event of a loss of hydraulic fluid, one system may still work because it is independent of the other system. Often the front left brake is linked with the right rear brake. Likewise the right front brake is linked with the left rear brake. Some cars like the Rolls-Royce, link the two front brakes with the right rear brake, and the two front brakes with the left rear brake. Also called "dual-circuit braking system." dual braking system: See dual brakes.

dual breaker points: A distributor, using two sets of breaker points, to increase the cam angle so that at high engine speeds, sufficient spark will be produced to fire the plugs.

dual carbs: Two carburetors on the same engine.

dual carburetors:

Two carburetors on the same engine.

dual carriageway: A British term for a divided highway (i.e., a road that has four lanes -- two in one direction and two in the other -- separated by a median).

dual-circuit braking system: See dual brakes

dual controls: A second set of controls for use by a driving instructor when teaching someone to drive

dual drive: [1] Tandem axles, both powered directly by the engine. [2] Colloquial term for twin screw.

dual exhaust system: See twin exhausts

dual fuel engine: An engine equipped to operate on two different fuels such as gasoline and LP-Gas

Dual Ghia: A vehicle brand of which the 1956-58 models are milestone cars.

dual ignition system: See twin ignition system

dual-line braking system: A braking system in which a towing vehicle and trailer are connected by two or more brake lines

dual mounting: Two tires mounted together on each side of an axle of several types: cast spoke type, disc wheel type (held on by double cap nuts or inner cap nuts and outer cap nuts), Chevrolet type, and motor wheel type

dual overhead cam engine: See double overhead cam engine.

dual-piston engine: See twin-piston engine

dual-piston master cylinder: See tandem master cylinder

dual purpose ship: Specially designed ship for carrying different types of cargoes such as ore and/or oil.

dual-range gearbox: See dual-range transmission

dual-range transmission: A transmission in a four-wheel drive vehicle and some motorcycles with two sets of ratios, usually a higher set for road use and a lower set for off-road use.

dual reduction axle: A drive axle construction with two sets of pinions and gears, either of which can be used

duals: [1] Two sets of exhaust pipes and mufflers -- one for each bank of cylinders. [2] Two tires on each end of an axle. Also see between duals kissing between duals dual spacing: A measurement in inches (or millimeters) from the center of the tread of one tire, to the center tread of the other tire in dual, which provides clearance between duals for air circulation.

dual-tone horn: See two-tone horn

Dubonnet suspension: An independent front suspension and steering arrangement used in the 1930s and '40s, in which the axle beam is rigidly attached to the vehicle frame, and the kingpins carry sprung steering and suspension arms, from which the wheels are mounted on stub axles

duct: A tube through which air, gas, or liquid is conducted. See NACA duct. Also see air duct naca duct oil duct ductile: Metal which can be bent, hammered, or drawn out into wire or sheet without fracturing

ductility: The ability of a material to undergo stretching or bending without fracturing

Duesenberg: A vehicle brand of which the 1925-1948 models are classic cars.

Click for books on Duesenberg

duesy: Expression to indicate quality, as "It's a duesy." The word is derived from the high quality Duesenberg automobiles.

dull: [1] A finish that is not shiny. [2] A blade, saw, or drill bit that is not sharp. Also see go dull dumbirons:

The front extensions of the side members of a chassis frarne in older designs, to which were fitted the front ends of the leaf springs carrying the front axle.

dummy: A stuffed figure made to look like a human being, used, for instance, when crash testing cars. Also called a crash test dummy. Also see crash test dummy side impact dummy dummy lights: [1] Exterior lights which do not work, but may enhance the appearance of a vehicle. [2] The idiot lights that indicate a condition, but does not give details as a gauge would do, e.g., an oil light that indicates low pressure. By the time it comes on, you may have damaged your engine.

dump: See end dump

dump body: A large truck's metal body which is generally hinged at rear and dumped by hydraulic means. The size is generally given in cubic yard water level capacity.

dumps: See bottom dumps

dump truck: [1] A large truck with a bed designed to be tilted at its front to unload its contents usually through a gate in the rear. [2] In Britain it is a small truck with a tipping container in front of the driver, used in construction, like a front-end loader

dump valve: A valve for relieving pressure, such as that between the turbocharger and the carburetor in some systems

dunnage:

Cushioning material placed among cargo to prevent their motion

duo-servo brake: A servo brake with one double-end wheel cylinder and two linked self-energizing brake shoes

duplex: Double, having two parts. Applies to motorcycle frames with two downtubes, and chains with double rows of rollers

duplex chain: A chain with two rows of rollers, used especially for timing chains. Also see simplex chain triplex chain DuPont: A vehicle brand of which the 1925-1948 models are classic cars.

durability: [1] The ability of a component or entire vehicle to last a long time. [2] The expected lifespan of a paint film

durable: The ability of something to be serviceable for a long time before being replaced

Duraspark system: Ford electronic ignitions system

duration: The length of time that an action is allowed to operate or that something is supposed to last. Also see spark duration valve duration durometer:

A device to indicate the hardness of rubber.

Duryea: See Stevens Duryea

dust boot: A covering (often shaped like an accordian) usually made of rubber or plastic to cover over a shaft, CV joint, etc.

dust cap: [1] A metal or plastic covering that fits into a hub shell to keep contaminants out of hub bearings. [2] A metal or plastic end cover for a spindle in a pedal or a cotterless crankset.

dust cover: A soft, flexible valve cap to protect the valve assembly from dust while in shipment and storage. It is not capable of sealing the air pressure and should not be used in service.

dust-free paint: A condition of paint which has hardened beyond being tacky so that any air-borne dust particles will not be imbedded in the paint.

dust sheet: A sheet for covering a car when in a garage and not in use. Also see car cover dust shield: Sheet metal disc or plate placed on the brake assembly to keep debris from brake assembly. Also called "splash shield."

duties: See customs duties

duty: See

heavy-duty light-duty duty cycle: Many solenoid-operated metering devices cycle on and off. The duty cycle is a measurement of the amount of time a device is energized, or turned on, expressed as a percentage of the complete on-off cycle of that device, in other words, the duty cycle is the ratio of the pulse width to the complete cycle width

duty-cycle solenoid: The duty-cycle solenoid is a computer-controlled device in a feedback carburetor that alters the mixture adjustment. Also called a mixture control solenoid

duty drawback: Import duties or taxes repaid by a government in whole or in part, when the imported goods are re-exported or used in the manufacture of exported goods.

duty paid value: In respect to imported goods, is the aggregate value for duty on imported goods.

duty waiver: forgiveness, in whole or in part, of import duties when certain conditions are met.

DVB: Acronym for delay vacuum bypass system

DVLA: Acronym for Driver and Vehicle Licensing Agency

DVLC: Acronym for Driver and Vehicle Licensing Center

DVOM: Acronym for digital volt-ohm multimeter

dwell:

[1] In a contact breaker ignition system, the number of degrees the breaker cam rotates from the time the breaker points close until they open again. Also called the "dwell angle" or "dwell period." [2] In a breakerless ignition system, the time during which the electronic control unit allows current to flow through the primary winding of the coil, which in ignition systems with a Hall generator is determined by the width of the vanes. Also see variable dwell dwell angle: See dwell.

dwell-angle control: A system which makes sure that the dwell is sufficient for all engine conditions

dwell-angle map: The pattern described by the electronic dwell-angle control, dependent on engine speed and battery voltage

dwell meter: An instrument which determines the number of degrees the breaker cam rotates while the breaker points are closed. Changing the point gap affects the dwell angle. When the breaker points are correctly gapped, the distributor can give the proper amount and duration of spark to the spark plugs.

dwell period: The time during which the primary circuit is closed and primary current flows through the ignition coil, given in crankshaft or distributor shaft degrees and therefore also called dwell angle. See dwell.

DWS: Acronym for deflation warning system

dwt: Deadweight ton(s)

Dykem-type metal bluing: A special blue dye used to check a valve job. When applied to the valve set to show up as a dark ring contrasted against the brightly finished top & bottom cuts, making

the seat easier to see and measure

dykes ring: A compression piston ring which is L-shaped when viewed from the end. When installed in the piston the horizontal part fits more deeply in the piston groove while the vertical side rubs against the cylinder wall. This style of ring gives good sealing and prevents piston-ring flutter during acceleration and deceleration of the piston. dynamic balance: When the center line of the weight mass of a revolving object is in the same plane as the center line of the object, that object would be in dynamic balance. For example, the weight mass of the tire must be in the same plane as the center line of the wheel. Static balance is made off the vehicle and determined with the tire stationary. Dynamic balance is made with the tire in rotation.

dynamic ignition timing: Before the introduction of a strobe light, ignition timing was done statically in that the distributor was moved a certain measured amount. With modern engines, a timing light or strobe light is used. It is connected, generally, with the spark plug of the number one cylinder. As power is provided to that cylinder from the coil, the timing light flashes. When the light is projected to the flywheel, the timing marks are illuminated. Moving the distributor will make the timing mark move closer to a fixed mark (retarded) or further away (advanced). Also called stroboscopic ignition timing. The opposite is static ignition timing

dynamic imbalance: Lack of balance in a rotating part such as a wheel, which can cause vibration and shudder

dynamic seal: oil seal between a moving and a stationary part. Opposite to static seal

dynamic supercharging: The pressurizing of the air/fuel mixture using the natural dynamic behaviour of the aspirated air, and not some mechanical device to compress it

dynamic timing meter: A GM diesel tool used for measuring timing while the engine is running by using a quartz sensor in the combustion chamber that measures the point of combustion and

converts this to timing in degrees of crankshaft flotation through the use of a magnetic crankshaft pickup and microprocessor

dynamo: A British term for a generator producing direct current. Also see alternator dynamometer: An electric or hydraulic machine used to measure the actual engine horsepower output and torque. An engine dynamometer measures horsepower at the crankshaft and a chassis dynamometer measures horsepower output at the wheels. Also see roller dynamometer dynastart: A combined generator and starter used on some cars in the 1920s and '30s, and more recently on two-stroke motorcycles

dynastarter: A combined generator and starter used on some cars in the 1920s and '30s, and more recently on two-stroke motorcycles

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [E] [Ea] [Eb] [Ec] [Ed] [Ee] [Ef] [Eg] [Ei] [Ej] [El] [Em] [En] [Ep] [Eq] [Er] [Es] [Et] [Eu] [Ev] [Ew] [Ex] [Ey]

E: Abbreviation for Economy Gear

EACV: Acronym for "electronic air control valve." A valve used in fuel-injection system, usually computer controlled, that controls the amount of air bypassing the throttle during idle. The more air that bypasses the throttle, the higher the idle speed

EAC Valve: electric air control valve. This is the GM version of a diverter air gulp valve, providing three functions in a single valve: 1. the normal diverter valve function, i.e., it diverts air on rapid increase in manifold vacuum; 2. it relieves pressure by diverting air to the air cleaner when the air injection system pressure exceeds a certain set level; 3. being solenoid-controlled, it allows air to be diverted under any desired operating mode Also see EAS valve EAMA: Acronym for "Egyptian Automobile Manufacturers Association."

ear: A projection in the shape of an ear, usually as a lug or support for other components such as the brackets which are part of the fork cover and to which the headlight is mounted on a motorcycle. It is also a spoiler behind the rear windows to improve stability in side winds. Also see

fork ear Earles forks: Long leading-link motorcycle forks, i.e., front suspension has a pivoting fork controlled by twin shock absorbers. Designed by Ernie Earles, they were used by many manufactures of motorcycles in the 1950s

early fuel evaporation system: (EFE) A system that heats the inlet manifold to provide a warm air/fuel mixture, reducing condensation and improving fuel evaporation, thus improving cold engine operation and reducing exhaust emissions. An EFE system operated by engine exhaust gas responds quicker to engine heat-up than systems heated by engine coolant; some EFE systems use an electric heater in the intake duct

early termination: A vehicle's depreciation is highest in the first few months after it leaves the dealer's lot. Since a lessee pays for depreciation in equal monthly payments, lessees who end a lease early have almost always used up more of a car's value than they've paid for. Therefore, lease contracts generally include penalties for early termination. Be aware of these penalties before you sign the lease contract and consider your ability to fulfill the contract.

earnings: See average weekly earnings

earth: British term for ground

earth connection: British term for ground connection

earth electrode: British term for ground electrode

earthmover: See A-2 tire.

earth return:

British term for ground return

earth strap: British term for ground strap

earth wire: British term for ground wire.

ease up on the accelerator: The action of releasing the accelerator partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of depress the accelerator or step on the accelerator.

ease up on the gas pedal: The action of releasing the gas pedal partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of depress the gas pedal or step on the gas pedal..

ease up on the throttle: The action of releasing the twist-grip or throttle lever partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of engaging the throttle or cranking on the throttle..

ease up on the throttle pedal: The action of releasing the throttle pedal partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of depress the throttle pedal or step on the throttle pedal..

easing fluid: Penetrating oil

east-west layout: transverse positioning of the engine across the car from left to right, found in many front-wheel drive designs. Also called transverse engine. The opposite is northsouth layout

EAS Valve:

The valve in an emission control system governing the airflow from the air pump in connection with the EAC valve. When its solenoid is energized, air is directed into the exhaust ports to increase oxidation and accelerate catalytic converter heat-up to operating temperature, and when its solenoid is de-energized, it switches airflow between the converter beds to help the oxidizing catalyst to decrease the CO and HC levels

easy out: A brand name for a screw extractor.

easy-out: A brand name for a screw extractor.

eat: to corrode and remove the metal from the front fender has been eaten away by rust

eat away: to corrode and remove the metal from the front fender has been eaten away by rust

eater: See rust eater

ebonite: hard black rubber compound especially one containing no filler

e box: Any electronic box including capacitive discharge ignition and computer controlled devices.

e-box: Any electronic box including capacitive discharge ignition and computer controlled devices. E-brake : See emergency brake

ECC:

Acronym for electronic climate control

eccentric: [1] Two circles, one within the other, neither sharing the same center, i.e., they are off-center. [2] A protrusion on a shaft that rubs against or is connected to another part, such as a cam on a camshaft. [3] A part transmitting an eccentric drive, such as a disc with a provision for a drive from its outer part, or an eccentric shaft

eccentric bolt: A bolt with centers of head and body on different axis so that one is off-center in relation to the other.

eccentric drive: A drive from a point not on the axis of the driving shaft, e.g., from the outer part of a disc, so that a reciprocating or up and down motion is transmitted; used in pumps or for a camshaft drive

eccentric rotor pump: rotor-type pump

eccentric shaft: A shaft transmitting eccentric motion

ECE test cycle: A 13 minute, three-part test of automotive emissions for compliance with emission standards, adopted by most European countries, simulating urban driving conditions, i.e., involving relatively long idling periods and speeds below 35 mph, emission characteristics at cruising speeds not being considered

echelon parking: A British term for angle parking

ECI: Acronym for electronically controlled injection

Eclat:

A 2+2 Coupe produced by Lotus from 1975 to 1982. This vehicle was the basis for the current Lotus Excel.

ECM: Acronym for "electronic Control Module" which is the master computer responsible for interpreting electrical signals sent by engine sensors and for activating automated engine components and processes accordingly in order to produce optimum performance.

ecological damage: damage to the environment, usually in the form of pollution, such as that caused by vehicle emissions

ecologically harmful: damaging to the environment automotive exhaust gases are ecologically harmful

economical: The determination of how much money or fuel is required to cover a particular distance. Good economy involves driving at a steady rate, avoiding rapid starts and stops, driving in the highest possible gear, avoiding using power- robbing components (e.g., air conditioning), proper tire inflation, etc.

Economic Cooperation: See Asia Pacific Economic Cooperation

economizer: A device for making a vehicle use less fuel, either by regulating the flow of fuel, or by admitting extra air to the air/fuel mixture -- especially when cruising

economizer valve: A fuel flow control device within the carburetor.

economy: The ratio between a product or service and its value. Also see corporate Average Fuel Economy epa fuel economy fuel economy

tuned for economy economy device: See economizer

economy gear: High gear designed for economical cruising often better than 1:1 ratio like an overdrive.

economy jet: An additional jet in a carburettor admitting extra air to the air/fuel mixture -especially when cruising

economy ratio: An overdrive gear ratio better then 1:1 for economical cruising

ECS: [1] Acronym for electronically controlled suspension. [2] Acronym for evaporation control system

ECT: Acronym for "engine coolant temperature sensor"

ECU: Acronym for "electronic Control Unit"

edge: See abutting edge beaded edge feather-edge feather edge leading edge trailing edge wiring an edge edge binding:

tape for securing the edges of carpets

edge guard: rubber or plastic, U-section strip fitted to panel edges to protect them against chipping, etc.

edge joint: A joint formed when two pieces of metal are lapped with at least one edge of each at an edge of the other.

edge protection: protection of edges against corrosion, e.g.. by weatherstrips

edge-ride: The tendency of crankshaft main bearings to ride up the radius (rather than seat on the journal) when the radius is too large

edge tire: See beaded edge tire

edge trim: rubber or plastic, U-section strip fitted to panel edges to protect them against chipping, etc.

Edison base: A light bulb base that is threaded.

Edison screw: A light bulb base that is threaded

Edsel: A model of automobile manufactured by Ford Edwardian car: A car built in Great Britain between 1905 and 1918

Click for books on Edsel

EEC: [1] Acronym for electronic engine control system. [2] Acronym for evaporative emission control system

EECS: Acronym for "evaporative emissions control system"

EESS: Acronym for evaporative emission shed system

EEVIR: Acronym for evaporator equalized valve in receiver

EFE: Acronym for early fuel evaporation system

EFE system: Acronym for Early Fuel Evaporation System

effect: See alteration effect barrier effect braking effect engine braking effect ground effect hall effect kadenacy effect liftoff effect load alteration effect roll steer effect self-centering effect synergetic effect synergistic effect effective: [1] actual rather than theoretical or potential. [2] producing an effect. Also see

cost-effective indicated mean effective pressure mean effective pressure effective deflection: deflection of a suspension system under a particular load

effective pressure: See brake mean effective pressure indicated mean effective pressure mean effective pressure effective stroke: working or power stroke in a two-stroke engine

efficiency: The accomplishment of something with the least amount of effort, energy, or fuel. See braking efficiency catalyst efficiency catalytic efficiency charging efficiency fuel efficiency mechanical efficiency thermal efficiency trapping efficiency volumetric efficiency effort: The force which is doing work on an object. Also see braking effort EFI: (EFi) Acronym for electronic Fuel Injection

EGC: Acronym for exhaust gas check valve

egg-crate grille: A radiator grille with crisscrossing bars forming gaps which are more or less square. One of the distinctive characteristics of Cadillac cars

EGI: Acronym for electronic gasoline injection

EGO: Acronym for exhaust gas oxygen sensor

EGR: Acronym for "Exhaust-gas recirculation." Also see negative transducer EGR valve vacuum modulated EGR EGRC: Acronym for EGR control solenoid

EGR control solenoid: (EGRC) energizes to allow manifold vacuum to the EGR gas temperature

EGRV: Acronym for EGR vent solenoid

EGR vacuum: A vacuum source above the closed throttle plate; used for control of ported EGR valves. Vacuum is zero at closed throttle

EGR valve: [1] A part of an EGR system mounted on or near the inlet manifold and controlled by inlet manifold vacuum, which is usually closed at idle and low speeds, but opens during acceleration, admitting exhaust gas to the inlet manifold. Most EGR valves are of the single diaphragm type, some are dual diaphragm valves connected to two separate vacuum sources to more closely match EGR function to engine loads; for the same purpose, EGR valves are frequently governed by additional regulating devices. [2] A valve used to introduce exhaust gases into the intake air stream. There are several types.

Also see integral backpressure transducer EGR valve ported EGR valve electronic EGR valve valve and Transducer assembly negative transducer EGR valve EGR valve position sensor: (EVP) A potentiometric sensor used in electronically controlled EGR system. Sensor wiper position is proportional to EGR valve pintle position, which allows electronic control assembly to determine actual EGR flow at any point in time

EGR vent solenoid: (EGRV) electrical solenoid that normally vents EGRC vacuum line. When EGRV is energized, EGRC can open the EGR valve

EGR venturi vacuum amplifier: A device that uses a relatively weak venturi vacuum to control a manifold vacuum signal to operate the EGR valve. Contains a check valve and relief valve that open whenever the venturi vacuum signal is equal to or greater than manifold vacuum

EIA: Acronym for "Electronics Industries Association."

eight: eight-cylinder engine, or a vehicle fitted with one; the cylinders may be in-line (a straight eight) or in a V-layout (a V-8). Also see flat eight straight eight V-eight 8 trk: Abbreviation for "eight-track" tape player found in many '60s and some '70s cars.

8-trk: Abbreviation for "eight-track" tape player found in many '60s and some '70s cars.

eight track:

See eight-track.

eight-track: An 8-track tape player found in many '60s and some '70s cars.

EIN: Engine Identification Number

eject: To push or throw out

eject button: button on a cassette player or CD player for taking out the cassette or CD

Elan: A two-seater roadster produced by Lotus from 1964 to 1974.

elapsed time: (ET) The length of time it takes a dragster to complete the one-fourth mile run.

elasticity: The ability to recover the original size and shape after being deformed, especially stretched, forces are released

elastomer: [1] A term which includes natural rubber and the many synthetic materials that possess rubber-like properties. [2] An elastic macromolecular material that at room temperature returns rapidly to approximately its initial dimensions and shape after substantial deformation by a weak stress and release of the stress. thermoplastic elastomers

elbow: A pipe or rod with a bend, usually at right angles. Also see mechanic's elbow ELC:

Electronic level control

Eldorado: A Cadillac vehicle brand of which the 1953-58, 67-70 Eldorado models are milestone cars. Also see the history of Cadillac Eldorado.

Click for books on Cadillac Eldorado

Eldorado Brougham: See Cadillac Eldorado Brougham

Electra: A model of automobile manufactured by Buick

Click for books on Buick Electra

electric: operated by or derived from electricity

electric air control valve: The EAC valve

electric air switching valve: EAS valve

electrical: relating to electricity

electrical balance: An atom or an object in which positive and negative charges are equal

electrical conductivity: The ability of a material to conduct electricity. The opposite is resistivity or resistance.

electrical screwdriver: A British term for an electric screwdriver

electrical spanner:

A British term for an ignition wrench

electrical system: The system that generates, stores, and distributes electrical current to crank the engine for starting and to keep it running by providing high voltage to the spark plugs; and to give power to the lights, the heater motor, radio, and other accessories. It is made up of the ignition system starter motor, battery alternator voltage regulator lights, electrical accessories and all the wiring, switches, and relays.

electric car: A car whose only power source is an electric motor and a number of batteries.

electric charge: A definite quantity of electricity, which-may be positive, as with protons, or negative, as with electrons. Also see coulomb electric current: The flow of electricity passing through a conductor

electric fuel pump: electrically powered gasoline or diesel pump which draws fuel from the tank and delivers it to the carburetor or fuel injection system

electric grid: The electrical system

electrician: See automotive electrician

electricity: See static electricity

electric mirror: An external door mirror which is controlled by an electric motor and operated by a switch inside the car

electric motor: A device which changes electrical energy into rotational motion. In addition to the starter and windshield wiper motors, which were the first electric motors to be added to the automotive electrical system, modern cars include a large number of small motors for driving such items as the electric windows, aerials, sunroofs, mirrors and seat adjustment, central locking and power hoods; electric-powered cars use large motors for their drive.

electric screwdriver: A tool which resembles a pistol which can accept screwdriver bits. It is similar to an electric drill.

electric top: A power convertible roof. The British term is "power hood"

electric vehicle: Cars, buses, vans or trucks which use dedicated or hybrid electric systems as their power source.

electric welding: Welding by using an electric current to melt both metal (work) and welding rod, or electrode

electric windows: Side windows which are raised and lowered by an electric motor which is operated by a switch.

electrochemical: Chemical (battery) production of electricity.

electrochemical corrosion: corrosion involving at least one electrode reaction

electrocoating: electrophoretic painting

electrode: [1] In a spark plug one electrode (the center electrode) is the center rod passing through the insulator. The side electrode is a rod welded to the shell of the spark plug. The distance between them is the spark gap. [2] In welding it is the metal rod that is used in arc welding. A substance which brings electricity up to the point where the arc is to be formed; in other words it is the material immediately adjacent to the arc proper and the one which carries the current to this point. In electric arc welding the electrode is usually melted and becomes a part of the weld. Also see center electrode coated electrode compound center electrode compound electrode covered electrode earth electrode ground electrode negative electrode outer electrode platinum electrode positive electrode side electrode spark plug electrode top electrode triangular ground electrode electrode adjusting tool: A British term for a spark plug gap gauge electrode gap: Spark plug gap

electrodeposition: A generic term for electrolytic processes in which a metal is deposited at the cathode from a solution of its ions, such as electroplating, or in which paint is deposited in an immersion process by means of electric current

electrode spark plug: See split electrode spark plug

electrogalvanizing:

An electroplating coating of zinc on metal that will rust (i.e., iron or steel).

electro-hydraulic pump: An electrically powered hydraulic pump used to create pressure in certain portions of the brake system. Typically found in GM Powermaster brake boosters and in ABS hydraulic control units

electrolysis: A method by which chemical reactions are carried out by passage of electric current through a solution of an electrolyte or through a molten salt

electrolyte: In automotive batteries, it is a sulphuric acid and water solution. It can be any solution (usually an acid) that will conduct electric current. The acid reacts with the battery plates (usually made of lead) to produce direct current (DC) electricity.

electrolytic: relating to electrolysis or an electrolyte

electrolytic cell: A cell consisting of electrodes immersed in an electrolyte solution for carrying out electrolysis

electrolytic corrosion: electrochemical corrosion causing the electrolytic removal of metal

electrolytic deposition: electroplating

electrolytic galvanizing: electrogalvanizing

electrolytic protection: cathodic protection

electromagnet:

A magnet produced by placing a coil of wire around a steel or iron bar. When current flows through the coil the bar becomes magnetized and will remain so as long as the current continues to flow.

electromagnetic: Magnetic (generator) production of electricity.

electromagnetic clutch: any clutch in which a magnetic force is used to hold the drive in engagement, such as that in the compressor drive of an air-conditioning system

electromagnetic induction: Voltage is induced in a coil of wire by moving coil through a magnetic field or by keeping coil stationary and moving magnetic field.

electromotive force: (EMF) A source of electrical energy required to produce an electric current, produced by devices such as batteries or generators and measured in volts. See voltage.

electron: A negatively charged particle that makes up part of the atom. Also see bound electrons free electrons electron flow: A current produced by the motion of free electrons towards a positive terminal, whose direction is the opposite to that of the current

electronic: Featuring semiconductors (usually transistors) as an operating medium. Also see fully electronic ignition high energy ignition system with electronic spark timing magnetically controlled electronic ignition electronic air control valve:

(EACV) A valve used in fuel-injection system, usually computer controlled, that controls the amount of air bypassing the throttle during idle. The more air that bypasses the throttle, the higher the idle speed

electronically controlled: Most items can be controlled by a mechanical means (squeeze a lever to move something) or by hydraulics (a lever pushes fluid which applies movement to something) or electronically (move a switch and a servo motor moves something)

electronically controlled transmission: A transmission that relies on sensors, an electronic control unit (ECU), and solenoids to control torque convertor lockup and shift points

electronically-controlled wastegate: A turbo-charger wastegate that is activated by an electric signal from a computer

electronic climate control: (ECC) An air conditioning system control which determines and maintains the preset temperature in the passenger compartment.

electronic cluster: A display showing various functions, including speedometer, tachometer, gauges, etc., using LEDs or LCD technology displaying symbols and bar graphs instead of numbers. The opposite is an analog cluster

Electronic control Assembly: ECA: A Ford vehicle computer consisting of a calibration assembly containing the computer memory, its control program, and processor assembly (the computer hardware)

electronic control module: (ECM) [1] The master computer responsible for interpreting electrical signals sent by engine sensors and for activating automated engine components and processes accordingly in order to produce optimum performance. [2] A GM term and also a generic term referring to the computer. The ECM is the brain of the engine control system receiving information from various sensors in the engine compartment. The ECM calculates what is required for proper engine operation and controls the different actuators to achieve it Also called "electronic control unit"

electronic control unit: (ECU) [1] A microprocessor and memory with electronic maps, forming the central part of an engine management system or of subsystems such as a fuel injection or ignition system. [2] The "brain" of an ABS system. The ECU reads impulses from the wheel speed sensors to determine if anti-lock braking needs to take place. If so, the ECU controls the cycling of the solenoid valves in the hydraulic control unit. Also called "Electronic Control Module"

electronic EGR valve: The EGR valve used in engine management system in which the EGR flow is controlled by the computer (usually by means of an EGR valve position sensor attached to the EGR valve). Operating vacuum is supplied by EGR solenoid valve(s)

electronic engine control: (EEC) [1] The engine management system which controls the ignition system and various other systems, including the exhaust gas recirculation and air-injection systems. [2] Ford's computerized engine control system. There are four versions: EEC-I controls engine timing. EEC-II controls engine timing and fuel (on engines with an FBC system). EEC-III-FBC is a refined version of EEC-II. EEC-III-CFI controls engine timing and fuel (on engine with an EFI system). EEC-IV is a refined version of the EEC-III system

electronic fuel injection: (EFI or EFi) A system that injects fuel into the engine and includes an electronic control unit to time and meter the flow. Fuel is delivered in intermittent pulses by the opening and closing of solenoid-controlled injectors. Also called pulsed injection

electronic gasoline injection: (EGI) Mazda's fuel injection system for the RX-7, RX-7 Turbo, 323, and 626

electronic ignition: See electronic ignition system all electronic ignition

capacitor controlled electronic ignition contact controlled electronic ignition contactless electronic ignition fully electronic ignition magnetically controlled electronic ignition electronic ignition system: An ignition system using electronic switching devices to assist or eliminate the mechanical breaker points. There are three basic electronic ignitions: contact controlled (the breaker points are retained but merely serve to trigger a transistor which switches the heavy primary current), magnetically controlled (transistors are used as the switching device for the primary current and the points are eliminated -also called "contactless" or "all-electronic"), and capacitor controlled (also called "capacitive-discharge system" and can be either all-electronic or breaker-point controlled).

electronic navigator: A trip computer which gives estimated time of arrival (ETA), amount of fuel left, average fuel consumption, etc.

electronic ride control: A suspension control system made up of a microprocessor-controlled, electronically adjustable air shock absorbers for automatic selection of the optimum damping characteristics depending on road surface and load conditions

electronics: See automotive electronics

electronic sensing device: An electronic device for vehicles with fuel injection. It detects changes in speed and driving conditions and determines the amount of fuel to be injected into the combustion chamber thus eliminating the need for carburetors.

electronic spark: See high energy ignition system with electronic spark timing

electronic spark advance: (ESA) the part of an ECU that controls ignition timing and dwell angle

electronic spark control: (ESC) The timing of the ignition by means of an ignition map, either integrated into the mapped ignition systems or available as a separate module to enhance transistorized ignition systems. Also called "electronic spark timing."

electronic spark timing: (EST) The timing of the ignition by means of an ignition map, either integrated into the mapped ignition systems or available as a separate module to enhance transistorized ignition systems. Also called "electronic spark control." Also see high energy ignition system with electronic spark timing electronic spark timing system: (EST) An ECM-controlled timing of ignition spark. This replaces the vacuum or centrifugal mechanism in the distributor and uses the computer to advance or retard the spark timing

electronic traction control: (ETC) A system for reducing wheelspin, incorporating wheel sensors. Also see antispin regulation electronic transmission: A system of controlling the shifting of gears in the transmission by means of electrical pulses sent to solenoids and relays. In mechanical transmissions, the operator moves levers which makes the transmission shift gears.

electronic transmission control: A system or module for controlling an automatic transmission

electronic voltage regulator: (EVR) a type of regulator that uses all solid state devices to perform the regulatory functions

electrons: See bound electrons free electrons

electropainting: Electrophoretic painting.

Also see cathodic electropainting electropaint tank: A tank in which items are immersed for electrophoretic paint application

electrophoretic painting: A process used to apply the first coat of paint (primer) to car bodies. The process involves using negatively charged paint particles (anodic electropainting) or positively charged paint particles (cathodic electropainting). The cleaned metal parts to be coated are immersed in a tank of electrodeposition paint, and the current is turned on, so that the paint particles are attracted by the positively charged paint particles

electrophoretic primer: Paint used to prime car bodies by the electrophoretic process

electro picker: A device which is electrically operated and is used to open locked car doors. It is available only to automotive locksmiths and the police. It consists basically of a vibrator with an attached steel blade. When the vibrating blade is inserted into a lock, it finds its way past the locating pins which would normally block anything but the original key

electroplate: The process of depositing gold, silver, chrome, nickel, etc., upon an object by placing the object in a special solution and then passing an electric current through the solution. The object forms one terminal, a special electrode the other. Direct current is used.

electroplating: The process of electrodeposition of metal or alloys from suitable electrolyte solutions. The articles to be plated are connected to the cathode in an electrolyte solution, and direct current is introduced through the anode of the metal to be deposited. Also see zinc electroplating electrostatic painting:

A painting method using the particle- attracting property of electrostatic charges, in which a direct current of approximately 100,000 volts is applied to a grid of wires through which the paint is sprayed to charge each particle, and the metal objects to be sprayed are connected to the opposite terminal of the high-voltage circuit, so as to attract the paint particles. Also called "Electrostatic Spraying"

electrostatic powder coating: (EPC) A painting process in which the outer parts of the body shell are coated with a powder dispersion by means of cathodic immersion, and in which the cavities are coated with cathodic electropaint

electrostatic spraying: A painting method using the particle-attracting property of electrostatic charges, in which a direct current of approximately 100,000 volts is applied to a grid of wires through which the paint is sprayed to charge each particle, and the metal objects to be sprayed are connected to the opposite terminal of the high-voltage circuit, so as to attract the paint particles. Also called "Electrostatic Painting"

electro vacuum relay EVR: A combination solenoid vacuum valve and electrical relay which locks out blower operation and closes the fresh air door in cold weather, and switches the system to the recirculating air mode during maximum system use

electrovalve: A solenoid valve

element: A group of plates in a battery. Three elements for a six volt and six elements for the twelve volt battery. The elements are connected in series. Also see air cleaner element air filter element filter element hall element hot-wire element open element glow plug temperature control element element glow:

See open element glow plug

element glow plug: See open element glow plug

Elliot: See Elliot axle reversed Elliot axle

Elliot axle: A solid bar front axle on which the ends span or straddle the steering knuckle. Also see reversed Elliot axle Elliott steering knuckle: Type of axle in which ends of axle beam straddle spindle

Elliot type axle: See elliot axle ellipsoidal headlight: A headlight with a reflector which is wider than it is high, and not circular; has replaced the parabolic reflector

elongation: The percentage increase in the length of a specimen when stressed to its yield strength.

ELV: Acronym for "End-of-Life Vehicles."

emblem: See wheel trim emblem

embrittlement: A reduced toughness in plastic or metal caused by age, heat or rough use. Also see hydrogen embrittlement

emergency: A sudden, unexpected occurrence, such as a breakdown or the failure of some part, which may be dangerous and demands immediate action.

emergency brake: A braking system which is independent of the main hydraulic system. It can be used to slow or stop the vehicle if the primary brakes fail, or to hold the vehicle stationary though the brake pedal is not depressed. It usually consists of a foot pedal or hand lever that actuates either front or rear brakes mechanically through a series of cables and linkages. It is also called the "parking brake" or E-brake.

emergency inflator: An aerosol can which inflates a punctured tire and injects sealing compound to provide at least a temporary repair

emergency transmitter: A transmitter no larger than a car radio, fitted inside the vehicle which enables a driver to radio for help from the security of his own car

emergency windshield: A sheet of clear plastic fitted in place of a broken windshield

emery cloth: A cloth coated in emery crystals like fine sandpaper for use as an abrasive on metals

EMF: Acronym for "electromotive force" See voltage.

Emily: An affectionate name for the RollsRoyce radiator mascot, the "Spirit of Ecstasy"

emission: The passing of gases and other toxic substances into the atmosphere. Also see automotive emissions crankcase emissions evaporative emission control system evaporative emissions

exhaust emission controls exhaust emissions low-emission low Emission Vehicle Standards particulate emission limit particulate emission emission control: A system for restricting the amount of noxious emissions. There are two standards for emission controls: level E for Europe and the more stringent level U for the United States. See exhaust emission control evaporative emission control system

Emission Control Information: See Vehicle Emission Control Information

emission controls: See exhaust emission control.

emission control system: See evaporative emission control system exhaust emission control system emission levels: amounts of toxic substances passed into the atmosphere by motor vehicles

emission limit: See particulate emission limit

emissions: Gases and other pollutants coming from a vehicle with an internal combustion engine. See emission

emission standards: specified maximum emission levels permitted from different classes of motor vehicle in different countries

Emission Vehicle:

See Low Emission Vehicle Standards

Emission Vehicle Standards: See Low Emission Vehicle Standards ultra Low Emission Vehicle Standards employment: total employment in each manufacturing facility, including total manufacturing employees, total support staff, and total engineering/R&D staff. Average number of workers employed by an establishment during the year. Production workers relate to the average number actually engaged in the manufacturing process. Administrative and non-manufacturing includes employees at head offices and sales offices.

employee benefits: the provision of direct (salary, bonuses, etc.) indirect (vacation leave, medical and dental plans, etc.) and deferred employee compensation (pensions, etc.).

EMS: Acronym for Engine Management System

emulsification: The process of making an emulsion

emulsion: A mixture of two liquids which do not fully mix, such as oil and water, or specifically of gasoline and air in a carburetor before it is discharged and fully atomized

emulsion tube: part of a fixed jet carburetor, in which air is introduced into the mixture through holes to help atomize it and correct excessive richness at higher engine speeds. A perforated tube which extends from an air bleed in the top of the air horn down into the main well. Admits air from the air bleed into the main well to emulsify the fuel in the main well. Improves idle response and stability when the engine is hot and prevents fuel percolation and general hot-starting problems. Also improves response in the main metering circuit during part throttle conditions. Also called main-well tube

enable: A microcomputer decision that results in an engine management system being activated and permitted to operate

enamel: Type of paint that dries to a smooth, glossy finish. It is easier to apply than cellulose. If cellulose is applied over it, the cellulose will lift (i.e., peel off). Also see finishing enamel porcelain enamel vitreous enamel enamelling: See vitreous enamelling

EN block: See EN-block.

EN-block: One piece -- such as an engine cylinder block cast in one piece.

enclosure: See speaker enclosure

end: See belt end big end bitter end bottom end drive end drive end bracket female end firing end front end front end alignment gudgeon pin end heavy-duty end cutting pliers high leverage end cutting pliers little end male end

nut end open end lease piston pin end piston ring end gap rear end rear end lift ring end gap small end stud end tie rod end top end wedge end end alignment: See front end alignment

end bearing: See small end bearing

end bracket: The cover containing a bearing at each end of a generator or alternator. Also called "end cover" or "end cover plate." Also see drive end bracket slip-ring end bracket end cap: The cap covering the end of a piece of trim or of a barrel fuse

end cover: The cover containing a bearing at each end of a generator or alternator. Also called "end bracket" or "end cover plate"

end cover plate: The cover containing a bearing at each end of a generator or alternator. Also called "end cover" or "end bracket"

end cutters:

British term for a "side cutter"

end cutting: See heavy-duty end cutting pliers high leverage end cutting pliers end cutting pliers: British term for "side cutter" Also see heavy-duty end cutting pliers high leverage end cutting pliers end dump: A term used to describe various dump trucks or trailers that tilt to unload at the rear.

end float: End play

end form: Any type of connector at the end of a hose or pipe.

end gap: See piston ring end gap ring end gap end gas: The last part of the fuel-air mixture that has been introduced into the cylinder but has not yet been consumed in the normal flame-front reaction.

end gear: See axle end gears.

end gears: See axle end gears.

end hexagon screwdriver: See ball end hexagon screwdriver

end lease: See closed end lease open end lease end lift: See rear end lift

end-of-lease purchase price: If there is a purchase option in the lease contract or agreement, this will be the agreed upon price for the purchase of the vehicle at the end of the lease-the stated residual value. This price may also include additional fees.

end-of term interest rate: See buy at end-of term interest rate

endoscope: An instrument used to see into the interior of hollow cavities such as box sections

end piece: See sill end piece

end play: The looseness in bearing clearance in an axial direction. Also see camshaft end play end speed: See top end speed

endurance test: A test of a material or system over a long period to determine when it will fail

enduro:

Off-road competition against the clock and usually over long distances

energize: To activate (a solenoid, relay, etc.) by providing sufficient energy

energizing: See self-energizing

energy: Capacity for doing work. It is measured in joules or kilowatt-hours. See high energy battery high energy coil high energy ignition system with electronic spark timing high energy ignition system kinetic energy potential energy energy-absorbing: The ability to absorb impact forces

energy absorbing bumper: See bumper system.

energy-absorbing bumper: See bumper system.

energy absorbing steering column: A steering column which collapses when the vehicle is involved in an accident.

energy battery: See high energy battery

energy coil: See high energy coil

energy conversion:

The changing of one form of energy into another or into work, such as that in the combustion process, the heat of which is used to turn the engine and thus create motion

energy ignition: See high energy ignition system with electronic spark timing high energy ignition system energy ignition system: See high energy ignition system high energy ignition system with electronic spark timing energy ignition system with electronic spark timing: See high energy ignition system with electronic spark timing

Energy Protection Agency: See EPA estimates.

energy retarder: See engine brake.

engage: [1] to come into contact and be locked together (with another part). [2] to bring (a part) into contact with another so that it is locked to it

engagement: The result of bringing into locking contact (e.g. of the clutch), or selection of a gear

engaging the throttle: The action of causing the throttle linkage to move so that more fuel enters the engine to increase the speed of the vehicle.

engine: A device for changing fuel energy to mechanical energy. The term applies to the primary source of power generation. In Britain there is a desire to make a clear distinction between "engine" and "motor" so that "motor" refers only to electric

power units (i.e., starter motor) and "engine" for gasoline or diesel powered units. However, in the U.S.A. the term "motor" can apply to both types. Yet, even in Britain, combustion driven vehicles are called "motor cars" and "motorcycles." Also see adiabatic engine air cooled engine all-alloy engine alloy engine aspirated engine balanced engine big-block engine boxer engine cam engine carburetor engine cih engine combustion engine cubic inch engine diesel engine dual-piston engine dual overhead cam engine electronic engine control engine types exchange engine external combustion engine F-head engine federal engine F head engine fire engine flat engine flooded engine four-cycle engine four-cylinder engine four-stroke cycle engine four cycle engine four stroke cycle engine front engine fuel-injected engine fuel injection engine HC engine high-camshaft engine horizontally opposed engine hydrocarbon engine I-head engine IC engine I head engine in-line engine

inclined engine indirect injection engine injected engine inlet over exhaust engine inline engine intake over exhaust engine internal combustion engine ioe engine L-head engine lean-burn engine L head engine long block engine longitudinal engine long stroke engine mid-engine naturally aspirated engine nominal engine speed normally aspirated engine OHV engine opposed engine over square engine pancake engine piston-valve engine piston engine plastic engine pre-combustion engine pushrod engine push rod engine quad-cam engine radial engine rear engine rebuilt engine reciprocating engine reconditioned engine rotary engine short block engine short engine short stroke engine side-valve engine SI engine single-cylinder engine six-cylinder engine sixteen valve engine slant engine small-block engine spark ignition engine

square-four engine square engine steam engine stirling engine straight engine stratified charge engine supercharged Engine SV engine T-head engine T head engine three-port engine three-valve engine traction engine transverse engine turbine engine turbocharged engine twelve-cylinder engine twelve-valve engine twin-piston engine twin cam engine twin camshaft engine two-cycle engine two-stroke cycle engine two-valve engine two stroke cycle engine U-cylinder engine under-square engine undersquare engine under square engine unit engine V-eight engine V-engine V-four engine V-six engine V-sixteen engine V-ten engine V-twelve engine V-type engine V-X engine valve-in-head engine vee engine V engine VR engine V type engine W-engine wankel engine

winding the engine X-engine X-type engine x. Liter Engine X engine engine adapter: A unit that allows a different engine to be installed in a vehicle and still bolt up to the original transmission.

engine analyzer: An electronic engine testing device which (because of its size) used to be placed in a cabinet or a movable stand. The modern units are often hand-held and are connected to the vehicle's diagnostic socket (as in the case of the diagnostic read-out box), which provides data on all aspects of the engine's state of tune

engine bay: The engine compartment.

engine block: The cylinder block.

engine block heater: See block heater

engine brake: (Energy Retarder or jake brake) A system that allows for slowing of a vehicle that is independent of the conventional braking systems. A driver would normally downshift to slow his descent of a hill, using engine compression. The engine brake increases the effectiveness of this regarding force.

engine braking effect: A retarding effect of an engine when the vehicle is in gear with the throttle closed. Also called a "jake brake"

engine calibration unit: An electronic component which can be specifically programmed to the design of each car model to control the M/C solenoid. Plugs into the Electronic Control Module (ECM). Also called a programmable read only memory (PROM)

engine capacity: The swept volume of an engine

engine compartment: The space where the engine is mounted. Also called the "engine bay." Also see cluttered engine compartment crowded engine compartment engine control: See electronic engine control engine control module

engine control module: (ECM) An advanced electronic computer which monitors engine conditions and then controls engine settings to optimize the combustion of the air/fuel mixture.

engine control system: See engine-control system.

engine-control system: A computer that regulates the operation of the engine by monitoring certain engine characteristics (rpm, coolant temperature, intake airflow, etc.) through a network of sensors and then controlling key variables (fuel metering, spark timing EGR, etc.) according to pre-programmed schedules.

engine coolant: Antifreeze liquid used in the engine's cooling system

engine coolant temperature sensor: (ECT) the thermistor sensor that provides coolant temperature information to the computer. Used to alter spark advance and EGR flow during warm-up or an overheating condition

engine cover: The panel which conceals the engine in a mid-engine car. Also called "access panel." Also see hood (British "bonnet") which covers the engine only in a frontmounted engine.

engine damage: Breakage, deformation, or scoring of the internal parts of an engine due to running at very high rpms for an extended period of time or with insufficient lubrication. A rod could break off and drive a hole into the cases; a valve could break off or imbed itself into the top of a piston; the piston could heat and expand and thus seize against the cylinder walls; or other types of damage could occur.

engine depression: Low pressure on the engine side of the throttle caused by piston suction in the inlet manifold

engine diagnostic connector: The electrical connector for plugging in the engine analyzer, forming an interface between the engine electronic controls and diagnostic unit, and used to read the engine data as well as any fault codes stored in the memory of the engine controller

engine displacement: To determine, multiply the volume of the space through which the head of the piston moves in the full length of its stroke by the number of cylinders in the engine. The result is given in cubic inches.

engineering: See automotive engineering badge engineering production engineering engine flywheel: A spinning plate located at the end of the crankshaft. See flywheel.

engine hoist: small crane for lifting an engine out of a motor vehicle, formerly incorporating a block and tackle, but now usually hydraulically operated. Also see gantry engine identification number:

(EIN) A number stamped on the engine which may or may not match the number on the vehicle identification plate. Also called "engine number"

engine knock: When the engine is operating, an audible noise may be heard when the fuel in the cylinders is ignited too early and/or spontaneously, resulting in colliding flame fronts and shock waves which cause high thermal and mechanical stress, and can severely damage the engine.

engine layout: [1] The type of engine, with reference to the arrangement of its cylinders and their number (as in a flat four, V-twin, or straight eight). [2] The location of the engine in the vehicle (as in a front mount, mid-mount, or rear engine. [3] The placement of the engine in the engine compartment: e.g., a transverse or inline engine

engine management system: (EMS) An electronic engine control system which covers at least the functioning of the fuel injection and ignition, but may also include emission controls and selfdiagnostics

engine map: See characteristic map. As an engine speeds up, the timing needs to be advanced. On older vehicles, this is accomplished mechanically with a counterweight advance in the distributor. In modern vehicles, the timing can be advanced progressively by means of a computer chip which is programmed to provide the ideal timing. It also provides other factors in some engines such as the opening and closing of valves, etc.

engine misfire: See misfire

engine modifications: Alterations to the specification of the engine to increase power output, improve economy, reduce emissions, etc.

engine mounting: A flexible support for the engine in which an elastic medium, usually rubber, is interposed between the lugs on the engine and the frame of the vehicle

engine noise: The amount of noise produced by the engine when it is running. Engine noise is more noticeable with a diesel at lower speeds

engine number: (EIN) A number stamped on the engine which may or may not match the number on the vehicle identification plate. Also called "engine identification number"

engine oil: Oil within the engine used to lubricate the moving components. At one time the oil was a single grade, but modern engines use a multigrade oil. Also see straight weight engine oil synthetic engine oil engine oil pan: See oil pan.

engine oil level warning light: A light on the instrument panel which comes on when the oil in the sump falls below a certain level

engine overhaul: When an old engine burns too much oil and loses power, it is dismantled and restored to the manufacturer's original tolerances by replacement of worn parts, reboring the cylinders, regrinding the crankshaft, etc.

engine parameters: A term used in the context of emission controls for those engine characteristics sensitive to engine performance, such as power/bhp, general engine performance, and fuel economy

engine performance tester: An engine analyzer

engine sequence test:

The test which determines how well oil will prevent engine rusting, corrosion, scuffing, wear, and the formation of sludge and varnish.

engine size: The engine displacement or capacity

engine speed: The number of revolutions per minute (rpm) at which the engine crankshaft turns. The vehicle itself may be stationary or in motion. Also see nominal engine speed engine speed limiter: A device which acts as a governor which cuts the power when a certain number of rpm is reached

engine speed sensor: In most cases, a magnetic pick-up that scans the flywheel teeth and produces one output signal per scanned tooth, or a hall generator in the distributor, whose signals are passed to the electronic control unit

engine subframe: A separate frame in which the engine is mounted

engine temperature sensor: A sensor used to monitor the temperature of the engine

engine timing: [1] The point of time when the spark ignites the air/fuel mixture (ignition timing) [2] The setting of the valves when they open or close (valve timing)

engine type: Over the years of engine development, several types or configurations have been made. All of them relate to the position of the valves and the camshaft (s) that operates them. •

air cooled engine -- An engine which is not cooled by antifreeze but by passing air past external fins.

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

diesel engine -- An engine with high compression that pressurizes the diesel oil fuel and fires the charge through compression not by a spark plug. DOHC -- double overhead camshafts F-head -- Side exhaust valve and overhead intake valve. flat engine four-stroke cycle engine hemi or hemi-head -- Engine using hemispherical-shaped (half of a globe or sphere) combustion chambers. horizontally opposed engine hydrocarbon engine I-head -- Both valves located directly over the piston. Also called valve-inhead or overhead valve engine. in-line engine internal combustion engine L-head -- Both valves on one side of the cylinder oversquare engine pancake engine radial engine rotary engine slant engine SOHC -- Single overhead camshaft. square engine steam engine stirling engine stratified charge engine straight engine T-head -- exhaust valve on one side and inlet valve on the other side of the cylinder and found on twin-camshaft engines. traction engine transverse engine turbine engine two-stoke cycle engine undersquare engine V-type -- Two sets of cylinders set apart in a V-formation like a V-8 or V-6 valve-in-head engine wankel engine X-type

engine warning light: See check engine warning light

enrichment: making the air/fuel mixture richer, i.e., increasing the fuel content.

Also see acceleration enrichment after-start enrichment cold start enrichment cranking enrichment full load enrichment full throttle enrichment hot start enrichment warm-up enrichment enrichment device: A circuit in a carburetor providing a richer mixture, operated by engine vacuum

enrichment unit: A circuit in a carburetor providing a richer mixture, operated by engine vacuum

enrichner: A fuel plunger which is used in a carburetor in place of a choke. By activating the plunger more gas is permitted into the intake area to enrichen the fuel-air mixture for easier starting. Also see choke entertainment: See in-car entertainment

entrepreneur: One who undertakes ownership of a business or enterprise

entrepreneurship: A person's ability to organize, manage, and assume risks of operating a business

entry: See illuminated entry system keyless entry system multi-entry remote keyless entry

entry-level version: basic model suitable as someone's first car

entry model: basic model suitable as someone's first car

entry system: See illuminated entry system keyless entry system envelope: [1] A thin rubber wrapper that surrounds the tread, sidewall and is tucked inside the curing rim during the pre-cured cold process retreading. It protects bonding materials from humidity within the chamber. [2] A cover enclosing something entirely, such as the glass of a lamp bulb. Also see outer envelope envelope separator: A porous plastic separator used in maintenance-free batteries to enclose the individual plates completely

enveloping body: See all-enveloping body

environmentally aware: An awareness of the dangers and threats to the environment caused by vehicle use and the taking of appropriate action to avoid them

environmentally friendly: Something that is harmless to the environment, or causing as little harm as possible

Environmental Protection Act: See canadian Environmental Protection Act

environment-conscious:

An awareness of the dangers and threats to the environment caused by vehicle use and the taking of appropriate action to avoid them

EPA: [1] Acronym for "Energy Protection Agency." Also see EPA fuel economy. [2] Acronym for "Environmental Protection Agency" which is responsible fol recommending environmental legislation and in the automotive sphere produces test cycles and estimates fuel economy EPA estimate: An American organization (Energy Protection Agency) which determines the fuel consumption of various vehicles. It takes into account city and highway driving. These figures may be helpful in comparing one vehicle against another. Your vehicle can greatly exceed these estimates with sensible driving, the use of cruise control obeying the speed limits avoiding rapid starts, coasting long before a stop light or sign. Also see EPA fuel economy EPA estimates: An American organization (Energy Protection Agency) which determines the fuel consumption of various vehicles. It takes into account city and highway driving. These figures may be helpful in comparing one vehicle against another. Your vehicle can greatly exceed these estimates with sensible driving, the use of cruise control obeying the speed limits avoiding rapid starts, coasting long before a stop light or sign. Also see EPA fuel economy EPA fuel economy: Laboratory fuel economy tests administered by the Environmental Protection Agency (EPA) using simulated weight and drag to re-create real driving conditions. The city fuel-economy test, also used to test emissions compliance is based on a drive through typical Los Angeles urban traffic of about twenty years ago. Such conditions in LA are no longer present. The highway test uses a higher, steadier speed averaging 79.5 kph (49.4 mph).

EPC: Acronym for Electrostatic Powder Coating

EP gear oil: An extreme pressure gear oil preventing metal-to-metal contact, used mainly in gearboxes and final drive units. Also called "EP lubricant"

epicyclic: See epicyclic gearbox.

epicyclic gear: A gear that operates around the circumference of another

epicyclic gearbox: A form of gear used by Benz in which small pinions revolve around a central or sun gear and mesh with an outer ring gear called the annulus. Type used in the Ford Model T. Also called planetary gearset "planetary transmission" and "sun-andplanet gears."

epitrochoid: A geometric path followed by a specific point located in a generating circle which is rolled around the periphery of a base circle.

epitrochoidal: A part of a circle which is not on the circumference of another circle around which it turns

EP lubricant: See extreme pressure lubricant.

epoxy resin: A thermosetting resin based on ethylene oxide or similar materials or derivatives, used in adhesives, fillers, and primers and other finishes

EPR: [1] Acronym for evaporator pressure regulator valve. [2] Acronym for exhaust pressure regulator

EPS: Acronym for electronically controlled power steering. EPS is used in more expensive models, such as the BMW Servotronic system where the assistance provided alters according to the speed at which the car is travelling

equalizer: A bracket or cable connector which balances tension equally on the cables to the parking brakes. See graphic equalizer compensator equalizer line: In air conditioner system, a line or connection used to operate certain control valves. Little or no refrigerant flows through the line

equal length header: An exhaust manifold where the runners from each cylinder are of equal length. Such a system allows exhaust pulses to meet at the collector or single pipe in a controlled sequence, thus enhancing cylinder evacuation and gas flow.

equal power distribution: A system in four-wheel drive vehicles which ensures that an equal amount of power is passed to the front and rear wheels

equal power split: A system in four-wheel drive vehicles which ensures that an equal amount of power is passed to the front and rear wheels

equation: See nernst equation

equilibrium: See thermal equilibrium

equipment: devices and systems fitted to a vehicle which are either essential or optional, and either fitted by the manufacturer (original equipment) or subsequently by the owner (after market equipment). Also see aftermarket equipment integral equipment low-bake equipment optional equipment

original equipment standard equipment equipment package: A combination of equipment provided by the manufacturer

ergonomics: [lit: The law of work] Technically, it means the biotechnology study of how human beings relate to their surroundings and how efficiently they perform in that environment. However, the meaning has also come to be used in a qualitative sense so that a vehicle has good or bad ergonomics meaning that the controls, switches, instruments, seats, pedals, and steering wheel suit the human driver.

erode: to remove a surface layer (by chemical action or by rubbing)

erosion: A reduction in size of an object because of a liquid or gas impact on the object.

error: See driver error

ESA: Acronym for Electronic Spark Advance

ESC: Acronym for Electronic Spark Control

escape trunk: A vertical trunk fitted with a ladder to permit personnel to escape if trapped

Escort: A model of automobile manufactured by Ford escutcheon:

Click for books on Ford Escort

A panel or part used to hide another part

ESR: Acronym for electric sunroof

EST: Acronym for electronic spark timing system

establishment: smallest operating entity producing a homogenous set of goods and services and is capable of reporting full range of production account variables to calculate "value added."

estate car: A British term for a station wagon

estimate: See estimates.

estimates: A guess on the part of a service department with respect to the nature of a vehicle's problem and cost of repairing it. Although most shops will stand by their estimate, there is also the situation where the problem is caused by something which will be more expensive to repair or may be less expensive. In the case where other components are also faulty (but the estimate did not include them), the shop may contact the customer with a revised estimate saying, "We can repair what we thought was the faulty part, but we found another defective part which also contributed to the problem once we took things apart. Now the cost will be more. Do you want us to go ahead and repair that component too?" In the case where a lesser solution repaired the problem, good shops will give you a bill that is much less than the estimate with an explanation like, "We thought we had to replace the expensive control box, but we found that one of its plugs had come loose." Also see EPA estimates ESV: Acronym for Experimental Safety Vehicle

ET:

Acronym for "elapsed time." The length of time it takes a dragster to complete the one-fourth mile run.

ETA: Acronym for "expected time of arrival."

ETC: Acronym for Electronic Traction Control

etching: [1] A roughening or disintegration of the paint surface, which can occur on small patches or over a wide area, through attack from bird droppings, soap deposits, industrial fallout, etc. Also called "lifting." [2] The removal of soil or the natural oxide film from an aluminium surface, giving a roughened surface which improves adhesion of the subsequent paint layer, or removal of the actual metal. [3] A system of marking car windows with the registration number so as to deter thieves. Also see caustic etching window etching etching primer: A primer for aluminum which has an etching effect to improve adhesion

etch primer: A primer for aluminum which has an etching effect to improve adhesion

ethanol: ethyl alcohol which is added to gasoline, typically in a mixture of 10% ethanol and 90% unleaded gasoline

ethyl acrylate: A polymer used in toughening rubber

ethylene glycol: A chemical solution added to the cooling system to protect against freezing. See antifreeze.

ethyl gasoline: Gasoline to which ethyl fluid (tetraethyl lead ethylene dibromide, ethylene dichloride, or another octane improver) has been added to improve the gasoline's resistance to knocking. It slows down the burning rate thereby creating a smooth pressure curve that will allow the gasoline to be used in high compression engines. It is a generic term describing premium or high-octane fuel. It was first sold in 1924.

ETRTO: Acronym for "European Tyre and Rim Technical Organisation."

Euromix formula: The basis for a standard test cycle covering both town driving and driving on the open road. In North America a similar is called the "Town and Country Formula"

eutectic alloy: A mixture of metals which has a melting point lower than that of any of the metals in the mixture, or of any other mixture of these metals.

evacuate: [1] To remove by pushing out. [2] To create a vacuum in an air conditioning system to remove all traces of air and moisture. Also called pump down

evaluation: See driver evaluation

EVAP: Acronym for evaporative emission control system

evaporate: to turn into a vapour

evaporation: The process of changing from a liquid to a vapor, such as boiling water to produce steam; evaporation is the opposite of condensation. Also refers to solvents in the paint escaping to the air.

Also see early fuel evaporation system evaporation control system: (EVAP or ECS) [1] A system for reducing evaporative emissions by means of a sealed fuel tank, a vapour-liquid separator, a three-way valve, an activated carbon filter, and a network of interconnecting hoses. A system used to prevent the escape of gasoline vapors to the atmosphere from the fuel tank and carburetor. Also called "evaporative Emission Control system"

evaporation system: See early fuel evaporation system

evaporative emission control system: (EVAP pr EEC) A system for reducing evaporative emissions by means of a sealed fuel tank, a vapour-liquid separator, a three-way valve, an activated carbon filter, and a network of interconnecting hoses. Also called "evaporation control system"

evaporative emissions: Vapours or fumes not emitted by the exhaust system, but escaping from the fuel tank, carburetor and crankcase, and accounting for about 40% of hydrocarbon emissions released by a gasoline engine without emission controls

evaporative emission shed system: (EESS) a Ford evaporative emission control system introduced in 1978

evaporative losses: Vapours or fumes not emitted by the exhaust system, but escaping from the fuel tank, carburetor and crankcase, and accounting for about 40% of hydrocarbon emissions released by a gasoline engine without emission controls

evaporator: The unit in an air conditioning system used to transform refrigerant from a liquid to a gas. It is at this point that cooling takes place as heat is removed from the air. Opposite to "condenser"

evaporator equalized valve in receiver:

(EEVIR) A unit similar in design to a valve-in-receiver type, except that it has an equalizer port of the expansion valve that allows for faster reaction time

evaporator pressure regulator valve: (EPR) and evaporator tem control device regulated by back pressure. Used on older Chrysler corp. System. Located in the compressor inlet. A system using this device is referred to as an EPR system

Evaporator temperature regulator valve: (ETR) A temperatukre-regulated evaporator temperature control device used on some early model Chrysler corp. system

EVAP system: Acronym for Evaporative Emission Control System

EVC: Acronym for Exhaust Valve Closes

even keel: A ship at even keel is when the keel is horizontal

EVO: Acronym for Exhaust Valve Opens

EVP: Acronym for EGR valve position sensor

EVR: Acronym for electronic voltage regulator

EVRV: Electronic vacuum regulator valve

EVT: Acronym for "Electromagnetic Valve Train."

EW: acronym for "electric windows"

examination: See metallographic examination

exc: Abbreviation for "excellent," as in exc condition.

Excalibur: A vehicle brand of which the 1965-69 model II Series I are milestone cars.

exchange engine: A replacement engine which is provided in exchange for a worn engine while the original engine is being rebuilt

exchange process: See charge exchange process

exchanger: See heat exchanger.

Excelsior: The 1925-1948 models with required application are classic cars.

excitation winding: Field winding

excite: To pass an electric current through a unit such as the field coils in the generator.

exciter coil: A primary coil which provides stepped up voltage to a second coil.

exciter winding:

Field winding

excluder: See draught excluder

ex-demonstrator: A vehicle which had been used as a demonstrator and is now available for sale

exducer: The outermost section of a turbine wheel, used to purge the turbine of exhaust gases

executive car: A large, powerful luxury car considered suitable for a business executive

exhaust: [1] To expel spent fumes. [2] The spent fuel after combustion takes place in an internal combustion engine. Sometimes it refers to the exhaust system. Also see dual exhaust system intake over exhaust engine raw exhaust gas residual exhaust gases tuned exhaust tuning the exhaust exhaust back pressure: any pressure holding back the flow of the gases in an exhaust system. Pressure exerted in exhaust system in reverse direction. Also called back pressure exhaust back pressure transducer valve: (BPV or BPS) a device sued to sense exhaust pressure changes and control vacuum to the EGR valve in response to these changes

exhaust cam: A separate camshaft controlling the opening and closing of the exhaust valves used in twin overhead camshaft engines

exhaust camshaft:

A separate camshaft controlling the opening and closing of the exhaust valves used in twin overhead camshaft engines

exhaust chamber: part of the two-stroke exhaust system designed to maintain a specified back pressure

exhaust cutout: A Y-shaped device that is placed in the exhaust pipe ahead of the muffler. The driver may channel the exhaust through the muffler or out the other leg of the "Y" where the exhaust passes out without going through the muffler. Also see cutout exhaust donuts: The small rubber hangers used to suspend the exhaust system from the chassis pan

exhaust emission: See exhaust emissions.

exhaust emission control: See exhaust emission controls

exhaust emission controls: Systems or adjustments designed to limit noxious gases in an engine's exhaust. Such controls can be grouped into two broad categories: those designed to reduce or eliminate the formation of harmful pollutants in the engine itself (e.g., retarded spark setting) and those designed to destroy or otherwise alter the pollutants after they have been formed (e.g., air injection, thermal reactors, and catalytic converters). Evaporative emission controls prevent gasoline vapors from escaping into the atmosphere from the fuel tank and carburetor and crankcase controls recycle fumes from the crankcase through the engine. exhaust emission control system: A general term for any system that reduces the harmful exhaust emissions of a motor vehicle, including one or all of the following systems: catalytic converter (with or without oxygen sensor air/fuel control), exhaust gas recirculation, secondary air injection or induction, and positive crankcase ventilation

exhaust emissions:

The unburned hydrocarbons, carbon monoxide, oxides of nitrogen, and other noxious gases emitted when gasoline is burned in an engine.

exhaust engine: See intake over exhaust engine

exhaust gas: gas which is the product of the combustion process and which is passed out of the cylinder through the exhaust valve or port into the exhaust system. Also see raw exhaust gas residual exhaust gases exhaust gas analyzer: An instrument for determining efficiency with which an engine is burning fuel. See exhaust-gas analyzer.

exhaust-gas analyzer: An instrument used to measure the exhaust gases (in parts per million, percent, grams per kilometer, or grams per mile) to determine both combustion efficiency and the amount of pollutants in the exhaust.

exhaust gas check valve: (EGC) a device that allows air injection system air to enter the exhaust manifold, but prevents a reverse flow in the event of improper operation of other components

exhaust gas oxygen sensor: (EGO) a device that changes its output voltage as the exhaust gas oxygen content changes when compared to the oxygen content of the atmosphere. This constantly changing voltage signal is sent to the processor for analysis and adjustment to the air/fuel ratio

exhaust gas purification system: An emission control system for diesel engines, which may consist of an exhaust scrubber, a diesel exhaust filter, and/or a catalytic converter

exhaust gas recirculation:

See exhaust-gas recirculation.

exhaust-gas recirculation: (EGR) An emission control system where some of the exhaust gases are rerouted from the exhaust manifold into the combustion chamber to make sure that all fuel is burned before entering the atmosphere. The process lowers the combustion temperature and reduces the formation of oxides of nitrogen (NOx) in the exhaust.

exhaust gas recirculation system: (EGR) a system used to control oxides of nitrogen (NOx) the exhaust gases are recirculated, lowering the engine combustion temperature, thereby reducing engine pollutants

exhaust gas: See exhaust gases.

exhaust gases: The burned and unburned gases which are expelled out of the exhaust system after combustion takes place. Also see exhaust emissions exhaust header: Steel tubing connecting pipes between the exhaust ports and the exhaust pipe. Usually a header has been polished to allow for better flow of the exhaust. Also see exhaust manifold exhaust heat control valve: (HCV) a valve which routes hot exhaust gases to the intake manifold heat riser during cold engine operation. Valve can be thermostatically controlled, vacuum operated or computer controlled

exhaust manifold: The connecting pipes between the exhaust ports of each cylinder and the exhaust pipe. It is usually made of cast iron. Sometimes called the "exhaust header " but it is usually made of steel tubing.

exhaust note:

The sound coming from the end of the exhaust pipe. It is usually described as pleasant, loud, throaty, or sporty.

exhaust oxygen sensor: Device that detects the amount of oxygen in the exhaust stream and sends that information the ECM. Also called an oxygen sensor or an O2 sensor

exhaust pipe: Pipe connecting exhaust manifold or header to the muffler. exhaust pollutants: Exhaust emissions

exhaust port: [1] The passage in the cylinder head which connects the exhaust valve and the exhaust manifold. The exhaust gases pass through the port to the exhaust manifold or header. [2] On two-stroke engines the exhaust port is cut into the cylinder wall because it does not have valves. Also see adjustable variable exhaust port variable exhaust port exhaust pressure regulator: (EPR) a device for increasing exhaust backpressure at specific times to increase exhaust flow to the EGR valve exhaust scrubber: A diesel exhaust gas purification system which cools the exhaust and separates nitrogen oxide and oil vapours from the gas stream

exhaust side: The side of the engine where the exhaust valves and exhaust manifold are located

exhaust stroke: The fourth stroke of a four-stroke cycle where the piston moves upward from bottom dead center to top dead center and pushes the burned exhaust gases out of the cylinder. exhaust system: The pipes, resonators and mufflers that carry the exhaust gases from the

exhaust manifold out into the atmosphere. 6

Also see dual exhaust system stainless-steel exhaust system twin exhaust system exhaust timing: exhaust control system developed especially for two-stroke motorcycle engines in order to enhance low and mid-range power exhaust treatment: any measures taken to reduce the pollutant concentrations in the exhaust of an internal combustion engine released into the atmosphere

exhaust tuning: Cutting the exhaust pipe to a length that provides maximum efficiency.

exhaust turbocharging: See turbocharging

exhaust valve: The valve through which the burned fuel charge passes on its way from the cylinder to the exhaust manifold. It is driven by the camshaft. When comparing an exhaust valve with an intake valve in the same engine, the part of the exhaust valve that seats into the head (i.e., not the stem) will have a smaller diameter than the intake valve. Also see sodium-cooled exhaust valve exhaust valve closes: (EVC) A mark on a valve-timing diagram exhaust valve opens: (EVO) A mark on a valve-timing diagram

expander: [1] A ring placed under a piston ring to increase ring pressure on the cylinder walls. For instance an oil control ring may have an expander ring to assist the oil-control ring to scrape oil off the cylinder wall and provide further sealing. See piston ring expander. [2] A device in a drum brake system (either hydraulic or mechanical) which forces the shoes apart into contact with the drum.

Also see bead expander piston skirt expander ring expander skirt expander tailpipe expander wedge expander expander spacer: See expander ring

expanding: See piston skirt expanding

expansion: An increase in size, for example: when a metal rod is heated, it increases in length and perhaps also in diameter. Expansion is the opposite of contraction. Also see piston expansion shell expansion expansion plug: A steel plug, slightly dished or cup-shaped. When driven into place it flattens to fit tightly in its seat. In an engine block, expansion plugs (also called freeze plugs or core-hole plugs) are inserted into the holes in the casting through which core was removed when casting was formed. They open into cooling passages and thus provide pressure relief should the engine coolant freeze and expand. See core plugs.

expansion stroke: See power stroke

expansion tank: When the engine is heated, the coolant expands to fill any available space (usually in the radiator). Before the introduction of coolant expansion tanks, the excess coolant was forced out of a vent tube and on the ground. The expansion tank collects the coolant so that when the engine cools off, the resultant vacuum sucks the coolant from the tank back into the radiator.

expansion tube:

A device that converts high pressure liquid refrigerant into low pressure liquid refrigerant (thus lowering its boiling point) before it passes through the evaporator. The expansion valve replaces the thermostatic expansion valve. It is also referred to as a fixed orifice tube

expansion valve: A part of an air-conditioning system, located between the condenser and the evaporator that regulates the flow of liquid refrigerant to the vaporator. If cooling needs are low, the valve is almost closed; as additional cooling is required, the valve opens wider so that more liquid refrigerant flows to the evaporator.

expected residual value: This is the projected or expected value of the vehicle at the end of the lease. Residual value is a measure of the vehicle's expected depreciation.

expenditures: See capital expenditures

experiment: See windsor experiment

Experimental Development Program: See scientific Research and Experimental Development Program

Experimental Safety Vehicle: (ESV) A special vehicle built for research into and testing of safety features; (compare SID)

exploded view: A drawing of a mechanism or structure which shows the parts separately but approximately in the position they occupy when assembled

explosion: A rapid disintegration of an object. See clutch explosion.

Export Restraint:

See Voluntary Export Restraint

expressway: A US multilane highway road with limited access to be used for rapid travel with few interchanges.

ext: Abbreviation for "exterior."

extension: A part which is inserted between a ratchet and a socket to provide access to nuts or bolts which are deeply inset or hard to reach. Also called "extension bar" or "extension piece." Also see brake extension fender extension load floor extension park brake extension piston extension screw valve extension wheel arch extension wing extension extension bar: See extension wobble extension bar extension housing: See transmission extension housing

extension piece: See extension

extension screw: See piston extension screw

extension spring:

A closed-coiled helical spring that offers resistance to a pulling force.

exterior mirror: The mirror that is usually mounted on the door. In Japan (and other countries) it was mounted on the front fenders. Also called "external mirror."

external combustion engine: An engine that burns its fuel outside the engine. A steam engine is an external combustion engine.

external diameter: The outside diameter of a cylinder, tube, or washer

external equalizer: See equalizer line

externally-balanced crankshaft: A crankshaft that requires external balancing weight, usually on the vibration damper of the flywheel, for balance

external micrometer: A micrometer for measuring external diameters

external mirror: The mirror that is usually mounted on the door. In Japan (and other countries) it was mounted on the front fenders. Also called "exterior mirror."

external mix air cap: A special type of air cap for spray guns. Air and fluid are mixed in the space outside the air cap, directly in front of the nozzle: the most common type of air cap. Also see internal mix air cap external thread: Thread consisting of projecting ridges on the outside of a part such as a bolt or screw (which fits into the corresponding internal thread of a nut). Also called male thread

external vane pump: A pump with either an elliptic rotating piston or an eccentrically mounted circular rotor

extinguisher: See fire extinguisher

extractor: A device for removing some object (e.g., bearing, bushing, sleeve, bolt, stud, etc.). See oil and water extractor screw extractor stud extractor extras: Optional items either supplied by the manufacturer at the buyer's request, or added later by the owner. Usually they are things like seat covers, floor mats, additional lights, sunroof, glass tinting, CD changers, etc.

extreme-pressure lubricant: (EP lubricant) A lubricant designed and compounded to withstand very heavy loads imposed on gear teeth.

extruder: A machine that shapes a rubber compound into a usable form. Uncured rubber is heated to soften and forced through dies having the desired shape and dimensions.

eye: A circular opening or hole, such as that at the end of a leaf spring or that formed at the end of a cable. Also see fish eye impeller eye spring eye towing eye eyebolt:

A bolt with an eye in place of a head, through which a cable can be passed, e.g. for lifting purposes

eyelet connector: A connector for electrical connections which is attached to a wire and has its ringshaped end pushed onto a round post or threaded terminal

eyelet pliers: Pliers for punching small holes, with a round stud in one jaw and a hole in the other

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [F] [Fa] [Fe] [Fh] [Fi] [Fl] [Fn] [Fo] [Fr] [Fu]

F: [1] Abbreviation for "Fahrenheit." [2] Acronym for "Field" or "Field terminal"

fabric: Material made from textile or man-made fibres

fabricate: To make, usually by a relatively complex process or from several parts

fabric body: A simple form of lightweight bodywork in which a waterproof, cloth-backed material is stretched over a wooden framework popular around 1930 and still used at a late, date by DKW and even postwar by Lloyd

fabric fatigue: A term used with tires in that the fabric degrades and results in tire cord breakdown due to repeated flexing and heat.

fabric hood: A British term for a fabric top of a convertible.

fabric top: A soft top for a convertible made from a textile (such as canvas) as opposed to vinyl

face: [1] To shave the outer edges of a bottom bracket shell or the upper and lower ends of a head tube to make them parallel with one another and square to the tube's centerline.

[2] A machinist's term that refers to removing metal from the end of a shaft or the face of a larger part, e.g., flywheel. [3] The front, visible, or working surface of a part (such as a valve) or a tool (such as a hammer). Also see attachment face bearing face cam face concave weld face door face full face helmet grille face panel inner attachment face inner mounting face mechanical face seal open face helmet valve face valve seat face weld face face cam: A cam system in which the eccentrics are situated on the face of a rotating disc

face hammer: See soft face hammer

face helmet: See full face helmet open face helmet facelift: Minor styling modifications made to a car model which may be approaching the end f its useful life, intended to improve the appearance and thus boost sales with minimum cost, including such features as restyled headlights, larger tail lights, added trim, and spoilers

Facel Vega: A vehicle brand of which the 1954-64 V-8 models are milestone cars.

face of weld:

The exposed surface of the weld.

face panel: See grille face panel

face seal: See mechanical face seal

facia: A front protective panel. Also spelled "fascia."

facing: See clutch facing hinge facing lock facing fact: Abbreviation for "factory."

factor: See casing factor consumer factors deadfreight factor horsepower weight factor horsepower-weight factor money factor pitting factor safety factor factory adjusted: Something that is set by the manufacturer when the vehicle was built and is not intended to be changed

factory options: Optional features which may be installed by the manufacturer upon request. Aftermarket options are those which are installed by a garage or consumer after the vehicle has been built and delivered to the selling dealership.

factory primer: A primer coat applied to new body panels in the factory for protection during storage, which in some cases has to be removed prior to painting because of paint compatibility problems

factory racers: Racing machines built and operated by the manufacturer

fade: A gradual reduction in efficiency. See brake fade.

fader: A device which adjusts the sound balance of front and rear speakers in a fourspeaker layout

fading: [1] A loss of brightness or colour in a paint finish. [2] Brake fade

failsafe system: A system which remains safe even when part of it fails, such as a dual-circuit brake system

failure: See adhesion failure brake failure intercoat adhesion failure secondary failure Fairlane: A model of automobile manufactured by Ford

Click for books on Ford Fairlane

Fairmont: A model of automobile manufactured by Ford

Click for books on Ford Fairmont

fahrenheit: Thermometer on which the boiling point of water is 212 deg. and the freezing point is 32 deg. above zero. To convert from Fahrenheit to Celsius, subtract 32 then multiply the result by 5 and divide by 9. To convert from Celsius to Fahrenheit, multiply by 9, then divide by 5. Now add 32 to the result.

fair: [1] to add a fairing to a body. [2] A vehicle in restorable condition needing only minor work to get all components working

fairing: A protective shell or enclosure at the front of a motorcycle which may house the headlights and signal lights. It is designed to improve the aerodynamic performance of the machine and/or provide rider comfort

Falcon: A model of automobile manufactured by Ford

Click for books on Ford Falcon

false air: Any air leak that introduces unmeasured air into the intake system between the airflow meter and the intake valves is false

family car: A car suitable for transporting a family, usually a four-door sedan, hatchback, or station wagon. It is becoming more popular for families to obtain a mini-van instead of a station wagon.

fan: [1] A fan is a rotating device with curved blades like a propeller. The primary fan in a vehicle is located behind the radiator. Some electric fans may be placed in front of the radiator. It draws air through the radiator so that the coolant looses its heat through the fins of the radiator. It is especially needed when the vehicle is idling or moving slowly. When the vehicle moves quickly, there may be no need for the fan. In some cases, the fan is automatically disengaged. The fan may be driven by a fan belt driven by the engine, or by electricity independent of the engine itself. [2] Other fans are located throughout the vehicle to push air from one location to another, especially for heating and ventilation. [3] The pattern emitted by a paint spray gun. Also see

cooling fan heater fan radiator fan motor radiator fan fan belt: A flexible rubber belt that connects various components in the engine compartment, i.e., alternator, water pump, emission controls, power steering pump, air conditioner compressor.

fan blade: A part of the fan projecting at an angle from the central hub, which draws the air through the radiator

fan clutch: A viscous (fluid) drive coupling device connected to the center of the fan to permit variable engine fan speeds in relation to engine speeds. The clutch engages and disengages the fan according to the engine temperature through a thermostat

fan cooling: A type of air cooling where a blower is responsible for transporting the amount of air required for the cooling of the engine past the cooling fins, which in turn dissipate the heat stored in them to the current of air flowing past them

fan motor: See radiator fan motor

fanning: The use of air pressure through a spray gun to speed up the drying of primer or paint--this is not recommended

fan pulley: A pulley on the hub of the radiator fan on which its driving belt runs

farewell tour: A year-long tribute or celecbration for a retiring driver and his racing fans.

Farman:

A vehicle brand of which the 1925-1948 models with required application are classic car.

farthing: See penny-farthing

fascia: Also spelled "facia." [1] A front protective panel usually located below the bumper. [2] In Britain it is the instrument panel.

fast: See light-fast

fastback: A design of car where the roof gently slopes to the rear end of the car. Any automobile with a long, moderately curving, downward slope to the rear of the roof. This body style relates to an interest in streamlining and aerodynamics and has gone in and out of fashion at various times. Some (Mustangs for one) have grown quite popular. Others have tended to turn customers off. Certain fastbacks are, technically, two-door sedans or pillared coupes. Four-door fastbacks have also been produced. Many of these (such as Buick's late 1970s four-door Century sedan) lacked sales appeal. Fastbacks may or may not have a rear-opening hatch. === carfast.jpg Also see two-door fastback fast charger: A battery charger which can charge a battery at a rate of 40 amps or more, used by garages and battery suppliers

fastener: See lift-the-dot fastener snap fastener fast idle: When the engine is cold, it needs to run faster to keep it from stalling. A cam on the carburetor forces the throttle open a little more when the choke is engaged.

fast idle cam: A cam in a carburetor which opens the throttle slightly when the choke is brought into operation, either automatically or mechanically

fast idle screw: A screw on a carburetor for adjusting the speed of the fast idle

fast idle solenoid: A solenoid operating in conjunction with an automatic choke to open the throttle slightly when the choke is in operation

fast lane: The outside lane (far left lane in North America, etc. or the far right lane in Britain, Australia, etc.). Also called the "passing lane"

fathom: A measure of length, equivalent to 6 linear feet, used for depths of water and lengths of anchor chain

fatigue: A condition of a material, especially a metal, causing loss of elasticity and tendency to fracture after long or repeated stress, even though the stress may be less than that which would cause failure under static conditions. Also see fabric fatigue metal fatigue fatigue limit: The maximum stress that a material can endure for an infinite number of stress cycles without breaking

fatigue resistance: The maximum stress that a material can endure for a given time without breaking

fatigue strength:

The maximum stress that a material can endure for a given time without breaking

fatigue test: A test on a material to determine the range of stress it will stand without failing, by subjecting it to rapidly varying stresses to establish its fatigue limit

fault: A defect which is either inherent in the vehicle as built (manufacturing fault) or which occurs during running. Also see intermittent fault no fault insurance fault diagnosis: The tracing of faults or error codes which can be determined by the in-built diagnostic system and an engine analyzer

fault insurance: See no fault insurance

fault memory: A part of the electronic control unit and of the diagnostic system that stores error codes to assist the mechanic in diagnosing problems.

fault reader: A device used in conjunction with the vehicle's diagnostic system, providing a readout of status of the various components

FBC: Acronym for Feedback Carburetor

FCAI: Acronym for "Federal Chamber of Automotive Industries" (Australia).

FCS: Acronym for feedback control system

FE analysis: Acronym for Finite-Element Analysis

featherbed frame: Famous Norton motorcycle frame design by the McCandless brothers. It was introduced in 1950 and was given its name by factory rider Harold Daniell

featheredge: See feather-edge.

feather edge: See feather-edge.

feather-edge: [1] The tapered edge of the paint where it meets the metal. The edges should be tapered or slanted so that no edge will be felt when a finger is passed over it. [2] To sand the edges of a repaired area until they merge into the surrounding paintwork.

feathering: [1] A type of tire wear in which the tread is worn down to a very thin edge [2] The application of gentle pressure on the throttle or brake pedal

feather key: A key with parallel faces whose ends may be round or square. It usually fits into a groove on a shaft and in a mating hole to secure the shaft in place.

feature: See kneeling feature passive safety features FEBIAC: Acronym for "Fédération Belge des Industries de L'Automobile et du Cycle 'réunies'" (Belgium)

Federal engine:

An American engine which meets US Federal emission standards and certified by the EPA for use in any state except California

federal side impact standard: Effective with the 1997 model year, all passenger cars are required to comply with Standard 214, side impact protection, as defined in the Code of Federal Regulations. Simply put, the entire structure, floor to roof, of all cars must be now be reinforced according to strict regulations. Interestingly, this standard does not yet apply to light trucks (minivans, compact pickups, SUVs).

Federal Test Procedure: (FTP) An American method of testing automotive emissions by simulating typical driving conditions

federal version: A vehicle that complies with U.S. emission standards which are less restrictive than the standards in California. Also called a "49-state car."

Fédération Internationale de l'Automobile: (FIA) The international umbrella motoring organization to which national motoring organizations are affiliated and racing is sanctioned. This includes FIA Formula One World Championship (the world's premier racing series also called Formula One racing or F1), International Sports Car Championship (BPR), International Touring Car Championship, and through the Concorde Agreement (agreement to operate racing series under the FIA's guidelines and rules) for participating country's car clubs. Events take place worldwide. The current president is Max Mosley and the V.P. of Marketing is Bernie Eccelestone who controls the series.

Fédération Internationale du Sport Automobile: (FISA) The intenational governing body of motor sport

fee: See acquisition fee agent fee disposition fee trauma fee feed: [1] To supply (fuel, oil, current, etc.)

[2] The supply of fuel, oil, current, etc. Also see foot feed gravity feed feedback: [1] The return of part of the output of a system to the input. Negative feedback causes self-adjustment of the system and therefore stability. Positive feedback causes instability. See closed loop system. [2] The information that a computer-controlled fuel system returns. The sensor measures the oxygen content of the engine's exhaust in order to keep the fuel-air ratio very close to the ideal proportion for combustion. Such tight control of the fuel-air ratio is required for the proper operation of three-way catalysts.

feedback carburetor: (FBC) A carburetor regulated by a closed loop system (an oxygen sensor, various other sensors, a computer, a duty-cycle solenoid or solenoid-controlled valve and a catalytic converter) providing and adjusting the air/fuel mixture quality to operate a catalytic converter

feedback carburetor actuator: A computer-controlled stepper motor that varies the carburetor air/fuel mixture

feedback control: A closed loop control

feedback control system: (FCS) a computer-controlled fuel system employing a stepper motor or a dithering solenoid that controls air-fuel mixture by bleeding precise amounts of air (determined by the computer) into the main and idle system of the carburetor

feedback potentiometer: A variable resistance device which monitors the position of the shaft to which it is affixed and reports the position to the control head

feeder: See wire feeder

feed gun:

See top feed gun

feed line: A pipe supplying liquid or gas.

feed pipe: A pipe supplying liquid or gas.

feed pump: A pump suppiymg, for example, fuel in regulated quantities

feel: The detection of the operation of a vehicle and its components. Brake feel involves detecting how effectively the brakes work; road feel conveys to the driver the way the suspension responds to the road. Also see brake feel on-center feel road feel steering feel feeler blade: A thin blade of spring steel of an exact thickness for measuring small gaps or clearances between parts, usually made in sets of various thicknesses pinned together at one end to form a feeler gauge

feeler gage: See feeler gauge.

feeler gauge: A thin strip or blade of hardened steel, ground to an exact thickness, that is used to check clearances between parts. Thicknesses increase by 0.001 inch. Also see step feeler gauge feeler strip: A metal strip of a specific thickness from which single feeler blades can be cut, appropriate when frequent measuring is required, to avoid using worn blades

FEI: Acronym for Fully Electronic Ignition

FEMA: Acronym for "The Federation of European Motorcyclists Associations" on http://mag-uk.org/fema/.

female: A fitting inside another part. Usually where two parts form a connection of some kind, the female part is the socket or hole into which another piece is inserted.

female end: The receptical into which the male end is inserted.

female thread: Internal thread like that within a nut.

fender: [1] A covering over the wheels to prevent mud from splattering. The British term for this part is "wing." [2] British term for "bumper." Also see bolt-on fender front fender inner fender panels rear fender fender arch: A smoothly shaped, rounded widening of the wheel arch area to extend the wheel arch further from the body and allow wider tires to be installed. The British term is "wing arch"

fender beading: A strip used to cover the seams between fenders that are not normally detached and adjacent body panels. In most cases, this strip is chromed and permanently attached (i.e., it is destroyed when it is removed and cannot be reused)

fender bender: A car accident in which only minor damage is done to body panels.

fender bumping hammer: A body hammer with a one-sided, fairly long head that is lightly curt,ed and terminates in a rounded section; it is used to reach fender curves from the inside

fender extension: A smaller panel in the bottom front area of the front fender that extends the fender toward the front panel and the wheel housing

fender landing section: A horizontal flange at the top of the flitch plates that provides the seating for the fenders; in most cases, it also includes the mounting threads or spot-welds for attaching the fenders

fender mirror: A rear-view mirror mounted on the fender. It used to be a common placement, but now the outside mirror is mounted on the door.

fender mounting: The top flange of the sidewalls in the engine compartment and its vertical extensions at the front and rear; the fender is welded or bolted to this edge along its entire length

fender panels: See inner fender panels

fender punch: A hole punch with a specially shaped head to fit over awkward fender panels, rain gutters, and wheel arches

fender rail: A length of metal trim surrounding a motorcycle fender.

fender skirt: A plate designed to cover a portion of the rear fender wheel opening. It was available either as stock equipment, as an optional extra, or as an aftermarket item.

fender splash apron: A panel on the inside of the fender to prevent splashing water from reaching certain areas of the fender, wheel housing, and A-post; as opposed to wheel house panels, it is usually flat and mounted in an upright position behind the front wheels

fender strengthening buttress: A horizontally closed section of triangular shape in the upper rear edge of the inner fender area that adds rigidity to this area

fender support bracket: A sheet metal brace used to attach the bottom edge of the fender to the body, to keep it from flexing and vibrating

Ferguson four-wheel drive: A transmission system in which power is distributed through a special viscous coupling differential, 37% to the front wheels and 63% to the rear wheels

Ferrari: A vehicle brand of which the V-12 (All Front Engined) (1947- Click for books on 70) models are milestone cars. Ferrari Also see Dino and Testarosa

ferrous: Something containing iron

ferrous metal: Metal containing iron or steel. Non-ferrous metals are aluminum alloys, brass, copper, or magnesium.

ferrule: A cap (cylindrical metal piece with a hole at each end) attached to the end of the cable outer housing to protect the cable housing from fraying.

ferrules:

See ferrule.

festoon bulb: A light bulb in the form of a small glass tube with caps at each end providing the contacts

FF headlight: A free-form headlight using a free-shape reflector

FFÖ: Acronym for "Fachverband der Fahrzeugindustrie Österreichs" (Austria)

FEU: Acronym for "Forty Foot Equivalent Units" for containers on ships

FFOT: Acronym for ford fixed orifice tube system

F head: See F-head engine engine type F-head: See F-head engine engine type F head engine: See F-head engine.

F-head engine: An engine having one valve in the head and the other in the block. The position of the valves create an "F" shape in combination with the combustion chambers. Also see engine type

FHP: Acronym for "friction horsepower"

F.I.: Abbreviation for "fuel injection."

FI: Acronym for "fuel injection."

FIA: Acronym for "Fédération Internationale de lAutomobile" -- An international umbrella motoring organization to which national motoring organizations are affiliated

Fiat: A vehicle brand of which the 1925-1948 models with required application are classic cars.

Click for books on Fiat

fiber: See carbon fiber glass fiber milled glass fiber fiberform: A patented process used in building composite automobile bodies.

fiberglass: A mixture of glass fibres and resin that when cured (hardened) produces a very light and strong material. It is used to build boats, car bodies, repair damaged areas, etc. It can also be spelled "Fibreglass." Also called "glass reinforced plastic."

fibreglass: A mixture of glass fibres and resin that when cured (hardened) produces a very light and strong material. It is used to build boats, car bodies, repair damaged areas, etc. It can also be spelled "Fiberglass."

fibreglass body: A body shell which is molded in one piece from fiberglass and has the advantage of lightweight and freedom from corrosion

fibreglass mat: A layer of chopped but irregular individual fibreglass strands dressed with a chemical to hold them loosely together, which when a resin is applied hardens into a strong material for repairing holes, e.g. in car bodies

fiber optics: The transfer of light through glass fibers. Cadillac, for instance, transfers the light of the headlight or taillight through fiber optics showing that the lights are actually on; rather than just an electrical connection which shows that the indicator light works.

field: [1] A particular body of interest or expertise. [2] The area covered or filled with an electric, magnetic, or gravitational force. See magnetic field primary magnetic field field coil: Insulated wire wrapped around an iron or steel core. When current flows through the wire, a strong magnetic force field is built up.

field intensity: The force acting on a unit electric charge or unit magnetic pole placed at a given point.

field terminal: (F) The input terminal on a generator

field testing: The testing of a vehicle or component as it would appear under normal conditions

field trial: The testing of a vehicle or component as it would appear under normal conditions

field winding: That part which produces a constant-strength magnetic field in an electric motor or generator, the field core being on the stator or the rotor depending on the type of motor or generator

fierceness: The tendency of a clutch to engage suddenly so that it is difficult to procede smoothly from a stop

Fiero: A model of automobile manufactured by Pontiac division of General Motors

Click for books on Fiero

FIEV: Acronym for "Fédération des Industries des Equipements pour Véhicules" (i.e., The French Vehicle Equipment Industries Association)

fifth: The top gear in a five-speed transmission

fifth gear: The top gear in a five-speed transmission

fifth wheel: [1] A wheel that is temporarily attached to a vehicle to test the accuracy of the speedometer, etc. [2] A trailer which has its tongue attached to the bed of a truck.

fifth-wheel travel trailer: A trailer which is towed by a pickup truck. The tongue of the trailer fits into the bed of the truck. Like a travel trailer, it comes with all the amenities of home. The master bedroom is over the truck bed.

fifty-fifty power split: An arrangement in a four-wheel drive transmission where equal amounts of power are delivered to the front and rear wheels

filament:

A fine wire inside a light bulb that heats to incandescence when current passes through it. The filament produces the light. Also see double filament bulb filament bulb: See double filament bulb

file: [1] A flat or rounded tool with a rough surface of hardened steel. When it is rubbed against metal, it removes small bits of metal leading to a smaller amount of base metal. [2] The action of removing metal by using a file. Also see bastard file body file bumping file coarse-cut file coarse file flat file half-round body file hand file ignition file ignition point file key file magneto file millsaw file multi-cut file multi-purpose file panel file points file rat-tail file round file single-cut file thread file warding file file card brush: A brush with angled wire bristles for cleaning between the teeth on a file or the threads on a bolt.

file handle:

A wood or plastic handle, which it fitted to the back end of a file.

filing: See draw-filing

fill: See radiator fill hole

filler: [1] paste usually with a polyester base which, when mixed with a hardener, forms a surface which can be sanded smooth and is suitable for repairs to dented or rusted bodywork. Also called "filler paste." [2] A primer filler. [3] an inert material added to paper, resins, and other substances to modify their poroperties and improve quality. [4] An opening through which some liquid can be poured (i.e., oil or gasoline). Also see anti-chipping filler battery filler body filler bumper filler flip-top filler cap fuel filler tube fuel filler flap glass reinforced filler paste high-build filler oil filler cap plastic filler polyester filler primer filler quarter light filler panel quarter window filler panel two-pack filler filler cap: A cover which seals off a filler hole. Also see flip-top filler cap oil filler cap filler door:

A hinged door (usually less than six inches square and painted the body color) which covers the gas cap and filler neck on some models.

filler flap: See fuel filler flap

filler neck: A funnel shaped part which is connected to the main container (gas tank, radiator, windshield washer reservoir, etc.) and is usually covered with a cap. Also see fuel filler neck filler panel: See quarter light filler panel quarter window filler panel filler paste: See glass reinforced filler paste

filler rod: A metal wire that is melted and added to the welding puddle to produce the necessary increase in bead thickness. Also see welding rod filler strip: A free flowing rubber used under the tread when added thickness is needed.

filler tube: See fuel filler tube

fillet: [1] A round joint between two parts connected at an angle. [2] Weld metal in the internal vertex, or corner, of the angle formed by two pieces of metal, giving the joint additional strength to withstand unusual stresses. Also see leg of fillet weld

fillet weld: Metal fused into a comer formed by two pieces of metal whose welded surfaces are approximately 90° to each other. Also see leg of fillet weld throat of a fillet weld fill hole: See radiator fill hole

filling: Repairing of holes or dents in bodywork with filler paste or body lead

filling station: A British term for a gas station

fillister screw: A set screw with a deep rounded head

fill line: See battery fill line

fill plug: A small screw-in plug in the steering box or similar, which is removed for topping up with oil.

fill up: [1] To put in the full amount of fuel as in "Fill up the gas tank, I'm down to a quarter of a tank." Often said, "Fill 'er up" or "Fill her up." [2] The amount needed to make a full tank as in "I need a fill up."

film: A thin layer or coating of something. See anodic coating anodic film heavy film build

lubrication film natural oxide film paint film film build: See heavy film build

film strength: The ability of a liquid like oil to withstand pressure

filter: A device designed to remove foreign substances from air, oil, gasoline, water, etc. Also see air cleaner air filter bypass filter canister air filter centrifugal force air filter centrifugal oil filter ceramic filter charcoal filter cuno filter diesel particulate filter fuel filter full-flow filter full-flow oil filter full flow filter full flow oil filter gas filter in-line fuel filter inline fuel filter integral fuel filter micro oil filter oil filter oil filter cartridge oil filter hole oil filter housing oil filter oil filter bypass valve oil filter wrench partial flow filter pod filter sock filter surface-type filter

vacuum filter filter bypass: See oil filter oil filter bypass valve

filter bypass valve: See oil filter oil filter bypass valve oil filter bypass valve filter cartridge: The replaceable porous part of some oil filters and air filters; but often refers to the whole filter. Also called "filter element." Also see oil filter cartridge filter element: The replaceable porous part of some oil filters and air filters; but often refers to the whole filter. Also called "filter cartridge." Also see air filter element filter hole: See oil filter hole

filter housing: See oil filter housing

filter screen: A piece of wire mesh in a pipe or surrounding an air filter which is designed to collect dirt and foreign matter

filter wrench: An oil filter wrench for removing the oil filter. Also see chain filter wrench oil filter wrench filtration:

The removal of dirt or suspended particles from a liquid or the air with the aid of a filter. Also see air filtration filtration system: See air filtration system

FIM: Acronym for "Fédération Internationale Motorcylistes," the governing body of international motorcycle sports

fin: [1] A thin metal object projecting from a surface and is used to dissipate heat. It is found on radiators and air-cooled engines. [2] Wings and airfoils used to improve a vehicle's aerodynamics, stability, or possibly aesthetics. Also see tail fin final drive: This is the end of the drive train before power is transmitted to the wheels. In a typical car, the engine (or electric motor) transmits its power through some sort of clutch into a transmission. Then the power is transmitted to differential gears that adjust the engine speed to the most efficient use intended. These final drive differential gears are either at the front axle or rear axle, depending on the vehicle's layout. A typical family car or one intended for high speeds will have a low numerical ratio, to give it speed and good fuel efficiency. A truck or performance car is likely to have a high numerical ratio for better pulling power or for better acceleration

final drive gear: The last gear in a drivetrain before the driven wheels. Usually it is in the differential.

final drive ratio: This is the ratio that describes the difference between the number of times the driveshaft must turn before the axle shaft turns once. In a final drive ratio of 3.55:1, for example, the driveshaft must turn 3.55 times before the axle will turn once. The number of teeth on the ring and pinion gears determine the ratio. In most instances, the ratio is not a simple number like 3.00:1 because the same teeth on the drive and

driven gears would always meet and cause wear.

final purchase price: This price is equivalent to the amount you would pay for the vehicle if you were buying or financing rather than leasing. The final purchase price does not include any 'down' payment by the lessee.

finance and control: Ownership of company (i.e., Canadian, U.S., Japanese, German, etc.); public or private; capital investments: Buildings, machinery and equipment, tooling programs.

finance company: See captive finance company

fine: [1] Something that is made of very small particles. [2] The position of threads on a bolt or nut that are very close together. See national fine thread

fine thread: See national fine thread

finger: A protruding piece which engages or triggers something. Also see clutch semi-centrifugal release fingers clutch release finger release finger fingers: See clutch semi-centrifugal release fingers release fingers finger tight: The torque required when securing something without the use of a wrench; but using only one's fingers.

finish: [1] The final coat of paint applied to a vehicle. See original finish. [2] The overall look of a vehicle so that the paint, for instance, is evenly applied, there are no bare spots, etc. Usually this word is used in the expression "fit and finish." [3] Surface refinement as in smooth finish. Also see acrylic finish baking finish krinkle finish metallic finish one-coat finish original finish specular finish finish coat: The final color coat applied to a vehicle.

finish hammer: A pounding device used for detail work in shaping a panel after it has been brought approximately into the right shape.

finishing enamel: The paint used as the top coat of a painting system -- usually before a clear coat is applied. Also called "finishing paint."

finishing hammer: See pick and finishing hammer

finishing paint: The paint used as the top coat of a painting system -- usually before a clear coat is applied. Also called "finishing enamel."

finish restorer: A polish or rubbing compound with very slight abrasive which is used to remove an oxidized paint surface to bring back its original lustre.

finishing stone:

A fine grain stone used at the completion of the honing process to give a smooth surface.

finite-element analysis: A reduction of a complex structure to its basic component parts so that these can be studied in a computer, especially in a CAD process. Also called "FE analysis"

finning: An arrangement of fins on a surface to aid cooling by improving the heat transfer rate, typically found on air-cooled engines

fins: A series of blades such as are found in the internal design of the torque converter. To create mechanical torque from hydraulic pressure, oil is forced under pressure through the torque converter. The inside of the converter is made up of layers of steel fins which zigzag in direction and vary in size. First the fins are large but as the layers go on, the fins decrease in size. This design generates greater hydraulic pressure as the oil passes through the converter, the strong flow of oil creates a fluid coupling which operates like a clutch, driving the wheels. Also see cooling fins fire: [1] To start an engine as in "I will fire up this engine." [2] To ignite the air-fuel mixture. Also see backfire fire appliance: A British term for fire engine

fireball combustion chamber: A combustion chamber design developed by the Swiss engineer May and introduced on Jaguar's V-12 engine in 1981

Firebird: A model of automobile manufactured by Pontiac division of Click for books on General Motors Firebird

fire engine: A vehicle built on a special truck chassis equipped with fire-fighting items such as ladders, pumps, hoses, etc.

fire extinguisher: A cylinder filled with a powder, foam, or liquid which can be sprayed on a fire to put it out.

fire point: The temperature at which the vapor continues to burn. See flash point.

fire ring: The circle of metal in a head gasket just where the piston comes through

firewall: The metal partition between the driver's compartment and the engine compartment. On front engine vehicles, it is located below the windshield; but on rear engine vehicles, it is located below the backlight (i.e., back window). It protects the driver and passengers from engine fires, noise, and fumes. The British term is "bulkhead."

firing: The process of igniting the air-fuel mixture in the combustion chamber. Also see backfiring shunt firing firing end: Part of the spark plug which extends into the combustion chamber

firing order: The sequence or order in which cylinders must be fired: 1, 5, 3, 6, 2, 4, etc. It differs from the cylinder sequence which starts with cylinder number one and goes to the last cylinder: 1, 2, 3, 4, 5, 6.

firing stroke: The power stroke

firm:

A business or institution comprising sole proprietorships, partnerships, companies and other forms of organizations.

first: The lowest gear in a transmission. In a bicycle, it is the gear ratio where the drive sprocket is the smallest and the driven sprocket is the largest. This gear is the best for starting from a stop or going up a hill.

first-aid kit: A box containing bandages, antiseptic ointment, and other basic medical requirements for treating injuries.

first gear: The lowest gear in a transmission. In a bicycle, it is the gear ratio where the drive sprocket is the smallest and the driven sprocket is the largest. This gear is the best for starting from a stop or going up a hill.

FISA: Acronym for "Fédération Internationale du Sport Automobile" which is the governing body of motor sport

fish eye: A small pit that forms in the finish coat of paint, usually due to insufficient or improper cleaning of the old coat.

fish eyes: Small pits that form in the finish coat of paint, usually due to insufficient or improper cleaning of the old coat.

fit: [1] Contact area between two parts. [2] The way in which two parts come together. [3] To attach or put into place. Also see clearance fit drive fit force-fit force fit hubcentric fit interference fit

press fit running-fit shrink fit sliding-fit fit and finish: The evaluative standard of a vehicle's cosmetics. Good fit and finish means all the body panels and trim are evenly spaced, aligned, and secure. The paint is evenly applied with no bubbles or pit marks.

fitment: See twin fitment

fitting: A small part that is attached to a larger apparatus. Also see air hold fitting bayonet fitting grease fitting zerk fitting fittings: See fitting

five-door: Body design typical of station wagons and most hatchbacks, with four side doors and a tailgate.

five-door hatchback: Essentially unknown among domestic models in the mid-1970s, the four-door hatchback became a popular model as cars grew smaller and front-wheel-drive versions appeared. Styling was similar to the original two-door hatchback, except for two more doors. Luggage was carried in the back of the car itself, loaded through the hatch opening, not in a separate trunk. === car-4hatch.jpg

five-link rear suspension: Independent rear suspension layout also used on live rear axles, in which each wheel is guided by two trailing links, two transverse links and a common track rod

five speed transmission: See five-speed transmission.

five-speed transmission: A manual transmission with five forward gears. Generally the fifth gear is an overdrive to allow the wheels to turn faster than the engine. See overdrive.

five-valve head: A cylinder head which has five valves per cylinder, usually three intake valves and two exhaust valves

fix: [1] To attach something securely. [2] To repair something

fixed-caliper disc brake: A disc brake with a caliper which cannot move, the caliper consisting of two halves which are bolted together and contain at least one cylinder and piston each

fixed-cam brake: A drum brake in which the cam is rigidly mounted in the backplate

fixed-choke carburetor: A carburetor where the choke tube or venturi is of predetermined size

fixed contact: The stationary point in a set of contact breaker points -- the other point moves

fixed cup: The right-hand cup of the bottom bracket of a bicycle, ordinarily not loosened or removed during bottom bracket disassembly. Also see adjustable cup fixed drive: A power transmission without differential action at the driven axle or between the driven axles in a four-wheel drive layout

fixed gear: A cog attached to a hub without a freewheel; it always turns as fast as the bicycle's wheel so that you cannot coast.

fixed head: [1] A non-removable cylinder head cast in one piece with the cylinder block. These heads were used in early automobile engines and, more recently, in some motorcycle engines. [2] A British term for a solid non-removable roof, or coupe.

fixed idle-air bypass: Some Rochester Quadrajet carburetors have idle air passages from the air horn to a point just below the throttle plates. Extra air through these passages allows the throttle plates to be more closed at idle, reducing the signal applied to the discharge nozzles for the main metering circuit and eliminating nozzle drip at idle

fixed-jet carburetor: This is the most common type of carburetor in which the jets and choke are of a predetermined size. The opposite is a variable-jet carburetor

fixed orifice tube: A device that converts high pressure liquid refrigerant into low pressure liquid refrigerant (thus lowering its boiling point) before it passes through the evaporator. The expansion valve replaces the thermostatic expansion valve. Also called an expansion tube

fixed price selling: Published fixed price displayed on a new vehicle eliminating need for negotiation.

fixed wheel: Same as fixed gear, the kind of rear wheel found on track bikes.

fixing bolt: A bolt used to hold a crankarm on an axle in a cotterless crankset. Also see crankarm fixing bolt

fixture: Device for holding goods in process while working tools are in operation that does not contain any special arrangements for guiding the working tools.

flag: See black and white checkered flag black flag checkered flag green flag green flag with yellow diagonal stripe national flag red flag white flag yellow flag flag down: The action of a pedestrian to stop a vehicle by using a hand signals (usually waving the arms laterally above the head). This is usually a sign of an emergency

flagship model: The prestige model or top model of a manufacturer's line of vehicles, e.g., "Cadillac is the flagship model for GM and Lincoln is the flagship model for Ford."

flags of convenience: Flags of nations which offer favorable tax structures and regulations. Ships registering under the laws of these nations are not always required to establish their home location in that country.

flake: The action of paint when it starts to come off the surface in small, thin sections

flake off: The action of paint when it starts to come off the surface in small, thin sections

flaking: The tendency of paint to lift away from the surface because of poor adhesion.

flame:

See cutting flame neutral flame oxidizing flame oxygen-hydrogen flame oxygen-lp gas flame reducing flame sheath flame flame cutting: Cutting performed by an oxygen-fuel gas torch flame which has an oxygen jet.

flame front: The term used to describe certain aspects of the fuel explosion in the cylinders. The flame front should move in a controlled pattern across the cylinder, rather than simply exploding immediately. Also see pinging flame glow plug: A glow plug that preheats the intake air by burning a small quantity of precisely metered fuel

flame paint: A popular (during the 1950s) special paint design applied to the front of custom cars. Large flames in yellow, orange, and red were painted on the side of the car from the back of the front wheels toward the back

flame trap: A device consisting of a valve or similar, preventing the escape of ignited blowback gases, usually located in the hose or pipe leading from the crankcase to the intake tract

flange: [1] A projecting rim or collar on an object for keeping it in place. [2] The parts of a hub shell to which spokes are attached and which secure the tire on the rim base. [3] The circle of metal inside the teeth on a chainring. Also see B-flange

body flange demountable flange heater flange J-flange K-flange rim flange spot-welded flange windshield mounting flange flange bolt: A bolt with a fillet as part of the bolt head

flanged: Something that has a flange

flanged head: A bolt head which has a fillet (i.e., it looks as though it already has a washer under the head; but the "washer" is part of the head)

flange height: A measurement from the top of the flange to the bead seat, and is the difference between the overall diameter and nominal rim diameter, divided by two.

flange joint: A coupling between two shafts formed of two disc-shaped flanges on the ends of the shafts which are bolted to each other

flanger: A tool for making a flange. Also see panel flanger flange seal: An L-shaped rubber seal used in some earthmover tubeless tire mountings. It prevents air loss between the tire beads and both the flange and rim base, and the flange and loose taper seat.

flange-type puller:

A puller with legs that fit behind a flange on a hub

flanging: The action of putting on a flange

flanging tool: A tool (like pliers) for making a flange by bending the metal

flank: [1] The side of a screw thread, rising from the bottom of the groove to the top of the ridge [2] one of the two flat parts of the face of a cam

flap: [1] A rubber protector used in tube-type truck tires to prevent injury to the tube by the bead toes and at the valve slot of the rim. [2] A flat piece of material attached along one side, often by a hinge and forming a small door for shutting off an opening. Also see anti-spray flap fuel filler flap mud flap sensor flap ski flap flare: [1] A flange or a cone-shaped end applied to a piece of tubing to provide a means of sealing two similarly angled areas formed in fitting the body and the nut. [2] A sudden burst of flame. [3] The spreading out of the hull form from the central vertical plans, usually in the front, much like the end of a trumpet. [4] A gradual spreading or widening of a tube. Also see double flare flared wheel arch: A wheel arch bent outwards around its circumference, usually to accommodate wider wheels and/or tires

flare nut:

A nut fitting over the flared end of a brake or fuel pipe at a union

flare nut spanner: British term for flare nut wrench

flare nut wrench: A wrench which looks almost like an open end wrench except the end curls around the nut further. The opening allows the wrench to slide over a tube or pipe to which a nut is attached, but not directly over the nut. Thus you have to slide it over the pipe first and then bring it up to the nut. The wrench has more faces than an open end wrench thus giving better gripping.

flaring tool: A tool used to form flare connections on tubing.

flash: [1] The first stage of the drying process of paint where most of the solvents evaporates. [2] A sudden burst of energy. [3] When crude oil is heated the lighter or more volatile vapor is separated and travels to the top of the tank. This travelling is called flash. [4] The impact of electric arc rays against the human eye. [5] The fin of surplus metal formed at the seam of a resistance weld. [6] To use your signal lights as in "My car was flashing left." [7] To rapidly switch the headlights off and on -- usually to indicate a warning. If you are behind someone and you flash your headlights, it means that you want him to pull over so you can pass. If you see someone flashing his lights, it could mean that there is a police car ahead so slow down; or it could mean there is danger ahead (e.g., deer on the road, an accident ahead, etc.).

flashback: Another term for blowback

flasher: [1] A flashing signal light. [2] An electronic switch apparatus controlling the operation of the signal lights, including their rate of flash; self-cancelling when the steering wheel is returned to the straight-ahead position. [3] An electronic relay which regulates the signal lights and emits a clicking or chiming sound.

Also see hatchback hazard flasher switch headlight flasher side flasher flasher switch: See hatchback hazard flasher switch hazard flasher switch flashover: Tendency of electrical current to travel down the outside of a spark plug instead of through the center electrode.

flash point: The point in the temperature range at which a given oil (especially diesel oil) in vapor form will ignite and flash into flame. The higher the flash point, the better the lubricating quality of the oil. The temperature at which the vapor continues to burn is called the "fire point."

flash time: The time required for a coat of paint to lose most of its solvent through evaporation.

flat: [1] When a battery has completely discharged, so that it cannot turn over the engine then the battery is said to be flat. [2] To be completely deflated, especially as the result of a puncture or a leaky valve. See flat tire. [3] A flat tire. [4] An engine having horizontally opposed cylinders. [5] A level area on an otherwise rounded surface. [6] To give a final light rubbing down to (paintwork or filler) with fine grade sandpaper or similar, to prepare the surface for a top coat. Also see battery is flat go flat keel, flat plate outboard flat hump outboard flat pente run flat across flats

flat base rim: A truck rim with no center depression. A demountable flange (consisting of 1 or 2 piece side/lock ring) permits the removal of the tire and holds it in place after installation. Also see flat base rim taper flat base rim taper: An obsolete form of rim with no taper at either bead seat.

flat battery: A British term for a dead battery

flatbed trailer: A trailer with a flat deck (and no sides or top) so that any size or shape item can be loaded (within reason) regardless of height, length, or width

flatbed truck: A truck with a flat deck (and no sides or top) so that any size or shape item can be loaded (within reason) regardless of height, length, or width

flat-bladed screwdriver: A screwdriver which has a blade at its end to fit slotted screws. This type is the least desirable screw giving the least amount of torquing ability. If the screwdriver does not fit well, the screw is easily damaged.

flat crank: A crankshaft having one of the bearing journals out-of-round.

flat eight: An eight cylinder engine with four cylinders on each side. The "left" bank of four cylinders is directly opposite the right bank.

flat engine: An engine where opposite cylinders are 180 degrees apart. This engine type is found on the following: VW Beetle, Corvair, Porsche six-cylinder, Subaru "quadrazontal," and BMW motorcycle engines.

flat file: A long, thin rectangular bar (like a blade) with angled grooves cut into the top and bottom of the larger sides and used to shape metal

flat four: A four cylinder engine with two cylinders on each side. The "left" bank of two cylinders is directly opposite the right bank.

flathead: An engine with all the valves in the block on one side of the cylinder. Also called "L-head" because the combustion chamber is L-shaped. flat hump: A raised and flattened portion on the bead seat of some wheel rims which retains the beads of an insufficiently inflated tire on the bead seat, thereby preventing the tire beads from jumping into the rim well. Also see outboard flat hump flat key: A small bar of any length but its width is greater than its height.

flat-nose pliers: A common pair of pliers where the ends of the jaws do not extend to a point (like long-nose pliers); but are cut short. Also called "flat-nosed pliers."

flat-nosed pliers: A common pair of pliers where the ends of the jaws do not extend to a point (like long-nose pliers); but are cut short. Also called "flat-nose pliers."

flat pente: A raised portion on the bead seat of some wheel rims which retains the tire beads of an insufficiently inflated tire on the bead seat, thereby preventing the beads from jumping into the rim well. This is a compromise between the contre pente and the flat hump contours and is mainly used on passenger cars made in France. Also see outboard flat pente flat plate:

See keel, flat plate

flat plate keel: The horizontal, centerline, bottom shell strake constituting the lower flange of the keel

flat position: A horizontal weld on the upper side of a horizontal surface.

flat position welding: Creating a horizontal weld on the upper side of a horizontal surface. Also called "downhand welding"

flat rate: A pre-determined length of time set down by the manufacturer that a particular repair job will take and is listed in the flat rate manual. If the flat rate is two hours, but the mechanic completes the job in more or less time, you will be charged for two hours. For the shop, flat rate encourages mechanics to work harder to beat the prescribed time, thus earning more for the shop and the mechanic; but it also hurts the shop when the mechanic cannot complete the job because of other contributing factors (i.e., a bolt which should have taken 10 seconds to remove breaks off and requires 30 minutes to remove). For the customer, flat rate means fair pricing for the same job no matter how long it actually took. Thus both Sam's labor bill and my labor bill to do the same work is the same cost. It can be unfair if the mechanic worked faster on my vehicle (because I keep it in excellent shape) than on Sam's vehicle (because his involved a lot more cleaning, etc. to do the job). Also, there is the danger that a mechanic may take shortcuts in order to beat the flat rate, but which may cause mechanical problems later. Charging by the actual time the mechanic takes is called straight time.

flat rate manual: A listing of almost every job that can be done on a vehicle with the time required for a mechanic to do the work. It is used in service shops to determine labor charges. If a mechanic completes the job before the flat rate time, the customer is still charged the flat rate time. If he exceeds the flat rate time, the customer is not charged for straight time, but the lower flat rate time.

flat seat: The seat of a spark plug which is sealed by means of a gasket

flat six: A six cylinder engine with three cylinders on each side. The "left" bank of three cylinders is directly opposite the right bank.

flat spot: [1] Refers to a spot during an acceleration period where the engine seems to lose power for a moment and will then begin to pull again. [2] Irregular wear in an isolated spot or spots around the tire tread. It is usually caused by locking the brakes so that the tire skids on the ground.

flat spring: A long bar that is bent in the middle. When pressure is applied to the outside ends, the middle flexes.

flat tank: Fuel tank shape used on early motorcycles

flat tappet: A tappet with a flat contact surface towards the cam lobe

flat tire: A condition where an air-inflated tire is no longer pressured up with air. The problem may be a cut in the casing or tube; or may be caused by a bad valve. When you experience a flat tire, no doubt some wit will tell you that your tire is flat only on the bottom.

flat-tip screwdriver: See flat-bladed screwdriver

flat-topped piston: A piston with a flat not domed crown

flat-top piston: A piston with a flat not domed crown

flat twin: A two cylinder engine with one cylinder on each side. The "left" cylinder is directly opposite the right cylinder. See horizontally opposed

flat washer: A disc like a coin with a hole in the middle

flaw: A defect usually in the surface of the paint

fl`che vélocio: A 24-hour team bicycle ride covering at least 360 kilometers held over the Easter weekend in France.

fleet: All the vehicles owned by a company or other organization

fleet car: A company will purchase a number of cars at a low price, often basic models, from one manufacturer. When the company decides to sell these cars, it will advertise that it was a flee car. Fleet cars have the advantage of regular maintenance; but the disadvantage of high mileage.

fleet sales: The purchase of vehicles by a business that meet a minimum requirement of units sold.

flex arm suspension: Rear axle design with torsionally flexible axle beam in line with the rear wheels and trailing links

flexibility: [1] Elasticity of a material. [2] The ability of an engine to go down to low speeds in a high gear and pull away smoothly without gearing down, which is governed mainly by its torque characteristics

flexible: [1] The ability to bend without breaking. [2] The ability of an engine to go down to low speeds in a high gear and pull away smoothly

flexible brake pipe: A pipe connecting the wheel cylinder to the rest of the system, which has to flex to allow for the up and down movement of the wheel

flexible coupling: A simple shaft coupling used where only small angles of misalignment between the two shafts occur, as in a steering column, the drive being transmitted either by tension-stressed fabric discs or pressurized rubber blocks

flexible drive: A drive consisting of a cable in an outer sheath, used for mainly light applications such as speedometers, rev counters and windshield wipers

flexible drive handle: A socket drive tool with a pivoting head for use with sockets, its length gives good leverage and access to difficult locations because of its ability to bend

flexural: A word referring to bending

flexural shock: A sharp shock when bending, which can break plastics

flexure: Bending. Also see stiffness under flexure flickability: The ease with which the bike can be leaned to the right or left around turns. High flickability means it leans quickly and easily, acting like a sportbike. Low flickability is how a cruiser handles -- not really designed for fast riding through the canyons. Lighter, smaller bikes are generally more flickable through turns.

flipper strip:

See ply turnup.

flip-top filler cap: A quick-release filler cap, as fitted to some sports and racing cars

flitch plate: A reinforcing plate for chassis members or wheel arches

float: [1] A small hollow tank which is more buoyant than the liquid in which it is immersed. In a carburetor it operates the valve (needle and seat) which controls the amount of fuel entering the carburetor. In the fuel tank, it indicates the amount of fuel. Older floats were hollow and made of metal, but newer ones were made of a solid synthetic material. [2] The action of the breaker arm when it is pushed out as the cam strikes the rubbing block; and before the arm can return after the cam has passed, the next cam strikes the block and re-opens it. In other words, the breaker arm never has the time to fully close before being opened again. Also see end float valve float floatation: The ability to float generally referring to large low pressure tires (i.e., the ability of a tire, to pass over soft surfaces without sinking in.)

float bowl: That part of a carburetor that acts as a reservoir for gasoline and in which the float is placed. The float controls the amount of fuel moving through the fuel valve.

float bumper spring: A small spring installed under the float tang to minimize float bounce and vibration

float chamber: British term for float bowl

floating: See

full floating axle fully floating axle floating axle: See full floating axle fully floating axle three-quarter floating axle floating caliper disc brake: A disc brake with a single piston, in which the caliper itself can move to bring both pads into contact with the disc

floating piston pin: A piston pin which is not locked in the connecting rod or the piston, but is free to turn or oscillate in both the connecting rod and the piston.

floating frame: A frame which holds the cylinder assembly and is supported by the mounting frame, usually made of heavy-gauge sheet steel.

floating cam: brake cam or other type of expander which is not rigidly mounted in the brake backplate of a drum brake, so that it can exert equal pressure on the two shoes

floating piston: a secondary piston

float level: [1] Height of the fuel in the carburetor float bowl. [2] The specific float setting that will produce the correct fuel level. [3] The float position at which the float needle closes against its seat, shutting off the fuel inlet valve to prevent further deliver of fuel

float needle: A needle in the carburetor which is activated by the level of fuel in the float bowl. As the level drops, the needle lifts and allows more fuel to enter the bowl

flood: [1] To allow too much fuel to enter the carburetor or the engine. [2] A condition where the fuel mixture is overly rich or an excessive amount has reached the cylinders. Starting will be difficult and sometimes impossible until the condition is corrected.

floodable length: The length of ship which may be flooded without sinking below her safety or margin line. The floodable length of a vessel varies from point to point throughout her length and is usually greatest amidships

flooding: A condition where the fuel mixture is overly rich or an excessive amount has reached the cylinders. Starting will be difficult and sometimes impossible until the condition is corrected. hot-wax flooding and hot-wax flooding unit

flooding unit: See hot-wax flooding unit

flood the carburetor: [1] An undesirable condition which occurs when the float in the carburetor is set too high. [2] A desired condition which allows extra fuel into older or simpler carburetors by pushing down the float with an extra lever (called a tickler) to give a richer mixture for starting

flooded engine: An engine which has too much fuel into the cylinders. It can be caused from trying to repeatedly start a car which refuses to start. If this condition continues, the engine oil could become diluted and should be changed.

floor: [1] The flat base panel of a vehicle. [2] A verb meaning to push the accelerator as far as it will go (i.e., to the floor). [3] The vertical transverse plate immediately above the bottom shell plating, often located at every frame, extending from bilge to bilge. Also see four-on-the-floor four on the floor load floor

load floor extension floorboard: The flat base panel of a vehicle. Originally it was the collection of wood planks which made up the floor of vehicle. The floor of the vehicle under the instrument panel.

floor change: [1] A gear shifter on the floor -- usually on the center console. [2] Some coins left on the floor after being negligently dropped there.

floor extension: See load floor extension

floor gearchange: A gear shifter on the floor -- usually on the center console.

floor pan: The metal structure on the bottom of the car. Almost all cars are unit body (or unibody) construction, and the floor pan provides the foundation for chassis stiffness. Your feet usually rest on a floor pan when you are in a car.

floorpan: The large stamped metal part of the car's body over which the carpet is laid. Usually assembled from several smaller stampings, the floorpan forms the floor and fixes the dimensions for most of the car's external and structural panels. It is also the foundation for many of the car's mechanical parts.

floor shift: When the shifting lever is placed in a vehicle, it usually occupies one of three primary positions: the dash (usually a pushbutton arrangement); the steering column; and on the center column between the driver and front seat passenger. Also see gearshift floor shifter: A gear shifter on the floor -- usually on the center console.

flow: [1] The passing of liquid or current through something. [2] The amount of liquid or current conveyed. Also see airflow electron flow full flow filter full flow oil filter gas flow L-jetronic air flow meter partial flow filter rotary flow vortex flow flow control: The regulation of the amount of fluid passing through a pump, especially important under changing operating conditions

flow detachment: The deviation of the gas flow into the cylinder from its ideal path, thus losing its stability, caused by swirl and/or improper combustion chamber design etc.

flow filter: See full flow filter partial flow filter flowmeter: A meter indicating the amount of liquid passing through, used for instance to supply information to a fuel consumption indicator. Also see air flow meter L-jetronic air flow meter flow oil: See full flow oil filter

flow oil filter: See full flow oil filter

flow rate: The amount of liquid conveyed by a pump per unit of time

flow scavenging: See transverse flow scavenging unidirectional flow scavenging flow through ventilation: See flow-through ventilation.

flow-through ventilation: A system which allows (or even forces) outside air into the passenger compartment through the dash and leaves through openings in one of the pillars (usually the Cpost) or rear quarter panels.

fluid: A substance which flows, e.g., a liquid or a gas. Also see automatic transmission fluid battery fluid brake fluid easing fluid hydraulic fluid releasing fluid silicone brake fluid transmission fluid washer fluid windshield washer fluid fluid capacities: The full amount of oil in the crankcase; water in the radiator and cooling system; or fuel in the gas tank; washer fluid in the reservoir tank; etc.

fluid clutch: A hydraulically acting coupling by which power can be transmitted, used as an automatic clutch with a driving and a driven rotor revolving in oil which acts as the transmission medium

fluid coupling: On a manual transmission, there is a mechanical connection between the engine and transmission through the clutch. On an automatic transmission a fluid coupling provides a viscous fluid to connect the engine output and the transmission. It transfers engine torque to the transmission input shaft through the use of two units with vanes (called a "torus") operating very close together in a bath of oil. The engine drives one torus causing it to throw oil outward and into the other torus which then begins to turn the transmission input shaft. A fluid coupling cannot increase torque above that produced by the crankshaft. Buick's Dynaflow is an example of this kind of coupling. fluid flywheel: A kind of fluid coupling in which the flywheel is the driving rotor

fluid level warning indicator: A warning light on the instrument panel which is illuminated when the level of fluid in the a system is too low

fluid reservoir: See brake fluid reservoir

fluorescent: Having the property of giving off light when bombarded by electrons or radiant energy

flush: [1] To cleanse a system by sending water or other liquid through a system. [2] To align two items so that they fit evenly or level. Also see reverse flush flush deck ship: A ship constructed with upper deck extending throughout her entire length without a break or a superstructure, such as forecastle, bridge or poop

flushing: To cleanse a system by sending water or other liquid through a system. Also see brake flushing flushing the cooling system

brake flushing flushing the brakes: See brake flushing.

flushing the cooling system: The process of circulating water through the cooling system to remove old coolant along with any dirt or rust. Back flushing means circulating the water from the engine to the radiator (reversing the normal direction of flow) in order to clean the system more efficiently. Also see reverse flush flushing oil: A thin oil used to clean out the sump, oil passageways, etc.

flush mounted speaker: A radio or stereo speaker mounted in a cutout in the interior trim so that it does not project out. The opposite of surmounted speakers.

flute: A groove in a cutting tool that forms a passageway for the exit of chips removed during the cutting process.

flutter: The rapid movement of engine valves. Also see bounce piston ring flutter wheel flutter flux: [1] The lines of magnetic force moving through a magnetic field. [2] An ingredient placed on metal being soldered or brazed, to remove and prevent the formation of surface oxidization which would make soldering or brazing difficult. Flux promotes the fusion of metals during the welding process.

fly:

See shift on the fly

flyer: A fast lap

flying bridge: The platform forming the top of the pilot house

flylead: A short electrical wire with a terminal at each end connect to a component

fly nut: A wing nut.

flyweight: See flyweights.

flyweights: Special weights which react to centrifugal force to provide automatic control of other mechanisms such as accelerators or valves.

flywheel: A relatively large and heavy metal wheel that is attached to the back of the crankshaft to smooth out the firing impulses. It provides inertia to keep the crankshaft turning smoothly during the periods when no power is being applied. It also forms a base for the starter ring gear and, in manual transmission, for the clutch assembly. Also see engine flywheel fluid flywheel flywheel generator: A small alternator of the rotating magnet type attached to one end of the crankshaft and spinning with it, acting as an additional flywheel; now used only in mopeds or scooters

flywheel magneto:

A magneto mounted in the flywheel of a small engine, often a two-stroke

flywheel puller: A specially designed tool with three arms and a center stud usedto removing the flywheel. The three arms are attached to three mounting points (either on the rim of the flywheel or into three threaded holes in the flywheel). The center stud is screwed into the center of the flywheel and pushes against the end of the crankshaft. As the stud pushes in, the flywheel is forced away from the crankshaft.

flywheel ring gear: A gear on the outer circumference of the flywheel. The starter drive gear engages the ring gear and cranks the engine.

flywheel turner: A special tool used for hand cranking the engine while working on clutches, gearboxes, etc. or doing jobs that require that the crankshaft be in a specific position. It consists of a handle and lever to hook into the starter ring teeth

FM: Frequency modulation. A term used to describe a type of radio frequency in which the frequency of the wave changes rather than the amplitude. Also see AM/FM FN: A vehicle brand of which the 1925-1948 models with required application are classic cars.

foaming: [1] The formation of bubbles in the oil of a transmission, differential, or shock absorber, etc. [2] The formation of bubbles in the oil and refrigerant of an air conditioning system caused by a rapid boiling out of the refrigerant dissolved in the oil when the pressure is suddenly reduced. If noted in the sight glass, this condition indicates a very low refrigerant level. Also see high pressure foaming low-pressure foaming FOB:

[1] Acronym for "Freight on Board." Used to describe when goods are loaded for free on a delivery vehicle at the seller's place of business, but the buyer has to pay transportation charges to the delivery destination. [2] When not an acronym, it refers to the device on a key chain which may contain your name or a company name, etc. See fob.

fob: A device to hold keys; sometimes called a "key fob." Also see key fob focal: See multi-focal

Foettinger coupling: A torque-converting fluid coupling.

fog: See rear fog light

fog coat: A fully reduced (thinned) paint that is sprayed at higher than normal air pressure or with the gun held at a greater distance than normal from the work. The object is to obtain a fast flash-off (evaporation) of thinner with minimum penetration of thinner into the old paint.

fog lamp: See fog light rear fog light fog light: [1] A light (usually in pairs) mounted at the front of a vehicle which is designed to give a wide low beam which penetrates fog and rain, etc. and illuminates the sides of the road [2] A red light mounted at the back of a vehicle which has the same intensity as a brake light to help following vehicles to see your vehicle. Also see rear fog light

fog testing: See salt fog testing

foil: A light, thin, blunt-edged sword from which an air foil is named. See air foil hydrofoil folder: See sheet metal folder

folding camping trailer: A lightweight unit used for camping. The ends fold out and the top is raised to reveal a camping unit. When being pulled, the ends fold down to make a compact unit. The lightweight allows it to be towed by most cars. The trailer can be unhitched from the car for easier parking or for leaving it at the campground while you go to town for supplies. The interior contains kitchen, dining room, and sleeping facilities. Often there is a stove and refrigerator.

folding rear seats: Rear seats in a hatchback, station wagon, or van which fold forward into the footwells to give a more or less flat loading area. Also see split folding rear seats folding top: The soft top of a convertible which can be folded away

follower: See cam follower valve follower follow-up spark: secondary spark occurring when a spark is extinguished and re-ignited in the course of the spark duration, especially if the mixture is turbulent

Fomoco: Abbreviation for "Ford Motor Co."

foot: See heavy foot pound foot roller foot lever foot brake: The main braking system operated by a foot pedal

footed: See light-footed

foot feed: A gas pedal operated by the foot

foot lever: See roller foot lever

foot pedal: One of four possible pedal located on the floor in front of the driver: gas pedal (accelerator), brake pedal, clutch pedal, or emergency brake pedal

footpedal cluster: The gas and brake pedals in a vehicle with automatic transmission and the gas, brake and clutch pedals in a manual.

footpeg: The metal post (usually covered in rubber) found on either side of a motorcycle upon which the rider or his passenger places his feet.

foot pound: See foot-pound.

foot-pound:

(ft-lb) A measurement of the work involved in lifting one pound one foot. In tightening, it is one pound pull one foot from the center of an object. Torque, or the twisting motion of an engine, is expressed in terms of foot-pounds at a certain rpm.

footprint: The area of a tire that makes contact with the ground

foot pump: A tire pump which is operated by pushing down a lever with a foot.

footrest: A place to rest the left foot when driving. See dead pedal.

footwell: A recess in the floor below the feet of the rear seat occupants, but may also be used for the space used by the feet of people in the front seats

footwell intrusion: A situation where an engine, for instance, occupies some of the space normally allocated for the feet of the driver and his passengers.

force: A push or a pull, it causes objects to change their motion. It is a vector quantity, with a particular direction and forces must be combined with special vector rules. In the SI (international system of units), it is measured in newtons (N); but the older measurement recorded force in pounds, ounces, and feet. Also see braking force centrifugal force centripetal force closing force cornering force damping force electromotive force tensile force ultimate cornering force force air filter:

See centrifugal force air filter

forced circulation: A cooling system which uses a pump to circulate the coolant. Also see thermosyphon cooling forced downshift: An automatic transmission system that enables a driver to accelerate rapidly. When the accelerator pedal is fully depressed, the transmission engages a lower gear to give this extra boost. Also called, "passing gear." The British term is "kickdown."

forced-feed lubrication: A lubrication system used in all modern four-stroke engines, in which an enginedriven pump forces the oil through passages in the engine castings, or through external pipes, to the main areas of stress in the engine

forced-induction system: A system in which either a conventional supercharger or a turbocharger, or even a combination of both, is used to increase intake pressure and force the mixture into the cylinders. Compare naturally aspirated engine force dryThe accelerated drying of paint by heat or air movement

force-fit: See force fit.

force fit: A force fit occurs when two items are hammered together to make them secure. See drive fit interference fit press fit Ford: [1] The second largest car manufacturer after GM. [2] The 1954 Crestline Skyliner is a milestone car. Click for [3] The 1957-59 Skyliner Retractable models are milestone cars. [4] books on Ford The 1955-56 Crown Vic Skyliner models are milestone cars.

[5] The 1946-48 Sportsman models are milestone cars. [6] The 1955-57 and 1958-60 Thunderbird models are milestone cars. Ford Aspire: A model of automobile manufactured by Ford

Ford Cortina: A model of automobile manufactured by Ford of England

Ford Crown Victoria: A model of automobile manufactured by Ford

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Ford Escort: A model of automobile manufactured by Ford

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Ford Fairlane: A model of automobile manufactured by Ford

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Ford Fairmont: A model of automobile manufactured by Ford

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Ford Falcon: A model of automobile manufactured by Ford

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Ford fixed orifice tube system: (FFOT) utilizes an accumulator instead of a receiver-drier and an orifice tube instead of an expansion valve. The accumulator is located at the evaporator outlet. A pressure sensing switch cycles compressor operation

Ford Galaxie: A model of automobile manufactured by Ford Fordism:

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The Encyclopedia Britannica first called the process of mass production by this name. However, mass production simply evolved in almost every industry at the beginning of the 20th century.

Ford Model A: An early model of automobile manufactured by Ford

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Ford Model T: An early model of automobile manufactured by Ford

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Ford Mustang: [1] A vehicle brand of which the 1965-67 GT/GTA V-8 models are milestone cars. [2] The 1969-70 Boss 302/Mach 1 models are milestone cars.

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fordor: A word coined by Ford for a 4-door sedan.

Ford Probe: A model of automobile manufactured by Ford

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Ford Taurus: A model of automobile manufactured by Ford

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Ford Tempo: A model of automobile manufactured by Ford

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Ford Thunderbird: A vehicle brand of which the 1955-57 and 1958-60 models are milestone cars.

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Ford-type lug: A special type of battery connection consisting of a flat lug with nut and bolt between the battery cables and terminal posts. Also called "Ford-type terminal"

Ford-type terminal: A special type of battery connection consisting of a flat lug with nut and bolt between the battery cables and terminal posts. Also called "Ford-type lug"

fore and aft adjustment: The ability to move, for example, a seat forward and backward

fore-and-aft flat twin: A flat-twin motorcycle engine mounted with the cylinders positioned in-line with the frame

forecar: Early three-wheeled vehicle with two-front wheels attached to a motorcycle-based frame. Passengers sat above the front axle

forecast: Prediction of future production or sales in the automotive industry.

forecastle: The raised part of the forward end of a ship's deck. It is used for the storing paints, tackle, deck stores, tarpaulins, ropes, etc.

forepeak bulkhead: The foremost main transverse watertight bulkhead designed to keep water out of the forward hold in case of bow collision damage. Also called collision bulkhead

fore perpendiculars: A vertical line at the intersection of the fore side of the stem and the summer load waterline. (See length between perpendiculars)

forge: To force a piece of hot metal into the desired shape by hammering it. Also see drop forged forged:

See drop forged

forged alloy wheel: See two-piece forged alloy wheel

forged aluminum: An engine piston that is formed under tremendous pressure. Forging creates a denser material that is much stronger but more expensive to make.

forging: [1] A process (usually involving hammering or squeezing) that transforms solid metal into shapes of varying cross-sectional material thickness, often involving heating. [2] A piece of forged metal alloy

forgiving: A characteristic of a component or vehicle which overlooks problems or mistakes that a driver might make. For example, a vehicle's handling may be forgiving in that even if the driver makes small inadvertent steering wheel movements, the vehicle continues to go straight.

fork: [1] The part of the bicycle frame that fits inside the head tube and holds the front wheel. Generally called the front fork. [2] The part of the bicycle frame where chainstays and seatstays join to hold the rear axle. [3] A shifting device that is U-shaped and moves gears back and forth on the shaft. Also see clutch fork clutch throwout fork front forks quad fork selector fork shifter fork shift fork shift forks throw-out fork throwout fork withdrawal fork fork blade:

One of the two parallel curved tubes that hold the front wheel of a bicycle.

fork blades: The two parallel curved tubes that hold the front wheel of a bicycle.

fork crown: The horizontal piece on the upper part of the front fork to which the fork blades attach on a bicycle.

fork ear: A metal piece which surrounds the front forks of a motorcycle and acts as a fork protector. The headlight shell is mounted to the protrusions from each protector

forked: A device which has one end in the shape of a "Y"

forked con rod: A special split connecting rod to take two pistons for uniflow-scavenging twostroke engines with two pistons per cylinder

forked rocker: A rocker arm operating two valves with its forked end

forked rocker arm: A rocker arm operating two valves with its forked end

fork lift: (Lift truck) A vehicle having metal arms extended in front for picking up and moving pallets or skids.

fork-lift truck: A small vehicle used tor loading in factories, warehouses, docks, etc., with two arms at the front projecting forward which fit into pallets and can be raised and lowered

fork rake: On a bicycle, the shortest distance between the front axle and an imaginary line extending through the head tube downward toward the ground. See rake.

fork tip: One of the slotted ends of the fork blades into which the front wheel axle fits on a bicycle.

fork tips: The slotted ends of the fork blades into which the front wheel axle fits on a bicycle.

form: See end form

formal hardtop: The hardtop roofline was a long-lasting fashion hit of the postwar car era. The word "formal" can be applied to things that are stiffly conservative and follow the established rule. The limousine, being the popular choice of conservative buyers who belonged to the Establishment, was looked upon as a formal motorcar. So when designers combined the lines of these two body styles, the result was the Formal Hardtop. This style has been marketed with two or four doors, canopy and vinyl roofs (full or partial) and conventional or opera-type windows, under various trade names. The distinction between a formal hardtop and plain pillared-hardtop coupe hasn't always followed a strict rule. === car-formhard.jpg

former: A shaped wooden block for use in panel beating, on which a desired shape is produced by hammering. Also see pulse former forming: See metal forming

formula: A detailed specification, e.g., for a particular class of motor racing. Also see euromix formula formula car:

An single seat race car with exposed wheels

Formula I: A formula according to which racing cars are built for the major Grand Prix races counting for the World Championship

formula One: A formula according to which racing cars are built for the major Grand Prix races counting for the World Championship

49-state car: A car that complies with U.S. emission standards which are less restrictive than the standards in California. See federal version.

49 state car: A car that complies with U.S. emission standards which are less restrictive than the standards in California. See federal version.

forty-nine state car: A car that complies with U.S. emission standards which are less restrictive than the standards in California. See federal version.

forward: The front part of a ship. Also see cabin forward primary forward brake shoe forward bias: Conductive condition that exists when current flows through a diode

forward brake shoe: See primary forward brake shoe.

forward perpendiculars: A vertical line at the intersection of the fore side of the stem and the summer load waterline (See length between perpendiculars)

forward welding: Fusing metal in the same direction as the torch flame points.

Föttinger coupling: See Foettinger

foul: [1] to clog or cover (a spark plug) with oil or soot/carbon deposits which can cause a loss of performance and engine misfire. [2] to get in the way of another part or obstruct it.

fouling: See carbon fouling

four: See flat four V-four four banger: Four cylinder engine. low temperature fouling

four barrel: See four-barrel carburetor.

four barrel carburetor: See four-barrel carburetor.

four-barrel carburetor: A carburetor with four barrels that work like dual carburetors, with the second carburetor (third and fourth barrels) cutting in only at high speeds. Usually found on large V-8 engines. Also see double-barrel carburetor single-barrel carburetor

four bolt mains: A term referring to the number of bolts needed to secure the each cap to a crankshaft rod. Most engines come with two bolt main; but racing engines have four.

4/C: Abbreviation for "four-color," usually referring to color photographs or slides. A term used in classified advertisements to indicate the availability of pictures of a vehicle.

four color: (4/C) Usually referring to color photographs or slides. A term used in classified advertisements to indicate the availability of pictures of a vehicle.

four cycle engine: See four-stroke cycle engine.

four-cycle engine: See four-stroke cycle engine.

four-cylinder engine: An engine with four cylinders usually in line; but can also be V-type or horizontally opposed. The in-line type is the most common in most small cars and in larger motorcycles.

four-door: A vehicle which has two doors on each side. This is the typical layout for family sedans

four-door hardtop: This is a four-door car styled to resemble a convertible, but having a rigid top of metal or fiberglass. Buick introduced a totally pillarless design in 1955. A year later most automakers offered equivalent bodies. Four-door hardtops have also been labeled sports sedans and hardtop sedans. By 1976, potential rollover standards and waning popularity had taken their toll. Only a few makes still produced a four-door hard- top and those disappeared soon thereafter. === car-4hard.jpg

four-door hatchback:

Essentially unknown among domestic models in the mid-1970s, the four-door hatchback became a popular model as cars grew smaller and front-wheel-drive versions appeared. Styling was similar to the original two-door hatchback, except for two more doors. Luggage was carried in the back of the car itself, loaded through the hatch opening, not in a separate trunk. === car-4hatch.jpg

four-door pillared hardtop: Once the "true" four-door hardtop began to fade away, manufacturers needed another name for their luxury four-doors. Many were styled to look almost like the former pillarless models, with thin or unobtrusive pillars between the doors. Some, in fact, were called "thin-pillar hardtops." The distinction between certain pillared hardtops and ordinary (presumably humdrum) sedans occasionally grew hazy. === car-4pillar.jpg

four-door sedan: If you took the wheels off a car, mounted it on poles and hired two weightlifters (one in front and one in back) to carry you around in it, you'd have a true sedan. Since this idea isn't very practical, it's better to use the term for an automobile with a permanent top (affixed by solid pillars) that seats four or more persons, including the driver, on two full-width seats. === car-4sedan.jpg

four-door station wagon: Since functionality and adaptability are advantages of station wagons, four-door versions have traditionally been sales leaders. At least they were until cars began to grow smaller. This style usually has lowerable windows in all four doors and fixed rear side glass. The term "suburban" was almost synonymous with station wagon at one time, but is now more commonly applied to light trucks with similar styling. Station wagons have had many trade names, such as Country Squire (Ford) and Sport Suburban (Plymouth). Quite a few have retained simulated wood paneling, keeping alive the wagon's origin as a wood-bodied vehicle. === car-4wagon.jpg

four-gas analyzer: Equipment for testing exhaust gas for hydrocarbons, carbon monoxide, carbon dioxide, and oxygen

four-link rear suspension: An independent rear suspension layout, also used on live rear axles, in which each wheel is guided by two control arms, one mounted longitudinally, the other mounted transversely or almost transversely, thus providing lateral location for the axle. A suspension setup that uses 4 rods (or links) to locate an axle. Depending on the arrangement of the links, a panhard rod or watts link may be used to control side to side motion. This type of suspension was used in most American designed rear

wheel drive cars built from the 60's, 70's, and 80's.

four on the floor: A four-speed manual transmission with floor mounted shift.

four-on-the-floor: A four-speed manual transmission with floor mounted shift.

4-point racing harness: A safety hamess anchored at four points, worn by some racing drivers

four-spark ignition coil: An ignition coil with two primary windings and one secondary winding

4-spd: Abbreviation for "four-speed," either manual transmission or automatic transmission.

four speed: A transmission which has four forward gears.

four-speed: A transmission which has four forward gears.

four-speed gearbox: A British term for a four-speed transmission

four-speed transmission: A manual or automatic transmission which has four forward gears. In most instances, the top gear is an overdrive.

four stroke cycle engine: See four-stroke cycle engine.

four-stroke cycle engine:

An engine requiring two complete revolutions of the crankshaft to fire each piston once. The first stroke down (intake stroke) pulls fuel and air into the combustion chamber. The second stroke up (compression stroke) compresses the mixture. The third stroke down (power stroke) comes about through the rapid burning of the compressed fuel mixture. The fourth stroke up (exhaust stroke) expels the exhaust gases from the cylinder. It is also called the "Otto cycle."

four stroke power cycle: See four-stroke cycle engine.

four-stroke power cycle: See four-stroke cycle engine.

four-stroking: A two-stroke engine which is running faultily as it fires only on every second cycle

fourth: The highest gear in a four-speed transmission or the second highest in a five-speed transmission.

fourth gear: The highest gear in a four-speed transmission or the second highest in a five-speed transmission.

four valve: An engine which has four valves (two intake and two exhaust) for each cylinder. Multiple valve systems offer better breathing.

four-way wheel wrench: A lug wrench shaped in the form an "X" with a socket at each end. Also called a "wheel nut spider."

four-wheel ABS: An anti-lock brake system that operates on all four wheels

four wheel alignment:

See four-wheel alignment.

four-wheel alignment: In most rear-drive vehicles only the front wheels need to have their wheels aligned because the rear wheels are on a fixed axle. However with front-drive vehicles and rear-drive vehicles with independent suspension, all four wheels need to be aligned. See alignment.

four wheel disc brakes: Disc brakes fitted to both front and rear wheels

four-wheel drift: A term that describes a cornering situation in which all four tires are operating at large slip angles so that a car gets into a sideways slide.

4WD: Acronym for "four-wheel drive." This term should be distinguished from FWD which is front-wheel drive.

four-wheel drive: (4WD) A type of drive system in which both front wheels are connected to its own differential and axles, and both back wheels are connected to its own differential and axles. Between these two differentials there is a transfer case which allows you, in the case of part-time four wheel drive, to switch between two-wheel drive and four-wheel drive. In full-time four-wheel drive power is sent to both differentials. Also see automatic four-wheel drive Ferguson four-wheel drive full-time four-wheel drive part-time four-wheel drive permanent four-wheel drive real-time four-wheel drive Torsen four-wheel drive four-wheel-drive high: (4WD Hi) A four-wheel drive, with the final drive ratio the same as when the vehicle is in two-wheel drive.

four-wheel-drive low: (4WD Lo) A separate low-ratio transfer case gear set designed for low-speed operation and maximum traction in difficult terrain. In virtually all systems, engaging 4WD Lo usually requires bringing the vehicle to a complete stop.

4WS: Acronym for "four-wheel steering."

four wheel steering: See four-wheel steering.

four-wheel steering: A vehicle where the rear wheels also turn when the front wheels turn to give a sharper and more accurate turn.

FPS: An acronym for "foot-pound-second"

FPS system: An imperial system of units, superseded by the SI (metric) system

fracturing: See stress fracturing

frame: [1] A bridge-like structural load-carrying members of a vehicle that support the engine and body and are in turn supported by the wheels of the vehicle. [2] Transverse members that make up the riblike skeleton of a ship. Also see A-frame ash frame backbone frame body and frame caliper frame cant frame chassis frame cruciform frame diamond frame

door frame floating frame integral body and frame construction ladder frame ladies' frame license plate frame mixte frame mounting frame panting frame perimeter frame platform frame space frame spectacle frame stern frame sub frame transom frame tube frame tubular backbone frame tubular frame twisted frame underslung frame X-type frame frame construction: See body and frame construction integral body and frame construction frame damage: A type of damage to the body that involves damage to the structural members of the car, usually resulting from accident impact

frame gauge: A measuring instrument for determining the misalignment of a car's body.

frameless: A vehicle without a frame such as a unibody construction

frameless construction: A unibody or unitary construction

frameless window: A door window which does not have a frame around the three sides (left, right, and top).

frame member: Any one of the sections of the structural components of the vehicle chassis

frame structure: All parts of the vehicle which contribute to the rigidity of the body, both for unibody designs and for vehicles with a separate chassis

framing: See body framing

franchise: Establishment that has the right to exercise the powers of a corporation.

franchised dealer: An automotive dealer which sells a particular brand, e.g., Anytown Ford is a franchised dealer for Ford cars and is authorized to sell Ford parts as well as provide service for Ford vehicles.

Franklin: A vehicle brand of which all the 1925-48 models except the 1933-34 Olympic Six are classic cars.

Fraschini: See Isotta-Fraschini

Frazer: A vehicle brand of which the 1947-50 Manhattan models are milestone cars.

Frazer Nash: A vehicle brand of which the 1925-1948 models with required application are classic cars.

free:

See asbestos-free hands-free lead free maintenance-free North American Free Trade Agreement pedal free play pedal free travel free bend test: Bending the specimen without using a fixture or guide.

freeboard: The distance from the waterline to the upper surface of the freeboard deck at side.

freeboard deck: Deck to which freeboard is measured

free electron: See free electrons.

free electrons: Electrons in the outer orbits around the nucleus of the atom. They can be moved out of orbit comparatively easy.

free height: The unloaded length or height of a spring

freeing port: An opening in the lower portion of a bulwark, which allows deck water to drain overboard

free length: The length of a spring, especially a valve spring, when no downward pressure is exerted on it

free pedal play:

The distance the clutch pedal can be depressed before it begins to disengage the clutch. Generally about 19-25 mm (0.5-1 inch) free pedal play is normal to be sure that slight resting of the foot on the pedal will not disengage the clutch. Without free pedal play, the throwout bearings and the clutch might wear out.

free play: [1] The amount of looseness in some component before it engages. [2] British term for lash. Also see pedal free play free radius: Measurement in inches (or millimeters) from the wheel axle centerline to the top of the tire when inflated. (The radius that is not under load.) Also called "unloaded radius."

free-revving: The ability of an engine to accelerate quickly to high engine speeds

free rolling wheel: A non-powered wheel position on a vehicle, such as steering axle, tag axle or trailer wheel positions.

free shape: A design shape of a component which is governed only by stylistic or functional requirements.

Free Trade: See North American Free Trade Agreement

Free Trade Agreement: See North American Free Trade Agreement Canada-U.S. Free Trade Agreement Free Trade Agreement of the Americas: (FTAA) An effort to unite the economies of the Western Hemisphere into a single free trade arrangement. The Heads of State of the 34 democracies in the region agreed to construct a "Free Trade Area of the Americas" and to complete

negotiations for the agreement by 2005.

free travel: The distance a pedal moves before it operates the actuating mechanism. Also see clutch pedal free travel pedal free travel freeway: A multiple lane highway without toll charges. All exits and entrances are made through overpasses and cloverleafs. Because there is no direct cross traffic, speeds can be over 60 mph (100 kph)

freeway bar: A component on a motorcycle which is a rod with a footrest on each end. The rod is mounted ahead of the engine to provide an alternate place to position the rider's feet.

freewheel: [1] Usually refers to the action of a vehicle on a downgrade when the overdrive over-running clutch is slipping with a resultant loss of engine braking. This condition will occur only after the overdrive unit is engaged but before the balk ring has activated the planetary gearset. [2] The removable cluster of gears at the rear wheel of a bicycle. Usually there are five or more gears. It also contains a ratcheting mechanism inside that allows the wheel to rotate forward while the pedals, chain, and gear sprockets remain still or move in reverse. The rear derailleur moves the chain from one gear to the other to change the gear ratio. The other end of the chain wraps around the chainwheel.

freewheel hub: A type of hub fitted to the front axle of some four-wheel drive vehicles, in which the drive to the front wheels can be disconnected when the front axle is not being driven

freewheeling: In a motorized vehicle, the illegal coasting by putting the transmission in neutral or disengaging the clutch.

freewheeling hub: A type of hub fitted to the front axle of some four-wheel drive vehicles, in which the drive to the front wheels can be disconnected when the front axle is not being

driven

freeze: [1] To reach a temperature in which a liquid turns into a solid. See antifreeze [2] To adhere firmly. [3] To stop. [4] An American (not Canadian) term for an engine which has seized. To an American, "My engine is frozen" means "seized" because it has run out of oil and overheated so that pistons expanded and won't move in the cylinder. To a Canadian, it means the coolant won't flow or the engine won't warm up.

freeze plug: A removable plug on the block which can pop out should the coolant in the block freezes and expands. See expansion plug. The British term is "core plug."

freeze-up: The failure of a unit to operate properly because of the formation of ice at the expansion valve orifice or on the evaporator coils or fins

freezing: When two parts that are rubbing together heat up and force the lubricant out of the area. As they create heat, they will expand and tear bits of metal from each other, then stick and refuse to move.

frenching: The customizing process of creating smooth curve shaping around the headlights, tail lights, licence plate frames, etc. so that the actual lights, etc. recede a little towards the interior of the panel opening and the chrome bezel or other surround looks as though it is part of the body panel. Also see tunnelling freon: A gas used as the cooling medium in older air conditioning and refrigeration systems. Usually called freon-12 or R-12. It has been replaced in automobiles with a new coolant designated 134A.

freon 12:

See freon-12.

freon-12: A gas used as the cooling medium in older air conditioning and refrigeration systems. It has been replaced in automobiles with a new coolant designated 134A.

frequency: [1] In relation to a radio station, number of cycles per second expressed in hertz at which it broadcasts. [2] The number of times a particular event is repeated. Also see digital frequency control natural frequency radio frequency interference frequency control: See automatic frequency control digital frequency control frequency interference: See radio frequency interference

Frequency Modulation: (FM) A term used to describe a type of radio frequency where the frequency of the wave changes rather than the amplitude. Also see AM/FM frequency scan button: A radio button which, when pressed, causes the tuner to scan the frequencies of stations with sufficient signal strength and plays that station for about 5 seconds before going to the next one. When the driver or passenger wants to listen to the currently played selection, he can press the same button (or a different one) to select that station. Often called a "scan button."

frequency valve: [1] A valve located in the fuel distributor of some vehicles with a continuous injection system and catalytic converter. This valve continually adjusts the air/fuel ratio to varying engine operating conditions, because it is controlled by a voltage

signal supplied by the oxygen sensor and by an ECM. [2] In Bosch CIS, a device that regulates pressure in the lower chamber of the differential-pressure valve, in response to a signal from the lambda (oxygen) sensor. Also called Lambda valve (Bosch's term) or a timing valve

fresco: See al fresco driving

fresco driving: See al fresco driving

fretting corrosion: corrosion occurring where two surfaces are in contact and friction results, e.g., at mechanical joints in vibrating structures

friction: The resistance to movement between any two objects when placed in contact with each other. Friction causes wear and heat. In an engine, it robs it of some of its potential power. Friction is not constant but depends on the materials, type of surface finish, amount of pressure holding the two objects together, and the relative amount of movement between the objects. Lubrication like oil, grease, and other materials like graphite reduce friction. Also see antifriction bearing coefficient of friction dry friction interleaf friction rolling friction slip friction static friction wet friction frictional: Caused by the friction between moving parts

friction bearing: A bearing made of babbitt, bronze, etc. There are no moving parts (like an antifriction bearing which has ball bearings). The smooth inner surface of the babbitt insert and the smooth surface of the shaft rub or slide against each other. To avoid disintegration, the bearing must use lubrication (i.e., wet friction). Friction bearings are less expensive and cheaper to service than antifriction bearings. Also

called "plain bearing."

friction clutch: A conventional clutch which transmits the power of the drive by mechanical friction, as opposed to a fluid coupling

friction damper: See friction shock absorber

friction disc: See clutch disc.

friction drive: A method of power transmission used on early cars where power is transmitted from a driving to a driven wheel by means of pressing one wheel against another at a right angle.

friction horsepower: (FHP) The amount of power consumed by an engine in driving itself. It includes the power absorbed in mechanical friction and in driving auxiliaries plus, in the case of four-stroke engines, some pumping power.

friction lining: wear-resistant friction material used for clutch and brake linings

friction losses: The loss of power due to friction between the moving parts of the engine

friction modifier: A substance which enhances the ability of oil to remain slippery. In most SH and SJ series oil, friction modifiers have been added to improve engine starting and prolong engine life. However, in engines with a wet clutch (i.e., the engine oil lubricates the clutch plates) such as motorcycle engines, oils with friction modifiers can cause the clutch to slip and may force the premature replacement of the clutch plates.

friction pad:

See brake pad

friction plate: A driven plate of a clutch to which the friction lining is attached

friction shifter: See friction shifters.

friction shifters: Conventional (non-index) levers of a bicycle that retain their position through the use of friction washers.

friction shock absorber: A shock absorber in which friction discs are inserted at the point where the two arms are joined, now no longer used in car suspensions

friction welding: The type of weld in which the necessary welding heat is generated by revolving one part against another part under very heavy pressure. When melting has occurred at the interface, pressure is maintained to consolidate the weld during cooling of the material

Friedrichshafen: See zahnradfabrik Friedrichshafen

friendly: See environmentally friendly

frit: Partly fused, vitreous substance, ground up and used as the basis for glazes and enamels

frogeye: A nickname for the Series I Austin-Healey Sprite produced from 1958-1962, which had the headlights projecting above the hood line

front:

[1] The forward end of a vehicle. [2] The seats closest to the front upon which the driver sits. Also see flame front independent front suspension lower front panel frontal crash: An accident in which the front end of a vehicle is damaged.

frontal impact: An accident in which the front end of a vehicle is damaged.

front apron: The panel behind and below the front bumper, joining the bottom ends of the front fenders

front axle: The axle to which the front wheels are attached

front-axle/rear-axle split: A dual-circuit braking system in which one circuit brakes only the front axle while the other circuit brakes only the rear axle.

front-axle and rear-axle split: A dual-circuit braking system in which each circuit brakes both the front axle and the rear axle

front bumper: A guard which protects the front of a vehicle. See bumper rear bumper front differential: differential in the front axle of a four-wheel drive vehicle

front end:

body area incorporating the leading edge of the fenders, the headlights, radiator grille and bumper, i.e., the full area that makes up the frontal appearance of the car

front end alignment: See front-end alignment.

front-end alignment: The adjustment of the camber and caster of the front wheels. See alignment.

front-end impact: An impact as the result of a head-on collision

front engine: A vehicle with its engine located at the front of a vehicle above the front suspension. This is the most common layout, which may be combined with either rear-wheel or front-wheel drive. Also see mid-engine car rear engine front fender: body section covering the front wheels, originally separate; but now in most cars faired in and part of the body shell

front fork: See fork.

front forks: See fork.

front nose section: The front section of a car's body that uses one single structure to make up the front end, i.e., including the radiator grille surrround, both fenders, front apron, etc. front panel: A panel joining the front fender and forming a mounting for the headlights, grille, and air ducts into the engine compartment, which is often identical with the front apron where no separate apron is fitted below the front panel. Also see

lower front panel front pillar: See A-pillar

front pipe: The first section of the exhaust system from the exhaust manifold to the silencer (or front silencer where there are two). Also see twin front pipe front-seat: The closed position of a stem type service valve to isolate the compressor. The system should never be operated with the valves in this position

front seat: seat in the front of passenger cabin for the front seat passenger

front seats: The front passenger's and driver's seats

front silencer: first and main silencer in an exhaust system where there are two

front spoiler: The air deflector on the front of a car, aerodynamically designed to cut the wind resistance around the car, for improved handling control, stability, traction, and better fuel economy

front suspension: The springs, shock absorbers, linkages, etc. which support the front wheels. See independent front suspension.

front triangle: Actually a quadrilateral with one short side, it is the section of a bicycle frame that consists of the head tube, the top tube, the seat tube, and the down tube. Also called "main triangle."

front wheel drive: See front-wheel drive.

front-wheel drive: (FWD) A vehicle that is pulled by its front wheels rather than being pushed by its rear wheels. The driveshaft and center floor hump is eliminated in front-wheel drive cars. The engine is located over the driving wheels so that it gains better traction in snow. Wear on the front tires can be severe.

front wheel tire clearance: The distance between the tire and the closest point on the vehicle laterally, longitudinally and vertically, checked lock to lock and all intermediate points.

front wing: British term for front fender

frost heaves: A condition of a roadway in which frost buildup beneath the surface causes the pavement to bulge

FRP: Acronym for "fiber reinforced plastic." Continuous mat or woven fibers impregnated with plastic resins to form a lightweight but extremely strong solid. These plastics are stronger per pound than steel. Commonly used fibers are aramid (kevlar), carbon fiber, nomex, and glass. These fibers are used alternatively to provide various levels of strength and weight.

frustum: The wide end of a bevel gear

fsh: An abbreviation used in classified advertisement indicating "full service history" is available.

FTA:

Acronym for Canada-U.S. Free Trade Agreement.

FTAA: Acronym for Free Trade Agreement of the Americas.

FTP: An acronym for "Federal Test Procedure."

FTP test cycle: An American method of testing automotive emissions for compliance with emission standards by simulating typical driving conditions. This system differs from other test cycles such as the European ECE test, so that the results cannot be compared

fuel: A combustible material used to produce energy. One of the essential factors in a combustion engine (Fuel, Air, Proper proportion of mixture, compression, timing, spark). Also see air-fuel ratio aviation fuel deceleration fuel cut-off diesel fuel early fuel evaporation system electric fuel pump electronic fuel injection EPA fuel economy in-line fuel filter inertia fuel cut-off switch integral fuel filter L-jetronic fuel injection system low fuel indicator port fuel injection proper proportion of air and fuel fuel accumulator: A device in the K-Jetronic fuel injection system which serves to absorb the initial pressure surge when a fuel pump starts

fuel additive:

A chemical preparation which is added to fuel to improve its properties

fuel advance system: Advances fuel delivery during cold starts on GM vehicle. Consists of a thermalsensitive solenoid on the intake manifold which sends a signal to the HPCA terminal, which opens a ball-check valve on top of the injection pump housing. With pump housing pressure reduced, the timing mechanism has less resistance to overcome and operates earlier, advancing fuel delivery 3 degrees

fuel air mixture: See fuel-air mixture.

fuel-air mixture: A combination of vaporized fuel and air which is brought into the cylinder through the carburetor or fuel injectors. When it is compressed and ignited, it produces the power needed to drive the engine.

fuel air ratio: See fuel-air ratio.

fuel-air ratio: The amount of fuel in comparison with the amount of air. This is the reciprocal of the air-fuel ratio.

fuel burner: Competition vehicle with an engine set up to burn alcohol, nitro, etc. mixture instead of standard pump gasoline. Also called "fueller."

fuel cap: A vented covering on the top of the tube leading to the fuel tank. Also called "gas cap."

fuel cell: A galvanic cell in which the oxidation of a fuel (e.g., methanol) is used to produce electricity.

fuel charge:

The air/fuel mixture delivered to the combustion chamber

fuel cock: A tap which can allow or restrict the flow of gasoline from the gas tank to the carburetor. An essential item on a motorcycle with gravity feed (i.e., no fuel pump) because if the fuel cock is left on after the engine is shut down, there is the possibility that gasoline could leak past the needle and seat in the carburetor so that the overflow in the float bowl will make its way into the cylinder and wash the walls and dilute the oil

fuel computer: A device which continuously displays the amount of fuel used over the distance since last set.

fuel consumption: The amount of fuel used, expressed in miles per gallon in Britain and the USA, whereas the international measure is litres per 100 kilometres. The US term is "fuel mileage." Also see average fuel consuption specific fuel consumption fuel consumption indicator: An instrument using a flowmeter to indicate mpg or liters/100 km at any given moment on a journey

fuel cut-off: See deceleration fuel cut-off inertia fuel cut-off switch fuel cut-off switch: A control device which manually or automatically turns off the flow of fuel. Also see inertia fuel cut-off switch fuel distributor: [1] A device constituting the mixture control unit together with the airflow sensor. [2] On Bosch CIS, the device that supplies the injection with pressurized fuel in proportion to air volume, measured by the airflow sensor plate. The fuel distributor

houses the control plunger and the differential-pressure valves. All fuel metering takes place inside the fuel distributor

fuel economy: The number of liters used per 100 kilometers of driving (a lower number is better); or the number of miles driven divided by the number of gallons used (a higher number is better). Also see EPA fuel economy Corporate Average Fuel Economy fuel efficiency: Although this factor is similar to fuel economy, it differs in that fuel efficiency involves getting the most amount of energy from an amount of fuel. It answers the question, "What percent of the fuel does this engine burn?"

fuel evaporation: See early fuel evaporation system

fuel filler flap: A piece of rubber about 4" square and very thin, which is located behind the filler door. When the door is opened, the flap falls down to protect the body from the fuel nozzle.

fuel filler neck: The upper end of the fuel filler tube leading down to the fuel tank, which accepts the fuel hose nozzle at the gas station

fuel filler tube: The tube leading down to the fuel tank

fuel filter: A device that removes impurities from the fuel before it gets to the carburetor. It is usually found near the carburetor in the fuel line that comes from the fuel pump (inline fuel filter), or inside the carburetor (integral fuel filter) or fuel pump (integral fuel filter). This unit must be cleaned or replaced on a regular basis, usually once a year or it will become clogged and restrict fuel to the carburetor. Without a filter, the jets and orifices in the carburetor will become clogged.

fuel gage: See fuel gauge.

fuel gauge: An instrument, usually located on the dashboard or center console, which indicates the amount of fuel in the fuel tank. Most gauges have a needle which fluctuates between "E" (empty) and "F" (full). Others show a digital readout of how many gallons or liters left in the tank. Also called "gas gauge."

fuel indicator: See low fuel indicator

fuel-injected engine: A gasoline engine with a fuel injection system rather than a carburetor.

fuel injection: (FI) A fuel system that uses no carburetor but sprays fuel either directly into the cylinders or into the intake manifold just ahead of the cylinders. It uses an electronic sensing device to deliver the correct amount into the combustion chamber. Throttle-body injection locates the injector(s) centrally in the throttle-body housing, while port injection allocates at least one injector for each cylinder near its intake port. Also see electronic fuel injection L-jetronic fuel injection system sequential fuel injection timed fuel injection fuel injection engine: A gasoline engine with a fuel injection system

fuel injection pump: A pump which receives fuel from the fuel tank (often through the fuel-feed pump in the case of diesel engines) and delivers it under pressure to the injectors

fuel-injection system test port: See pressure tap

fuel injector: [1] An injector in a fuel injection system which sprays gasoline into the inlet ports, or diesel either directly into the combustion chamber or into a pre-chamber. [2] In all fuel-injection system (except Bosch CIS, CIS/Lambda, and CIS-E systems), a spring loaded, solenoid (electromagnetic) valve which delivers fuel into the intake manifold, in response to electrical signals from the control module in the CIS, etc. System., the injector is simply a spring-loaded, pressure sensitive valve which opens at a preset value See fuel injector nozzle.

fuel injector nozzle: The device that works like a hypodermic needle to inject the proper amount of fuel into the combustion chamber in response to signals from an electronic sensing device on cars with fuel injection systems. It receive fuel at low pressure and shoot it into the engine cylinders at predetermined intervals under higher pressure. Also called "fuel injector valve" or just "fuel injector."

fuel injector valve: See fuel injector nozzle.

fuel knock: See detonation.

fuelie: Fuel-injected car.

fueller: See fuel burner.

fuel line: The metal, plastic, or rubber hose or pipe through which the fuel passes from the fuel tank to the fuel pump to the carburetor or fuel injector nozzle.

fuel mileage: A measurement or calculation of the number of miles per amount of fuel -- usually measured in miles per gallon.

fuel mixture: A mixture of gasoline and air. An average mixture, by weight, would contain 16 parts of air to one part of gasoline. See air-fuel mixture.

fuel pressure: The pressure under which fuel is delivered to the injectors by the fuel pump, governed by the pressure regulator

fuel pressure regulator: A pressure-activated diaphragm valve that maintains the pressure in a fuel system to a pre-set value above manifold pressure, particularly in a fuel injection system

fuel pump: A vacuum device, operated either mechanically or electrically, that is used to draw gasoline from the tank and sends it into the carburetor or fuel injector nozzles. Mechanical pumps have a rocker arm that is activated by a cam on the camshaft; the arm causes a diaphragm to move up and down, thus pulling the gas through the pump. Some electrical pumps have a rocker arm which is activated electrically and does the same thing as the mechanical pump. Other electrical pumps are located at the bottom of the fuel tank and push the fuel through the fuel lines. Also see electric fuel pump fuel pump shut-off switch: A switch which shuts off the electric fuel pump and fuel to the engine in the event of a major collision

fuel pump switch: A switch which shuts off the electric fuel pump and fuel to the engine in the event of a major collision

fuel rail: A manifold tube feeding the injectors in a fuel injection system. A special manifold designed to provide a large reservoir of pressurized fuel for the fuel injectors, which are attached between the rail and the intake runners or the cylinder head. The fuel rail also serves as a mounting place for the fuel damper (if equipped) and the fuel pressure regulator

fuel ratio: See air fuel ratio

fuel return line:

A pipe returning surplus fuel to the tank from the carburetor(s) or to the inlet side of the injector pump

fuel starvation: The failure of the fuel system to supply sufficient fuel to allow the engine to run properly, due to a blockage or vapour lock or malfunction of the fuel pump

fuel supply: The delivery of fuel to the carburetor or injection system

fuel system: A system that stores, cleans, and delivers the fuel to the engine in proper quantities to meet the varying needs that arise as you drive. It is made up of the fuel tank, fuel lines, fuel pump, fuel filter, and carburetor or the fuel injection system.

fuel tank: The storage compartment, under the trunk in most cars, that holds the fuel for the vehicle. Also called the "gas tank."

fuel tank sender: A level sensor in the gas tank which sends information about the amount of remaining fuel.

fuel tank vapor valve: A valve mounted in the top of the fuel tank. Vents excess vapor and pressure from the fuel tank into the evaporative emission control system

fuel-vacuum separator: Used to filter waxy hydrocarbons from the carburetor ported vacuum to protect the vacuum delay and distributor vacuum controls

fuel vapor: [1] atomized air/fuel mixture heated in the engine, ready for combustion [2] fumes given off by gasoline

fuel vapor recirculation system: An emission system which traps the excess gasoline vapor, condenses it back to liquid form, and then sends it back to the gasoline tank. Also called evaporative

emission control system

fuel vapor recovery system: (FVR) a valve responsible for venting excess fuel vapor and pressure from the fuel system to the EEC system

fulcrum: The support (often wedge-shaped) on which a lever pivots in raising an object.

fulcrum pin: A pin which acts as a pivot, such as a kingpin

fulcrum ring: One of two rings on either side of a clutch diaphragm spring on which it pivots

full bore: A term expressing top speed or full throttle.

full cam: A type of camshaft for race car engines which increases lift of valve, speed of valve opening and closing, length of time valve is held open, etc. Also called race cam, three-quarter cam, or semi-race cam, depending upon design

full cap: A condition of retreading where new tread rubber is added to the buffed casing, and covers the crown and shoulder areas.

full dip treatment: A painting process in which the whole body shell is immersed, used for applying protective primers

full face helmet: A helmet which covers the whole head including the chin.

full floating axle:

See full-floating axle.

full-floating axle: A rear drive axle that does not hold the wheel on nor does it hold the wheel in line or support any weight. It merely drives the wheel. Used primarily on racing cars and trucks. Also see axle full flow filter: See full-flow oil filter.

full-flow filter: See full-flow oil filter.

full flow oil filter: See full-flow oil filter.

full-flow oil filter: An oil filter that filters all of the oil passing through the engine before it reaches the bearings.

full house: An engine that is fully modified and equipped for all-out performance.

full leather: A car interior in which the door trim, dash, seats are covered in leather

full leather upholstery: A car interior in which the door trim, dash, seats are covered in leather

full load: An engine operating conditions where the accelerator is fully depressed, i.e., the throttle is fully open, which does not necessarily mean high engine speed

full load enrichment:

The provision of a richer mixture when the throttle is fully opened. On some system, the computer goes open-loop during full-load enrichment

full lock: [1] A condition in which a detachable component (e.g., seat belt buckles) is securely attached. [2] The maximum angle attained by the wheels when the steering wheel is turned to its full extent

full panel: A body part that may be made up of several other subassemblies and is fairly complex and cumbersome, e.g., a complete bulkhead assembly incorporating the windshield pillars

full pressure: See oil full pressure system

full service history: (fsh) The documents which show all the work performed on a vehicle, especially the regular service required by the manufacturer

full-size car: The largest type of car according to the American system. It is a designation no longer used because even "full-size cars" are now about the size of what was the compact car. In 1970, for instance, a Chevrolet Impala was a full-size car, a Chevelle was an intermediate, and a Nova was a compact. When cars smaller than the Nova came out (i.e., Chevette), they were called sub-compacts.

full-size spare: A spare wheel and tire combination which is the same size as the rest of the wheels. Compare space saver spare

full-skirt piston: A former piston style which had a full-annulus skirt, without the cutaway section of modern slipper pistons

full throttle: The fully open position of the throttle. Also called "wide open throttle"

full throttle enrichment: See full load enrichment

full-time four-wheel drive: A condition where all four wheels are always being driven by the drivetrain. It may include the option of part-time (that is, shifting into 2WD for dry pavement) operation, and may or may not have Hi and Lo 4WD speed ranges. The British term is "permanent four-wheel drive."

full trailer: See trailer.

full wave rectifier: See rectifier.

full-wave rectifier: See rectifier.

fully electronic ignition: (FEI) A distributorless, mapped ignition system with cylinder-selective knock control, dwell-angle control, and digital idling speed stabilization

fully floating axle: A live rear axle assembly in which the axle shafts serve only to transmit torque to the wheel. The total vehicle weight and cornering loads are transferred directly from the wheel bearings to the axle housing. Also see semifloating axle fully galvanized body: A body shell which, except for aluminum and plastic parts, is produced entirely of double-sided galvanized steel and galvanized fasteners or which is immersed in galvanizing fluid

fumes: Foul-smelling vapors given off by a liquid or a gas, which may be poisonous

functional:

[1] Capable of working even if it is not working to its peak performance. [2] Practical, designed not for esthetics; but solely with a particular use in mind

fund licence: See road fund licence

funnel: A cup-shaped object tapering at the bottom to a small hole and a spout, used for pouring oil, fuel or water into relatively small openings

funny car: A car equipped with a powerful engine, used for drag racing. Usually has special body (such as fibreglass) mounted on special lightweight frame and suspension system.

furnace: See annealing furnace reducing furnace tunnel furnace fuse: [1] A protective device (usually enclosed in glass or plastic) which has a thin wire between two terminals. The wire will break or melt when the current draw exceeds the capacity of the fuse. In this way, the circuit is protected from overload. [2] The action of melting when a piece of metal turns to a liquid state and sometimes unites itself to a nearby component. [3] A failure of an electrical component because of a blown fuse. Also see continental-type fuse fuse box: A contaner with a removable cover that holds the fuses for the various electrical circuits, which are all routed through it

fuse capacity: See fuse.

fusible link:

Special length of smaller gauge wire designed to "blow" if heavy current flows in circuit

fusion: Two metals reaching the melting point and flowing or welding themselves together.

FVR: Acronym for fuel vapor recovery system

FWD: Acronym for "front- wheel drive"

FYI: Acronym for "For Your Information."

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [Ga] [Ge] [Gi] [Gl] [Go] [Gr] [Gu]

g: A unit of measurement for lateral acceleration, or "road-holding." One "g" is equivalent to 981 cm (32.2 feet) per second every second, the rate at which any object accelerates when dropped at sea level. If a car were cornering at 1.0 g -- a figure that very few production cars are able to approach -- the driver's body would be pushing equally hard against the side of the seat as against the bottom of it. Most fast sedans accelerate about 0.8 g.

G7: Seven industrial countries consisting of the United States, Japan, Germany, France, the United Kingdom, Italy and Canada, whose leaders have met at annual economic summits since 1975 to coordinate economic policies.

gage: [1] A standard SAE designation of wire sizes, expressed in AWG (American Wire Gage). The larger the gage number, the smaller the wire. Metric wire sizes are expressed in cross-sectional area, which is expressed in square millimeters. Sometimes the spelling "gauge" is also used to designate wire size. However, it is becoming standard to use "gage" for wire size and "gauge" for instruments. Americans often use "gage" for instruments. Also see adjusting gage compression gage dial gage feeler gage fuel gage gas gage oil gage oil pressure gage plain gage tubing temperature gage tire gage vacuum gage

gage tubing: See plain gage tubing

gain: See steering gain

gaiter: A dust boot

gal.: Abbreviation for "gallon." A US gallon (3.785 liters) is 20% smaller than an Imperial gallon (4.546 liters).

GALFAN: A trademark for a special type o hot-dip galvanized steel sheet with a coating consisting of a zinc alloy containing 5% aluminum and rare earths

gallery: A channel or tube usually found within the engine block for the transfer of fluid or gas. See oil gallery.

gallon: A US gallon (3.785 liters) is 20% smaller than an Imperial gallon (4.546 liters).

Galvalume: trademark for a special type of hot-dip galvanized steel sheet with a coating consisting of 55% aluminum, 43.4% zinc and 1.6% silicon

galvanic: concerned with an electrical current

galvanic cell: cell which converts chemical energy into electrical energy by irreversible chemical reactions

galvanic corrosion:

Corrosion due to the action of a galvanic cell. Compare bimetallic corrosion

galvanize: The action of plating with zinc by hot dipping or electrodeposition to protect from rust. Also see hot-dip galvanize galvanized body: See fully galvanized body

galvanized coating: zinc or zinc based coating applied by galvanizing

galvanize differentially: The action of obtaining different coating thicknesses on the two sides of the sheet of iron.

galvanizing: The application of zinc coatings on the surface of a metal, by hot dipping or electrodeposition. Also see cold galvanizing dry galvanizing electrolytic galvanizing high-build galvanizing mechanical galvanizing rack galvanizing spin galvanizing wet galvanizing galvanizing bath: A bath for hot-dip galvanizing or electrogalvanizing

galvannealing: A thermal process which gives improved adhesion to hot-dip galvanized steel sheets

galvanometer:

An instrument used to measure the pressure, amount of, and direction of an electric current.

gamma layer: part of the zinc-iron alloy layer on hot-dip galvanized iron and steel containing 2128% iron

gangway: A narrow hanging staircase used by persons entering or leaving a vessel from the pier or boat

gantry: A structure with an overhead beam, used for lifting out an engine. Compare engine hoist.

gap: [1] The distance between the center terminal (electrode) and the outer terminal (electrode) through which the spark must travel in a spark plug. Also see spark plug gap air gap. [2] The distance between the points in contact breaker points. See point gap. [3] The distance between two vehicles travelling down the road as they go in the same direction. Generally a safe distance is a minimum of two seconds behind the vehicle in front. [4] The distance between the two ends of piston rings. Also see air gap annular gap contact breaker gap contact gap door gap electrode gap end gap piston ring end gap piston ring gap plug gap point gap points gap ring end gap ring gap

spark air gap spark gap spark plug gap surface gap gap bridging: A formation of carbon or other deposits across the spark plug gap which shorts out the plug

gap coil tester: See spark gap coil tester

gap insurance: This covers you against additional losses not covered by your auto insurance in the case of an accident in which the vehicle is totaled. Most auto insurance will cover the actual cash value of the vehicle and what is owed on the lease contract, including early termination fees. Gap insurance is most important in the early years of a lease when the difference between the value of the car and what is owed are greatest. Some manufacturers now include Gap insurance in their leases.

gapping: See plug gapping

gap spark plug: See surface gap spark plug

gap style: The arrangement or shape of the spark plug electrodes

gapper: A device for determining the distance between two metal contacts. See feeler gauge.

gapping: Adjusting the distance between the electrodes of a spark plug or the points of contact breaker points. Also see plug gapping.

garage: [1] A building in which a motor vehicle is kept. [2] The premises on which motor vehicles are repaired or serviced and/or where fuel is sold. [3] To keep in a garage

garaged: A reference to a vehicle which is kept in a garage, as in My car is always garaged. The abbreviation in advertisements is gar'd.

garage jack: A powerful hydraulic jack used in garages

Garages: See Morris Garages

garboard strake: The strake of bottom shell plating adjacent to the keel plate.

gar'd: An abbreviation used in classified advertisements for "garaged"

garden gate: A nickname for the plunger-sprung frames used on Norton motorcycles from the late 1930s

garnish molding: The upper molding on a door panel used to retain the door trim panel to the door assembly

garter: See lip seal with garter spring

garter spring: A long, thin coil spring with ends joined to form a ring. Also see lip seal with garter spring

gas: [1] A non-solid material. It can be compressed. When heated, it will expand; and when cooled, it will contract (such as air.) [2] A common term for gasoline. The British term is "petrol." [3] A term for LPG or propane. Also see bottled gas [4] A term referring to the exhaust gases. See exhaust emissions. [5] To apply the throttle. Also see compressed natural gas depress the gas pedal ease up on the gas pedal end gas exhaust gas recirculation exhaust gas analyzer exhaust gas purification system exhaust gas hot gas welding inert gas system liquified natural gas liquified petroleum gas natural gas oxygen-LP gas flame oxyhydrogen gas pumping the gas pedal pump the gas pedal raw exhaust gas spent gas unleaded gas gas analyzer: See exhaust gas analyzer

gas-arc: See inert gas-arc welding

gas-arc welding: See inert gas-arc welding

gas brakes:

See pumping the gas brakes

gas burner: Competition vehicle with engine set up to operate on standard pump gasoline instead of an alcohol, nitro, etc., mixture. Also called "gasser."

gas chamber: A pressure chamber of a single-tube shock absorber

gas damper: A gas shock absorber

gas discharge headlight: A motor vehicle headlight with a gas discharge lamp

gas discharge lamp: A discharge lamp in which light is generated by gas discharge

gas discharge light: A discharge light in which light is generated by gas discharge

gas-driven generator: a generator which turned by a gas engine.

gaseous: Referring to gas

gaseous discharge lamp: A gas discharge lamp

gaseous discharge headlight: A A gas discharge light

gases: also See

CFC gases exhaust gases greenhouse gases residual exhaust gases gas filter: A device for screening the gasoline to remove the impurities. See fuel filter.

gas flame: See oxygen-lp gas flame

gas flow: The flow of the air/fuel mixture or the exhaust gases in an engine

gas gage: See gas gauge.

gas gauge: An instrument, usually located on the dashboard or center console, which indicates the amount of fuel in the fuel tank. Most gauges have a needle which fluctuates between "E" (empty) and "F" (full). Others show a digital readout of how many gallons or liters left in the tank. Also called "fuel gauge."

gas guzzler: A vehicle which uses a lot of gasoline per mile.

gasket: A material made of asbestos, cardboard, cork, paper, rubber, or soft metal placed between two metal parts to insure proper sealing. Also see base gasket blown head gasket cylinder head gasket head gasket liquid gasket oil pan gasket rocker cover gasket sump gasket tappet gasket

valve cover gasket gasket kit: also See bottom end gasket kit top end gasket kit gasket punch: A tool used to cut out holes in a sheet of gasket material to shape a gasket to size.

gasket scraper: A scraper with a sharp chisel edge for removing old gasket material from a surface before installing a new gasket

gas metal-arc welding: Welding using a continuously fed consumable electrode and a shielding gas. Also called "sigma welding."

gasohol: A blend of gasoline and ethanol alcohol that usually is 90% gasoline and 10% ethanol. Ethanol is the alcohol found in intoxicating beverages. It may attack rubber and plastic parts of fuel systems not designed to handle alcohol-blended fuels, but it is not poisonous to human beings like wood alcohol or methanol.

gasoline: A hydrocarbon fuel used in the internal combustion engine. Gasoline is refined from crude oil which is made up of fossilized plant and animal remains. Also see ethyl gasoline lead-free gasoline leaded gasoline oxygenated gasolines premium gasoline pump gasoline reformulated gasoline regular gasoline unleaded gasoline gasoline pump:

A device which pulls fuel from an underground storage tank into a vehicle's gas tank.

gas pedal: The device actuated by the operator's foot for increasing or decreasing the amount of fuel entering the combustion chamber. Also called "throttle pedal." Also see accelerator depress the gas pedal ease up on the gas pedal pumping the gas pedal pump the gas pedal step on the gas pedal take foot off the gas pedal gas pockets: Cavities in weld metal caused by trapped gas.

gas prop: A gas-assisted strut like a hatch strut, hood strut, or tailgate strut

gas pump: A device at a service station which pulls gasoline from a storage tank (usually located underground) into the vehicle's gas tank. Commercial units also record the amount of fuel dispensed as well as the cost.

gas purification: See exhaust gas purification system

gas recirculation: See exhaust gas recirculation

gasser: A vehicle which uses gasoline in the engine to run. See gas burner.

gas shock: A gas-assisted shock absorber

gas shock absorber: A gas-assisted shock absorber

gassing: The small hydrogen bubbles rising to the top of the battery electrolyte during battery charging.

gas spring: A pressurized, nitrogen-filled sphere, used in Hydragas and hydropneumatic suspension systems

gas station: A place where gasoline is dispensed.

gas system: See inert gas system

gas tank: The container for holding or storing fuel. See fuel tank.

gas-tight: sealed to prevent the passage of gas

gas tungsten-arc welding: Welding using a tungsten electrode and a shielding gas.

gas turbine: An internal-combustion rotating engine with one main moving part: the rotor with pinwheel-like blades attached. Air is compressed by the first rows of blades and delivered to the combustion chambers, from which the exhaust is directed to pass the remaining blades and to generate the power. Power is extremely smooth due to the absence of explosions and reciprocating parts.

gas welding: A welding process widely used in body repair shops (now being gradually replaced by MIG welding). Also called oxyacetylene welding. Also see

hot gas welding gate: [1] The slotted guide for the gearshift of an internal combustion engine. [2] The slotted guides in a shift drum. [3] A tailgate. Also see J gate transmission shifter shift gate waste gate gate transmission: See J gate transmission shifter

gate transmission shifter: See J gate transmission shifter

GATT: Acronym for General Agreement on Tariffs and Trade.

gauge: This is the British and Canadian spelling while in the United States it is sometimes spelled without the "u" (gage). It is becoming standard to use "gage" for wire size and "gauge" for an instrument. [1] An instrument that registers the quantity of a substance, e.g., ammeter, boost gauge, fuel gauge, gas gauge, in-dash gauge, oil gauge, oil level gauge, oil pressure gauge, oil temperature gauge, outside temperature gauge, temperature gauge, tire gauge, tire pressure gauge, turbo gauge, vacuum gauge, voltmeter, and water temperature gauge. [2] A tool for measuring clearances, pressures, sizes, etc. also See adjusting gauge B & S gauge brake gauge caliper gauge compression gauge compression tester depth gauge dial gauge disc brake gauge feeler gauge

frame gauge ignition gauge screw pitch gauge sighting point gauge spark plug gauge thread gauge thread pitch gauge throttle gauge tire tread gauge tram gauge tread depth gauge vernier gauge wheel alignment gauge [3] A measurement of tubing. See plain gauge tubing

gauge manifold: The one essential diagnostic tool required for every air conditioner service procedure. A typical gauge set includes high and low side gauges and valves for checking, measuring and controlling pressure and vacuum, and a third valve for controlling discharging, evacuation and charging procedures. Also called "gauge set"

gauge set: See gauge manifold

gauge tubing: See plain gauge tubing

gauntlet: A long-sleeved leather glove used by motorcyclists to prevent wasps from flying up the sleeve, as one did to me.

GAWR: Acronym for "Gross Axle Weight Rating."

Gaylord: A vehicle brand of which the 1955-57 models are milestone cars.

G-clamp:

A screw-activated clamping device in the shape of the letter "G"

GCW: Acronym for gross combination weight.

GCWR: Acronym for gross Combined Weight Rating

gear: Wheel-like part with teeth cut into the rim. When one gear meshes with another gear, it causes the second gear to drive the other and in this way transmits power. When the gears are different sizes (different number of teeth on each gear) the mechanical average is changed. Also see axle end gears bevel gear bottom gear camshaft gear center gear change gear cluster gear constant mesh gears counter gear crankshaft gear crawler gear differential gears differential side gear double helical gear drive gear driven gear driving gear economy gear end gear EP gear oil fifth gear final drive gear first gear fixed gear flywheel ring gear fourth gear granny gear helical gear herringbone gears

high gear hypoid oil hypoid gear idler gear intermediate gear internal gear pump internal gear left hand gear lever low gear mating gears member of the gear train overall gear ratio passing gear pinion gear planetary gear differential planetary gear set planetary gear planetary gears planet gear planet gears reverse gear reverse idler gear reversible gear puller ring gear running gear second gear shift gear side gear sliding gear spider gear spiral bevel gear spur gear starter ring gear steering gear stepped planet gear straight-cut gear sun-and-planet gears sun gear third gear timing gear top gear valve gear wide-step gearing worm gear gear arm:

See steering gear arm

gearbox: The device in the drivetrain consisting of an input shaft, a system of gears, and an output shaft that multiplies engine torque. A manual transmission consists of a clutch assembly plus a gearbox; and automatic transmission generally consists of a torque converter plus gearbox. Also see automatic gearbox auxiliary gearbox auxilliary gearbox change-speed gearbox close-ratio gearbox constant mesh gearbox cotal gearbox crash gearbox dual-range gearbox epicyclic gearbox four-speed gearbox high/low range gearbox manual gearbox mesh gearbox planetary gearset pre-selector gearbox preselector gearbox rack and pinion gearbox reduction gearbox sliding-mesh gearbox steering gearbox two-speed gearbox wilson gearbox gearbox input shaft: A shaft which transmits power from the clutch to the gearbox

gearbox output shaft: A shaft which transmits the drive out of the gearbox

gearchange: A British term for the process of changing gears or shifting gears. Also see central gearchange

column gearchange dashboard gearchange floor gearchange steering column gearchange gearchange cables: British term for shifting cables used to operate gears in some transmissions. In most vehicles rods and joints are used because cables tend to stretch.

gearchange linkage: A system of rods and joints used to operate the gearbox. British term for shifter linkage

gearchange mechanism: A system of rods and joints used to operate the gearbox. British term for shifter mechanism

gear changer: See column gear changer

gear differential: See planetary gear differential

gear drive: See bevel gear drive

geared: also See high-geared low geared gear grease: A heavy liquid grease that fills the differential and manual transmission to lubricate the gears. Also called "differential grease."

gear indicator:

A display which shows the particular transmission gear that has been selected.

gearing: [1] The combination or system of gears or sprockets designed to transmit power. [2] The ratio between the drive gear and the driven gear. also See alpine gearing crossover gearing double reduction gearing half-step gearing wide-step gearing wide range gearing wide step gearing gear knob: British term for the knob at the end of a lever, i.e., shifter knob

gear lever: A device which is attached to the side of a steering column or to the center console which will allow the operator to change the gears of the transmission. Also called "shift lever." Also see left hand gear lever. gear oil: A heavy oil which is rated at 80 to 100 weight viscosity used in enclosed units containing gears. This oil infrequently or rarely needs changing. Also see EP gear oil gear puller: A tool with two or more jaws and pressure screw for pulling off gears, bearings, pulleys, etc. Also see reversible gear puller gear pump: The simplest oil pump with two gear wheels. Also see internal gear pump

gear range: choice of gears in an automatic transmission. The typical gear ranges are: P - Park, R - Reverse, N - Neutral, D -Drive, L - Low

gear ratio: The relationship between the number of turns made by a driving gear to complete one full turn of the driven gear. If the driving gear turns four times to turn the driven gear once, the gear ratio would be 4 to 1. In most instances, the gear ratio is not even like 4:1 because the same teeth would be meshing with each other. Thus a ratio of 4.11:1, for instance, means that a particular tooth on one gear may eventually mesh with every one of the teeth on the other gear. Changing the tire size will change the effective gear ratio. Also see overall gear ratio gear selector: The device (e.g., lever or rod or pushbutton) for choosing the desired transmission gear. See gearshift.

gear selector indicator: An indicator positioned in the instrument cluster or on the centre console shift gate indicating which gear has been selected in an automatic transmission

gearset: A group of two or more gears used to transmit power. Also see planetary gear set ravigneaux planetary gear set simpson gear set simpson planetary gear set gear shaft: See steering gear shaft

gearshift: A device which allows the operator to move the transmission gears into various configurations. Most often the gearshift is located on a lever on the steering column or on a lever on the floor between the driver and front passenger. Some older Chryslers had pushbutton controls on the dash.

gearshifter: A device which allows the operator to move the transmission gears into various configurations. Most often the gearshift is located on a lever on the steering column or on a lever on the floor between the driver and front passenger. Some older Chryslers had pushbutton controls on the dash.

gearstick: A British term for the stick used by the driver to change gears. Also called a "shifter" or "shift lever."

gear tooth: The indentation on the edge of a gearwheel

gear train: A system of gears that transmits drive from one shaft to another. Also see member of the gear train gear transmission: See bevel gear transmission

gear-type oil pump: The simplest oil pump with two gear wheels

gearwheel: A gear

gel: [1] A substance like jelly. See silica gel. [2] to become like jelly

gel cell battery: A battery where the acid is in the form of a gel so that in the event of a spill, acid does not leak out -- especially recommended for electric scooters and power chairs

gel coat:

[1] A thin layer of plastic resin covering fiberglass panels. [2] An outer layer of GRP (glass reinforced plastic) moldings which gives a smooth surface that may be coloured

gel-coat resin: A resin similar to general lay-up resin but with an additive to make it thixotropic, i.e., it does not run down vertical surfaces; used to make the gel coat in moldings

gelling drier: A drier for PVC sealants

Gemmer steering: A cam-and-roller steering

General Agreement on Tariffs and Trade: (GATT) Signed in 1947, the GATT was a formal multilateral agreement aimed at expanding and liberalizing world trade. The World Trade Organization which is the successor to the GATT came into existence on January 1, 1995.

general cargo: Non-bulk cargo. The cargo may be of various kinds

general corrosion: In contrast to pitting, a type of corrosion which affects the entire surface of a metal

Generalized Preferential Tariff: (GPT) system of non-reciprocal tariff preferences for the benefit of developing countries. It grants duty-free or preferential entry to imports for eligible developing countries up to a certain dollar value or import percentage limit.

General Motors: (GM) or (GMC) The largest American vehicle manufacturer including Chevrolet, Buick, Pontiac, Oldsmobile, Saturn, Cadillac, GMC trucks, and HUMMER. It has subsidiaries and associates in Britain (Vauxhall), European continent (Opel, Fiat, and Saab), Australia (Holden), Asia (Subaru, Fuji, Suzuki)

general purpose lacquer thinner:

A type of thinner that may be used for both lacquers and synthetic enamels without causing lifting or other paint faults

general purpose pliers: Any kind of typical multi-purpose pliers.

generate: To produce.

generator: [1] A mechanism which generates or produces some substance, i.e., electric generator, acetylene generator. [2] An electromagnetic device for producing direct current electricity. It was replaced by an alternator in the early '60s. Its problem was that a generator recharged the battery only at high speeds. The British call it a "dynamo." Also see AC generator alternator DC generator flywheel generator gas-driven generator hall generator pulse generator solar generator third brush transistorized ignition with inductive pulse generator Geo: A model of automobile manufactured by Suzuki for GM geometry: The design, layout, or arrangement of parts. Also see steering geometry GHGs: Acronym for "Greenhouse Gases."

Ghia:

Click for books on Geo

See dual Ghia

gib head key: See gib-head key.

gib-head key: A special bar of any length like a flat key or square key, but one end is specially shaped to prevent the key from going all the way through.

girder: A continuous member usually running fore and aft under a deck for the purpose of supporting the deck beams and deck. Also see center girder longitudinal girder girder forks: Type of forks common on early motorcycles, comprising rigid beams attached to the steering head by parallel links that allowed movement

girder spanner: A British term for an adjustable wrench with jaws at right angles to the handle.

girl's bike: A bicycle where the horizontal top bar (of a "boy's bike") is angled down from the steering tube down to the bottom bracket and is usually parallel with the down tube. See ladies' frame.

Giuletta: See Alfa Romeo.

Giulia: See Alfa Romeo.

GL: [1] A term referring to gold line tires marketed in the late '60s and early '70s. [2] (short for) Grand Luxe, meaning more luxurious than a standard model, L (= Luxe); (compare CL)

glad hands: A separable mechanical connector used to join air line hoses when combination vehicles are coupled together.

gland: A seal that stops fluid under pressure from leaking past a rotating or reciprocating shaft or rod. Also see packed gland glandless: Something without a seal

glare: [1] strong, bright light (e.g., from oncoming traffic) [2] to shine too brightly; to dazzle

glass: [1] A transparent, hard, amorphous, brittle substance which is made by fusing together one or more of the oxides of silicon, boron, or phosphorus, with certain basic oxides (e.g., sodium, magnesium, calcium, potassium), and cooling the product rapidly to prevent crystallization or devitrification. The melting point varies between 800°C and 950°C but it is worked at higher temperatures. The tensile strength of glass resides almost entirely in the outer skin; if this is scratched or corroded, the glass is much more easily broken. [2] The transparent windows in a vehicle. Also see body glass compound glass door glass laminated glass laminated windshield glass milled glass fiber safety glass sight glass tempered glass tinted glass toughened glass glass area:

The window surface area of a vehicle body; may also refer to the whole area of the body above the waistline. Also called the greenhouse.

glass channel: A U-shape metal guide which holds the bottom edge of a roll-up automobile window and fits inside the door. The British term is "window channel."

glass fiber: A very thin glass thread, used loosely or in woven form as an acoustic, electrical, or thermal insulating material and as a reinforcing material in laminated plastics. Also see milled glass fiber glass fibre: A very thin glass thread, used loosely or in woven form as an acoustic, electrical, or thermal insulating material and as a reinforcing material in laminated plastics

glass holder: A tool with suction cup(s) to hold and carry a sheet of glass

glass pack muffler: A straight through (no baffles) muffler using fibreglass packing around a perforated pipe to deaden exhaust sound.

glasspaper: An abrasive paper coated with particles of glass, used for smoothing and polishing

glass reinforced filler paste: A polyester filler that has strands of fibreglass added into the filler paste to increase the rigidity of the repair

glass reinforced plastic: (GRP) The basic material for the manufacture of fibreglass body shells and panels; it is made up of several layers of fibreglass mat or cloth and various types of resins

glass seal: a conducting seal in the middle of some spark plug insulators connecting the top and bottom parts of the central electrode

Glass's Guide: A monthly publication of second-hand car prices

glass sphere: reinforcing filler in the form of particles as opposed to fibres

glass tampering detector: A part of a vehicle alarm system that detects glass being struck or broken

glaze: A highly smooth, glossy finish on the cylinder walls. As the piston rings rub up and down the cylinder, the rings polish the cylinder wall. Cylinder wall glazing reduces sealing efficiency. The only cure is to have the cylinder deglazed.

glaze breaker: An abrasive tool used to remove the glaze from cylinder walls prior to the installation of new piston rings. Also called "deglazer."

glazed: [1] Something that is fitted with glass. [2] Something with a smooth, polished surface

glaze lining: A brake lining that has been overheated and become smooth and glossy

glazing: [1] The use of special putty to fill minor imperfections when doing body repair [2] Glass fitted or about to be fitted in a window. Also see lead glazing spot glazing glazing strip: molded rubber strip for mounting windshields and other fixed glass

g-loads:

Gravitational loads, expressed in multiples of the force of gravity acting on an object. In a car, these can be felt in acceleration, braking or cornering. In most passenger cars, these loads seldom exceed 0.3 or 0.4 Gs in any direction, unless in an urgent situation. Race cars can achieve several Gs, due to excellent tires and prepared racing surfaces.

Global Positioning Satellite: The technology which allows a vehicle to be tracked anywhere in the world with near-perfect accuracy. The Global Positioning Satellite (GPS) system was first used by the military, but has been adopted by companies such as General Motors for use with their OnStar communication system. Several after-market communication systems using GPS are also available

gloss: The ability of a paint to reflect images when polished. Also see high gloss specular gloss glove: See barrier cream invisible glove silicon glove glovebox: A small compartment (often with a lock) located in the dash in front of the passenger (not the driver) into which small items (owner's manual, maps, first aid kit, etc.) are placed.

glove compartment: British term for glovebox

glow: to burn without a flame. Also see flame glow plug open coil glow plug open element glow plug pencil-type glow plug

glow coil: filament in a glow plug

glow pencil: A pencil-like heating element of a sheathed-type glow plug

glow plug: An electrical element located in the combustion chamber of a diesel engine which helps to heat up the air in the chamber so that the diesel fuel will be ignited more quickly. Often they are connected in series so that when one becomes defective the others are inoperative. Also called a "heater plug." Also see coil glow plug flame glow plug open coil glow plug open element glow plug pencil-type glow plug self-regulating sheathed-type glow plug sheathed-type glow plug spiral-type glow plug sr sheathed glow plug wire glow plug glow plug indicator: A monitoring element in a preheater system, which changes the colour of its filament in line with the plug and indicating readiness for starting

glow plug starter switch: The key switch for turning on the preheating system of a diesel engine and starting the car.

glow time: The preheating time of a diesel engine

glow tube: See glow plug

glycol:

also See ethylene glycol antifreeze. glycote: See poly-glycotes.

glycotes: See poly-glycotes.

GM: Acronym for "General Motors Corp."

GMC: Acronym for "General Motors Corporation."

GND: Abbreviation for "ground"

go dull: A condition of paint that has lost its luster

go flat: A condition of paint that has lost its luster.

goggles: protective spectacles against dust and glare. Also see safety goggles gold plating: The electrolytic deposition of gold

goodies: See bolt-on goodies

goods: See heavy goods vehicle

goods vehicle: See heavy goods vehicle

good will warranty: Normal warranty specifies that a product is covered for manufacturer's defects for a period of time or distance of use. If the item has gone beyond the normal warranty, the dealer may offer some warranty in order to keep your business. The dealer may pick up the costs for parts and labor, or just the labor, or 50% of the overall costs, or just a nominal sum.

go off: A British term for beginning to harden, the initial phase of the hardening process of plastic body fillers. The American term is "kick"

gooseneck map light: A flexible-stemmed map lamp

gouge: a flat, relatively large dent that has no hard contours so it can be reshaped by shrinking using heat or with a hammer and dolly

gouging: Cutting of a groove in the surface of a metal using a gas cutting torch of an arc-air cutting outfit.

governor: [1] A device designed to automatically control the speed or position of some part (i.e., engine speed or transmission speed). Governors are used to prevent an engine from exceeding its maximum rpms. They are also used on rental vehicles to prevent operators from speeding. [2] A governor on the output shaft of a hydraulically controlled transmission converts line pressure into governor pressure. In electro-hydraulically controlled transmissions, the governor is replaced by a sensor. Also see centrifugal governor transmission governor

governor plate: See contact breaker plate

governor pressure: Pressure in an automatic transmission control that varies in accordance with vehicle speed and acts on the command valves, where it opposes the control pressure

governor valve: (GV) An automatic transmission control valve which converts line pressure into vehicle-speed dependent governor pressure.

governor weight: A centrifugal advance mechanism or advance weight

GPM: Acronym for "gallons per minute."

GPS: Acronym for "Global Positioning (via) Satellite."

GPT: Acronym for "Generalized Preferential Tariff."

grab: [1] The action of brakes to seize the drum or disc suddenly when the brake pedal is pressed. [2] the action of a clutch to take up the drive suddenly when the clutch pedal is released. Also called "snatch." Also see fierceness grabber: See webbing grabber

grab handle: [1] A strap or part of a car door interior used to pull the door shut. Also called "door handle."

[2] An inside strap located above the door which is used to steady a passenger during sharp cornering. At one time this handle was found only on the passenger side; but in newer cars it is also on the driver's side. [3] A handle on the tongue of a trailer, used to move the trailer manually

grade: [1] The steepness of the road on a hill. [2] The composition of gravel and rock, etc. of a road surface (thus the vehicle used to smooth it is a grader). [3] The strength factor of a fastener (i.e., nuts and bolts). In US fasteners, grade 2 has a tensile strength of 60,000 psi; grade 5 = 120,000 psi; grade 7 = 133,000 psi; grade 8 = 150,000 psi; grade ASTM A574 = 170,000 psi. In metric fasteners, grade 4.8 = 60,900 psi; grade 8.8 = 120,350 psi; grade 9.8 = 130,500 psi; grade 10.9 = 150,800 psi; and grade 12.9 = 176,900 psi. [4] The quality of oil. See oil grade. [5] A British term for the degree of sandpaper coarseness. The US term is grit.

grader: A road construction vehicle with a large blade which scrapes gravel to smooth or level a surface. Graders are also used to remove snow from roads.

gradient: [1] the slope or inclination of a road; [2] a measure of the slope, expressed as the ratio of height (or drop) to horizontal distance; a steep hill might be 1 in 4, while a gradual slope might be 1 in 10

grading: See quality grading

graduated tint: The tinted stripe at the upper edge of a windshield

graft copolymer: A copolymer in which polymeric side chains have been attached to the main chain of a polymer of different structure

Graham-Paige: A vehicle brand of which only the Custom body of 1925-1948 with required application are classic cars.

grain alcohol: Ethanol

grain coarsening: roughening of the surface of a material

grain growth: roughening of the surface of a material

Grand Am: A model of automobile manufactured by Pontiac division of General Motors

Click for books on Grand Am

Grand Luxe: (GL) A model that is more luxurious model than a standard model

Grand National: A model of automobile manufactured by Buick

Click for books on Buick Grand National

Grand Prix: [1] An international car race from which points are scored towards the World Championship. [2] A model of automobile manufactured by Pontiac division of General Motors Grand Touring: (GT) A term used for a sportier car. See Gran Turismo.

Grand Touring-injection: (GTi) A GT car with fuel injection.

Grand Touring Prototype: (GTP). Also see camel Grand Touring Prototype

Click for books on Pontiac Grand Prix

granny gear: Colloquial term for the tiny inner chainring on a triple chainring crankset of a bicycle. Needed for climbing steep hills especially with a loaded bicycle.

Gran Turismo: (GT) A car which combines the features of both the sedan and sports car. It features excellent engineering and road handling with relative comfort. Made in two-seater and four-seater models with cramped rear seats.

graph: A diagram showing the relationship between certain numbers or quantities in the form of a line

graphic display unit: A dashboard panel displaying a plan of the car with illuminated parts representing doors left open, lights switched on, etc.

graphic equalizer: A unit in a car stereo system that adjusts the audio output signal strength separately for individual frequency ranges; individual frequencies can be emphasized to compensate for specific acoustic conditions

graphics: See splashed graphics

graphite: A form of carbon used in making brushes for motors and generators and as a lubricant

graphite grease: heavy-duty grease containing graphite, used for brake cables, etc.

graphitic corrosion: selective corrosion of grey cast iron, resulting in preferential removal of metallic constituents, leaving graphite

grass heat shield:

A metal shield fitted underneath a catalytic converter to reduce the risk of its heat starting an accidental grass fire

gravel: A mixture of rocks and sand where the rocks are usually less than 1 inch (25 mm) in diameter.

gravel gun: equipment used to hurl crushed stone at objects, such as test panels, to test them for chipping resistance

gravel road: A road which is covered with a layer of gravel. Also called a secondary road or an improved road.

graveyard: See auto graveyard

gravity: The attractive force exerted by one body on another. All bodies which have mass have this property. The pull of the earth upon objects so that they fall at the rate of 981 cm (32.2 feet) per second every second. Also see center of gravity g specific gravity gravity, center: The force which causes a body to fall to the earth. See center of gravity.

gravity feed: A fuel supply system where the gas tank is mounted higher than the carburetor. This system was used in some older cars where the gas tank was located in front of the windshield and in many motorcycles.

gravity-feed spray gun: A type of paint spray gun, in which paint flows downward from a container mounted on its top, thus reducing the amount of compressed air required

Gray Market Vehicles: Cars that have been imported into the country through unauthorized means. It is likely they won't meet American safety and emission standards. These cars have significantly lower values than vehicle imported through normal channels.

grease: [1] A lubricant (made from oil and metallic soaps) which reduces the friction between moving pieces of metal and also prevents moisture from causing metal to rust. [2] To lubricate or coat with grease. Also see base grease dielectric grease differential grease gear grease gear grease graphite grease lithium base grease lithium grease lube grease lube grease white lithium grease. grease fitting: A device that seals in and allows the addition of more grease, or some other type of lubricant, to cushion two moving parts, allow them to move freely, and prevent them from wearing each other away. Found on ball joints, steering knuckles, tie-rod ends. Also called "zerk fitting."

grease gun: A small, hand-operated pump that can be loaded with grease and used for lubricating the grease fittings on a vehicle. Adapters can be attached to the grease gun so that grease can be forced even into sealed bearings.

grease nipple: A small, one-way valve used for injecting grease into a bearing

grease pencil: A writing device which writes in grease or wax. It is used to mark tires because it can be easily rubbed off.

grease seal: A circular metal disk covered in rubber or plastic with a center hole, an edge on the outside circumference, and another edge on the center hole with a spring to retain tension on the shaft that fits into the hole. It is used to keep grease and oil from leaking out and protects bearings from dirt and water. Also called "oil seal."

Great Lakes ship: Cargo ship used to carry cargo on the Great Lakes. Most carry bulk cargoes of grain, iron ore or coal.

Green: See British Racing Green

green flag: A green flag is used to restart the race. The pace car will pull off the track into pit lane and the race resumes. Note: the race cars do not come to a stop on the track at anytime, unless a red flag is thrown.

green flag with yellow diagonal stripe: The green flag with a yellow diagonal stripe signals a slower driver to move over on the track and let the leaders proceed. This usually occurs near the end of a race when the slower car is many laps behind. This flag is to ensure safety for the cars still racing for the win.

greenhouse: The glass area of a car or truck.

greenhouse gases: (GHGs) Group of gases which individually act to trap solar energy near the earth. GHGs for which emission levels have been estimated are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulphur hexafluoride (SF6), carbon tetrafluoride (CF4), carbon hexafluoride (C2F6) and hydrofluorocarbons (HFCs). green stage: the initial hardening phase during which the resin or filler has hardened but has not yet set solid; this occurs immediately after the resin or filler has kicked (British: gone off).

green tire: The complete rubber/fabric/steel tire just before being cured.

grey market: the grey market describes the purchase by intermediaries of product which is not supplied to them by the "authorized" distribution channel of the supplier. Thus, a warehouse club in Canada that sells a stereo bought in the U.S. or elsewhere from other than the manufacturer is supplying grey market goods. While grey market products are frequently the same as would be available from conventional channels in Canada, the grey market assumes responsibility for service or repair where the manufacturer declines this support.

grid: The lead screen or plate to which the battery plate active material is attached. Also see electric grid lead-antimony grid plate grid grid-controlled ignition system: A microprocessor-controlled ignition system with electronic ignition timing by means of an ignition map stored in the control unit memory

grid dolly: A special shrinking dolly with a large, flat groove

grill: Alternate spelling of "Grille."

grille: A grating or crosswork of bars usually as an ornamental cover of the radiator which allows air to cool the engine. Also see speaker grill egg-crate grille radiator grille surround radiator grille slatted grille

grille face panel: A metallic grating which surrounds the radiator. Also called a "grille panel."

grille panel: A metallic grating which surrounds the radiator. Also called a "grille face panel."

grille surround: See radiator grille surround

grind: To remove metal from an object by means of a revolving abrasive wheel, disc, or belt. Also see valve grinding valve seat grinding. grinder: A device to remove metal from an object. Also see angle grinder bench grinder brake shoe grinder mini-grinder suction valve grinder valve grinder grinding: also See valve grinding valve seat grinding grinding compound: See valve grinding compound

grinding disc: An abrasive disc

grinding paste:

An abrasive paste used for reseating valves

grinding tool: See valve grinding tool

grinding wheel: An abrasive wheel used for grinding (usually a composite of hard particles in a resin filler)

grindstone: A rotating abrasive disc for rubbing away metal and for sharpening tools

grip: [1] The adhesion of a tire to the road surface; important for roadholding and safe braking. [2] A rubber or rubber-like tube which fits on the end of a pipe (i.e., handlebars or a tool). Also see hot grip lateral grip wet grip mole grips vice grips vise grips grip channel: A steel channel spot-welded to a vehicle body to keep rubber seals in place

grip in the wet: a vehicle's roadholding ability in the rain or on a wet surface

grip wrench: Locking pliers

grit: [1] A measure indicating the sizes of the abrasive particles in a grinding wheel, usually expressed by a figure denoting the number of meshes per linear inch in a sieve through which the particles will pass completely.

[2] Siliceous sediment, loose or indurated, the component grains being angular. Sometimes applied to a hard coarse-grained sandstone. [3] Hard particles, usually mineral, or natural or industrial origin, retained on a 200 mesh test sieve (76 μm). Also see P grit numbers grit blasting: [1] A sandblasting process where grit is used to clean the metal surfaces and is available in various grades for coarse or finer blasting on thin steel. [2] A cleaning of the spark plug electrodes by bombarding them with abrasive particles

grit number: A classification of sand paper by fineness of the grit particles. Also see P grit numbers GRND: Abbreviation for "ground"

grommet: A rubber or plastic ring around a hole in metal (to protect a cable or pipe)

groove: [1] A channel or gouge in metal (see piston ring groove) or in the tread of a tire. [2] Another name for a viable racing lane on the race track. [3] The space between the ridges of a bolt thread. Also see cracking groove oil groove piston ring groove piston ring groove cleaner ring groove tread groove groove cleaner: See piston ring groove cleaner

groove cracks:

Splitting or cracking of the rubber (undertread) at the base of the grooves, between tread ribs. Primarily caused by growth in textile casings.

grooved compression ring: A scraper-type piston ring

groove insert: See top ring groove insert.

groove weld: A welding rod fused into a joint which has the base metal removed to form a V, U, or J through at the edge of the metals to be joined.

grooving: The cutting of a tread design into tread rubber where a design does not already exist. Also altering an original design, i.e., cross-grooving to increase traction.

grooving hammer: A wide-nose peen hammer

gross: See tonnage gross

gross axle weight rating: (GAWR) A US maximum specified load capacity of an axle.

gross bhp: See SAE gross bhp

gross combination weight: (GCW) The weight of a truck and trailer combination and its entire contents.

Gross Combined Weight Rating: (GCWR) The maximum load rating -- including passengers, cargo, and trailer -- for a particular vehicle. A vehicle's GCWR will typically be higher than its GVWR, since gross vehicle weight ratings are determined by axle ratings, and a trailer has its own axles.

gross horsepower: See SAE gross horsepower

gross margin: The return an intermediary achieves on the selling price of the article. That is, if the intermediary buys a product for $1 and sells it for $1.50, the margin is calculated. For example, .50 divided by $1.50, or 33%.

gross registered tons: See tonnage

gross ton: 2240 pounds. Also called "long ton."

gross train weight: Same as gross combination weight.

gross vehicle weight: (GVW) Maximum legal weight at which a vehicle can be operated. The total weight of a fully equipped truck and payload.

Gross Vehicle Weight Rating: (GVWR) Curb weight plus the payload. The most the loaded vehicle can weigh, generally determined by suspension system, tire size, and brake capacity. A vehicle's GVWR is usually displayed on a label on the door or door-latch pillar.

ground: (GND or GRND) [1] Terminal of battery that is connected to the metal framework of the vehicle so that the frame acts as a conductor of electricity. In North America, the negative terminal is grounded. In British terms, it is called "Earth." Also see battery ground negative ground positive ground [2] A result of grinding.

Also see cam-ground piston. ground and polish: To cut and polish a crankshaft bearing surface to precision specifications.

ground clearance: The vertical distance between level ground and the lowest fixed item on a vehicle (usually one of the differentials).

ground clearance control: A small lever near the park brake of cars with hydropneumatic suspension that allows ground clearance to be increased for crossing rough terrain or when changing a wheel

ground clearance sensor: An instrument that senses the distance between the ground and car (for selflevelling air suspension)

ground connection: A wire or other metal strip for connecting a component to the vehicle chassis or body

ground contact area: the contact patch of a tire

ground effect: The phenomenon that occurs when the airflow between a moving object and the ground creates downforce.

ground electrode: The side electrode of a sparking plug. The opposite is the center electrode triangular ground electrode

grounding: The action of a vehicle when some part of its undercarriage touches the ground (e.g., when going over a curb). In some cases the vehicle can become high-centered

so that the vehicle is stationary because the driving wheels are no longer touching the ground. [2] Contact of the bottom of a ship with the sea floor

ground piston: See cam ground piston

ground return: The return path of an electrical circuit, provided by a ground connection

ground strap: A wire cable or braided wire strap to transfer electricity. It can be found between the engine block and the chassis because the engine is isolated from the chassis by rubber mounts. Also called battery strap. See ground wire.

ground wire: The wire which goes from the negative post of the battery to the frame on negative ground vehicles. Another ground wire may be a thick wire or braided wire cable which connects the engine to the frame. Since many engines are rubber mounted, there may be no metal contact between the engine and the frame apart from the ground wire which may also be called the ground strap. In British terms, it is called "earth wire."

group: See plate group

group of seven: (G7) seven industrial countries consisting of the United States, Japan, Germany, France, the United Kingdom, Italy and Canada, whose leaders have met at annual economic summits since 1975 to coordinate economic policies.

growler: An instrument used in testing starters, generator, and armatures.

grown tire: A tire that, with use, has slightly increased in size

growth:

also See tire growth grain growth GRP: (fiber)glass reinforced plastic

GRRF: Acronym for "Groupe de travail en matière de Roulement et de Freinage" (i.e., Working Party on Brakes and Running Gear)

grub screw: A fully threaded, headless screw. Also see setscrew GT: Acronym for "Gran Turismo" or "Grand Touring."

GTi: Grand Touring-injection. A GT car model with fuel injection

GTO: [1] Acronym for "Gran Turismo Omologato." [2] A model of automobile manufactured by Pontiac division of General Motors GTP: Acronym for "Grand Touring Prototype." Also see Camel Grand Touring Prototype GTS: Acronym for "Global Tire Standard."

GTW: Acronym for gross train weight.

Click for books on Pontiac GTO

guarantee: A promise by the manufacturer to fix or replace a specific part if it does not last for a specific time period or distance.

guard: also See chain guard dog guard edge guard oil pan guard side radiator guard splash guard stone guard sump guard gudgeon pin: British term for a piston pin or wrist pin.

gudgeon pin boss: British term for piston boss

gudgeon pin circlip: A British term for piston pin circlip

gudgeon pin end: British term for piston pin end

Guibo coupling: A doughnut-shaped type of flexible coupling

guide: A device which allows a long shaft to do its job without flexing. also See cable guide oversize valve guide valve guide glass's Guide guide coat:

A thin coat of paint designed to highlight imperfections

guide driver: also See valve guide driver guided send test: Bending a specimen in a definite way by using a fixture.

guided vehicle system: See automated guided vehicle system

guide reamer: See valve guide reamer

guide remover: See valve guide remover

guide seal: See valve guide seal

guillotine: A bench tool for cutting sheet metal. The sheet is pulled in by two adjustable rollers (one above and the other below) as the tool cuts the metal in either a straight line or a curve as desired.

gull-wing door: A roof-hinged door that opens upward. It was first used on the Mercedes-Benz 300 SL in the early 1950s

gulp system: See air gulp system

gulp valve: A vacuum-controlled valve that admits fresh air to the inlet manifold during deceleration to prevent backfiring in the exhaust system; its vacuum signal is

governed by a thermovalve and a solenoid valve to ensure that the gulp valve action does not interfere with cold start enrichment. Also see air gulp valve air bypass valve gum: The oxidized portions of the fuel that form deposits in the fuel system or engine parts. Also see curing gum cushion gum repair gum gum deposit: A sticky deposit that occurs when gasoline remains unused in the tank for a period of time. The use of detergent in gasoline (or pouring in some fuel stabilizer) helps prevent its formation.

gum stock: Rubber compounds containing only the necessary ingredients for vulcanizing. Reinforcing fillers are not present in gum stock. Also see cushion gum. gun: [1] To press the accelerator hard to make the engine roar at top rpm. [2] A device for applying paint or grease. also See airless spray gun blow gun compressed-air spray gun gravel gun gravity-feed spray gun grease gun paint gun pressure-feed spray gun rivet gun spray gun suction-feed spray gun top feed gun

gun nozzle cleaning unit: See spray gun nozzle cleaning unit

gunwale bar: See stringer bar

gusset: A triangular plate secured across an angle to reinforce a joint

gusset plate: A triangular plate secured across an angle to reinforce a joint

gut: To strip the interior of the vehicle. May also refer to removing the internal baffles from a muffler.

gutted muffler: A muffler with no silencing baffles. Makes a very loud sound.

gutter: [1] The recessed part on a truck rim base that holds the lock ring in place. [2] A channel at the edge of a road to carry away rainwater

gutter bevel: Truck rims are bevelled to provide for the gutter and this bevel matches a 28° taper at the inside of the cast spokes, holding the rim in place.

GV: Acronym for governor valve

guzzler: See gas guzzler

GVW: Acronym for "Gross Vehicle Weight" -- the total weight of a fully equipped truck and payload.

GVWR: Acronym for "Gross Vehicle Weight Rating" -- the standard or rating of a vehicle's carrying capacity. It includes the weight of the vehicle, fuel, fluids, and full payload.

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [Ha] [He] [Hi] [Ho] [Hu] [Hy]

H: [1] A letter rating for tires to indicate that they are theoretically rated for speeds up to 210 kph (130 mph), as in P185HR13. The next higher rating is V and the one lower rating is T. [2] Système International (SI) symbol for henry

habits: See driving habits

hacksaw: handsaw for cutting metal, with a narrow blade attached to a frame

HAI: Acronym for heated air inlet system

hair: See helmet hair

hairline crack: A tiny stress crack which forms due to strains in the material or extreme temperature differences; as opposed to crazing, a single crack of this type will often occur alone

hair pin: A securing device shaped somewhat like a "U" in which one leg is straight, but the other has a series of waves or bends. Insert the straight leg into the hole of a rod so that the "bent" leg will encircle the rod.

hairpin valve spring:

A valve spring formed from a wire or metal strip bent to form two levers emanating from a half-loop or coil; used on some classic cars and bikes

half: See crankcase half

half link: Every chain has rollers which are connected by side plates or keepers. When counting the number of links in a length of chain, it is easiest to count the number of side plates on one side of the chain and multiplying the number by two. When a chain needs to be an odd number, a half link is included. The term "half link" is a misnomer. It should be called a single link. The side plate on a half link is not flat but has a step down shape.

half moon key: See half-moon key.

half-moon key: A driving key serving the same purpose as the regular key but it is shaped somewhat like a half circle. Also called a "woodruff key."

half-moon slip joint pliers: A multiple-slip joint pliers with groove joint

half-round body file: A body file with domed file surface for working reverse-crowned panels

half-round file: A special file that's flat on one side and convex on the other

half shaft: A rotating shaft that transmits power from the final drive unit to one side of the drive wheels, but usually refers to the two shafts that connect the road wheels to the final drive with independent rear suspension or front-wheel drive as opposed to the axle shafts of a live rear axle. Also called an axleshaft

half step gearing:

See half-step gearing.

half-step gearing: A gearing system of a bicycle in which a shift between chainrings in a double chainring set is equivalent to half a gear step on the freewheel.

halftrack: vehicle with caterpillar tracks over the rear wheels to provide motive power but steered by normal front wheels

half wave rectifier: See rectifier.

half-wave rectifier: See rectifier.

Hall effect: in electrical conductors where electric current flows perpendicular to a magnetic field, a so-called Hall voltage is produced perpendicular to the direction of current flow and to the magnetic field

Hall-effect ignition system: transistorized ignition with Hall generator

Hall-effect sensor: A hall generator

Hall-effect switch: A hall vane switch

Hall element: A pulse generator that makes use of the Hall effect and consists of a rotor with vanes, a conductive element with a permanent magnet and the Hall IC. Also called "Hall generator." When the air gap is unobstructed, a Hall voltage is generated; when a vane stands in the air gap, the magnetic flux cannot reach the Hall IC. Hall generators used as ignition pulse generators have as many vanes and Hall windows as the engine has cylinders, dwell being determined by the width of the vanes. Hall generators used in electronic-map ignition systems to provide the engine starting

signal have only one Hall window

Hall generator: A pulse generator that makes use of the Hall effect and consists of a rotor with vanes, a conductive element with a permanent magnet and the Hall IC. Also called "Hall element." Also see transistorized ignition with Hall generator Hall IC: A solid state device with the actual Hall generator and integrated circuits for voltage amplification and potential reversal, producing the pulses for the control unit

Hall module: A Hall IC

Hall sensor: A hall generator. Also see transistorized coil ignition with Hall sensor Hall vane switch: A "switch" that makes use of the Hall effect. When the air gap is free, a magnetic field acts on the Hall IC and the Hall voltage reaches its maximum (high). When a rotor vane obstructs the air gap, shielding the Hall IC from the magnetic flux, the Hall voltage reaches its minimum (low). The signal produced is a square wave

Hall voltage: See hall effect

halogen: One of the chemical elements fluorine, chlorine, bromine, iodine, or astatine. Also see quartz halogen bulb halogen bulb: A bulb containing a trace of a halogen, such as iodine. A halogen bulb gives off a brighter light. Also see

quartz halogen bulb halogen headlamps: Tungsten-halogen bulb used in sealed beam unit or as separate bulb in composite headlamp

halogen headlight: high intensity reflector with inner halogen bulb, precision lens, and 3-prong attachment. Don't touch the glass of a halogen bulb with your fingers. The oil left on the glass will cause the glass to break or reduce the life of the bulb. If the glass is accidentally touched, it may be cleaned with methylated spirits or rubbing alcohol on a soft cloth

Hamlin switch: a suspended-mass-type sensor used in new air bag systems; avoids the ecological problems associated with the earlier mercury-type switches

hammer: [1] A hand tool with a metal head and a handle. It is used to force one item against or through another. Several types of hammers are available: air hammer ball peen hammer ballpein hammer ball pien hammer blacksmith hammer body hammer brass hammer bricklayer hammer bumping hammer caulking hammer chipping hammer claw hammer club hammer copper-faced hammer deadblow hammer demolition hammer drilling hammer drywall hammer fender bumping hammer finish hammer framing hammer grooving hammer machinists' hammer nail hammer

nylon hammer panel hammer peen hammer pein hammer pick and finishing hammer pick hammer planishing hammer prospector's pick ripping hammer riveting hammer rotary hammer rubber mallet shingler's hammer shingler's hammer shrinking hammer sledge hammer slide hammer soft face hammer tack hammer tile setter hammer tinner's hammer tinner's hammer two-way hammer wide-nose peen hammer wing bumping hammer and wood mallet. [2] To hit with a hammer.

hammer drill: electric hand drill that hammers as well as rotates

hammerform: A shaped wooden block used in panel beating, on which a desired form is produced by hammering

hammer welding: metalworking technique that includes gas welding, preferably without the use of filler rod, followed by hammer and dolly work on the welded joint to smooth out any remaining imperfections

hamper:

See height hamper pitch control

hamper pitch: See height hamper pitch control

hamper pitch control: See height hamper pitch control

hand: See left hand gear lever left hand monkey wrench left hand thread right hand thread right hand turn signal third hand handbook: A manual which gives instructions or information. Also see owner's handbook owner's manual handbrake: A brake operated by a hand lever. It may also refer to the park brake.

handbrake turn: 180° turn achieved by applying the handbrake (acting on the rear wheels) hard when the vehicle is starting to turn

handbrake warning light: A light on the instrument panel that illuminates when the handbrake is applied; on most new cars it has been superseded by a multifunction brake warning light

handcrafted: Something that is built by hand rather than in an assembly line (i.e., mass produced).

hand crank: Before Cadillac invented and produced electric starters, engines were started by means of a handle which was inserted into the front of the engine and rotated manually. After 1930 it became obsolete.

hand drill: A power-driven device for boring holes or (with the correct attachment) removing or securing screws and bolts

handed: Something that is made for a specific side of a unit. For example, left hand arm rests are not interchangeable with right hand arm rests. Also see left handed monkey wrench handed monkey: See left handed monkey wrench

handed monkey wrench: See left handed monkey wrench

hand file: A flat file for shaping metal, with a rectangular cross section, constant blade width and one smooth edge

hand gear: See left hand gear lever

hand gear lever: See left hand gear lever

hand lapped valves: A process of grinding valves by hand so that there is a perfect match between the valve and its seat.

handle: [1] The reaction of a vehicle under a particular circumstance, especially regarding cornering, roadholding, and maneuvring.

[2] to deal with or to cope with (e.g., "the tires can handle 50 psi" means the tires can withstand pressure up to 50 psi). [3] a CB user's code name. Also see boot handle door handle drive handle file handle flexible drive handle grab handle offset handle pull-out door handle ratchet handle spinner handle starting handle trunk handle handlebar: A steering device found on bicycles and motorcycles.

handlebar bag: a container, usually leather and nylon, which mounts on the front of a bicycle's handlebars.

handlebar riser: A bracket which lifts the base of the handlebar up higher.

handling: The relative ability of a vehicle to negotiate curves and respond to road conditions. It is a factor of the weight of the vehicle, the suspension, tires, air flow, etc. Also see neutral handling performance handling system handling system: See performance handling system

hand monkey: See left hand monkey wrench

hand monkey wrench: See left hand monkey wrench

hands: See glad hands

hands-free: A car cell phone that allows the driver to dial and talk on the phone without handling the phone.

handshaker: A passenger car with a manual transmission

hand shield: An eye and face protector held in the hand. It enables a person to look directly at the electric arc through a special lens without being harmed.

hand thread: See left hand thread right hand thread hand turn: See right hand turn signal

hand turn signal: See right hand turn signal

hanger: [1] A flexible ring or strap to hold a pipe, e.g., an exhaust pipe. [2] A mounting bracket, e.g., a spring hanger for a leaf spring. [3] A component of sighting point gauges, used to install the gauge at the vehicle chassis. Also see dropout hanger spring hanger hangover:

A modification of custom cars with separate chassis, e.g., pick-ups, which raises the floorpan and lowers the body, to give the impression that the body has been pulled down over the chassis right down to street level

hard aground: A ship which has gone aground and is not able to move under her own power.

hard anodic coating: hard, wear-resistant, oxide layer produced in an anodic oxidation process

hard anodizing: A special type of anodizing adapted to the production of thick, hard, abrasionresistant films

hardboard: A board-like building material made of compressed wood chip fibres and sawdust

hard chromium plating: An electrolytic deposition of a hard, wear-resistant, chromium layer

hard-dry: The condition of paint when it is hard enough to polish

harden: [1] The action of turning from a liquid to a solid. [2] To set or to cure. [3] The action of making the surface a metal tougher. See case harden.

hardened: See case-hardened chrome-hardened hardened pushrods: Specially treated pushrods designed for use with pushrod-guided rocker arms

hardener:

Chemical added to plastic filler to induce hardening as used in auto body repair.

harness: A bundle of electrical wires. For convenience in handling and for neatness, all wires going to certain part of the vehicle are bundled together into a harness

harness ties: Self-tightening nylon straps used to bundle wires into harnesses. Once tightened, they can't be removed unless they are cut

harness wrap: One of several materials used to bundle wires into manageable harnesses: See loom split loom loom tape harness ties hardening: The process of paint, epoxy, or glue becoming hard. The drying or hardening of paint film goes through several stages. The first stage is called "dust-free"; at this stage, the paint has hardened sufficiently to prevent dust from becoming embedded in the paint film. The second stage is called "touch-dry"; at this point, the paint film can actually be touched with light finger pressure. The third and final stage is referred to as "hard-dry"; at this point, the paint film is hard enough to polish. Also see age-hardening hardness: The toughness of the surface of a metal. See brinell hardness indentation hardness rockwell hardness shore hardness hard pedal: A loss in braking efficiency so that an excessive amount of pressure is need to actuate brakes

hard rubber: See ebonite

hard-sided caravan: A British term for a trailer with foldable, hard wall panels

hard-sided trailer: A trailer with foldable, hard wall panels

hard solder: Uniting two pieces of metal with a material having a melting point higher than "soft" solder: e.g., silver soldering

hard spots: Shiny bluish/brown glazed areas on a brake drum or disc friction surface, caused by extreme heat. Hard spots can usually be removed by resurfacing

hard stop: Hard braking, but not necessarily with locked wheels

hardtop: A two-door or four-door vehicle without a center door post, i.e., no B-post. It gives the impression of uninterrupted glass along the side of the car. The term is derived from "hardtop convertible." Other generic names have included sports coupe, hardtop coupe, or pillarless coupe. In the face of proposed rollover standards, nearly all automakers turned away from the pillarless design to a pillared version by 1976-77. Also see colonnade Hardtop formal Hardtop four-door Hardtop four-door Pillared Hardtop two-door hardtop hardtop convertible: An automobile with a fixed roof that does not retract into the trunk, but gives the appearance of being a convertible hardtop stand:

A foldable stand that holds a detached hardtop in a vertical position when stored

hard-top trailer: A holiday trailer with a hard top and (most often) canvas sides.

hard trim: Instrument panel moldings, center consoles and similar plastic trim

Hardy disc: a disc-style flexible coupling

Hardy-Spicer joint: A type of universal joint commonly used with prop shafts

Hardy-Spicer universal joint: A type of universal joint commonly used with prop shafts

harm: See bodily harm

harmful: See ecologically harmful

harmonic balancer: Also called vibration damper. It usually is a solid crankshaft fan belt pulley that has a weight ring bonded by rubber to the inner crankshaft-mounted ring. The outer ring absorbs and cancels out crankshaft vibrations that otherwise might cause the crankshaft to break. Formerly, two gearwheels carrying an unbalanced weight, mounted in bearings below the middle main crankshaft bearing, driven at twice engine speed and rotating in opposite directions to counterbalance the secondary vibrations in a four-cylinder reciprocating engine. Also see crankshaft pulley damper harness: [1] A belt system used with child seats and in cars, consisting of two shoulder belts and two lap belt portions fastened by a central buckle.

[2] A wiring harness. Also see 4-point racing harness brinell hardness safety harness wiring harness hat: The portion of a detachable brake disc that comes in contact with the wheel hub

hatch: [1] The rear opening of a vehicle which allows passage into its cab. [2] A hatchback. [3] A tailgate. [4] An opening in a deck through which cargo and stores are loaded or unloaded. Also see cross-hatch cross hatch hot hatch hatchback: A car design in which the rear trunk and lid are replaced by a rear hatch that includes the backlight (i.e., rear window). Usually the rear seat folds down to accommodate more luggage. Originally a hatch was a small opening in the deck of a sailing ship. The term "hatch" was later applied to airplane doors and to passenger cars with rear liftgates. Various models appeared in the early 1950s, but weather-tightness was a problem. The concept emerged again in the early 1970s, when fuel economy factors began to signal the trend toward compact cars. Technology had remedied the sealing difficulties. By the 1980s, most manufacturers produced one or more hatchback models, though the question of whether to call them "two-door" or "three-door" never was resolved. Their main common feature was the lack of a separate trunk. "Liftback" coupes may have had a different rear-end shape, but the two terms often described essentially the same vehicle. Also see five-door hatchback four-door hatchback liftback station wagon hatchback coupe: Originally a small opening in the deck of a sailing ship, the term "hatch" was later applied to airplane doors and to passenger cars with rear liftgates. Various models appeared in the early 1950s, but weather-tightness was a problem. The concept

emerged again in the early 1970s, when fuel economy factors began to signal the trend toward compact cars. Technology had remedied the sealing difficulties. By the 1980s, most manufacturers produced one or more hatchback models, though the question of whether to call them "two-door" or "three-door" never was resolved. Their main common feature was the lack of a separate trunk. "Liftback" coupes may have had a different rear-end shape, but the two terms often described essentially the same vehicle. === car-2hatch.jpg Also see three-door hatchback coupe two-door hatchback coupe hatch battens: Flat bars which are wedged against hatch coamings to secure tarpaulin

hatch beam: Portable beam across a hatch to support hatch covers

hatch coaming: The vertical plating bounding a hatch for the purpose of stiffening the edges of the opening and resisting water entry

hatchway: An opening in a deck through which cargo and stores are loaded or unloaded

hat section: See top hat section

haul: See long-haul

hawse pipe: Tube through which anchor chain is led overboard from the windlass on the deck

hawser: Strong rope or steel cable used for securing or mooring ships

hazard:

See road hazard

hazard flasher switch: A switch (usually located on the steering column below the steering wheel) which makes all the signal lights flash simultaneously, to warn other vehicles that your car is disabled or going very slowly down the road. Also called "4-way warning light switch."

hazardous wastes: Automotive wastes that are on the EPA's list of hazardous materials or that have one or more hazardous characteristics

hazard warning flasher: Actuates warning system of flashing front and rear turn signal lamps

hazard warning switch: A switch (usually located on the steering column below the steering wheel) which makes all the signal lights flash simultaneously, to warn other vehicles that your car is disabled or going very slowly down the road. Also called "4-way warning light switch."

HB: Acronym for "hatchback."

HC: Acronym for unburned hydrocarbons. They are at their worst with very rich or very lean mixtures. They combine with NOx in sunlight to form photochemical smog.

HC engine: A high-camshaft engine; the camshaft is located much higher than the crankshaft, (although not in the cylinder head), allowing for the use of shorter pushrods, thus improving the engine's revving ability.

HCV: [1] Acronym for "Heavy Commercial Vehicles." [2] Acronym for exhaust heat control valve

HD:

Acronym for "heavy duty."

HDPE: Acronym for "High-density polyethylene"

hdtp: Abbreviation for "hardtop."

head: [1] The upper part of something. [2] A term used to express the increase of energy content in a fluid pumped, expressed in units of energy per unit of mass, usually simply ft (feet). [3] A part of the engine which covers the piston and creates the combustion chamber. The proper name is cylinder head. Also see blown head gasket button head cheese head comet head composite headlight crossflow cylinder head cylinder head double-overhead cam exhaust header F-head F-head engine five-valve head fixed head flanged head flathead gib-head key headers head gasket headlight headliners head restraint headset heads up display head tube hemi head high compression head I-head I-head engine

interchangeable head torque wrench Jaguar Drophead jet head L-head L-head engine Lagonda Drophead mixing head negative suction head octagonal head bolt overhead cam overhead valves Phillips head screw piston head rear head restraints round head round head bolt sealed beam headlight spark head speedometer head steering head T-head test head thermal head two-valve head valve-in-head engine valve head X-flow cylinder head head ache rack: A colloquial term for the roll bar (safety bar) above the head of the driver

head bolt: See cylinder head bolt octagonal head bolt round head bolt head engine: See F head engine I head engine L head engine T head engine

header: [1] The action of diving or crashing into something. [2] An exhaust manifold. See headers. The British term is "headpipe." [3] A part at the top of another part. Also see exhaust header high-performance header tuned header twin header windshield header header bar: The front lateral bar of a roof which attaches to the top of the windshield frame; usually made of sheet steel shaped to match the top front edge to the curvature of the windshield

header bow: The front lateral bar of a roof which attaches to the top of the windshield frame; usually made of sheet steel shaped to match the top front edge to the curvature of the windshield

header panel: An exterior body panel located just ahead of the hood and surrounds the radiator. Also see windshield header panel headers: [1] The down pipe connecting the exhaust manifold to the front of the muffler or to the connector pipe. The British term is "headpipe." [2] A special exhaust manifold that replace the stock manifold. It is designed with smooth flowing lines to prevent back pressure caused by sharp bends, rough castings, etc. Also see exhaust manifold header tank: The top radiator tank in a thermosyphon water cooling system

head gasket:

The gasket at the top of the cylinder and sits between the cylinder and the head. It keeps the coolant out of the cylinders and retains compression in the cylinder. Also called cylinder head gasket. Also see blown head gasket

heading angle: The yaw angle.

head key: See gib head key

headlamp: In Britain, "headlamp" refers to the actual unit, whereas "headlight" is used for the unit as well as for its function and where emphasis is on the actual light produced by the lamp. In North America the terms are interchangeable. Also see circular headlamp headlamp delay system: Automatically controls headlamp ON-OFF operation after ignition & main lighting switch are turned OFF

head land: The uppermost piston land, subject to the highest thermal load

headlight: The main light on the front of a vehicle. In Britain, "headlamp" refers to the actual unit, whereas "headlight" is used for the unit as well as for its function and where emphasis is on the actual light produced by the lamp. In North America the terms are interchangeable. See composite headlight concealed headlights ellipsoidal headlight ff headlight gas discharge headlight gaseous discharge headlight halogen headlight hide-away headlights high beam homofocal headlight

inner headlight low beam mf headlight multi-focal headlight outer headlight pe headlight polyellipsoidal headlight pop-up headlights rectangular headlight retractable headlights sealed beam headlight sloping headlight twin headlight headlight adjusting screw: A screw which moves the headlight up or down, left or right to align the beam of light

headlight beam setting: British term for headlight adjusting screw

headlight body: A sheet metal pot welded or screwed to the front fender that provides the housing for the headlight and its bulbs and wiring

headlight bucket: The headlight housing of cars or motorcycles having separate headlights not integrated into the body line

headlight cover: [1] A rigid or flexible protection against dirt or stone damage when lights are not being used. On some vehicles, when the lights are turned on, the covers are flipped up by an electric or vacuum operated device. [2] A clear protective cover which is permanently mounted in front of the headlights to protect the headlight itself from damage.

headlight dimmer switch: A switch which changes the headlight from high beam to low beam or from low beam to high beam. In older vehicles, the switch was located on the floor to the left of the driver's left foot. In newer vehicles, it is found on a stalk projecting from the steering column beneath the steering wheel. In Britain it is called the "headlight

dipper switch." Also called, "dimmer switch."

headlight dipper switch: British term for headlight dimmer switch. Also called "dipswitch"

headlight flasher: On some vehicles, when you flick the direction indicator lever upwards against spring pressure, the headlights flash on and off quickly

headlight leveling: A system that compensates for a heavy load in the trunk which pushes the front of the car up and causes the headlights to project upward. The leveling system levels out the projection of the light. Some will do it automatically while others have a manual control.

headlight leveling control: usually a manual control with a vertical thumbwheel that adjusts the height of the headlight beam

headlight mounting panel: A sheet metal panel for rectangular headlights that is spot-welded to the front section of modern cars where the radiator grille and the headlights are mounted adjacent to each other; provides the mounting points for the headlight

headlight on/off delay system: A system with two functions: when activated, it can automatically turn ON the headlights during darkness and OFF during daylight; it can also be set to keep the headlights ON for up to approximately three minutes after leaving the parked vehicle; useful in dark, high-risk areas. The system is controlled by a photovoltaic cell on the dashboard

headlight retractor indicator lamp: A light on the dash that illuminates when the headlight covers are opening or closing

headlight visor: [1] A partial lid which encircles only the top part of the headlight.

[2] An attachment between headlight rim and lens, used only on some classic cars

headlight wash/wipe: A system that cleans the headlights with a jet of water and a small wiper blade

headliner: Fabric or vinyl upholstery on the interior of the roof of a vehicle. The British term is "headlining."

headliners: See headliner.

headlining: A British term for headliner: a soft lining on the inside of a car roof.

head nut: See cylinder head nut

head-on collision: An accident in which two cars hit each other's front end. Also called "head-on crash."

head-on crash: An accident in which two cars hit each other's front end. Also called "head-on collision."

headpipe: A British term for the header -- the down pipe connecting the exhaust manifold to the front of the muffler or to the connector pipe. Also see twin headpipe headrest: Another term for head restraint

head restraint:

An extension on the upper portion of the seatback. Some are permanently attached and other are adjustable. They are designed to reduce whiplash injuries caused by sudden stopping or collisions. They limit the rearward motion of the head and neck. Some head restraints contain radio speakers or even TV sets. Also see rear head restraints headroom: The distance between the top of a passenger's head and the inside of the vehicle roof

head screw: See phillips head screw

headset: On a bicycle, the combination of cups, cones, and ball bearings that creates the bearing mechanism that allows the fork column to rotate inside the head tube.

heads up display: (HUD) A system of mounting gauges so that the read-out is shown on the windshield. In this way the driver does not have to take his eyes off the road to see how his vehicle is performing.

head tester: See cylinder head tester

head torque: See interchangeable head torque wrench

head torque wrench: See interchangeable head torque wrench

head trim: The lining of the roof.

head tube: The shortest tube in the main triangle of a bicycle, the one inside of which the fork column rotates.

Healey: [1] See Austin Healey. [2] A brand of vehicle of which the 1949-50 Silverstone models are milestone cars.

heat: That which increases the internal energy of a body by changing the motion of the molecules. This causes a change in temperature, volume, or state of the body. Also see grass heat shield manifold heat control valve heat- affected zone: That part of the base metal which has been altered by the heat from the welding, brazing, or cutting operation.

heat balance: See thermal equilibrium.

heat checking: Small cracks on a brake disc or drum friction surface caused by heat. Heat check can usually be removed by resurfacing

heat checks: Cracks in the clutch pressure plate

heat conductivity: Speed and efficiency of heat energy movement through a substance.

heat control: See manifold heat control valve

heat control valve: See heat-control valve manifold heat control valve

heat-control valve: A valve which is controlled by temperature changes. When the ambient temperature is cold or the engine has not warmed up, it is closed so that some of the hot exhaust gases passes by the intake manifold to pre-heat the fuel mixture going to the cylinders. As the engine warms up, the valve opens up and no exhaust gases pass by the intake manifold. If the valve does not operate properly, the engine has difficulty in start up or the fuel may cause vapor locking.

heat cracking: A pattern of small, irregular cracks (e.g., on brake discs)

heat crossover: A passage from one exhaust manifold up, over, and under the carburetor and on to the other manifold. Usually found on V-8 or V-6 engines. This crossover provides heat to the carburetor during engine warmup.

heat dam: A thin groove cut into the head of a piston between the top ring groove and the top of the piston. The heat, instead of passing through the aluminum of the piston to the ring, encounters the heat dam. This helps to minimize heat transfer.

heated air inlet system: (HAI) a system that operates during cold weather and cold start. Brings warm, filtered air into the engine to control the volume of air entering the engine, vaporize the fuel better and reduce HC and CO emissions

heated exhaust gas oxygen sensor: (HEGO) an EGO sensor with a heating element

heated intake: A device that helps to vaporize the gasoline in a cold engine. The thermostat in the air cleaner horn is connected to the outside of the exhaust manifold. When the engine is cold, the thermostat closes a damper in the air cleaner horn so that air going to the carburetor does not come through the open end of the horn. Instead the air comes from above the hot exhaust manifold. As the engine warms up, the thermostat opens the damper so that air is taken in from the end of the horn.

heated rear window: A rear window with a heating element that demists (defogs) inside and defrosts (deices) the outside either by fine wires embedded or etched in the glass or by a heater

and fan.

heated tool welding: A welding process in which the parts to be welded are pressed against a heated plate and subsequently pressed together to produce a fusion weld

heated windshield: windshield with a heating element to facilitate defrosting (de-icing)

heater: A device which gives off heat. In automobiles, it heats the interior of the vehicle. In a water-cooled engine the coolant is channelled through the heater in the passenger compartment. Some cars used an electric or gasoline heater because they had no engine coolant (e.g., the Volkswagen Beetle). Also see backlight heater block heater cylinder block heater engine block heater inlet manifold heater intake manifold heater manifold heater parking heater rear window heater system heater air pipe: A channel section incorporated into the side member or other structural sections that is designed to provide a flow of warm air into the interior of the vehicle, above all into the footwells (e.g., as used on the VW Beetle)

heater blower: electric fan to boost heating and ventilation. Also called "heater fan"

heater fan: electric fan to boost heating and ventilation. Also called "heater blower"

heater flange: heating element for preheating the intake air in small diesel engines

heater plug: See glow plug

heater-plug indicator: See glow plug indicator

heater system: See rear window heater system

heat exchanger: A device, such as a radiator, used either to cool or heat by transferring heat from one object to another.

heat index: A number representing the effect of temperature and humidity on humans by combining the two variables into an apparent temperature. Introduced as a replacement for the temperature-humidity index. Later replaced by the Canadian introduced Humidex

heating: See rear window heating

heat of condensation: The heat liberated by a unit mass of gas at its boiling point as it condenses to a liquid. Equal to the heat of vaporization

heat of vaporization: The heat absorbed per unit mass of a given material at its boiling point that completely converts the material to a gas at the same temp. Equal to heat of condensation

heat path: The path along which heat passes from the spark plug tip to the water jacket

heat range: Refers to the operating temperature of a given style of spark plug. Plugs are made to operate at different temperatures depending upon the thickness and length of the porcelain insulator as measured from the sealing ring down to the tip. In this way it

transfers heat from the combustion chamber to the cylinder head. The speed at which it transfers heat is considered in terms of hot and cold plugs. A hot plug transfers heat slowly, causing the plug to operate at a higher temperature. A cold plug transfers heat more quickly, thus operating at a lower temperature. If a plug is too cold, it will foul. If it is too hot, it will cause preignition.

heat range reserve: the distance to the start of pre-ignition under further increasing thermal loading of the spark plug. This reserve is expressed in degrees crankshaft, the amount by which the factory-set ignition timing can be further advanced without preignition occurring

heat riser: [1] An area, surrounding a portion of the intake manifold, through which exhaust gases can pass to heat the fuel mixture during warmup. [2] The flapper in the exhaust manifold that is closed when the engine is cold, causing hot exhaust gases to heat the inlet manifold, thus providing better cold engine operation; a thermostatic spring opens the flapper when the engine warms up

heat shield: A sheet metal part, usually reflective, often asbestos-lined. It protects heat-sensitive components from heat radiation of the exhaust system. Also called "heat shroud." Also see grass heat shield heat shroud: See heat shield

heat shrinking: shrinking dents in panels using a gas welder to heat local areas of the dents

heat shrink tube: A thin, rubber-like hose through which bare an electrical wire is placed. When the tube is heated, it shrinks to fit the wire, thus protecting the wire from touching other wires, etc.

heat sink: heat removing component, such as the fins on an air-cooled cylinder

heat soak: heat from the engine warming the carburetor and other parts of the fuel system which can cause vapor lock and may make restarting difficult

heat transfer: The transfer of thermal energy from one material to another by means of thermal conduction, convection or radiation; heat transfer is possible only from a high to a low temperature level

heat treatment: A combination of heating and cooling operations timed and applied to a metal in a solid state in a way that will produce desired properties.

heaves: See frost heaves

heavy: See tail heavy

heavy braking: The action of applying the brakes fast and hard especially during an emergency stop. Opposite to light braking

heavy cable: Cable that is used for severe service where high strength is required. Opposite to light cable

heavy clutch: having a stiff operation, e.g., requiring considerable effort to push down the pedal on cars and trucks; or squeeze the lever on motorcycles. Opposite to light clutch

heavy-duty: (HD) Something that is built for heavy loads or severe use. Opposite to light-duty

heavy-duty diagonal cutting pliers: diagonal cutting pliers with a special joint and handle design for extra cutting power

heavy-duty end cutting pliers: end cutting pliers with a special joint and handle design for extra cutting power

heavy-duty ring wrench: A strong single end box wrench for use with a tubular handle. It can be used without the handle for quickly spinning on nuts or, with the handle slipped on, for final tightening or reaching otherwise inaccessible nuts

heavy-duty truck: vehicle weighing from 26,001 to 33,001 lbs. Also included off-highway trucks. Also see medium-duty truck light-duty truck heavy-duty wrench: A tool which can withstand severe use (and abuse) before breaking

heavy film build: excessive thickness of paint coating

heavy foot: To drive at full throttle or high speeds as though the driver's foot were very heavy so that the natural pressure of the foot against the throttle pedal caused high speeds

heavy goods vehicle: (HGV) A British term expressing a vehicle capable of carrying heavy loads and requiring a special licence to drive HGV licence

heavy paint: thickly coated. Opposite of light paint

heavy phosphating: application of extremely heavy phosphate coatings

heavy sheet metal: Thick sheet metal for severe use beyond the average. Opposite of light sheet metal

heavy side pattern: An oval spray pattern that is thicker toward the left or right hand side, i.e., it takes the shape of a crescent oriented towards the right or left. This is often caused by a clogged horn hole at the air cap of the spray gun

heavy steering: having a stiff operation, e.g., requiring considerable effort to turn the steering wheel. Opposite of light steering

heavy traffic: A road with a lot of moving vehicles. Opposite of light traffic

heavy yellow boot: A Denver boot

heel: [1] The end of the brake shoe which rests against the anchor pin. See brake shoe heel. [2] The wide end of a tapered gear tooth such as found in the differential gears. See tooth heel. [3] The rubbing block on the contact breaker lever. [4] A bead heel. [5] The inclination of a ship to one side. Also see cam heel heel and toe: A driving technique where the driver places the left side or the toes of his right foot on the brake pedal and the right side or the heel of his right foot on the throttle pedal so that he can simultaneously brake and blip the throttle for a downshift. This is done to lessen the strain on the gearbox and drivetrain and makes for smoother driving.

heel and toe wear: Uneven wear of tread blocks on a tire. The trailing edge of the block often tends to wear at a faster rate that the leading edge.

heelboard: The vertical transverse sheet metal panel running across the width of the car interior at the front edge of the rear seat well; this panel links the rear seat well to the

floorpan and provides rigidity for both panels. Also called "heel plate." Compare toeboard

heel dolly: A dolly in the form of a heel of a foot to shape and straighten dented panels, usually by holding the dolly behind the metal to be shaped and hammering the metal.

heel plate: The vertical transverse sheet metal panel running across the width of the car interior at the front edge of the rear seat well; this panel links the rear seat well to the floorpan and provides rigidity for both panels. Also called "heelboard." Compare toeboard

HEGO: Acronym for "heated exhaust gas oxygen." See HEGO sensor

HEGO sensor: A device which detects heated exhaust gas oxygen.

HEI: Acronym for "high energy ignition"

HEI-EST: Acronym for high energy ignition system with electronic spark timing

height: See clearance height crush height flange height installed height metacentric height ride height section height thread height height adjustable steering column: A steering column which can be lengthened or shortened to suit the individual driver

height corrector: An automatic leveling control in hydropneumatic suspension systems

height hamper pitch control: See bump stop

height regulator: An automatic leveling control in hydropneumatic suspension systems

heim joint: An extremely rigid articulating joint, commonly known as a "spherical rod-end," used in any precision linkage. Heim joints are often used in the suspension links of race cars because they locate wheels very precisely.

helical: A spiralling shape such as that made by a coil spring. In the shape of a helix. Also see double helical gear helical differential: Virtually all gears in modern cars are cut with a spiral helix angle rather than straight meshing. Straight gears are simpler to manufacture, but are extremely noisy.

helical gear: A gear that has the teeth cut at an angle to the center line of the gear. This kind of gear is useful because there is no chance of intermittent tooth-to-tooth operation because there are at least two teeth engaged at any time. Also helical gears tend to operate quieter than straight-cut gears. Also see double helical gear helical spring lock washer: A locking device for threaded fasteners

helical teeth:

curved gear teeth on the edge of a gearwheel, cut at an angle to its axis

Helicoil: A trade name for a coil-type thread insert, commonly used to replace a stripped spark plug thread

helium leak test: A pressure test using helium

helix: A spiral, like the thread on a screw or a coil spring in a suspension system

helm: Steering wheel installed on the bridge or wheelhouse of a ship to turn the rudder during manoeuvering and navigation

helmet: [1] A protective device for the head of bicycle and motorcycle riders as well as race car drivers. [2] A protecting hood which fits over the arc welder's head, provided with a lens of safety glass through which the operator may safely observe the electric arc. Also see full face helmet open face helmet helmet connector: A special type of lug for connecting a battery with tapered terminal posts. Also called "helmet lug."

helmet hair: The condition of a person's hair after wearing a helmet for a period of time. Short hair tends to stand on end while long hair tangles and/or becomes flat.

helmet lug: A special type of lug for connecting a battery with tapered terminal posts. Also called "helmet connector."

helper leaf:

An additional spring device (usually another leaf spring) which permits a greater load on the axle. Also called "helper leaf."

helper spring: An additional spring device (usually another leaf spring) which permits a greater load on the axle. Also called "helper leaf."

hemi: Engine using hemispherical -shaped (half of a globe or sphere) combustion chambers. The valves are cocked at 45 degrees from the piston top. Mopars, despite their fame, are not the only cars with hemi heads. See engine type.

hemi head: See hemi.

hemispherical combustion chamber: A round, dome-shaped combustion chamber. This shape permits larger valves and straighter intake and exhaust ports for improved breathing. Its small surface area in comparison to volume reduces the amount of heat loss. It is used in high performance cars and racing engines.

henry: (H) A unit of inductance, equal to the inductance of a circuit in which the variation of current at the rate of one ampere per second induces an electromotive force of one volt. The term was named after US physicist, J. Henry (1797-1878)

herringbone gear: See herringbone gears.

herringbone gears: Two helical gears operating together and so placed that the angle of the teeth form a "V" shape. See double helical gear

hesitation: The term used to describe a problem in drivability. The engine momentarily fails to respond to a push on the accelerator. The cause is usually a lean fuel-air mixture (i.e., more air than fuel) or retarded timing.

hexagon: See double hexagon socket

hexagonal: having six sides

hexagonal bolster: A tool that allows a screwdriver to be turned with a wrench for extra torque to loosen tight screws

hexagonal collar: A tool that allows a screwdriver to be turned with a wrench for extra torque to loosen tight screws

hexagon bit: A screwdriver bit with six sides

hexagon bolt: A bolt with a six-sided head

hexagon key: A key for hexagon recess screws, 90° offset at one end. Also called an Allen key

hexagon screwdriver: See ball end hexagon screwdriver

hexagon socket: See double hexagon socket

hex bit: A screwdriver bit with six sides

hex bolt: A bolt with a six-sided head

hex key:

A key for hexagon recess screws, 90° offset at one end. Also called an Allen key

hex wrench: See Allen Wrench.">

Hg: Chemical symbol for mercury

HGV: Acronym for heavy goods vehicle

h.f.s.: Abbreviation for "heated front seat" as found in advertisements

hidden wiper: A wiper system with a parking position below the normal visibility range

hide-away headlights: See concealed headlights

hideaway wiper: A wiper system with a parking position below the normal visibility range

hiding: The ability of a paint to obscure the surface to which it is applied.

HIF carburetor: type of SU carburetor with a horizontal integral float chamber

highball: A term used in car sales, the practice of stating a very high trade-in price to a customer who is known or expected to be shopping around, comparing prices. When the customer finds that other dealers cannot match the trade-in price, he will return to the original dealer, only to be told that the inflated figure was a mistake (e.g., based on wrong assumptions as to the trade-in's clutch condition, etc.). Many customers will then accept a new, lower price because they are tired of shopping around.

Also see lowball high beam: All cars have at least two levels of lighting for night driving. The low beam is used when there are other vehicles approaching or when you are following another vehicle. The high beam is used when driving on poorly lit roads where there is no visible traffic. The high beam light may be an integral part of the headlight assembly or is the inboard light when there are two lamps on each side of the vehicle. When the lamps are stacked vertically, the high beam is the upper one. When the high beam switch is activated, the low beam lights may or may not be switched off. In a system with factory installed day-time running lights, the high beam light is illuminated at a lower intensity. The British term for "high beam" is "main beam."

high beam indicator: A blue light on the instrument panel which comes on when the high beams are activated. Also called "beam indicator." The British term is "main beam indicator."

high-build filler: A spray primer that leaves a relatively thick coat on the panel surface to cover up minor imperfections that would otherwise show up very prominently in the final color coat

high-build galvanizing: A galvanizing process in which extremely heavy zinc coatings are applied

high-camshaft engine: See hc engine

high carbon steel: A very hard steel, as opposed to plain carbon steel. Hypereutectoid steels containing more than 0.8% carbon. Such steels consist of iron carbide (cementite) and pearlite when slow cooled. They are capable of being heat treated to high hardness, but tend to be brittle. Used for metal working formers and fine edge cutting tools (e.g., files)

High-centered: vehicle is stationary because the driving wheels are no longer touching the ground.

high center rim: A raised center rim design, used in the cts wheel

high compression head: A cylinder head with a smaller combustion chamber area thereby raising the compression. The head can be custom built or can be a stock head milled (cut) down.

high crown panel: A panel shape that curves rapidly in all directions, e.g., around the headlights of older cars. The opposite is low crown panel

high crown spoon: A spoon with a broad working surface and a heavily rounded tip that is ideal for using as a dolly or a lever in confined areas, such as headlight housings or rounded body sections above the waistline

high-density polyethylene: (HDPE) A very tough, chemically resistant thermoplastic, with a "soapy" touch; e.g., used for blow-molded parts such as fuel tanks or other moldings, such as bumpers

high energy battery: An innovative battery type developed for electric cars

high energy coil: A coil which generates higher ignition voltage and/or offers increased spark efficiency; ballasted

high energy ignition: (HEI) an electronic ignition system used by GM

high energy ignition system: (HEI) An ignition system which provides more ignition power (higher voltage at higher amperage) than normal systems; a typical HEI includes an electronic control unit and magnetic pick-up in combination with mechanical ignition timing

high energy ignition system with electronic spark timing:

(HEI-EST) A system consists of an electronic distributor, with the ignition coil mounted on the distributor cap on 6- and 8-cylinder models or externally on 4cylinder models; the ignition timing is performed electronically by the electronic control module. (Used on several GM models since 1983.)

high gear: The top gear or the cruising gear of a transmission. It is usually the highest number, i.e., fifth gear of a five-speed transmission.

high-geared: [1] A transmission (even like the chain system on a bicycle) where a large gear drives a small one. The larger the drive gear and the smaller the driven gear the higher the gear ratio. It will result in high speed, but is poor for getting started from a stop. [2] A vehicle's transmission system which has a higher than usual gearing, to improve fuel economy.

high gloss: very shiny, bright appearance

high impedance voltmeter: A voltmeter with high opposition to the flow of electrical current. Good for reading circuits with low current flow, such as found in the CCC system

high leverage diagonal cutting pliers: diagonal cutting pliers with special joint and handle design for extra cutting power

high leverage end cutting pliers: End cutting pliers with special joint and handle design for extra cutting power

high lift rocker arm: See high lift rocker arms.

high lift rocker arms: Custom rocker arms designed so that a standard lift of the push rod will depress or open the valve somewhat more than the stock lifter.

high load condition:

Occurs when the air conditioner system must operate continuously at maximum capacity to supply enough cold air

high/low range gearbox: See dual-range gearbox

high/low range transmission: See dual-range transmission

high-mounted brake light: Third brake light mounted in the middle of the rear window or on some cars integrated in the trailing edge of the rear deck spoiler

high-performance: producing better than average results

high-performance header: A special exhaust manifold, which is not made of cast iron as usual, but of specially designed, curved and welded steel tubes, to produce a smooth flow path for the exhaust gases, avoiding any sharp bends; less heavy, less sturdy and more expensive than an ordinary manifold; usually replaces the down pipe

high pressure: Operating under a lot of pressure e.g., braking systems or diesel fuel injection

high pressure foaming: A process in which plastics are foamed under high pressure (6-50 bar). The opposite is low-pressure foaming

high pressure line: The line carrying high pressure liquid and gas from the compressor outlet to the expansion valve inlet

high pressure relief valve: Located somewhere on the high side of the air conditioning system often next to the receiver drier this safety valve protects the system against excessive pressure

high revs: Towards the top end of the scale of engine revolutions

highrise manifold: See high-rise manifold.

high-rise manifold: An intake manifold designed to mount the carburetor or carburetors, considerably higher above the engine than is done in the standard manifold. This is done to improve the angle at which the fuel is delivered.

high side: In air conditioning systems, the high side (i.e., high pressure side or discharge side) is located between the compressor and expansion valve or orifice tube and includes the condenser. The opposite is low side

high-side service valve: A device, located on the discharge or high side of the compressor, at which high side pressure can be checked and other service operations can be performed

high-speed bleeds: Main air bleeds; located in the air horn

high-speed circuit: Main metering system

high speed direct injection: (HSDI) A system for rapid injection of fuel into a diesel engine

high spot: A raised area on a panel surface

high-tension: (HT) capable of operating at a relatively high voltage

high-tension circuit:

See secondary circuit

high-tension distributor: A distributor, in electronically controlled ignition systems, which has no controlling functions or advance mechanism

high tension lead: High voltage wire from the ignition coil. May also indicate the secondary wire from the ignition coil to the distributor and wires from the distributor to the spark plugs.

high tension leads: See high-tension leads.

high-tension leads: The wire which goes from the ignition coil to the distributor and the wires which go from the distributor to each of the spark plugs. See high tension lead.

high-tension winding: See secondary winding

high-voltage distribution: See static high-voltage distribution

high-voltage reserve: The difference between the available ignition voltage and the ignition voltage required at a given moment

highway: Any public road outside the cities with a foundation and a hard surface. Originally, the highway was a "way higher than the ground," e.g., as opposed to stage coach tracks. Since similar speed limits exist in the USA and Canada for all types of highways, both single or multilane (usually between 50 and 70 mph or 80 and 110 kph), the terms "highway driving speeds" and "highway driving" should not be associated with speeds higher than 70 mph (110 kph). Also see expressway freeway motorway

highway bar: An auxiliary lateral piece of metal (usually chromed for good appearance) fitted to the front down tubes or frame. Folding pegs may be found at each end. The bar allows the rider to position his feet straight ahead for variety in leg position when riding long distances. Also called "hi-way bar."

Highway Code: official British code of conduct for all road users

highway peg: A folding footrest which is mounted on the ends of a highway bar

hillholder: A mechanically or electromechanically engaged device for preventing accidental rearward movement of a vehicle prior to driving away; found mainly in automatic transmissions

Hillman: A model of automobile manufactured in England

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hinge: See door hinge

hinge bow: See main bow

hinged-caliper disc brake: An old disc brake design formerly used on motor cycles; superseded by slidingcaliper disc brakes

hinged quarter window: A rear side window between the B-post and the C-post and/or in the case of station wagons, between the C-post and the D-post. It is provided with hinges to allow it to be opened

hinge facing:

A part of the door frame that includes the bracing and threaded plate for mounting the hinge to the door. It is not to be confused with the hinge panel that is part of the hinge pillar of the body shell.

hinge panel: sheet metal panel spot-welded to the A-post or rear of the front fender that accommodates the hinges for the front door

hinge pillar: The vertical structural element that carries the front door hinges; the upper end of the hinge pillar is usually the side of the windshield frame. Also called A-pillar

hinge pillar reinforcement: The vertical section behind the visible A-pillar

hinge plate: The reinforcing plate between the hinge and the door panel which distributes the forces acting on the hinge bolts over a larger area of the panel

hinge post: See hinge pillar

hinge tapping plate: The threaded plate housed in a sheet metal cage spot-welded to the hinge pillar or, in some cases, to the door frame; the door is bolted to this plate and may be adjusted within certain limits, as the plate can be moved about in its sheet metal cage

hip belt: See lap belt

hi perf: Abbreviation for "high performance," also called "hi-po" or "hi po."

hi po: See hi-po.

hi-po:

See hi perf.

Hispano Suiza: A brand of vehicle of which the 1925-1948 models are classic cars.

history: See full service history

hitch: [1] To connect or couple up a motorhome or trailer to a towing vehicle. [2] The bracket used to connect a vehicle to a trailer or motorhome. See towing hitch

hitch ball: A metal ball with a bolt attached to it. It is secured to a bracket on a vehicle in order to mount a trailer hitch. British term is "towball"

hitch pin: A heat-treated, hi-strength steel pin ranging from a diameter of 7/16" to 1-1/4" and a length from 3-1/2" to 7". A flange is at one end and a hole (through which a hair pin can be inserted) at the other end. The hitch pin secures the hitch to the receiver.

hi-way bar: An auxiliary lateral piece of metal (usually chromed for good appearance) fitted to the front down tubes or frame. Folding pegs may be found at each end. The bar allows the rider to position his feet straight ahead for variety in leg position when riding long distances. Also called "highway bar."

hog: [1] A colloquial term for a Harley Davidson motorcycle. [2] A person who persists in driving by using the full lane or both lanes at a slow speed so that it is impossible to pass him. See road hog

hogging: Straining of the ship that tends to make the bow and stern lower than the middle portion (See Sagging)

hoist:

See chain hoist engine hoist hoisting rope: Flexible wire rope for lifting purposes, generally being of six strands with 19 wires in each strand and in most cases having a hemp rope at the center. Also called wire rope

hold: The large spaces below deck for the stowage of cargo. Also see intermediate hold holdback: A mark-up of a certain percentage that the dealer pays the manufacturer on each new car that is added to his stock; this amount is rebated to the dealer after the car is sold

hold ceiling: A covering usually of wood, placed over the tank top for its protection

hold down clamp: See battery hold down clamp distributor hold-down clamp hold-down clamp: See battery hold down clamp distributor hold-down clamp hold-down pin, spring and retainer: The most common method of retaining a brake shoe to the backing plate. The pin passes through the backing plate and brake shoe. The spring and retainer are fastened to the pin, which holds the shoe against the backing plate

holder: See

beverage holder bit holder brush holder bulb holder coin holder cup holder glass holder tap holder hold fitting: See air hold fitting

hold-in coil: A separate relay coil, such as the hold-in winding in a starter solenoid, which is energized by contacts that close when the relay pulls in, to hold the relay in its energized position after the original operating circuit has been broken. Also called "holding coil."

holding: See road holding

holding coil: A separate relay coil, such as the hold-in winding in a starter solenoid, which is energized by contacts that close when the relay pulls in, to hold the relay in its energized position after the original operating circuit has been broken. Also called "hold-in coil."

holding winding: A part of a relay designed to hold it in the on-position. Compare pull-in winding. Also called "hold-in winding."

hold-in winding: A part of a relay designed to hold it in the on-position. Compare pull-in winding. Also called "holding winding."

hold-off valve: See metering valve

hold-open:

See door hold-open spring

hold-open spring: See door hold-open spring

hold out: The ability of a surface to keep the top layer of paint from sinking in or being absorbed

hole: See access hole bolt hole countersunk hole cubby hole drain hole limber hole oil filter hole pilot hole radiator fill hole spurt hole squirt hole stud hole valve hole wheel bolt hole hole circle: See wheel bolt hole circle.

hole cutter: See variable hole cutter

hole cutting snips: Snips with pointed cutting blades for cutting holes in sheet metal material

hole plug: See core hole plug

hole punch:

[1] A tool like pliers used in autobody repair to form holes along the edge of a repair panel; the panel can then be plug-welded to the substructure at these holes [2] A tool for poking holes in leather and fabric

holesaw: A cylindrical-shaped saw for use with power tools, for cutting holes in sheet metal material, e.g., in car bodies for installation of aerials

hole theory: Assumption that movement of a free electron from atom to atom leaves a hole in the atom it left, which is filled by another free electron

hollowing: The action of forming a deeply crowned panel from a piece of sheet steel on a hollowing block or a shot bag, using special mallets and hammers

hollowing block: A shaped wooden block on which a desired shape is produced by hammering

holographic combiner: A semi-reflecting layer embedded in laminated windscreen glass; used for head-up displays

home: See limp home mobile home homofocal headlight: A type of headlight with two reflectors, the inner one has a shorter focal length than the main one

homokinetic joint: See constant velocity joint

homologation: An official recognition of a special version of a standard car as a production model, to make it eligible for racing

Honda: An automobile and motorcycle manufacturer in Japan

Click for books on Honda

Honda Accord: A model of automobile manufactured by Honda Click for books on Honda Accord Honda Civic: A model of automobile manufactured by Honda

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Honda CRX: A model of automobile manufactured by Honda

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Honda Del Sol: A model of automobile manufactured by Honda Click for books on Honda Del Sol Honda Passport: A model of automobile manufactured by Honda Click for books on Honda Passport Honda Prelude: A model of automobile manufactured by Honda Click for books on Honda Prelude Honda S2000: A model of automobile manufactured by Honda Click for books on Honda S2000 hone: [1] To remove metal with a fine grit abrasive stone in order to meet precise tolerances. [2] The device or tool which is rotated in a cylinder to remove slight imperfections in the cylinder wall. See cylinder hone.

honeycomb: A pattern of hexagonal shapes, like bees' cells. Also see ceramic honeycomb

honing: The precision machining process used to resurface bores and shafts

honing stone: A tool used for the final smoothing operation, e.g., when repairing a cylinder wall

hood: [1] The part of the vehicle body which covers the top of the engine in front engine vehicles. In mid-engine cars the panel which conceals the engine is called the "engine cover" or access panel. In rear-engine cars the panel which conceals the engine is called a "deck lid." [2] A British term for the roof of a convertible. Also see fabric hood hydraulic hood power hood hood badge: An emblem reflecting the name or logo of the car manufacturer and is secured to the front end of the hood. Some are bolted or pasted flat to the front, others stand upright on fixed or pivoting rods.

hood bar: A British term for one of at least four struts that support a roof. Usually made of tubular or sheet steel

hood bow: A British term for one of at least four struts that support a roof. Usually made of tubular or sheet steel

hood bump rubber: A thick rubber strip which is secured to the vertical panel on which the hood is lowered

hood bumper: See hood bump rubber

hood landing panel:

The panel on which the hood is lowered. It also houses the hood locking mechanism

hood liner: A material secured to the underside of the hood to provide sound insulation. It is usually made of polyethylene, polypropylene, polyurethane, or a fabric of polyester

hood lock: A mechanism which is made of a peg on the front end of the underside of the hood and a sliding latch on the panel above the radiator. The sliding latch is released by a lever under the hood or by a lever under the dash in the passenger compartment. See hood release

hood pin: A pin designed to hold a hood closed.

hood pin kit: A pair of hood pins and brackets which secure the hood of competition cars and "would-be" competition cars

hood pins: Pins designed to hold a hood closed.

hood release: A device which releases the hood lock. The trigger, located under the dash in the passenger compartment, is attached to a cable which controls the hood lock.

hood rod: A bar or rod which keeps the hood in an open position. The rod is located under the hood. Once the hood is raised, the rod is swung upright and the free end is placed in a notch or hole in the hood to keep it in place

hood stick: An old British term for hood bar

hood tape: A fabric covered beading which keeps the hood on older cars from rubbing on the paint below them.

hooke joint: See cardan joint.

hooke universal: See cardan joint.

hook: The curved, dropped section of a set of turned-down handlebars of a bicycle.

hooks: The curved, dropped sections of a set of turned-down handlebars of a bicycle.

hook up: [1] To connect. [2] To meet with someone.

hooped: A colloquial expression meaning damaged or out of order as in Your engine is hooped.

hop: See wheel hop.

hopping: See code hopping

hopping up: Increasing engine performance through various modifications.

Horch: On 14 November 1899, August Horch (1868-1951) established the company A. Horch & Cie. in the Ehrenfeld district of Cologne, Germany. Here he developed his first car, which was completed at the beginning of 1901. The company moved to Reichenbach in Saxony in March 1902 and converted to a share-issuing company two years later. On May 10, 1904, A. Horch & Cie. Motorwagen-Werke AG was established in Zwickau. The 1925-1948 models are classic cars.

horizontal: Lying flat, not upright

horizontal adjuster: A screw for adjusting the lateral aim of the headlight beam

horizontal draft carburetor: See side draft carburetor

horizontal draught carburetor: See side draft carburetor

horizontal keiretsu: A keiretsu system where the keiretsu member companies have shareholdings in each other. The opposite is vertical keiretsu. The member companies own relatively small chunks of shares in one another and are each centered on a core bank; the keiretsu system helps insulate company managements from stock market fluctuations and take-over attempts, allowing long-term planning and engagement in innovative projects; it is a key element of the automotive industry in Japan

horizontally opposed engine: An engine possessing two banks of cylinders that are placed flat or 180 degrees apart. This configuration gives a lower center of gravity which improves handling. As well it has a lower hood height to improve aerodynamics. Also called a "boxer" engine. Also see flat engine horizontal position: A weld performed on a horizontal seam at least partially on a vertical surface.

horn: A device for sounding an alarm. On some entry level vehicles, a single horn makes a high pitch beep. On more expensive vehicles, the sound is made with two or more horns. The sound is made by an electrical charge which activates and deactivates a coil. The sound is then magnified by the shape of the horn. Large truck horns make a very loud noise because the sound is made by passing compressed air through the

sounding device. A Claxton horn makes a sound that resembles the word "A-hoogah." Also see air cleaner horn air horn blast horn bull horn bumper horn claxton horn dual-tone horn ocean liner blast horn overrider two-tone horn horn boss: A relatively large pad in the centre of the steering wheel which sounds the horn when depressed

horn button: A relatively small button on the steering wheel or the end of the signal light lever which sounds the horn when depressed

horn rim steering wheel: A steering wheel which had a thin metal strip on the inside of the rim. When it was pressed, the horn sounded.

horn ring: A thin chrome ring which was smaller than the steering wheel which sounded the horn when pressed. This style was found on older vehicles.

horn switch: An electrical device which engages the horn.

horsepower: (HP) A measurement of the engine's ability to perform work. One horsepower is defined as the ability to lift 33,000 pounds one foot in one minute. To find horsepower, the total rate of work in foot pounds accomplished is divided by 33,000. If a machine was lifting 100 pounds 660 feet per minute, its total rate of work would be 66,000 foot pounds per minute. Divide this by 33,000 foot pounds per minute to arrive at 2 horsepower. In metric terms, it is the ability to raise 250 kilograms a distance of 30 centimeters in one second. It is also equal to 745.7 watts.

See brake horsepower friction horsepower indicated horsepower net horsepower rated horsepower road load horsepower SAE gross horsepower SAE horsepower SAE net horsepower horsepower screw: A screw in the cover of adjustable wastegates to vary the spring height, which adjusts boost pressure; screwing down adds HP but may destroy the engine

horsepower weight factor: See horsepower-weight factor.

horsepower-weight factor: The relationship between the total weight of the vehicle and the horsepower available. By dividing the weight by the horsepower, the number of pounds to be moved by one horsepower is determined. This factor has a great effect on acceleration, gas mileage, and all around performance.

hose: A flexible tube used to convey liquid. In most automobiles, hoses connected independent components like the radiator, water pump, and heater. Also see acetylene hose braided hose brake hose overflow hose radiator hose shark tooth pliers radiator hose vacuum hose hose clamp: An adjustable metal ring, wire, or band placed around a hose where it connects to a metal pipe, to prevent leaks and to keep the hose in place. Hose clamps are tightened in one of three ways. In single wire clamps, it is tightened by spring tension of the clamp. In worm-gear clamps, by a worm screw. In strap-and-bolt clamps, by a screw. The British term is "hose clip."

hose clamp installer: A special tool for the installation of ear-type clamps, used e.g., on some types of CV joint boots, filters, cooling systems, and vacuum lines

hose clamp pliers: A special tool used to remove and install hose clamps

hose clamps: See hose clamp

hose clip: A British term for hose clamp

hose clip installer: British term for hose clamp installer

hose clip pliers: British term for hose clamp pliers

hose pinch-off pliers: A special tool to pinch off hoses when servicing the cooling system; pivoting jaws squeeze hoses shut so there is no need to drain the system

hot: Connected to the battery positive terminal, energized

hot cap: The conventional method of retreading in which uncured rubber is added to a buffed casing and cured in the mold at temperatures of approximately 290°-300°F. This temperature allows uncured rubber to flow in the matrix forming the tread design during vulcanization. Also see cold cap Hotchkiss:

A brand of vehicle of which the 1925-1948 models, with required application, are classic cars.

hotchkiss drive: The method of connecting the transmission output shaft to the differential pinion by using open driveshafts. The driving force of the rear wheels is transmitted to the frame through the rear springs or through link arms connecting the rear axle housing to of the vehicle. Combines both steering axis and camber angles. hotchkiss suspension: A live-axle rear suspension in which leaf springs handle both the axle's springing and its location. See hotchkiss drive.

hot dip: to coat metal parts by immersion in molten metal, such as tin or zinc

hot-dip aluminizing: The deposition of aluminium coatings by hot dipping

hot-dip galvanize: to apply a zinc coating by hot dipping

hot gas: The state of the refrigerant between the compressor and the condenser

hot gas welding: A welding process involving the joining of thermoplastic materials by softening with a jet of hot air, then joining them at the softened points

hot grip: Electrically heated handlebar grips used on snowmobiles

hot hatch: high-performance hatchback

hot idle compensator:

A small air valve that allows fresh air to enter the manifold and lean the mixture when the engine is hot

hot lash: The valve adjustment on a engine equipped with solid lifters

hot plug: A spark plug which has a long insulator nose which absorbs more heat and dissipates heat slowly. A colder plug is used in a hot engine while a hot plug is used in a cold engine. Thus if the plugs are fouling too much, try a hotter plug. If the plugs are coming out white, try a colder plug. The ideal color of the center insulator nose should be a light chocolate brown.

hot rod: A production car that has been modified by the owner in the attempt to increase acceleration and top end speed. Although the term can be applied to any modified car, it is usually reserved for vehicles produced from 1930 to 1940's. Typically the engine is modified, and some body panels removed. Many were painted with a design of flames behind the front wheels to give the appearance that this vehicle was "hot" -- thus the name.

hot soak: Occurs when the engine is topped during hot weather or after it has been run long enough to be fully warmed up; also the period during which the phenomenon known as percolation occurs

hot spark plug: See hot plug

hot spot: [1] Refers to a comparatively thin section or area of the wall between the intake and exhaust manifold of an engine, the purpose being to allow the hot exhaust gases to heat the comparatively cool incoming mixture. [2] Also used to designate local areas of the cooling system which have above average temperature.

hot spraying: A spray process in which paint is preheated in a paint container so that its viscosity is reduced and it can be atomized without being diluted with a solvent

hot start: The starting of a hot engine may be difficult if it has been stopped for a few minutes; the accumulation of gasoline vapor in the air filter and inlet manifold, caused by the rise in engine temperature when left standing when hot, can be dissipated by slowly pressing the accelerator right down and turning the engine over until it fires

hot start enrichment: A fuel mixture enrichment when starting a hot engine

hot starting: See hot start

hot-start pulse relay: A fuel injection component which operates the cold-start valve intermittently to improve starting when the engine is hot; installed in the cold-start valve circuit in some CIS-equipped engines

hot water vacuum valve: A vacuum actuated valve which controls the flow of coolant through the heater core

hot wax: wax-based material used for hot-wax flooding

hot-wax flooding: A special cavity-sealing process developed by Volkswagen, which uses a solventfree wax injected into the cavities of bodies preheated to 60°C

hot-wax flooding unit: A device for hot-wax flooding consisting of a preheating zone, a flooding zone and a drip-off zone

hot wire: [1] The positive wire coming from the battery or generating system. [2] As a verb, it indicates the starting procedure when by-passing the ignition key and normal starting procedure.

hot-wire airflow meter: A constant-temperature hot-wire sensing device, used in electronic fuel injection systems, which measures the rate of a mass airflow into the engine by measuring the current needed to keep the hot wire at the same temperature

hot-wire element: An element in a hot-wire air-flow meter

hot-wire sensor: See air mass sensor

hour capacity: See ampere hour capacity

house: See deck house full house pilot house wheel house house bridge: An erection fitted on the upper or superstructure deck of a ship. The officers' quarters, lounge are usually located in the bridge house

house panel: See wheel house panel

housing: A container or casing for mechanical components such as bearings, gears, etc. See axle casing axle housing bearing housing bell housing brake drum camshaft housing

clutch housing converter housing differential housing oil filter housing rear axle housing rear axle housing, banjo type rear axle housing, split type torque converter housing transmission extension housing transmission housing turbine housing valve body housing wheel housing housing banjo: See axle housing banjo rear axle housing, banjo type housing split: See axle housing split rear axle housing, split type hovercraft: A ground vehicle that is supported by a cushion of air to reduce friction. As well as travelling on the land, hovercraft can travel on the sea or swampy terrain.

HP: Acronym for "horsepower."

HPV: Acronym for "Human Powered Vehicle."

HSDI: Acronym for "high speed direct injection" for a diesel engine

HT: [1] Acronym for "hardtop."

[2] Acronym for high-tension

HT circuit: See secondary circuit

HT distributor: A distributor, in electronically controlled ignition systems, which has no controlling functions or advance mechanism

HT lead: See spark plug wire

HT outlet: See coil tower

hub: [1] On a bicycle, the center of a wheel consisting of a shell to which spokes attach and contains an axle along with two sets of bearings, bearing cones, lockwasher, locknuts, and parts for attaching the wheel to the frame. [2] The base of a wheel with studs protruding from its face upon which the wheel itself is mounted to an automotive vehicle. Also see central locking hub freewheel hub freewheeling hub safety hubs splined hub wheel hub hub brake: Any type of brake (disc, drum, or coaster) that operates through the wheel hub rather than the rim.

hubcap: The covering that fits over the end of the wheel spindle to keep dust and water away from the wheel bearings and brakes. It is often a styling feature, but it also acts as a good container for keeping the lug nuts from being lost when changing tires. When a vehicle becomes stuck in the snow, it can also be used as a temporary shovel. Also called wheel cover.

Also see moon hub cap: See hubcap

hub carrier: [1] A part of the suspension system which carries a rear wheel hub on a front-wheel drive vehicle, or on a rear-wheel drive vehicle with independent rear suspension. [2] Another term for steering swivel

hub-center steering: Steering system in which the wheel pivots about its center point; the axle is normally fixed

hubcentric fit: A spigot mounted wheel

hublock: In 4-wheel-drive vehicles, it is inefficient to have the front wheels connected when not needed. Most older vehicles required a person to get out and manually switch each front hub. Now these hubs can be changed remotely with a switch inside the vehicle. Also see pulse vacuum hublock hubodometer: A register mounted on the axle hub which shows the distance the vehicle travelled. It is popular to record mileage for leasing of vehicles or tires particularly on trailers, since there is no other odometer present.

hub plate: The central element of a clutch driven plate which carries the splined hub

hub puller: A special tool, of both jaw and slide hammer design, used to remove wheel hubs on vehicles by a pulling action

HUD: An acronym for "heads up display" which is a system of mounting gauges so that the read-out is shown on the windshield. In this way the driver does not have to take his eyes off the road to see how his vehicle is performing.

Hudson: A brand of vehicle of which the 1929 Series L is a classic car. All Click for books 1948-49 models are milestone cars. The 1951-54 Hornet models on Hudson are milestone cars. hull: Body of a ship which floats on the water

Humber: A brand of vehicle of which the 1925-1948 models, with required application, are classic cars.

humidifying tower: The air saturator tower in salt spray test chambers

humidity: See relative humidity

humidity chamber: A test chamber for simulating tropical and subtropical conditions

humidex: (short for humidity index) is a number which combines the air temperature in Celsius and the amount of humidity in order to give a single number to represent the perceived discomfort of weather that is hot and humid. It was devised by Canadian meteorologists and first used in 1965. The humidex is widely used in Canada and has been accepted in a number of other countries. Range of humidex Degree of comfort Less than 29

No discomfort

30 to 39

Some discomfort

40 to 45

Great discomfort; avoid exertion

Above 45

Dangerous

Above 54 Heat stroke imminent The humidex is calculataed with the following formula: Humidex = (air temperature) + h where h = (0.5555)*(e - 10.0); e = 6.11 * exp(5417.7530 * ((1/273.16) - (1/dewpoint)))

hump: A raised portion on the rim bead seat of passenger car wheels, retaining the beads of an insufficiently inflated tubeless tire on the bead seats, thereby preventing the tire beads from jumping into the rim well. Also see flat hump hump rim outboard flat hump outboard round hump round hump safety bead seat safety rim hump mode: An operating condition where the transmitted torque in a viscous coupling rises to a value several times higher than the value produced in the so-called viscous mode, due to internal clamping, i.e., metal friction of the coupling discs

hump rim: designation for a rim featuring a safety contour (round hump, flat hump, combination hump) either on the outer or on both bead seats. This protection is particularly important with tubeless tires, where sudden deflation can occur if the tire beads leave the bead seats and drop into the well. Compare hump and safety bead seat

hundredweight: (cwt) An obsolete unit of weight measurement, used in some classic-car manuals. 1 British cwt = 5080 grams; 1 US cwt = 4535 grams

hunting: [1] The uneven running of an engine, due to air/fuel mixture being too rich. [2] The action of some automatic transmissions when a vehicle is climbing a hill. The transmission constantly shifts between fifth gear and fourth gear

hunting tooth: An extra, odd tooth on a gearwheel, designed to ensure the same teeth do not always mesh together, thus reducing wear

Hurst six-speed shifter: Upgraded shifter for manual transmissions which make the distance between gears shorter. The power band is more continuous from the bottom of first gear to the top of sixth. This means that when you shift, the amount of acceleration you experience will be more even throughout all the levels of the transmission. The result is that you can make the car accelerate faster and gain more control (through enhanced consistency) in turns or any application of power. Hurst also manufactures many other shifters with 2 to 6 gears for a variety of cars. Linda Vaughn has been their spokeswoman for many years.

HVAC: Acronym for "heating, ventilation, and air conditioning" system

H valve: A type of expansion valve used by Chrysler Corp

HVAN: Acronym for "Heavy Van" (e.g., Mitsubishi Canter).

hwy: Abbreviation for "highway."

hybrid car: A car with a hybrid propulsion system

hybrid propulsion: Two distinct but interdependent forms of propulsion, such as an electric motor and an internal combustion engine, or an electric motor with battery and fuel cells for energy storage

hybrid technology: Film circuits combined with integrated circuits, used especially for trigger boxes or electronic control units

Hydragas: See moulton Hydragas suspension

Hydragas suspension: See hydropneumatic suspension Moulton Hydragas suspension hydraulic: [1] When a quantity of water, oil, or other fluid is forced along one end of a line, it also forces against the other end of the line. Because these fluids (unlike a gas) cannot be compressed, when they are forced into a smaller cylinder they multiply the amount of force. Thus a driver can apply a small amount of force on the pedal or lever and a great amount of force is applied to the brake. Used in power steering, clutches, and brake systems. [2] When used as a verb, it means that oil or excessive gasoline has entered the combustion chamber so that when compression takes place, the fluid cannot be compressed. Something has to give and it is usually the connecting rod that bends. It is found in the expression, "the engine hydrauliced."

hydraulic accumulator: See accumulator (def. 3)

hydraulic actuator: Unit in an anti-lock brake system that can increase brake pressure, decrease brake pressure, or hold brake pressure steady based on signals it receives from the control module

hydraulic actuators: The hydraulically operated struts which control the movement of the wheels in an active ride suspension system

hydraulically-activated brakes: A motorcycle system where the brakes use hydraulic fluid instead of a cable. When the lever/pedal is squeezed/pressed, hydraulic fluid forces the pistons to put pressure on the brake pads which rub against the brake disc and cause enough friction to stop the bike. A master cylinder that contains the hydraulic fluid sits on the handlebar near the brake lever.

hydraulically-assisted brakes: See brake booster.

hydraulically-activated clutch: Found in a motorcycle, the clutch is engaged/disengaged via hydraulic fluid instead of a cable. When the lever is squeezed, hydraulic fluid forces the pushrod to disengage the clutch. A master cylinder that contains the hydraulic fluid sits on the handlebar near the clutch lever.

hydraulically-assisted clutch: A clutch operated by hydraulic pressure.

hydraulic assisted brakes: See brake booster.

hydraulic brakes: See brake booster.

hydraulic brake booster: hydraulic pressure supplied by the power steering pump, or a separate hydraulic pump, which is used to assist in applying the brakes; used on cars and on some trucks

hydraulic assisted brakes: Brakes operated by hydraulic pressure. See brake booster.

hydraulic braking system: Brakes operated by hydraulic pressure

hydraulic control block: A control valve assembly

hydraulic control unit: The portion of an anti-lock brake system that houses the solenoid valves and electro-hydraulic pump

hydraulic fluid: A special oil used in hydraulic systems, such as power steering, self-leveling suspension, to operate the system of master and slave cylinders. Also compare brake fluid and automatic transmission fluid

hydraulic hood: British term for hydraulic top

hydraulic jack: A device used to lift a vehicle by using hydraulic pressure.

hydraulic lift: A device used in a service garage to raise a vehicle so that a mechanic can look at or repair components under the vehicle.

hydraulic lifter: See hydraulic valve lifter.

hydraulic modulator: A device which regulates hydraulic fluid pressure in an ABS. Also see hydraulic control unit hydraulic pressure pump: An engine-driven pump which supplies oil under pressure to operate, e.g., power brakes or power-assisted steering

hydraulics: The study of pressure and flow in liquids. A hydraulic jack uses oil under high pressure to lift large objects more easily.

hydraulic tappet: British term for hydraulic valve lifter

hydraulic top:

A convertible top which is raised and lowered by a hydraulic system; depending on engineering, a hydraulic top can operate fast, silently, and with tremendous power. Also see power top tensile force hydraulic valve lifter: A lifter that uses hydraulic oil pressure to maintain no clearance between metal parts so that valve noise is reduced. Also it reduces wear on the valves and eliminates periodic valve adjustments.

hydraulic wedge: A hydraulic jack with ends designed to reach behind dented double panels and to press them back into shape by the hydraulic action of the wedge-shaped ends

Hydraulique Minerale: See liquide Hydraulique Minérale

hydroactive suspension: See hydropneumatic suspension

hydrocarbon: (HC) A compound made up of hydrogen and carbon (e.g., gasoline, petroleum products, etc.). Hydrocarbons are also found when gasoline is burned in an engine and thus produce visible smog even though hydrocarbons make up only 0.1% of emissions. Also see total hydrocarbons unburnt hydrocarbons hydrocarbon engine: An engine using petroleum products, such as gas, liquefied gas, gasoline, kerosene, or fuel oil as a fuel.

hydrocarbon plastics: Plastics based on resins made by the polymerization of monomers composed of carbon and hydrogen only

hydrocarbons:

See hydrocarbon

hydrodynamic clutch: See fluid coupling

hydrodynamic torque converter: See torque converter

hydroelectric power: See hydro-electric power.

hydro-electric power: Electricity produced by using the kinetic energy of water.

hydrofoil: A vessel which skims the surface of the water and the shaped pieces on the bottom of the vessel which act like "water wings" to give it lift.

hydrogen: A gas formed of the single element hydrogen. It is considered one of the most active gases. When combined with oxygen, it forms a very clean flame which, however, does not produce a very high temperature or very much heat.

hydrogen embrittlement: A process which results in a decrease of the toughness or ductility of a metal due to absorption of hydrogen

Hydrolastic: See moulton Hydrolastic suspension

Hydrolastic suspension: A proprietary suspension system incorporating a conical rubber spring compressed by hydraulic pressure; this system also provides a hydraulic interconnection between front and rear wheels on one side of the vehicle. Also see moulton Hydrolastic suspension

hydrometer: A device to determine the weight of a liquid. It is used to test battery electrolyte and the percentage of coolant in the cooling system.

hydroplaning: A phenomenon of driving when water builds up under the tire tread, causing it to lose contact with the road. Caused by speed, water depth, tread depth, and inflation pressure. Slowing down will usually restore normal tire contact with the road. Also called aquaplaning.

hydropneumatic suspension: A suspension system which uses a gas and a liquid which are separated by a flexible bladder. The setup causes the suspension to maintain a preset height. Used in Citroën cars.

hydropulser: A hydraulically operated system that can excite vibrations of various frequencies in a car; serves to find and eliminate noise sources

hydrostatically inflate: To inflate with water instead of air. Also see liquid ballast hydrostatic drive: See hydrostatic transmission

hydrostatic gauge: Gauges, such as gas tank gauge, in which the depth of the gas in the tank controls the air in the connecting line to the instrument, which registers the depth on a scale or dial

hydrostatic steering: A power steering system without mechanical steering links, but is controlled entirely by hydraulics

hydrostatic test:

pressure test using water

hydrostatic transmission: A drive by means of hydraulic motors, particularly where the drive is to each wheel of an off-road vehicle

hygroscopic: Something that tends to absorb moisture

hypoid axle: A driving axle with a hypoid gear

hypoid gear: A type of spiral bevel gear in which the drive pinion shaft is located below the center of the ring gear. This setup is used to lower the height of the driveshaft and thus lower the floor of the vehicle. hypoid oil: A special lubricant for hypoid gears

hysteresis: The energy lost and not returned, when tire materials are subjected to stress in any direction. Lost energy is converted to heat through molecular interaction, and since rubber has poor thermal conductivity, internal temperatures of a tire can build up rapidly under repeated flexing.

Hyundai: An automobile manufactured in Korea

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DICTIONARY OF AUTOMOTIVE TERMS "I" [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [Ic] [Id] [If] [Ig] [Ih] [Il] [Im] [In] [Ir] [Is] [It]

I: Short form for "injection" indicating that the engine is fuel-injected, e.g., GTi, EFi, 1.6i, SSEi

IAC: Acronym for idle air control valve

I&C systems: Acronym for "instrumentation and control systems"

IAR: Acronym for integral alternator/Regulator

IASCA: Acronym for "International Auto Sound Challenge Association."

I-beam: A steel beam that is shaped like the letter "I" when you look at the cross section

I-beam suspension: A suspension which uses an I-beam. The wheels on opposite sides of the vehicle are linked by a solid member, usually an I-beam but sometimes a tube. This minimizes the pieces needed for the suspension, but weighs slightly more, so is seldom used on high-performance vehicles. It was most common on older car front suspensions, but is now most commonly used on the rear of front-wheel-drive vehicles. Also see twin I-beam suspension I-beam axle:

See rigid axle

IC: See hall IC

ICE: Acronym for "in-car entertainment"

ice: See de-ice

ICEI: Acronym for "Internal Combustion Engine Institute, Inc."

IC engine: Acronym for "internal combustion engine"

icer: See de-icer

ice scraper: A small plastic hand-held implement for scraping frost and ice away from windshields and windows. A CD disc does the job even better because it always keeps its edge. Some ice scrapers are located at the end of a brush stick.

icing: A condition where ice forms at the edge of the carburetor throttle plate/butterfly. It restricts the flow of the fuel-air mixture when the throttle butterfly is at or near the idle position. It causes the engine to stall. Ice forms because of rapid vaporization of the fuel which lowers the temperature of the mixture and causes the moisture in the air to freeze. It can occur when the temperature is between -2 to 13°C (28 to 55° F) and the relative humidity is above 64%. It usually occurs after the engine is started and before it has reached operating temperature. Also see carburetor icing. icing switch:

A device that cuts off the compressor when the evaporator temperature drops below a predetermined level

ID: Acronym for "inside diameter."

identical part: See shared component

identification: See engine identification number program comparison and identification identification color: [1] A particular color for a specific amperage of fuse. [2] A color scheme for wiring

identification number: See engine identification number vehicle Identification Number IDI: Acronym for "integrated direct ignition" system

idiot light: See idiot lights.

idiot lights: A colloquial term for the indicator lights on the dashboard which are illuminated when the vehicle is experiencing some problem such as a lack of oil, overheating, failed brakes, low fuel, etc. The alternative is to install gauges which indicate the level of fluids and temperature. A combination of both gauges and lights is ideal.

idle: The engine speed when the vehicle is not moving. The engine's slowest practical speed.

Also see fast idle fast idle cam fast idle screw fast idle solenoid tick over idle air bleed screw: A screw found on some carburetors which allows air to enter the carburetor when the throttle is closed, so that the vehicle can idle. It also prevents the formation of deposits in the throttle area. The adjustment of this screw is part of a basic tune-up. Also see bleed screw idle air control valve: (IAC) on fuel injection vehicle, a valve that allows air to bypass the throttle plate(s), increasing idle speed. The valve is operated by an electric solenoid or motor. The vehicle computer controls the amount of opening to regulate idle speed for varying conditions such as cold string and air conditioner compressor load

idle air jet: A hole in a fixed-jet carburetor through which air is drawn into the idle system

idle cam: See fast idle cam

idle channel restriction: Used on carbureted vehicle. Does the same thing as the idle feed restriction, but is located in the idle passage just below the idle air bleed instead of the bottom of the idle tube. In the primary idle channel, the amount of fuel emitted by the idle discharge port is adjustable because there is a screw with a tapered tip extending into the port. On the secondary side, the idle discharge port uses a fixed idle channel restriction with no adjustment

idle circuit: At idle and low speeds, the carburetor system supplies enough fuel to the engine to keep it running. When the vehicle gets up to speed (usually about 24 kph or 15 mph) the idle circuit kicks out of operation so that fuel is supplied by the main metering system. Also called the "low-speed circuit."

idle discharge hole: Used on carbureted vehicle. The hole through which the idle mixture enters the airstream flowing past the throttle plate. Also called curb-idle port

idle feed restriction: Used on carbureted vehicle. A metering orifice that controls the amount of fuel that can enter the idle tube. Also called idle orifice or idle jet.

idle jet: A carburetor jet within the idle system which supplies a constant amount of fuel for the formation of the idle mixture

idle limiter: Any device that limits the maximum richness of the idle air/fuel mixture in the carburetor. Also aids in preventing overly rich idle adjustments. Limiters take either of the two following forms: And external plastic cap or a internal-needle type located in the idle passages of the carburetor

idle limiter cap: An external plastic cap on the head of the idle mixture adjustment screw to maintain preset emissions levels and prevent unauthorized tampering

idle mixture: The mixture of air and fuel (usually about 14:1) being fed to the cylinders.

idle mixture adjustment screw: See idle mixture screw

idle mixture screw: A tapered screw located on the outside of the carburetor which controls the proportion of the fuel-air mixture. It is now illegal to adjust these if limiter caps are present. If you turn the screw clockwise, the mixture will be leaner while turning it the other way results in a richer mixture.

idle orifice: The idle restriction tube or idle jet

idler:

[1] A gearwheel between a driving and a driven gear in a gear train which may serve to reverse the original direction of rotation of the driven wheel. [2] A free-turning pulley or wheel which serves to maintain tension in a belt drive. Also see reverse idler gear idler arm: In a parallel relay-type steering linkage, it is one of the connecting levers. The steering gearbox is attached to a pitman arm which converts rotary motion to lateral motion. The pitman arm connects to a transverse centerlink which connects to the idler arm attached to the frame side rail on the opposite side of the vehicle. The ends of the centerlink connect to two adjustable tie rods that transmit the lateral movement of the centerlink to the steering arms at each steering knuckle.

idler gear: A gear that is placed between two other gears to reverse the direction of rotation of the output gear. Also see reverse idler gear idler pulley: [1] The pulley in a rear derailleur that stays farthest from the freewheel cogs and functions to keep tension on the chain of a bicycle. [2] A small pulley located about half way from the front to back of a long chain such as found on a tandem bicycle. [3] A spring-loaded pulley designed to maintain the tension of the timing belt or a cam chain.

idle screw: See fast idle screw

idle solenoid: See fast idle solenoid

idle speed: This is the speed of the engine with the following conditions: The transmission is in neutral (or park in automatic transmissions), the engine is fully warmed up, the choke butterfly is fully open, and there is no extra accessories in operation (i.e., air conditioner, radio, lights). Also called "idling speed"

idle speed actuator: An electronically-controlled air bypass around the throttle. Also called idle-speed stabilizer or a constant idle system

idle speed adjustment: The alteration of the engine idle speed.

idle speed control: (ISC) maintains the idle speed of the engine at a minimum level. There are currently two types of computer controlled idle speed control: DC motor ISC and air bypass ISC

idle speed control motor: (ISC) and ECM controlled motor that extends or retracts a plunger that contacts the throttle level, which regulates the position of the throttle valve to compensate for an additional load, such as the air conditioner, power steering pump, etc. On the engine. Although it regulates idle speed, it is not used to adjust the curb idle speed. ISC motors are commonly used on carbureted and throttle body injected (TBI) vehicles

idle speed screw: A screw located at the bottom of the carburetor on the outside which keeps the throttle from closing completely when the vehicle is idling and thus controls the idle speed. This is adjusted as part of a basic tune-up.

idle speed stabilizer: A device which ensures steady engine rpm at idle speed. An electronicallycontrolled air bypass around the throttle. Also called idle speed actuator or a constant idle system

idle stop solenoid: A small cylinder located on the outside of the carburetor on some cars. It prevents the vehicle from continuing to idle after the ignition switch has been shut off (i.e., dieseling). The position of the striker rod in the cylinder can be adjusted in a tuneup to the correct specifications.

idle stop valve: A solenoid-operated valve which cuts off fuel in the idle system of a carburetor and so stops the engine from running-on when the ignition is switched off

idle system: At idle speed, the throttle valve is closed to such an extent that the airflow underneath the plunger no longer forms a sufficient vacuum; the fuel is then supplied via an auxiliary system, the idle system, which consists of the idle jet, the idle air jet, and the mixture control screw

idle tracking switch: (ITS) used on CFI vehicle to inform the EEC if the throttle is in contact with the DC motor

idle transfer port: A port drilled into the carburetor body slightly above the idle port to allow extra fuel/air emulsion into the airstream during the transition period when the throttle plate is opening from its idle (closed) position to a larger (cruising) opening angle. Also called idle transfer slot

idle transfer slot: A port drilled into the carburetor body slightly above the idle port to allow extra fuel/air emulsion into the airstream during the transition period when the throttle plate is opening from its idle (closed) position to a larger (cruising) opening angle. Also called idle transfer port

idle vacuum valve: (IVV) used in conjunction with other vacuum controls to dump air injection system air during extended periods of idle, to protect the catalyst

idling: The action of an engine as it turns over at low speed with minimum throttle. Also see sonic idling idling circuit: The passages, jets, etc. in a fixed-jet carburetor which provide idling mixture to the carburetor barrel

idling drag: The forward motion of a vehicle with automatic transmission, with engine at idle and selector lever in position "D" (Drive). Also called "creep"

idling speed: See idle speed

IFI: Acronym for "Industrial Fasteners Institute."

IFS: Acronym for "independent front suspension."

ignite: To set fire to; to catch fire

igniter: A bridge igniter with detonator in an air bag system.

ignition: A process which initiates the combustion of the compressed air/fuel mixture in the combustion chamber. In a spark-ignition engine, the mixture is ignited by an electric spark; in a diesel engine, the self-igniting mixture must be preheated by glow plugs when a cold start is performed. Also see autoignition battery ignition breaker-triggered transistorized ignition capacitor controlled electronic ignition capacitor discharge ignition system capacitor discharge ignition coil ignition compression ignition contact controlled electronic ignition contactless electronic ignition contactless ignition conventional ignition direct ignition system distributorless ignition system dual ignition system dynamic ignition timing electronic ignition system electronic ignition

four-spark ignition coil fully electronic ignition grid-controlled ignition system hall-effect ignition system high energy ignition system with electronic spark timing high energy ignition system inductive ignition system integrated Direct Ignition System magnetically controlled electronic ignition magneto ignition map-controlled ignition mapped ignition mechanical ignition timing multi-spark ignition coil multiple-spark ignition coil oscillating pick-up ignition system particulate ignition temperature piezoelectric ignition post-ignition reference ignition pattern required ignition voltage self-ignition single-coil twin ignition solid-state ignition spark ignition surface ignition thyristor ignition transistorized coil ignition transistor ignition transistorized ignition twin plug ignition twin spark ignition ignition advance: The extent to which the ignition spark is made to occur earlier. The opposite is ignition retard. Also see ignition timing ignition amplifier: A device used to increase the electrical signal in an electronic ignition system

ignition angle: The angle, measured in degrees crankshaft, by which the ignition is advanced.

Also see spark ignition angle ignition cable: A general term to designate the high-voltage cables of the ignition system, from the ignition coil to the distributor and from the distributor to the spark plugs. Also called "ignition leads"

ignition capacitor: The electrical part which interrupts the primary current with low loss and suppresses most of the arcing between the contact breaker points in conventional coil ignitions

ignition circuits: See primary circuit secondary circuit ignition coil: A pulse transformer which is a part of the ignition system. It receives a small amount of electrical voltage from the battery and steps up the low "primary" voltage and amplifies it into a big jolt of voltage of about 20,000 volts, and sends it to the spark plugs via the distributor. It is made of two windings and a core of iron. The primary coil has about 200 turns of relatively heavy wire. The secondary windings may have as much as 22,000 windings of fine wire. As electricity travels through the primary winding, it produces a magnetic field in the coil. When the points open, the magnetic field collapses and the movement of the magnetic field induces current in the secondary windings of the coil. The voltage is stepped up in proportion to the ratio of secondary to primary turns and the distributor directs this high voltage to the spark plug. Also called just "coil." Also see exciter coil field coil four-spark ignition coil multi-spark ignition coil multiple-spark ignition coil single-spark ignition coil ignition coil resistor: A ballast resistor

ignition control unit:

A general control unit of electronic ignition systems, usually with current and dwell angle control, driver and output stage, in some cases with electronic spark timing functions. Compare electronic control unit

ignition delay: The time lag between ignition triggering and the production of a spark

ignition disabler: A standard feature of car alarm systems

ignition distributor: See distributor.

ignition engine: See spark ignition engine

ignition file: A tool for filing ignition points and other small objects. Also called contact file, magneto file, points file, or point file

ignition gauge: A blade or wire-type feeler gauge used to check gaps on ignition systems, such as air gaps between permanent magnet and trigger wheel on electric ignitions

ignition key: A key which is inserted into an ignition lock located in the passenger compartment (usually on the steering column or on the dash) and is used to switch on the ignition

ignition lag: The time lag between fuel injection and combustion in a diesel engine

ignition lead: A general term to designate the high-voltage cables of the ignition system, from the ignition coil to the distributor and from the distributor to the spark plugs. Also called "ignition cable"

ignition map:

An electronic map stored in the electronic control unit of ignitions with electronic spark timing and containing the most favorable ignition angle/ignition point for every operating point of the engine. Spark timing is optimized on the basis of fuel type and consumption, torque, exhaust gas, knock limit, engine temperature, etc.

ignition module: See ignition control unit

ignition oscilloscope: An oscilloscope used especially for ignition tune-ups; usually integrated in an engine tester

ignition pattern: A display of the waveforms in the primary or secondary circuit of an ignition system in the firing order of the engine; optionally parade or display pattern and stacked or raster pattern. Also see reference ignition pattern ignition point: [1] The moment of spark firing. [2] breaker points.

ignition point file: See ignition file

ignition points: See breaker points.

ignition retard: Ignition which occurs after top dead center

ignition setting: See basic ignition setting

ignition switch: A control device that is generally operated with a key that closes and opens an electrical current to connect and disconnects the ignition system from the battery so

that the engine can be started and stopped as desired. The key should not be removable when the engine is running. It usually has various positions which, besides starting the engine, allow the user to operate the accessories without engaging the engine or to check the bulbs in the warning lights on the dashboard.

ignition system: The system that provides the electrical current or spark to ignite the air-fuel mixture in the combustion chambers. It includes the battery or magneto which sends electricity to the ignition coil if the ignition switch is on. The coil amplifies the electrical charge and sends it to the distributor where it goes through the points and is modified by the condenser. The distributor sends it along the high tension lines (spark plug wires) to the spark plugs where it ignites the air-fuel mixture. Also see ballast ignition system battery ignition system continuous AC Ignition System conventional ignition system direct ignition system distributorless ignition system dual ignition system electronic ignition system grid-controlled ignition system hall-effect ignition system high energy ignition system with electronic spark timing high energy ignition system ignition inductive ignition system integrated Direct Ignition System oscillating pick-up ignition system semiconductor ignition system twin ignition system ignition temperature: See flash point particulate ignition temperature ignition timing: It is important that the spark coming from the spark plugs ignites the air-fuel mixture at the correct moment determined by the manufacturer of the engine. Often this is a few degrees before top dead center (BTDC). Suppose the specs indicate that it should be set at 5 degrees BTDC, but in actuality it is set at 6 degrees. In that case, the timing is advanced. If it were set at 4 degrees, the timing is retarded.

Incorrect ignition timing may result in poor performance and excessive fuel consumption. Also see basic ignition setting basic ignition timing dynamic ignition timing mechanical ignition timing static ignition timing stroboscopic ignition timing ignition-timing control: See vacuum ignition-timing control

ignition toolkit: A set of small tools usually comprising 8 small open-ended wrenches (sizes: 3/16 7/16 in), a feeler gauge, a small screwdriver and a points file

ignition transformer: A unit that transforms the primary voltage resulting from the capacitor discharge to the required high voltage

ignition transistor: A transistor that switches the primary current of a transistorized ignition system

ignition voltage: The voltage at which the spark jumps across the electrodes; 30,000 volts are quite common today. Also see required ignition voltage ignition wrench: A small, open-ended wrench about 3 inches (75mm) long. It had two jaw openings set at different angles to the handle, e.g., 15° at one end and 60° or 75° at the other. (The British term is electrical spanner). The available jaw sizes were the following: 15°

75°

Length

13/64" 15/64"

3"

7/32"

1/4"

3"

1/4"

7/32"

3"

9/32" 5/16" 3-1/2" 5/16" 9/32" 3-1/2" I head: An overhead valve engine. See I-head engine engine type I-head: An overhead valve engine. See I-head engine engine type I head engine: An engine where both intake and exhaust valves are placed directly over the piston. The cam is located in the block and the valves are activated by pushrods and rocker arms. Also called "overhead-valve engine" or "valve-in-head engine."

I-head engine: An engine where both intake and exhaust valves are placed directly over the piston. The cam is located in the block and the valves are activated by pushrods and rocker arms. Also called "overhead-valve engine" or "valve-in-head engine."

IHP: Acronym for "indicated horsepower." Indicated horsepower developed by an engine and a measure of pressure of explosion within cylinder express in pounds per square inch

IHRA: Acronym for "International Harmonized Research Activities."

IICC: Acronym for "Insurance Information Center of Canada."

illuminated:

Lit up

illuminated entry system: An additional courtesy lighting system which illuminates the door entry area when the door is ajar; consists usually of lights in the lower door panels and footwells

illumination control: A switch which dims the interior dash lights

imbalance: A lack of balance due to uneven weight distribution. Improper wheel balance due to uneven weight distribution on the tire and wheel assembly is one of the most common causes of vibration. When one side of the tire and wheel assembly is heavier than the other, centrifugal forces try to throw the heavy area outwards as the wheel turns. Also see dynamic imbalance spin imbalance wheel imbalance IMCO: Acronym for "improved combustion"

IMEP: Acronym for "indicated mean effective pressure"

IMI: Acronym for "institute of the Motor Industry", a British organization for managers in the motor industry

immerse: To dip into or submerge in a liquid

immersion treatment: See tin immersion treatment zinc immersion treatment

immobile: A vehicle that is unable to move

immobilize: To make immobile

immobilizer: A device that makes something immobile (such as a Denver boot)

impact: A sudden, hard, physical contact. Also see federal side impact standard front-end impact frontal impact impact screwdriver lateral impact pendulum impact test impact absorber: An impact-damping element located between the bumper and bumper mounting to keep impact energy from being transferred into the car body

impact adhesive: A contact glue that provides adhesion when two coated surfaces are pressed together

impact air bag: See side impact air bag

impact bar: See side impact bar

impact break: A rupture to a tire resulting from the shock of striking a chuck-hole, rock, curb, etc. and not caused by cutting.

impact cushion:

Some child seats secure the child by an impact cushion in addition to the seat belt or straps

impact damage: Damage that has been caused to the wall of a tire by contact with a curb or deep pothole, etc.

impact driver: See impact screwdriver

impact dummy: See side impact dummy

impact intrusion beam: See side impact intrusion beam

impact pipe: A simplified version of an impact absorber

impact resistance test: A determination of the resistance to breakage by flexural shock of plastics, as indicated by the energy extracted from "standardized" pendulum-type hammers, mounted in standard machines, in breaking standard specimens with one pendulum swing

impact-resistant: Something that is stiffened (to a certain degree) to resist the force of a collision

impact screwdriver: A tool which features a mechanism that converts the impact from a hammer into a powerful torque for loosening (or tightening) threaded fasteners. Also called "impact driver."

impact sensor: An open switch that is designed to close when an crash occurs that is severe enough to warrant air bag deployment. See crash sensor

impact socket: A heavy duty socket for use with air or electric power impact tools. Impact sockets are designed to stand up to the extreme stress of these tools and can be used in combination with special impact accessories such as extensions, universal joints, and adapters. These accessories are also designed to withstand the stress of air or electric power impact tools

impact standard: See federal side impact standard

impact strength: The ability of a material to resist shock loading strain

impact stress: The force per unit area imposed on a material by an abruptly applied force

impact swivel ball universal joint: The swivel ball type universal joint is the most common type for use with impact sockets

impact test: See pendulum impact test

impact wrench: A pneumatic or electric tool for use with impact sockets

impeller: [1] A rotating member of a centrifugal pump which is equipped with vanes to convert mechanical energy into fluid energy. A rotor or wheel with blades or vanes used in pumps to drive and circulate fluid. Also see volute [2] A fluid coupling or torque converter -- the driving member connected to the crankshaft via drive plate and converter cover which generates the fluid flow inside the converter. The driving torus in the fluid coupling or torque converter of an automatic transmission. Also see bladed impeller

compressor impeller mixed-flow impeller vane wheel impeller impeller eye: The inlet area of an impeller in a pump

impeller pump: A centrifugal and side-channel pump

Imperial: A vehicle brand of which the 1955-56 models are milestone cars.

Click for books on Imperial

imperial gallon: A quantity of 4.546 liters. Also called "UK gallon." It is 20% larger than a US gallon

Imperial phaeton: See sport and Imperial phaeton

imperial sedan: A drop or sliding glass partition between the driver's compartment and the tonneau is the distinguishing feature between this type and the sedan, which it resembles in all other respects. Also see sport and Imperial phaeton impermeable: Not capable of leaking fluid

impervious: Not allowing gas to pass through

import: See captive import

importer: An organization that typically operates at arms length or under contractual agreement with manufacturers to bring products made in another country into Canada.

Import Measures Act: See special Import Measures Act

import nameplate: Vehicles sold by manufacturers primarily located outside North America whether assembled Overseas or in North America.

improver: See viscosity index improver

IMSA: Acronym for International Motorsports Association.

inbedability: The ability of a precision insert bearing to allow a small abrasive particle to imbed itself in the bearing material so it will not scratch the surface of the journal.

inboard: Located near the vehicle center rather than at the outside. Opposite of outboard

inboard brake: See inboard brakes.

inboard brakes: Most cars have the brakes associated with the wheel. Drum brakes, for instance, are located in the wheel hub itself. Disc brakes are found attached to the wheel. However, inboard brakes are not located within the wheel. Instead, they are found attached to the differential housing or axle shaft. Thus they are generally located only on the rear of the vehicle. Some racing cars (i.e., Formula 1) have them on the front as well. Inboard brakes mean a reduction in unsprung weight and usually better cooling.

inboard motor:

An engine which is located within a boat rather than being attached to the back (outboard motor).

inboard starter: A bendix starter

in-car entertainment: (ICE) A car audio system, typically consisting of a radio/cassette player and perhaps a CD player. The term also includes a CB radio, TV, VCR, DVD available on some models (e.g., limousines and sleepers on large trucks)

in-car sensor: A dual bimetal strip that samples passenger compartment air and controls a vacuum modulator. The vacuum modulator controls the heating or air conditioner blend door to maintain a constant temperature in the passenger compartment

incipient crack: A crack which has just started to form

incl: Abbreviation for "includes," as in price incl. tax.

inclination: A set angle. See kingpin inclination steering-swivel inclination steering axis inclination swivel axis inclination incline: [1] A slope [2] to slope

inclined engine: An in-line engine in which the cylinders are inclined to the vertical. Also called a "sloper" or "slant six" (e.g., Chrysler's 6-cylinder engine

inclined plane: A wedge used to raise a load more easily. The load moves, not the wedge.

inclinometer: See clinometer

included angle: The sum of the "Camber" and "Kingpin inclination" (or steering axis inclination) angles. This angle is designed into the steering knuckle and must remain constant.

inclusions: See slag inclusions

incomplete thread: A thread with incomplete thread profile

increased shank: A shank diameter greater than thread diameter

increasing adapter: An adapter whose male end for the socket is bigger than the female end for the drive handle. The opposite is a reducing adapter

in-dash gauge: A gauge mounted in the instrument panel

indentation: A concentrated panel damage or specific dent that may be caused when a car hits a relatively small obstacle, i.e., the hitch ball of another car

indentation hardness: The resistance of a metal (or plastic) surface to indentation when subjected to pressure by a hard pointed or rounded tool

independent front suspension: (IFS) A suspension system where the two front wheels are sprung independently from each other. It has the advantage over a beam axle suspension because it allows

the engine to be positioned further forward and lower between the wheels. In this way there is more room for the passengers, the position of the hood is lower, the vehicle has a lower center of gravity, and the unsprung weight is reduced. When the front wheels are not independently sprung, there is some caster wobble and shimmy that make it difficult to hold on to the steering wheel. Also see independent suspension independent lessor: Independent lessors are usually individual businesses that can provide for the lease of virtually any make or model of vehicle. Independent lessors, like dealers, can write custom leases, including those with different conditions and special mileage considerations.

independent rear suspension: (IRS) A suspension system where the two rear wheels are sprung independently from each other. It has the advantage over a beam axle suspension because the unsprung weight is reduced, the ride and handling over rough roads are improved, and a larger trunk with a lower floor can be placed between the wheels. Also see independent suspension multi-link independent rear suspension independent repair shop: A small service outlet offering specialized repair services. They usually do not sell gasoline.

independent suspension: A suspension system that allows each wheel to move up and down without undue influence on the other wheels. Thus independent suspension on the rear wheels means that if only the right rear wheel hits a bump, the left rear wheel is not affected by it. Generally it is more expensive to manufacture independent suspension.

index: See anti-knock index load index viscosity index index improver:

See viscosity index improver

index shifter: See index shifters.

index shifters: bicycle levers that "click" into distinct positions that correspond to certain freewheel cogs and don't require fine-tuning after each shift.

indicated horsepower: (IHP) A measure of the power developed by the burning fuel within the cylinders. The theoretical power of an engine calculated from the MEP in the cylinders rather than at the shaft. IHP includes BHP plus the power lost to friction, and pumping needed for the induction of the fuel and air charge into the engine and the expulsion of combustion gases

indicated mean effective pressure: (IMEP) The average pressure within an engine cylinder during a working cycle, calculated from an indicator diagram

indicated pressure: See mean indicated pressure

indicator: [1] An instrument which reveals the condition of a particular component. [2] A British term for a signal light. [3] An instrument for recording engine cylinder pressure. See battery charge indicator battery discharge indicator battery state indicator beam indicator brake pad wear indicator catalyst indicator dial gauge dial indicator direction indicator warning light direction indicator discharge indicator fluid level warning indicator

fuel consumption indicator gear indicator gear selector indicator glow plug indicator headlight retractor indicator lamp heater-plug indicator high beam indicator low fuel indicator low pressure indicator main beam indicator self-cancelling indicator semaphore indicator slow down indicator tread-wear indicator treadwear indicator turn signal indicator indicator diagram: A cylinder pressure chart, plotted against the working cycle of a piston or engine

indicator lamp: See headlight retractor indicator lamp

indicator light: A light on the instrument panel that lights up to show the operation of something, such as the illuminated arrow that indicates the direction in which a vehicle is about to turn, the high beam indicator, battery charge indicator, oil pressure light, cruise control light, etc.

indicator warning light: See direction indicator warning light

indirect‘bmage: A type of damage not caused by immediate impact but by the spread of the impact force into other areas of the body, e.g., bulging or dents at the rear of the front fender and the leading edge of the door in the case of direct accident damage to the front edge of the front fender. The opposite is direct damage

indirect injection: A type of fuel injection in which the air-fuel mixture does not go into the main combustion chamber but into some kind of prechamber; injection pressures are

lower than with direct injection and ignition lag is short

indirect injection engine: A British term for a pre-combustion engine, i.e., a diesel engine using indirect injection

indium: A metallic element with the symbol "In" and atomic number of 49. It is used in the manufacture of transistors and as a bonding material for acoustic transducers.

induce: To cause or to bring about

induce a voltage: To produce a voltage by electromagnetic induction

inducer: In a turbocharger, the section of the compressor wheel that draws air or air/fuel mixture into the compressor

inductance: See mutual inductance

induction: [1] The imparting of electricity into one object, not connected, to another by the influence of magnetic fields. Found in automobiles in coils and solenoids. [2] The intake of air and fuel through the carburetor, inlet manifold, and inlet ports into the combustion chamber. Also see ram induction air induction cold air induction ram induction reed valve induction timing self-induction third port induction induction coil:

See coil.

induction hardening: Method of heating cast iron (e.g., valve seats) to approx 1700° F which hardens it to a depth of 0.05 to 0.08 inches

induction manifold: See inlet manifold

induction noise: The noise caused by the intake of air by an engine at full throttle

induction period: The time during the charge changing process of the engine that allows for the intake of the fresh charge into the cylinder while the inlet control, i.e., the valve or port, remains open

induction pipe: The duct, typically an alloy manifold, between the throttle and cylinder head; the absolute pressure in the induction pipe, the so-called intake vacuum, is indicative of engine load and is used to control many engine-related functions

induction pod: The port in the cylinder wall of a two-stroke engine which is used for the admission of the fresh charge into the cylinder

induction stroke: A British term for the intake stroke, i.e., the phase of the 4-stroke cycle during which the intake valve is open and the piston descends from TDC to BDC, drawing air (in a diesel engine) or an air/fuel mixture (in a spark ignition engine) into the cylinder

induction system: [1] The system that brings the fuel-air mixture to the cylinders in a spark ignition engine. It includes the carburetor or fuel injection system, air cleaner, intake manifold, intake ports, and intake valves. [2] Air intake system used to cool the car.

induction system intake configuration: See variable volume induction system intake configuration

induction timing: See reed valve induction timing

inductive ignition system: An ignition system where the primary energy is stored in an inductor or an ignition coil

inductive pick-up: See transistorized ignition with inductive pick-up

inductive pulse generator: See transistorized ignition with inductive pulse generator

inductive pulse pick-up: See magnetic pick-up assembly

inductive winding: See pick-up coil

Industrial Classification: See North American Industrial Classification System and standard Industrial Classification

industrial tire: A heavy duty tire for use on forklifts, lowbed trailers, etc.

industrial solid: A non-pneumatic tire (either entirely rubber or a regular tire with a solid rubber core to replace the tube), used most often on forklifts where the possibility of a flat tire is a constant problem.

Industrie Normen:

See Deutsche Industrie Normen

industry: See automobile industry Institute of the Motor Industry inert: Something that lacks a chemical action; the property of the separators used between the plates of a battery

inert arc welding: A family of arc welding processes in the fusion welding category. The welding pool is surrounded by a layer of inert shielding gas to keep oxygen from the weld; TIG welding is a typical inert arc welding process and is mainly used for repair work

inert gas-arc welding: Surrounding the arc with a gas which does not react with the electrode and base metal and keeps the atmosphere away from the arc.

inert gas system: A system of filling the space above the cargo oil in tankers with carbon dioxide from the boiler exhaust so as to prevent explosion.

inertia: That force which tends to keep a stationary object from being moved, and tends to keep a moving object in motion. Some effort is needed to get the object moving if it is stopped, and to stop an object if it is moving. Also see moment of inertia polar moment of inertia inertia drive: A Bendix drive which has a heavy piston moving along the shaft under the momentum of its own weight or inertia when the shaft turns inside it

inertia fuel cut-off switch:

See fuel pump shut-off switch

inertia pinion: A pinion used in an inertia drive

inertia reel: Generally the seat and shoulder belts are loose so that the drive and passenger can have the freedom to move forward to adjusting the instruments on the dash, etc. However, when the vehicle decelerates quickly, as in a crash or panic stop situation, the occupants need to be restrained by the belts. The belts are locked by the inertia reel as it senses the rapid change of deceleration.

inertia reel seat belt: A 3-point seat belt with an automatic retractor reel. This type of seat belt allows the wearer to move while the vehicle is stationary or in steady motion but locks to restrain the wearer on sudden deceleration or impact

infant safety seat: See baby seat

infinitely variable transmission: (IVT or CVT) Most transmissions, whether manual or automatic have a fixed number of forward gears (from 2 to 10 or more). Belt driven vehicles (like snowmobiles) have an infinite number of positions of engagement. The infinitely variable transmission is sensitive to the changes in the throttle position and adjusts the gear ratio accordingly. In this way, the most efficient gear ratio is selected thus improving fuel economy. Also called "continuously variable transmission."

inflammable: Capable of being easily ignited and of burning quickly

inflatable air-bag system: See supplemental restraint inflatable air-bag system

inflatable restraint: See supplementary inflatable restraint

inflate:

To fill with air. Also see hydrostatically inflate inflation: See load and inflation table over inflation inflation control seam: A system of inflation control seams on advanced air bags to control the inflation speed and inflation characteristics. Also called "tear seam," whose negative connotations are perhaps inappropriate in a safety-related context

inflation pressure: See tire pressure

inflation table: See load and inflation table

inflator: See emergency inflator

inflator unit: An assembly beneath the folded air bag, consisting of a combustion chamber with a bridge igniter, a detonator, and a priming charge surrounded by the solid propellant, and a metal filter. A signal from the trigger unit causes the bridge igniter to fire the detonator, which in turn fires the priming charge and then the solid propellant. The nitrogen thus generated flows through a metal filter and reaches the air hag cleaned and cooled

information centers: Visual displays which alert driver to certain vehicle conditions

infrared: See non-dispersive infrared analyzer

infrared analyzer:

An instrument used to measure unburned hydrocarbons and CO discharged from a vehicle exhaust pipe. See non-dispersive infrared analyzer

infrared radiant drier: An infrared lamp which accelerates the drying of large areas of fresh paint

infrared rays: Heat rays which emanate from both the arc and the welding flame.

infrared remote control: (IR) the control of an operation by means of an infrared beam transmitted to a receiver (e.g., garage door, central locking, car alarm system, etc.)

ingress: Entry, as in "sealant is used to prevent the ingress of moisture."

inhibit: To hinder or to prevent

inhibitor: A substance added to oil, water, gas, etc., to prevent action such as foaming, rusting, etc. The opposite is catalyst. Also see corrosion inhibitor reverse inhibitor valve rust inhibitor inhibitor switch: See starter inhibitor switch

inhibitor valve: See reverse inhibitor valve

inject: To introduce a fluid (into something) under pressure

injected engine:

See fuel-injected engine

injection: See air injection direct injection electronic fuel injection fuel injection engine fuel injection pump fuel injection high speed direct injection indirect injection engine indirect injection L-jetronic fuel injection system multi-point injection multiple-point injection port fuel injection reaction injection molding reinforced reaction injection molding sequential fuel injection single point injection solid injection throttle body fuel injection throttle body injection timed fuel injection timed injection vapor injection water injection wax injection injection engine: See fuel injection engine indirect injection engine injection fuel: In Bosch CIS, the pressure of the fuel in the lines between the differential-pressure valves and the injectors. Also called injector pressure

injection lag: The time interval (expressed in crankshaft degrees) between the nominal start of injection pump delivery and the actual start of injection at the nozzle

injection manifold: See air injection manifold

injection-molded: Produced by an injection molding machine or process

injection molding: A method for the fabrication of thermoplastic materials. The viscous resin is squirted, by means of a plunger, out of a heated cylinder into a water-chilled mold, where it is cooled before removal. This method is also used with thermosetting molding powders. Also see reaction injection molding reinforced reaction injection molding injection moulding: British term for injection molding

injection molding machine: A machine used to produce preformed plastic body panels

injection period: The length of time for which fuel is sprayed into the intake ports or combustion chamber during fuel injection. It is controlled by the electronic control unit. The injection period depends mainly on engine speed and the amount of induced air and is normally between approx. l.5 and 9 milliseconds

injection pressure: In Bosch CIS, the pressure of the fuel in the lines between the differential-pressure valves and the injectors. Also called injector fuel

injection pump: A pump which receives fuel from the fuel tank (often through the fuel-feed pump in the case of diesel engines) and delivers it under pressure to the injectors. Also see fuel injection pump

injection pump governor: Device which controls fuel deliver to limit the minimum and maximum engine speeds, as well as intermediate throttle positions

injector opening pressure: The point at which injection pump fuel pressure overcomes nozzle valve-spring resistance, or combustion chamber pressure, so that fuel is injected into the precombustion chamber

injection reaction: See air injection reaction

injection system: See air injection system continuous injection system L-jetronic fuel injection system steam injection system injector: Refers to the pump system (used in a fuel injection system) that squirts or injects a measured amount of gasoline into the intake manifold in the vicinity of the intake valve. In the diesel engine fuel is injected directly into the cylinder. In a Continuous Injection System (CIS), the injectors atomize the continuous flow of fuel injected under pressure into the intake ports of the engine; a valve in the injector nozzle stops the flow of fuel when fuel pressure drops below a certain point; in a CIS, the quantity of fuel is regulated by the fuel distributor's metering unit; in other fuel injection systems, the fuel system delivers a constant supply of fuel at a constant pressure to the injector, and an electronic sensing and control system produces electrical current pulses of appropriate duration to hold open the injector solenoid valves; as fuel pressure is held constant, varying the pulse duration increases or decreases the amount of fuel passed through the injectors. Also see cold start injector fuel injector nozzle fuel injector valve fuel injector injector nozzle: The tip of the injector, either of multi-hole design for direct injection or pintle design for indirect injection.

Also see fuel injector nozzle injector valve: See fuel injector valve

injury: See bodily injury whiplash injury inlet cam: The cam responsible for the actuation of the inlet valve in DOHC engines

inlet camshaft: The cam responsible for the actuation of the inlet valve in DOHC engines

inlet line: A pipe or hose on the intake side of a component, through which a fluid is supplied by gravity from a reservoir or tank located at a higher level; e.g., from coolant expansion tank to radiator, or from brake fluid reservoir to master brake cylinder

inlet manifold: British term for intake manifold describing the component which guides the intake air to the cylinder head intake ports; usually an aluminium casting or a GRP molding, with one intake opening and as many outlets as there are cylinders in the engine

inlet manifold heater: See flame glow plug

inlet over exhaust: Valve layout used on some early machines in which the exhaust valve was mounted to the side of the engine and the mechanically operated inlet valve was positioned above the exhaust

inlet over exhaust engine:

(IOE engine) A British term for "intake over exhaust engine" describing an engine design used on early cars. Also called F-head engine The intake and exhaust valves are arranged vertically in a lateral chamber of the combustion chamber and face one another; the side valve (usually the exhaust) is actuated directly by the camshaft, which usually rotates in the cylinder block; the overhead valve (usually the intake) is located in the cylinder head and actuated via a pushrod and rocker arm

inlet pipe: See intake manifold.

inlet port: A British term for intake port

inlet stroke: A British term for intake stroke

inlet tract: A British term for intake tract

inlet valve: A British term for intake valve.

inlet valve closes: (IVC) A British term for intake valve closes

inlet valve opens: (IVO) A British term for intake valve opens

in-line: Engine layout in which the cylinders are arranged in a row, and in-line with the wheels of the machine

inline engine: See in-line engine.

in-line engine:

An engine in which all the cylinders (usually three or more) are arranged in a straight row (either vertically or slanted). The pistons drive a common crankshaft. Also called a "straight engine."

inline fuel filter: See in-line fuel filter.

in-line fuel filter: A fuel filter which is placed within the fuel pipes coming from the fuel tank or fuel pump. To install it, a segment of the fuel line is cut and removed. The filter is inserted to replace the removed segment of the line.

inline fuel heater: A heater which is integral to the fuel line on a diesel engine fuel prior to the filter to keep paraffin crystals from stopping fuel flow. The heater warms the fuel by 20° F

in-line power steering: Power-assisted steering applied within the steering box or rack

in-line pump: A pump whose suction and discharge branches are arranged in line for direct installation into the pipework; special foundations are unnecessary, and the absence of shaft couplings eliminates alignment problems

inner attachment face: The part of the brake disc directly fixed to the wheel hub

inner cap nut: (sleeve nut) A securing device on a dual mounted disc wheel type where it threads directly on the stud and holds the inner wheel in place against the hub. Also see outer cap nut inner cone: A small, innermost part of the flame at the tip of a blowtorch, the shape of which indicates the torch adjustment

inner cylinder:

The working chamber of a double-tube shock absorber

inner dead center: See top dead center

inner fender panels: The vertical panels mounted to the left and right of the engine bay that provide the mounting flanges for the fenders and the top suspension attachment

inner headlight: The inner one of twin headlights usually for high beam only. The opposite is outer headlight

inner liner: The innermost layer of a tubeless tire which provides an airtight barrier

inner mounting face: See inner attachment face

inner race: The inner track of a ball bearing

inner sill: The hidden part of the sill located behind the outer sill panel, which serves to reinforce the underbody. It is also called "longitudinal member" or "side member"

innerspring seat: A sturdy, sofa-like seat design using spring coils as damping elements; used mainly by Mercedes-Benz

inner tube: A doughnut-shaped rubber or latex air chamber which normally is inserted into a non-tubeless tire to hold pressurized air. It contains an air valve to inflate the tube.

inorganic: Pertaining to or composed of chemical compounds which do not contain carbon as the principal element, i.e., matter which does not come from plants or animals. The

opposite is organic

input: See gearbox input shaft reference input step steering input input shaft: The shaft delivering power into a mechanism. The shaft from the clutch into the transmission is the transmission input shaft. Also called clutch shaft. Also see gearbox input shaft transmission input shaft input variable: The object of measurement and control; e.g., pressure, temperature, etc.

insert: [1] When referring to bearings it indicates a replaceable shell-type bearing made to extremely close tolerances and generally used for main bearings and connecting rod bearings. [2] When referring to valves it indicates replaceable valve seats made of hard, heatresisting metal that are screwed or shrunk into the cylinder head. [3] When referring to spark plugs it indicates replaceable threads which are installed into damaged spark plug holes so that spark plugs can be installed. Sometimes known by the trade name "Heli-coil." [4] Piston liners or cylinder sleeves. [5] As a verb, it is the technique of permanently joining plastics and other materials, e.g., embedding steel clips in a molded plastic cover. Molded-in inserts are placed into the injection mold cavity so that the melt flows around them during injection; post-molding inserts may be installed by press-fit or ultrasonic methods. Also see bumper insert groove insert precision insert bearing thread insert top ring groove insert valve seat insert insert bearing:

A removable, precision made bearing which insures specified clearance between bearing and shaft. Also see precision insert bearing insert socket: A socket for use with a slogging ring wrench which raises the wrench above the surface, thus preventing hammer damage to floor or equipment

insert tap: See spark plug insert tap

inside caliper: A machinists' caliper used to check inside dimensions. See caliper.

inside calipers: A machinists' caliper used to check inside dimensions. See caliper.

inside corner weld: Two metals fused together; one metal is held 90 degree to the other. The fusion is performed inside the vertex of the angle.

inside diameter: (ID) The internal diameter of a cylinder or tube

inside pry spoon: A specialized pry bar designed to reach behind brackets and reinforcing bars to pry the metal. The pointed end of the inside pry spoon is placed at the high point of a dent, which is then forced out

inside spring caliper: An inside caliper with spring for accurate setting

insolation: Exposure to the rays of the sun

inspection:

A type of examination which serves to evaluate the operating condition of a component or system; the inspection may identify the need for servicing or repair. Also see rust inspection inspection lamp: A British term for a trouble-shooting light.

inspection lot: Certain quantity of a particular item chosen at random for quality testing

inspection mirror: A tool used to inspect hidden areas on automotive parts. It consists of a long rod (sometimes telescoping) with a small mirror at one end.

inspection pit: A pit in the floor of a garage providing working space underneath a vehicle

install: To put something in position ready for use

installation: Putting something in position ready for use. The opposite is removal

installed height: [1] The height at which something is placed in position. [2] The spring's measured length or height, as installed on the cylinder head. Installed height is measured from the spring seat to the underside of the spring retainer

installed market: See mechanic installed market

installer: See clamp installer clip installer

hose clamp installer hose clip installer valve stem seal installer instant spare: An emergency inflator

Institute of the Motor Industry: (IMI) British organization for managers in the motor industry

instruments and controls: A general term covering all gauges, indicators, switches, regulators, and buttons

instrument cluster: [1] An array of separate gauges in one housing; a major component of the instrument panel including analog or digital instruments and indicators, but no controls except for the trip mileage reset button on some cars. [2] Several gauges integrated into one instrument, making one unit combining several functions, e.g., engine temperature, oil pressure and fuel gauge; if one gauge fails, the entire instrument cluster must be replaced

instrument panel: The panel below the windshield which accommodates the instruments and controls. Also called dash, dashboard, or fascia

insulate: To cover with non-conducting material, so as to prevent the transmission of heat, electricity, or sound

insulating cap: The insulated top of the coil tower

insulating tape: PVC tape (usually black) for wrapping around electrical connections

insulation: [1] Any material which does not conduct electricity. It is used to prevent the flow or leakage of an electrical conductor.

[2] Any material which does not readily conduct heat. Used to keep heat or cold out of something. [3] The process of insulating.

insulator: A unit made of a material that will not conduct electricity. The electricity in a copper wire covered with a plastic sleeve (insulator) cannot penetrate the sleeve. Also see spark plug insulator insulator nose: The tip of a spark plug

insulator tip: The tip of a spark plug

insurance: See automobile insurance car insurance collision insurance comprehensive insurance gap insurance motor insurance no fault insurance insurance premium: A regular payment for an insurance policy

int: Abbreviation for "interior."

intake: See air intake cold air intake heated intake intake manifold intake port

intake stroke intake tract intake stroke intake valve ram intake manifold intake cam: The cam responsible for the actuation of the inlet valve in DOHC engines

intake camshaft: The cam responsible for the actuation of the inlet valve in DOHC engines

intake charge: The mixture of fuel and air that flows into the engine.

intake configuration: See variable volume induction system intake configuration

intake manifold: The connecting tubes between the base of the carburetor and the port openings to the intake valve or intake ports. The air-fuel mixture travels from the throttle body into a chamber called the plenum which feeds individual tubes (called runners) which lead to the individual intake port. Its purpose is to transfer the air-fuel mixture to each cylinder. It is usually an aluminium casting or a GRP molding, with one intake opening and as many outlets as there are cylinders in the engine. Also called "inlet pipe." The British term is "inlet manifold." Also see ram intake manifold variable intake manifold intake manifold heater: See flame glow plug

intake over exhaust engine: (IOE engine) An engine design used on early cars. Also called F-head engine. The intake and exhaust valves are arranged vertically in a lateral chamber of the combustion chamber and face one another; the side valve (usually the exhaust) is actuated directly by the camshaft, which usually rotates in the cylinder block; the overhead valve (usually the intake) is located in the cylinder head and actuated via a pushrod and rocker arm

intake pipe: The duct, typically an alloy manifold, between the throttle and cylinder head; the absolute pressure in the induction pipe, the so-called intake vacuum, is indicative of engine load and is used to control many engine-related functions. The British term is "induction pipe"

intake plenum: See plenum chamber

intake port: The passage in the cylinder head which connects the intake manifold to the intake valve through which the fuel-air mixture proceeds on its way to the cylinders. The British term is "inlet port."

intake stroke: In a four-stroke cycle engine, it is the piston's first stroke down in pulling fuel and air into the combustion chamber as it causes a partial vacuum. The phase of the 4-stroke cycle during which the intake valve is open and the piston descends from TDC to BDC, drawing air (in a diesel engine) or an air/fuel mixture (in a spark ignition engine) into the cylinder. The British term is "induction stroke" intake tract: A branch of the intake manifold leading to an intake port. Also see intake stroke intake tract intake valve: The poppet valve that opens to permit the fuel mixture into the cylinder. It closes during the compression and combustion strokes. Some engines have more than one intake valve to each cylinder. The British term is "inlet valve."

intake valve closes: (IVC) A mark on a valve-timing diagram. Also see EVC intake valve opens: (IVO) A mark on a valve-timing diagram.

Also see EVO integral: An essential component of something. See integral part of.

integral alternator/regulator: (IAR) a type of regulator mounted at the rear of the alternator

integral backpressure transducer EGR valve: Combines inputs of exhaust backpressure and EGR ported vacuum into one unit. Requires both inputs to operate on vacuum alone there are two common designs: Poppet and tapered pintle

integral body and frame construction: See unitary construction

integral color anodizing: An anodizing process in which the color is produced by using special electrolytes

integral equipment: Any device or system that is designed for a vehicle and installed in it by the manufacturer, rather than being added on to a finished vehicle at a later date.

integral fuel filter: A fuel filter which is part of the fuel pump or part of the carburetor rather than one that is attached to a fuel line (in-line fuel filter).

integral molded seat: A seat with integrated 3-point seat belt

integral part of: A necessary part of something, e.g., the cam lobe is an integral part of the camshaft.

integral-type power assisted steering:

See in-line power steering

integral-type power steering: See in-line power steering

integrated child safety seat: A fold-down child safety seat located in the center of the rear seats that is part of the original car. This seat includes seat belts, and are generally not as good as aftermarket safety seats. They are not as adjustable or comfortable. There is generally little or no side protection and the child normally must sit with his legs sticking straight out. When not in use, the seat can be folded away, much like an armrest.

integrated child seat: A rear seat that can be converted into a child seat. Also see integrated child safety seat Integrated Direct Ignition System: (IDI) A distributorless ignition system consisting of two separate ignition coils, an ignition module, a secondary conductor housing mounted to an aluminum cover plate, a crankshaft sensor, and electronic spark timing

integrated roll cage: The cage or framing of the car serves the dual purpose of protecting the passenger while also creating a place to hang all the car's components -- engine, steering, sheet metal, etc. An integrated roll cage is one that is claimed to be especially safe and designed to protect the passenger in the case that the car rolls. It is called integrated because it is part and parcel of the overall framing for the car's components and thus sturdier.

integrated safety belts: Consist of a shoulder belt and a lap belt. Whereas the cars of the 60s had the option of being ordered without seat belts, today's cars have an integrated safety belt as standard equipment.

intellectual property rights: (IPR) The right to possess or control the use of intellectual property, such as trademarks, copyrights, patents and trade secrets.

intel-plate: The disc between the driven plates in a twin plate clutch

intensify: To increase or concentrate, such as to increase the voltage of an electrical current.

intensity: See field intensity

interactive wishbone: The patented suspension system used on the front of the new Lotus Elan which maintains precise suspension geometry without transmitting undue road harness to the passengers. The result is the elimination of torque steer and bump steer, and a very comfortable ride.

inter-axle differential: Gear device equally dividing power between the axles and compensating for unequal tire diameters. Also called center differential

intercell connector: A lead strap or connector that connects the cells in a battery

inter-cell link: An electric conductor that carries electric current between the adjacent cells of a battery

interchangeable head torque wrench: A wrench that does not have the usual square drive for use with sockets, but is designed to accept special interchangeable heads

interchannel competition: The rivalry between different channels of the distribution system. For example, independent retailers competing with manufacturers' outlets.

intercoastal:

Domestic shipping routes serving more than one coast.

intercoat adhesion failure: A situation in which one coat of finish peels off or can easily be stripped off with masking tape from another layer underneath. This may be caused by excessive bake time of coatings, resulting in too hard a finish, poor flatting of coats, providing poor keying of coats, or very low film thickness

intercooler: A device which cools the air entering the carburetor or fuel injection system. Colder air has more oxygen molecules than warm air. Thus cooler air gives more power and better fuel economy. An intercooler looks like a radiator. It contains large passages for the intake flow, and uses either outside air or water directed over it to lower the temperature of the intake flow inside. Also called a "charge-air cooler" or "chargecooler." Compare "aftercooler."

intercooling: The cooling of the charge air between compressor and engine

intercostal: Made in separate parts; between floors, frames or beams, etc; the opposite of continuous

intercrystalline corrosion: A small outbreak of rust occurring along crystal boundaries of metals or alloys

interest: See net interest rate

interest rate: See base interest rate buy at end-of term interest rate net interest rate interference: [1] Difference in angle between mating surfaces of a valve and a valve seat.

[2] The noise from the ignition system that affects radio and TV reception. Suppressors are used to minimize interference and on modern vehicles the main suppressors are the spark plug leads. Also see radio frequency interference interference fit: A condition of fit (contact) between two parts that requires pressure to force the parts together. Usually the shaft is slightly larger than the hole so that they must be pounded or forced or driven together. Also called "force fit," "press fit," or drive fit.

intergranular corrosion: A small outbreak of rust occurring along crystal boundaries of metals or alloys

interior: The inside of a vehicle

interior light: The courtesy light which illuminates when the doors are opened or when an interior switch is activated.

interior light switch: There are two types of switches which turn on the interior lights: One is located on the door posts and is activated when the door is opened or closed. The other is found on the dash and may be incorporated into the headlight switch.

interior mirror: The rear-view mirror located centrally near the top of the windshield. Also see exterior mirror interior noise level: The level of noise inside the vehicle, typically in the range from 45-90 dBA from idle to full throttle; at 70 mph between 66-87 dBA

interior payload: The amount of weight that a vehicle can carry. The capacity of the usable area in the vehicle's interior. It is defined by cubic feet. This includes the seating area for passengers as well as the cargo space

interior trim: The panels, linings, decorative facings, upholstery, and covers inside a vehicle

interleaf friction: The friction between individual leaves of a leaf spring

interlock: [1] to fit gear train members together. [2] A device in a change-speed gearbox which prevents two gears from being engaged at the same time. Also see accelerator interlock clutch starter interlock parking interlock shift interlock starter interlock starting interlock intermediary: firm or organization that operates between the producer of the goods and the end purchaser. Thus, the members of the distribution channel noted above are intermediaries or "middlemen."

intermediate: [1] between two things or two extremes [2] See intermediate car

intermediate car: A designation no longer used because even "full-size cars" are now about the size of what was the compact car. In 1970, for instance, a Chevrolet Impala was a full-size car, a Chevelle was an intermediate, a Nova was a compact. When cars smaller than the Nova came out (i.e., Chevette), they were called sub-compacts.

intermediate coat: Any coat of paint between the first coat (primer) and last coat (finish)

intermediate drive plate:

A disc between the driven plates in a twin plate clutch

intermediate gear: Any gear in the auto transmission between first and high. Usually refers to second or third gears

intermediate hold: A term dating from the early days of three-speed automatic transmissions; today represented by the position "2" on the selector quadrant

intermediate plate: A disc between the driven plates in a twin plate clutch

intermediate rim taper: A rim with one tapered bead seat of 5° at the fixed flange.

intermediate rod: See relay rod

intermediate shaft: A rotating shaft joining two other shafts

intermetallic compound: An alloy of two metals in which a progressive change in composition is accompanied by a progression of phases with varying crystalline structures

intermittent: Not constant but occurring at intervals.

intermittent fault: A problem which comes and goes (and annoyingly never occurs when the car is taken in to the garage for repair!)

intermittent weld: Joining two pieces and leaving unwelded sections in the joint.

intermittent wiper control: A device which operates the wipers at preset intervals; typically adjustable from 2 to 40 seconds. It usually includes a "mist action" which makes only one swipe and then stops. Most often used in conditions of light drizzle or snow, mist, and spray from other vehicles

internal bowl vent: A tube designed to vent excess fuel vapors from the fuel bowl back into the carburetor during acceleration and cruising conditions

internal circlip pliers: A special pliers with pointed jaw tips for the installation and removal of internal circlips

internal combustion engine: (IC) An engine that burns fuel within itself as a means of developing power (unlike an external combustion engine such as a steam engine). Although the term "internal combustion engine" covers all types of reciprocating and rotary engines, it is typically used with reference to four-stroke gasoline and diesel engines

internal damage: Injury to the body shell that is not usually visible from the outside. Such damage is often caused by rust from the inside of panels and fenders, so the damage becomes visible only in an advanced state of decay

internal diameter: See inside diameter

internal gear: An internally toothed annulus gear

internal gear pump: A gear pump which has one rotor with internally cut teeth meshing with an externally cut gear idler; a crescent-shaped partition is used to prevent liquid from passing back to the suction side of the pump; a typical oil pump, characterized by quiet operation and high capacity

internal micrometer:

A micrometer for inside measurements such as distances between two parallel surfaces or inside diameters of cylinder and main bearing bores

internal mix air cap: A special type of air cap for spray guns. Air and material are mixed inside the gun and are ejected through a single orifice. This design is used only for pressure-feed guns, primarily for spraying heavy viscous materials. Compare external mix air cap

internal resistance: The resistance inherent in a voltage source, such as a battery. The internal resistance of a battery is made up of several individual resistances, e.g., between the plates and the electrolyte, the plate resistances, the resistance of the electrolyte to ion flow, and internal connectors

internal thread: The thread on the inside of a nut or similar into which the external thread of a bolt or screw fits. Also called "female thread"

internal vane pump: See sliding-vane pump

Internationale de l'Automobile: See fédération Internationale de l'Automobile

Internationale du Sport Automobile: See fédération Internationale du Sport Automobile

international load line certificate: A certificate issued after the vessel has been surveyed and load lines marked on her sides.

International Motorsports Association: (IMSA) The sanctioning body of sports car prototype racing in the United States. Current categories include World Sports Cars (WSC) a series for purpose-built race cars, GTS-1 for vehicles resembling street cars but which have custom-made chassis and highly modified engines and GTS-2 which are race cars made from street cars but with modified engines, transmissions and suspensions. Major events sanctioned by IMSA include the Rolex 24 Hours of Daytona and 12 Hours of Sebring, the longest running sports car race in the United States.

International Standards Organization: (ISO) A Geneva-based organization established (in its present form) in 1947 to standardize units of measurement and technical design

international tonnage certificate: A certificate issued by a government department in accordance with the International Convention of Tonnage Measurement of Ships stating the gross and net tonnages

international waterways: International straits, inland and interocean canals and rivers separating the territories of two or more nations which are can be navigated by both merchant ships and warships with no restrictions

interplate: See intermediate drive plate

interrupter: See breaker points thermostatic interruptor circuit breaker interruptor: See thermostatic interruptor

intersection: A road junction. See busy intersection controlled intersection interval: See service interval

interval operation:

See intermittent operation

intrachannel competition: Rivalry between channel participants at the same level in the distribution channel. For example, department stores competing with one another.

intracoastal: Domestic shipping routes along a single coast.

intrusion: See footwell intrusion

intrusion beam: See side impact intrusion beam

inventories: The book value of inventory owned and held in a particular country.

inverted telescopic forks: an older name for upside-down forks

Invicta: A vehicle brand of which the 1925-1948 models are classic cars.

invisible glove: See barrier cream

invoice: See dealer invoice

IOE: Acronym for inlet over exhaust

IOE engine:

See inlet over exhaust engine

ion: An electrically charged particle formed by losing or gaining electrons; particles of this type make a solution of certain chemicals a conductor of electricity

ionic-current measuring method: A measure of the conductivity in the spark gap in order to select a spark plug of the correct heat range

ionic-current measuring technique: A measure of the conductivity in the spark gap in order to select a spark plug of the correct heat range

IPR: Acronym for "Intellectual Property Rights."

iridescent: A display of the spectrum of glittering, shimmering colors; often changing as the position or angle from which they are observed, changes

iron: [1] A colloquial term for any automobile. [2] A metal used for making steel. [3] A tire lever or tire iron. [4] A soldering iron. Also see bumper iron cast iron chilled iron laminated iron core pig iron soldering iron tire iron iron core: See laminated iron core

IR remote control:

See infrared remote control

IRTE: Acronym for "Institute of Road Transport Engineers" A British organization set up to increase the competence and professionalism of vehicle drivers and owners

IRS: Acronym for "independent rear suspension."

ISC: Acronym for idle speed control

ISC motor: Acronym for idle speed control motor

ISDT: Acronym for "International Six Day Trial" (a motorcycle race)

island: See traffic island

ISO: Acronym for international Standards Organization

Isolastic: Name for an engine/swingarm rubber mounting system used by Norton on its early Commando motorcycles

isolate the battery: See disconnect the battery

isolator: An item that prevents interaction between two components

iso-octane:

Liquid hydrocarbon used to determine the octane rating of fuels; (see also octane number)

Isotta-Fraschini: A vehicle brand of which the 1925-1948 models are classic cars.

Isuzu: A Japanese manufacturer of SUV, truck, and automobiles Click for books on Isuzu Itala: A vehicle brand of which the 1925-1948 models are classic cars.

ITS: Acronym for idle tracking switch

IVC: Acronym for inlet valve closes

IVO: Acronym for inlet valve opens

IVT: Acronym for "Infinitely Variable Transmission."

IVV: Acronym for idle vacuum valve

Izod method: An impact resistance test in which the specimen is held as a vertical cantilever beam and is broken by a single swing of a pendulum, with the line of initial contact at a fixed distance from the specimen clamp and from the centerline of the notch and on the same face as the notch

Izod test: An impact resistance test in which the specimen is held as a vertical cantilever beam and is broken by a single swing of a pendulum, with the line of initial contact at a fixed distance from the specimen clamp and from the centerline of the notch and on

the same face as the notch

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Ja][Je][Jo][Ju]

jack: [1] A device for lifting the vehicle, or part of the vehicle, off the ground to facilitate repairs. THE MOST COMMON JACKS body jack bottle jack bumper jack garage jack hydraulic jack jib-jack pillar jack scissors jack side-lift jack tire jack tower jack tripod jack trolley jack [2] A characteristic of swing-axle rear suspensions. Cornering forces can act on these suspensions to lift the body of the vehicle so that the outer wheel tucks or jacks under the vehicle. When carried to the extreme, jacking forces could tip the vehicle over.

jacker: See car jacker

jacket: See cooling jacket Japanese lantern-type jacket tube water jacket jacket tube:

See Japanese lantern-type jacket tube

jacking: See car jacking

jack knife: The action of a vehicle (tractor) with a trailer in which the trailer and the vehicle form a "V" instead of normally being pulled in a straight line. Usually this is the result of a skid in which the trailer swings around dangerously and tries to overtake the cab.

jackshaft: See intermediate shaft

jack stand: A safety device that keeps the vehicle from falling to the ground if the lifting jack is removed or faulty. Most jobs require two jack stands for safety. Also called an axle stand

jack up: to raise using a jack

jacking point: A strengthened place on the underbody to put the jack. Small cars have one point on each side but larger cars may have two

Jaguar: A vehicle brand of which The 1932-1940 SS models except 4-cyl. Click for books are classic cars. The 1957-64 3.4/3.8 Sedans are milestone cars. on Jaguar Jaguar E-type: A model of automobile manufactured by Jaguar in England. Click for books on The 1961-67 E-Type models are milestone cars. Jaaguar E-type Jaguar Mark: A model of automobile manufactured by Jaguar in England. The 1946-48 models with 2.5 Litre, 3.5 Litre Mark IV (not 4-cyl.) are

Click for

classic cars. The 1951-54 Mark VII and '54 Mark VII M models are milestone cars. The 1956-57 Mark VIII models are milestone cars. The 1958-61 Mark IX models are milestone cars. The 1962-64 Mark X models are milestone cars. Jaguar XJ: A model of automobile manufactured by Jaguar in England

books on Jaguar Mark series

Click for books on Jaguar XJ

Jaguar XK: A model of automobile manufactured by Jaguar in England. The 1945-54 XK 110 models are milestone cars. The 1954-57 KX 140 models are milestone cars. The 1958-61 XK 150 models are milestone cars.

Click for books on Jaguar XK

Jaguar Drophead: A vehicle brand of which the 1951 Mark V Drophead is a milestone car.

jake brake: A device which shuts off the exhaust valves manually so that in the exhaust stroke, the burned gasses cannot escape through the exhaust valves. Instead they press against the head of the piston and causes the piston to slow down. When the intake valve opens, some of the exhaust escapes out the intake valve and gives a distinctive loud rapping noise. Jake brakes are used in large truck engines to assist in slowing the vehicle. Many municipal bylaws prohibit the use of jake brakes because of the excessive noise.

jalopy: a worn-out old car

jam: See traffic jam

JAMA: Acronym for "Japan Automobile Manufacturers Association"

jamb switch: A push-button light switch located in a door jamb (e.g., for courtesy lights, trunk light)

jam nut: [1] A second nut on a screw or bolt which locks against the first nut (i.e., jams against it) so that the nut won't come loose. [2] A self-locking nut

jam on the brakes: The action of quickly depressing the brake pedal (pulling the brake lever on a motorcycle or bicycle) especially in an emergency situation.

jam the brakes: The action of quickly depressing the brake pedal (pulling the brake lever on a motorcycle or bicycle) especially in an emergency situation.

JAP: English engine manufacturer. Founded in 1903 by John A. Prestwich, the company was bought by Villiers in 1957

Japanese lantern-type jacket tube: A web-type jacket tube of a steering column which, on impact, folds like a Japanese lantern

jaws: See towing jaws

Jeantaud axle and steering: See Ackermann steering

Jeep: A SUV which was originally manufactured by Willys, then owned Click for books by AMC, and now owned by Chrysler. on Jeep jelly: See petroleum jelly

Jensen: A vehicle brand of which the 1925-1948

Click for books on Jensen

jerking: See jolting

jerk pump: one of the pumping elements of an in-line injection pump

jerry rigged: A corruption of the term "jury rigged."

jet: [1] A small precision-made hole. Often a brass fitting placed inside one of the passages of a carburetor to control the flow of gasoline, air, or air/fuel mixture. [2] The nozzle containing such a hole. Also see air correction jet air jet compensating jet economy jet idle air jet idle jet main jet metering jet pilot jet scavenging jet jet adjuster: A nut that regulates the volume or strength of the air/fuel mixture in a variablechoke carburetor

jet bearing: bearing in a Stromberg carburetor

jet carrier: A removable plug in a carburetor containing the jet

jet head:

A removable plug in a carburetor containing the jet

jet needle: A tapered needle in a carburetor jet

jet process: A process by which the thickness of hot-dip galvanized coatings on steel strips can be regulated, allowing the application of coatings of different thicknesses on the two sides of steel strips. When leaving the zinc melting pot, the strip passes two jets through which air, gas, or vapor is directed on the steel strip to remove superfluous zinc. The coating thickness decreases with the strength of the jet

jetronic: See K-jetronic le-jetronic mono-jetronic jet tube: A tube that houses the main jet in an SU carburetor

J-flange: The most widely used rim flange type for passenger car wheels; the J-flange is 17.3 mm in height

J gate transmission shifter: The center console-mounted transmission shifter in Jaguars. The shifter has the normal pattern down the right side (park, reverse, neutral, low, and drive) while on the left side the driver can select 2nd, 3rd, 4th and 5th manually to have more control over the car. And, no clutch is required.

jib-jack: lever-type towerjack

jig: device used in the accurate machining of good in process by holding the goods firmly and guiding tools exactly to position. Also see

welding jig Jim: See big Jim

JIT: Acronym for "Just-in-Time."

JJD wheel: A safety wheel which can be run when deflated. Two independently inflated tires are seated on a double rim consisting of two single rims. The JJD wheel has excellent aquaplaning properties; a reliable tire pressure control system is required, however, since a defective tire is not easily detectable

job: A particular piece of work. Also see botched-up job lube job piston ring job ring job valve job jockey pulley: [1] On a bicycle, the pulley in a rear derailleur that stays closest to the freewheelcogs and guides the chain from cog to cog during a gear shift. [2] A free-turning, spring-loaded idler used to keep tension on the timing belt. Also called "jockey wheel"

jockey wheel: A wheel used to maintain tension in a chain or belt. See jockey pulley

joggle: [1] A slight step along the edge of a panel to provide a level mounting and welding surface so that it can be overlapped against the adjacent panel for subsequent lap or spot welding. [2] to join by means of a joggle

joggler:

A metalworking tool used for creating a joggle

joiner work ceiling: The overhead finished surface in quarters, etc.

joint: [1] Where two pieces meet when a structure is made of smaller pieces. [2] A flexible or firm connector between two rods. Also see ball joint ball joint rocker arm ball joint steering knuckle ball universal joint bevel joint butt joint cardan joint cold solder joint constant velocity joint constant velocity universal joint corner joint CV joint doughnut joint dry joint edge joint flange joint half-moon slip joint pliers hardy-spicer joint hardy-spicer universal joint heim joint homokinetic joint hooke joint impact swivel ball universal joint lap joint plunging joint pot joint Rzeppa-type joint Rzeppa-type universal joint sliding joint slip joint splined joint T-joint tripod joint U-joint U joint

universal joint velocity joint joint boot: See cv joint boot

jointed shaft: See universally jointed shaft

joint pliers: See half-moon slip joint pliers

joint rocker arm: See ball joint rocker arm

joint separator: See ball joint separator

joint socket: See universal joint socket

joint splitting tool: See ball joint separator

joint steering knuckle: See ball joint steering knuckle

joint venture: an international business collaboration between foreign interests and private parties from a host country in which two or more parties establish a new business enterprise to which each contributes and where ownership and control are shared.

jolting: The effect caused by harsh clutch release. The car body jerks repeatedly in a longitudinal direction

Jordan: A vehicle brand of which only the Speedway Series "Z" of 1925-1948 are classic cars.

joule: The international unit of measurement of energy, work, and heat. One joule equals the work done when a force of 1 newton moves a body 1 meter.

jounce: The action of bouncing. When speaking of shock-absorbers, it is the compression stroke while "rebound" is the opposite.

jounce and rebound: See bump and rebound

jounce buffer: See jounce bumper

jounce bumper: An elastic cushion used to stiffen the suspension gradually as it approaches the end of its jounce travel. Also called "jounce buffer." Also see bump stop jounce bumpers: Elastic cushions used to stiffen the suspension gradually as it approaches the end of its jounce travel. Also see bump stop. journal: That part of a shaft that is prepared to accept and support a bearing. The area on the crankshaft that fits into the lower portion of the connecting rod. A layer of oil and metal bering cushions the impact during the power stroke to prevent the crankshaft from being crushed by the swiftly descending piston and connecting rod. Also see camshaft journal crankshaft journal

joyride: [1] A reckless drive in a stolen car. [2] To go for a joyride

joyrider: Someone who goes for a joyride

J-type vent tubes: Special tubes located on the top of marine carburetors that direct any overflow from the carburetor bowl(s) back into the throttle bores. USCG-approved method of preventing fire in the engine compartment of the inlet valve sticks in an open position

jubilee clip: A worm-gear hose clip

judder: [1] to shake or vibrate. [2] shaking or vibration. See brake judder clutch judder wheel judder wiper blade judder juggernaut: A British term for a very large transport truck (i.e., goods lorry); compare road train

juice brake: See hydraulic brakes.

juice brakes: See hydraulic brakes.

Julian: A vehicle brand of which the 1925-1948 models with required application are classic cars.

jumble: See autojumble

jumper: See puddle jumper

jumper cable: See jumper cables.

jumper cables: Cables used to start a disabled vehicle by conducting electrical current from the battery of one vehicle to another so that the disabled vehicle can be started and begin to generate it own power. The British term is jump leads

jump lead: British term for jumper cables or booster cables

jump spark: A high tension electrical current which jumps through the air from one terminal to the other.

jump start: The act of using jumper cables on a weak battery to start a disabled vehicle.

junk: [1] Scrap; unwanted material, e.g, unwanted car parts. [2] to scrap, to throw away unwanted material.

junk ring: A flexible ring used in the cylinder head to provide a seal with the inner sleeve of a sleeve valve engine

junkyard: A place where cars are sent for scrap. Also called "auto graveyard" or "auto wrecker's lot."

jury rig:

The action of cobbling something together instead of put together according to specifications.

jury rigged: Something that is cobbled together instead of put together according to specifications.

just-in-time: (JIT) refers to the movement of material to the necessary place at the necessary time. It is part of a business philosophy based on achieving excellence in a manufacturing company through the continuous elimination of waste.

just-in-time system: A system of production where components are delivered as they are required rather than keeping them in store

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Ka] [Ke] [Ki] [Kl] [Kn]

Kadenacy effect: when a port of a two-stroke engine opens abruptly, as is the case with a rectangular exhaust port, the cylinder pressure gives rise to a positive pressure wave transmitted down the exhaust pipe at the speed of sound

KAIDA: Acronym for "Korea Automobile Importers and Distributors Association."

Kaiser: A vehicle brand of which the 1954 Darrin 161 is a milestone car. The 1951-52 Deluxe and Deluxe Virginian are milestone cars. The 1951-53 Dragon models are milestone cars. The 1954-55 Manhattan models are milestone cars. The 1949-50 Vagabond models are milestone car. The 1949-50 Virginian (Hardtop) models are milestone cars.

Click for books on Kaiser

Kaizen Activities: activity through which continuous improvement is sought.

KAM: See keep alive memory

KAMA: Acronym for "Korean Automotive Manufacturers Association"

kamm back: It was once thought that a long tapered end in the shape of a vehicle would give it the most aerodynamic configuration. W. Kamm discovered that the length of the end would have to be so long as to make the vehicle impractical. There would also be an increase in surface area which would also create its own frictiondrag. He found that if he cut the theoretically long tail in half he would have both good aerodynamics and minimal surface drag. This sharply cut off rear end is named after him.

kamm tail: It was once thought that a long tapered end in the shape of a vehicle would give it the most aerodynamic configuration. W. Kamm discovered that the length of the end would have to be so long as to make the vehicle unpractical. There would also be an increase in surface area which would also create its own frictiondrag. He found that if he cut the theoretically long tail in half he would have both good aerodynamics and minimal surface drag. This sharply cut off rear end is named after him.

kangarooing: A colloquial term for moving forward in a succession of sudden jerks as a result of improper use of the clutch, (a characteristic of beginner drivers or those not used to standard shifting)

Karosserie: German term for coachwork.

KD: Acronym for kickdown

keel: The principal fore-and-aft component of a ship's framing located along the centerline of the bottom and connected to the stem and stern frames. Also see bilge keel center vertical keel even keel flat plate keel keel blocks: Heavy wood or concrete blocks on which ship rests during construction or drydocking

keel, flat plate: The horizontal, centerline, bottom shell strake constituting the lower flange of the keel

keelson:

See center keelson

keep alive memory: (KAM) fault memory. A series of vehicle battery powered memory locations in the computer which allows it to store input failures identified during normal operation for use in later diagnostic routines. KAM even adopts some calibration parameters to compensate for changes in the vehicle system

keeper: [1] A vehicle that is worth keeping because it will be worth more in the future. [2] A device which holds something in place. See valve keeper. [3] A person who uses or stores a vehicle whether he is the owner of it or not. See registered keeper

keiretsu: A Japanese word referring to the large groups of companies that are a characteristic feature of the Japanese economy, especially in the auto industry. Keiretsu companies do business first and foremost among themselves; tight supplier-buyer relationships within the keiretsu system are a barrier to the penetration of foreign goods in Japan because, everything else being equal, keiretsu members prefer to buy from other keiretsu members; the keiretsu system is a controversial issue in USJapanese trade relations. Also see horizontal keiretsu vertical keiretsu KE-Jetronic: This third generation K-Jet system combines mechanical control with electronic regulation of the mixture. Many of the sensors it uses are the same as those used in L-Jetronic systems. VW, Audi, And Mercedes refer to it as CIS-E

KE-Motronic: This Bosch system is similar to KE-Jetronic, except that it has ignition-timing control and all the other features as any other Motronic system.

Kennedy key: two keys in a tangential configuration

kerb:

A British term for a curb -- a stone or cement ridge between the road and the sidewalk.

kerb weight: British term for "curb weight" -- the weight of a vehicle with fuel, oil, and coolant; but without occupants, luggage, or cargo.

kerfs: See sipes

kerosene: [1] fuel for jet engines [2] A solvent used to remove grease. The British term is "paraffin." Also spelled "kerosine"

kerosine: [1] fuel for jet engines [2] A solvent used to remove grease. The British term is "paraffin." Also spelled "kerosene"

kevlar: The brand name of a synthetic fabric that is clothlike in feel and is used by motorcyclists when riding in cold weather. In racing, the material of choice for NASCAR Winston Cup cars. Kevlar was chosen by NASCAR because of its durability, because it would hold up under problems on the race track. This material ensures that the nose piece holds its shape, even up to 200 mph. Any drastic changes in the shape of the nose piece will ultimately, and consequently, have a profound effect on the car's handling

key: [1] A parallel-sided piece inserted into a groove cut part way into each of two parts, which prevents slippage between the two parts and they rotate together. Used to secure gears, pulleys, cranks, handles, etc. [2] A metal instrument for turning locks and key-operated switches. [3] An L-shaped tool for turning recessed screws (e.g., Allen key). [4] A roughened surface which provides a basis for subsequent layers of paint or filler. [5] To adhere to a lower layer. [6] The act of a vandal who scratches the finish of a car with his key or other sharp instrument.

Also see allen key Allen wrench car key drain plug key feather key flat key gib-head key half-moon key hexagon key hex key ignition key kennedy key nordberg key P&W key parallel key Pratt and Whitney key primary key secondary key square key valve key woodruff key. keyed: See color-keyed

key file: A small file with a length of 100 or 150 mm (4 or 6") for sharpening key holes and other small components, available in standard shapes, e.g., as flat tapered, flat parallel, half round, three square, square, or round file

key fob: A device to hold keys.

keyhole: A term applied to the enlarged root opening which is carried along ahead of the puddle when making a plasma arc weld or with some other types of welding.

keyless entry system: A system which allows you to lock and unlock your vehicle's doors and trunk without using a key. One system is operated by punching a typically five digit code into a calculator-style keypad located on the driver's door; if more than five seconds

elapse between button pushes, the system will abort, requiring you to start again. Another system uses a dedicated frequency in a special key fob. Pressing the "lock" button will lock all doors and sound the horn for a very short beep. Pressing the "unlock" button once will unlock only the driver's door; but pressing it twice will unlock all the doors. Also see remote keyless entry keyseat: The groove or slot where a key rests. Also called keyway

keystone frame: A diamond-type motorcycle frame in which the engine serves as part of the structure

keyway: A slot cut in a shaft, pulleyhub, wheel hub, etc. A square key is placed in the slot and engages a similar keyway in the mating piece. The key prevents slippage between the two parts. Also called "keyseat."

K-flange: A rim flange type for passenger car wheels; the K-flange is 19.3 mm in height and rarely used today. Compare j-flange

Kia: A model of automobile manufactured in Korea

Click for books on Kia

kick: A term for beginning to harden, the initial phase of the hardening process of plastic body fillers. The British term is "go off"

kickback: See steering kickback

kickdown: (KD) A British term for a forced downshift, i.e., a device on a automatic transmission which allows the driver to switch to a lower gear during hill climbing or passing. Instead of manually moving the gear selector, he simply pushes down hard on the accelerator. This gear is sometimes called "passing gear"

kickdown switch: An electrical switch that will cause a transmission, or overdrive unit, to shift down to a lower gear. Often used to secure fast acceleration. Also called "kickdown valve"

kickdown valve: A mechanically or electrically operated valve which actuates a downward gearchange if the accelerator pedal is fully depressed

kicker: See tire kicker

kick panel: A vertical panel wall enclosed by several structural members (e.g., the side panel ahead of the A-pillar that extends up to the sides of the bulkhead and is limited by the floorpan at its bottom end)

kickplate: See scuff plate

kick strip: See scuff plate

kick start: To start a motorcycle engine by kicking a pedal downwards

kickstarter: A pedal lever and ratchet mechanism for kick starting an engine

kickup: A raised section of the frame and body to provide clearance for the front and/or rear suspension system or axles

kickup pipe:

An exhaust pipe section including the elbow or "U" around the rear axle

kidney dolly: See toe dolly

killer: See rust killer

kill switch: A special switch designed to shut off the ignition in case of an emergency. Also see tether kill switch kilometer: (km) A unit of length. 1 km = 0.6213712 miles (about 5/8 mile); 1 mile = 1.609344 km. In Canada it is pronounced KILL-oh-mee-ter, but elsewhere it is pronounced kull-LAW-mitt-er. Colloquially it is referred to as a "klik" or "klick"

kilometer per hour: (km/h or kph) A unit of velocity KPH MPH 30

19

31

20

48

30

50

31

60

37

64

40

70

44

80

50

90

56

97

60

100

62

110

68

113

70

kilometre:

British and Canadian spelling of kilometer

kilopascal: (kpa) SI measurement of pressure (1000 pascals)

kinetic balance: See static balance.

kinetic energy: The mechanical energy possessed by a body due to its motion. It may be calculated from the formula: Kinetic energy = 1/2 mass x (velocity)ý.

kingpin: A hardened steel pin that is passed through the steering knuckle and axle end. The steering knuckle pivots about the kingpin. A vertical or inclined shaft about which a steered wheel pivots. In newer cars the kingpin has been replaced by ball joints. The British term is "trunion."

kingpin axis: The centerline of the ball joints in a front suspension system. Also called "swivel axis"

kingpin inclination: (KPI) The angle made of the kingpin axis to the perpendicular as viewed from the front. An alignment adjustment where the tops of the kingpins are tipped inward toward each other. This places the center line of the steering axis nearer the center line of the tire-road contact area. Thus when the vehicle comes out of a turn, the steering wheel returns to the straight-ahead position. Also called "steering axis inclination" or "swivel-axis inclination"

kingpin offset: A geometric parameter which is "positive" if the kingpin axis intersects the wheel plane at or below ground level, or is "negative" if the point of intersection is above ground level. Also called "scrub radius"

kink: [1] twist or sharp bend in a hose

[2] to form a kink

Kissel: A vehicle brand of which the following models: 1925-26 all models, 1927 8-75, 1928 8-90 and 8-90 White Eagle, 1929 8-125 and 8-90 White Eagle, 1930 8-125 are classic cars.

kissing between duals: The intermittent contact of tires in dual as they flex; caused by inadequate dual spacing or by overload.

kit: A set of tools, parts, etc. See body styling kit bolt-on kit bonnet pin kit first-aid kit hood pin kit lowering kit repair kit straightening kit tune-up kit kit car: car that is assembled (often by the DIY enthusiast) from its constituent parts; usually with a GRP body shell

K-jetronic: A commonly used mechanical fuel injection system made by Bosch in which the amount of fuel injected continuously under pressure into the inlet ports is controlled by an airflow meter. Term used by Bosch to describe the original continuous injection system. The K is short for kontinuerlich, "continuous." Airflow i measured by a circular plate inside the airflow sensor part of the mixture control unit. Fuel delivery was purely mechanical, in relation to airflow, until 1980, i.e., there were no electronics used in the K-Jet system. VW, Audi, and Mercedes call it CIS

K-Jetronic with Lambda: Second-generation K-Jet system, which began in 1980, uses a feedback loop consisting of an oxygen sensor and a control unit to provide some electronic control of the air-fuel mixture. This system is also called "CIS with Lambda" Lambda is the

Bosch term for an oxygen sensor

klick: See kilometer

klik: See kilometer

km: Abbreviation for kilometer

km/h: Abbreviation for kilometer per hour

knee, beam: Bracket between a deck beam and frame

kneeling feature: A device that is put on a van or bus, which allows the entire right side to become lower thus offering someone who has trouble going up steps easy access to the vehicle.

kneuter valve: This is the unknown part that causes a car's weird problems that a mechanic cannot find or repair.

knife: See jack knife putty knife

knifing stopper: fine grade filler for minor dents and chips

Knight: See Stearns-Knight Willys-Knight

KNK: Acronym for knock sensor

knob: See choke knob gear knob mixture control knob shifter knob spinner knob knobby: See knobby tire.

knobby tire: On a bicycle or motorcycle, a heavy-duty tire with large rubber knobs spaced relatively far apart to provide traction in wet, muddy terrain.

knobby tires: See knobby tires.

knock: [1] A general term used to describe various noises occurring in an engine; may be used to describe noises made by loose or worn mechanical parts. [2] Preignition, or detonation. Also see anti-knock agent carbon knock diesel knock engine knock fuel knock spark knock knock additive: See anti-knock additive

knockback: The action of a brake disc with excessive runout pushing back the brake pads when the brakes are not applied

knock control: A device which retards the spark advance when detonation occurs. The retard mode is held for a certain time, typically 20 seconds, after which the knock control reverts to normal operation

knocker: A colloquial term for a panel puller

knocking: [1] Noise created by part movement in a loose or worn bearing. [2] A condition, accompanied by an audible noise, that occurs when the gasoline in the cylinders burns too quickly. This is also referred to as detonation.

knock limit: The degree of spark advance before detonation

knock off: A single, large wing nut for fastening a wheel to the hub. Easily removed and replaced, it is struck (knocked off) with a mallet on the wings. Also called a "spinner."

knock-off wheel: A splined-hub wheel with one central locking nut (spinner) which is knocked on and off with a soft-headed hammer

knock-on: A knock off nut

knock resistance: See octane number

knock sensor: (KNK or KS) a piezoelectric accelerometer mounted on the engine to detect the high-frequency vibrations caused by detonation. Since an engine gives the best power and efficiency as it approaches detonation, the knock sensor can relay this information to a computer which can control the factors leading to detonation. Also called detonation sensor

knot: A unit of speed in nautical mile (6,080 feet or 1,852 meters) per hour.

knuckle: [1] the joint of a hinge through which the pin passes; [2] The hinged joint between two rods or tubes. also See ball joint steering knuckle steering knuckle knuckle angle: See steering knuckle angle

knuckle arm: steering arm. Also see steering knuckle arm knuckle pin: See kingpin

knurl: [1] A series of small ridges on nuts and knobs to provide a grip for fingers. [2] To indent or roughen the finished surface of a piece of metal by pressing a series of cross-hatched lines into the surface and thereby raising the area between these lines.

knurled nut: A thumb nut with knurled sides

knurling: roughening with knurls

KPH: Acronym for "kilometer per hour." Speeds in Canada and Europe are posted in kph. To convert kph to mph, divide by 1.609344. Thus 50 kph is about 30 mph; 70 kph is 44 mph; 90 kph is 56 mph; 100 kph is 62 mph; 110 kph is 68 mph. Maximum speed

in Canada on its freeways is 110 kph. Also abbreviated "km/h"

KPI: Acronym for kingpin inclination

krinkle finish: hard-wearing, usually mart black finish, often used for rocker covers

KS: Acronym for knock sensor

Kyoto Protocol: international agreement among industrialized countries to reduce greenhouse gas emissions negotiated in Kyoto, Japan in December 1997. Canada committed to reduce its greenhouse gas emissions by 6 percent of 1990 levels between 2008 and 2012.

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [La] [Le] [Lh] [Li] [Lo] [Lu]

L: [1] Low gear in an automatic transmission. [2] Designation for luxury or luxe

l/100 km: This is the metric measurement of fuel consumption or fuel economy. The lower the number the more economical the vehicle. Thus a vehicle that gives 7 l/100 km is better than one that gives 8 l/100 km. A vehicle that gives 7.3 l/100 km is giving 32.2 mpg US and 38.7 mpg Imperial.

LAADA: Acronym for "Latvian Authorized Automobile Dealers Association."

Labelling Act: See American Automobile Labelling Act

labour: An engine which is struggling to keep turning due to lack of revs or the use of too high a gear

labouring: A British term for "lugging" which indicates an engine having difficulty in turning.

lacquer: [1] A fast drying automotive body pyroxylin paint. [2] A glossy coating made by dissolving cellulose derivatives in a rapidly evaporating solvent. Also see clear lacquer general purpose lacquer thinner

lacquer thinner: See general purpose lacquer thinner

ladder bars: A rigid triangular suspension devices used to locate an axle front to rear. These are used almost exclusively in drag race cars due to the fact that they bind when cornering. A panhard rod or a watts link is used to locate the axle side to side.

ladder chassis: See ladder frame

ladder frame: A type of frame design which has two long parallel sections which run from the front to the rear of the vehicle. In various places there are shorter sections which connect the long sections. The result looks like a ladder. The connecting pieces hold various components such as the engine. This design is not used today because it is too heavy and lacks rigidity. Also called "ladder chassis"

laden weight: See gross vehicle weight.

lading: The load or freight that a vehicle carries. Also see bill of lading ladies' frame: The type of frame in which the top tube is replaced by a second down tube to make mounting and dismounting the bike easier.

lag: also See ignition lag lead and lag turbo lag Lago:

See talbot Lago

Lagonda: A vehicle brand of which all 1925-48 models except Rapier are classic cars. See the 1938 Lagonda. The 1948-49 V-12 models are milestone cars.

Lagonda Drophead: A vehicle brand of which the 1949-53 2.5 Liter Drophead Coupes are milestone cars.

lake pipes: Nonfunctional side pipes attached along the lower sides of a vehicle for decorative purposes only. Also called "Lakes pipes" or "lakers"

laker: A type of ship which trades only in the Great Lakes of North America. The cargo is usually grain and ore.

lakers: Nonfunctional side pipes attached along the lower sides of a vehicle for decorative purposes only. Also called "lake pipes" or "Lakes pipes"

Lakes pipes: Nonfunctional side pipes attached along the lower sides of a vehicle for decorative purposes only. Also called "lake pipes" or "lakers"

Lakes ship: See Great Lakes ship

lambda: [1] Eleventh letter of the Greek alphabet. In upper case it looks like "A" without the cross bar. In lower case it looks like an up-side-down "y". [2] Bosch's term for oxygen

lambda control: Bosch's term for a closed loop system that adjusts the air-fuel ratio to lambda-1, based on sensing the amount of excess oxygen in the exhaust

lambda control valve: See frequency valve

lambda probe: See oxygen sensor

lambda sensor: See oxygen sensor

Lambda valve: In Bosch CIS, a device that regulates pressure in the lower chamber of the differential-pressure valve, in response to a signal from the lambda (oxygen) sensor. Also called frequency valve or a timing valve

lambda window: A narrow range (where lambda = 1), which yields the lowest emission values for CO, NOx, and HC

Lamborghini: A model of automobile manufactured in Italy

Click for books on Lamborghini

laminate: [1] To build up or construct out of a number of thin sheets which are bonded together. The magnetocoil has a laminated core. [2] A sheet of material made of several different bonded layers. Also see sandwich laminate laminated: Something made up of many layers.

laminated glass: A sandwich-type construction of two or more panes of glass laminated together with an extremely tough, crystal-clear plastic film; on severe impact, laminated glass will crack, but not shatter like ordinary glass, nor craze over like toughened glass

laminated iron core: The core of an ignition coil consisting of pieces of soft iron laminations, insulated from one another

laminated windshield: Older safety windshields were made of tempered glass which is heat treated so that the surface is very tough. When a vehicle with tempered glass is involved in an accident, the windshield shatters into a spider web of little crystals. Its adhesive property is greatly diminished so that an object (your body) can easily be ejected through the windshield. Laminated windshields, however, are made with two sheets of glass with a thin layer of rubbery plastic in between. When your head hits the windshield, the windshield bows out without being punctured. The plastic sandwich prevents the glass from splintering. The "plastic sandwich" can also contain a tint to reduce heat in the passenger compartment and protect the eyes from glare (like sunglasses). Compare toughened windshield

laminated windshield glass: See laminated windshield.

laminating: Covering sheets with a particular layer or covering molded parts with a specific plastic film

lamination: [1] The act of laminating. [2] A thin layer. [3] A structure made up of thin layers

lamp: A device for giving off light without being consumed itself. Also see auxilliar driving lamp blowlamp clearance lamp dome lamp driving lamp fog lamp gas discharge lamp gaseous discharge lamp headlight headlight retractor indicator lamp

inspection lamp linear lamp linear source lamp marker lamp numberplate lamp parking lamp puddle lamp rear fog lamp rear lamp cluster rear license plate lamp repeater lamp side marker lamp spot lamp strobe lamp tail lamp test lamp warning lamp lamp aperture: An opening in a sheet metal panel for mounting the headlight or taillight

lamp blackening: The blackening of a light bulb; gradual blackening of conventional, i.e., nonhalogen light bulbs, occurs as a result of metal vapor deposition on the glass envelope which reduces light emission; severe blackening indicates imminent bulb failure

lamp cluster: A group of lights behind a cover; the rear lights of most cars are grouped together in clusters. Also see rear lamp cluster lamp panel: A panel that encloses part or all of the headlight or taillight cutout and may extend across the width of the car to include both cutouts; in the latter case, it forms an additional panel to be joined to the smaller front or rear valances

lamp socket: A device which holds a light bulb and provides electricity to the bulb. The British term is bulb holder

lamp unit: A sealed light unit with reflector and lens all-in-one

Lanchester: A vehicle brand of which the 1925-1948 models with required application are classic cars.

Lancia: A vehicle brand of which the 1925-1948 models with required application are classic cars. The 1959-64 Flaminia Zagato models are Click for milestone cars. The 1961-63 Flaminia GT Two Passenger Coupe or Convertible are milestone cars. The 1962-66 Flavia Coupe are milestone books on cars. The 1951-59 Aurelia B.20 and B.2O Coupe are milestone cars. The Lancia 1953-59 Aurelia B.24 Spyder and Convertible are milestone cars. lancing: See wax lancing

land: The smooth, open area of a grooved surface, such as the bands of metal between the grooves in a piston which carry the piston rings. The metal separating a series of grooves. Also see head land piston lands top land landau: A closed-type body on the sides, it has provision for opening or folding the fabric top over the rear quarter. This precludes the use of rear quarter windows. Landau irons are fairly common but not a mandatory feature.

landau bar: See landau bars.

landau bars: S-shaped bars or irons on the C-post. On convertibles, they are functional; but decorative on other body styles.

landaulet: A classic car style characterized by the fact that only the rear seats were protected by a hard or convertible top, whereas the driver was exposed to the open air in order to be more aware of road and weather conditions; an imitation landaulet style is still found on some American sedans. Also called landau

landaulet sedan: This body style is similar to the landau sedan in appearance, but with a stationary rear quarter. Landau irons are mounted on the rear quarter but are non-functional.

landing: See hood landing panel

landing panel: also See bonnet landing panel hood landing panel landing section: See fender landing section

land management: See bureau of land management

Land Rover: An SUV built in England

Click for books on Land Rover

lands: The piston metal between the ring grooves. See piston lands.

lane: [1] A narrow road, often in the country. [2] A track on a road, defining lines of traffic. Also see crawler lane fast lane

passing lane splitting lanes lantern-type jacket tube: See Japanese lantern-type jacket tube

lap: [1] One complete trip around a race track or route laid out for racing. [2] To fit two surfaces together by coating them with abrasive and then rubbing them together (e.g., to lap valves into valve seats). [3] The upper surface of the human body from waist to knees when seated. [4] A rotating disc covered with fine abrasive for polishing. Also see pace lap turn a lap lap belt: A 2-point belt pulled across the hips, or lap belt portion of a combined lap/shoulder belt; mostly only on the rear center seat, on some models on all rear seats. See submarining

lap joint: [1] A piston ring gap in which the two ends of the ring are shaped like the letter "L". [2] A welding term describing a union in which the edges of the two metals to be joined overlap one another.

lapper: See valve lapper

lapping compound: See valve lapping compound

LaSalle: A vehicle brand of which the 1927-1933 models are classic cars.

lash: [1] The amount of free motion between two components (e.g., two gears). The British term is "free play." also See

backlash valvelash whiplash [2] Acronym for "Lighter Aboard Ship": a ship designed to carry floating containers or lighters.

last station memory: An audio and video term describing the circuit which ensures that when the unit is turned on, the tuner automatically tunes to the station that was received before the unit was turned off

latch: A fastening device for a door or panel. It consists of a small metal bar, either mounted on the movable part (always on doors and on some tailgates), or on the car body (always on hoods and trunks), which engages with a striker on the opposite part. Also see door latch latching pillar: See B-pillar

latch pillar: See B-pillar

late braking: Braking later into the turn, thus moving the entry point and axis of the vehicle

latent heat: The heat absorbed or radiated during a change of state at constant temperature and pressure. Called latent cause it is hidden--cannot be felt or measured with a thermometer

latent heat of condensation: The amount of heat given off when a substance changes from a vapor to the liquid without changing temperature

latent heat of evaporation:

The amount of heat required to change a liquid into a vapor w/o raising the temperature of the vapor above that of the original liquid

lateral: Relating to the side.

lateral acceleration: The acceleration created when a vehicle corners that tends to push a vehicle sideways. Because of centrifugal force, the vehicle is pushed outward. For this reason, you need to accelerate a little as you reach the apex of the curve to pull you through the curve. An inexperienced driver may panic in a curve as the lateral acceleration pushes his vehicle into the left lane. He might hit the brakes to slow the motion only to find that the problem actually increases. The proper way to take a sharp corner is to slow down before the curve, then accelerate at the apex of it to bring the vehicle around. To increase your frustration, try following an inexperience driver as he drives on mountain roads. He maintains his speed to the corner and brakes at the apex. Also see acceleration lateral air passage: A passage at the nozzle of a spray gun for shaping the spray pattern to a long or elongated oval

lateral arm: A suspension member connecting the upright to the chassis. See transverse arm.

lateral atomization orifice: An additional passages at the nozzle of a spray gun for supplying additional air to break up the paint into smaller droplets

lateral clearance: The smallest distance laterally between the tire and the nearest fixed point of the vehicle.

lateral grip: The ability of a tire to maintain its course, or remain under normal steering control, while being subjected to directionally disturbing influences

lateral impact: A side crash

lateral link: A suspension link that is aligned to resist sideways motions in a wheel.

lateral run-out: [1] Amount of side movement of a rotating wheel, tire, or the rotor from the vertical. [2] A tire assembly that does not run true to its plane; i.e., a damaged wheel moving in a wobbling, side to side manner.

lateral runout: See lateral run-out

lateral stability: Limiting side movement. (1) Tread grooves running circumferentially around the tire resist side forces for maximum traction on sums. (2) Stabilizing tread plies limit side to side movement of the tread ribs caused by the expansion and contraction of tread areas as sidewalls flex. Also called lateral grip

lateral stiffness: The resistance of a vehicle body structure to lateral impact

lateral tire clearance: The distance between the tire sidewall and the nearest point on the vehicle, reduced by any increase in rim offset and 1/2 any increase in tire section from the existing tire.

lathe: A device for shaving the metal from the outside or inside of a cylinder. Also see brake drum lathe law: also See Newton's law Pascal's law

lay-by: A British term for a "rest stop," i.e., a place at the side of a road where drivers can stop (to rest)

layer: A certain weld metal thickness made of one or more passes. Also see anodic oxide layer catalytic layer gamma layer zinc-iron alloy layer layer of pure zinc: The top layer on hot-dip galvanized steel which, in contrast to zinc-iron alloy layers, almost completely consists of zinc

layer thickness: A coating thickness (indicated in micrometers or millimeters)

laying up: The process of adding several layers of fibreglass mat and resin to form a GRP shell

layout: See drive layout east-west layout engine layout north-south layout Layrub coupling: A universal joint using four molded rubber inserts mounted on a round steel plate

layshaft: A British term for a countershaft -- the intermediate shaft between and parallel to the input and output shafts, carrying the two pairs of gearwheels which provide the required changes in gear ratio

lay-up resin:

The resin substance used to laminate GRP parts. The resin available on the do-ityourself market for fibreglass mat repairs also belongs to this category

lazy tongs: [1] Any device with extensible arms (often in the form of a series of crossed, hinged bars) for handling objects at a distance. [2] A specific type of pop rivet gun with such arms

lb: Abbreviation for "pound."

LCD: Acronym for "Liquid Crystal Display." An optical, digital display used in the instrument panel

LCV: Acronym for "Light Commercial Vehicle."

LDC: Acronym for lower dead center

LDPE: See low-density polyethylene

Lea: A vehicle brand of which the 1950-54 Francis 2.5 Liter Eighteen Sports models are milestone cars.

lead: [1] [pronounced LEED] A short connecting wire which makes electrical contact between two points. [2] [pronounced LEED] The distance from the thread crest of a bolt or screw to the adjacent crest of the same thread, i.e., the distance a screw thread advances in one full turn. [3] [pronounced LED] A soft, toxic, heavy metal used in storage batteries, and as an anti-knock agent added to gasoline in the form of tetraethyl lead. Also see body lead

coil lead high tension lead HT lead ignition lead jump lead low tension lead paddling the lead red lead spark plug lead spongy lead tetraethyl lead tetramethyl lead lead-acid battery: A system of lead plates and dilute sulphuric acid; used as a starter battery and as a traction battery in electric vehicles

lead and lag: The terms referring to the time between a valve opening and TDC or BDC (valve lead), and the time between TDC or BDC and a valve closing (valve lag); (compare valve overlap)

lead-antimony grid: See grid

lead ballast: See dry ballast.

lead burning: Joining two lead pieces by melting or fusing the metal where they touch each other

lead deposit: Lead particles that separate from the battery plates during normal operation

lead dioxide: A combination of lead and oxygen, as found in the storage battery. Lead dioxide is reddish brown in color

leaded gasoline:

Gasoline to which lead has been added as an anti-knock agent

leaded petrol: British term for leaded gasoline

leaders: See loss leaders

lead free: Until 1973 all new vehicles used gasoline that had tetraethyl lead or some other lead compound as an additive to increase octane rating and reduce knock or detonation. In 1973, almost all new cars required lead-free gasoline (unleaded gas). The exhaust valves in older cars were lubricated by the lead, so they were redesigned to accommodate the new gasoline. To offset the detonation problem, the compression ratio was also reduced. Lead-free gasoline was introduced to remove the lead in the exhaust fumes as a health hazard.

lead-free gasoline: See lead free

lead-free petrol: British term for lead free gasoline

lead glazing: A faulty spark plug condition caused by molten lead salt deposits that solidify into a yellow, brown, or green glaze

leading: Forward or at the front. Also see double leading brake shoe leading arm: A suspension system which has two long arms that extend forward from the pivot points of the arms. The wheels are attached to the forward end of these arms. The Citroën 2CV has this form of independent suspension. Compare trailing arm

leading brake shoe:

also See primary forward brake shoe single leading brake shoe double leading brake shoe leading edge: The forward edge (e.g., of a body panel). Compare trailing edge

leading link: A suspension link that is aligned to resist longitudinal motions in a wheel; it is mounted to the chassis behind the wheel. The axle is mounted at the front end of two short links that pivot at the bottom of solid forks, The link s are sprung to control movement. A long leading-link system has a complete fork that pivots behind the wheel

leading shoe: The British term for primary shoe, the shoe of a brake drum system which pivots outwards into the approaching drum. Compare trailing shoe

lead loading: The process of filling dents and damaged areas of the bodywork with body lead

lead peroxide: A poisonous compound used, for example, as an electrode in batteries

leads: See carbon-core leads high-tension leads high tension leads and low tension leads

lead sled: See leadsled

leadsled: A typical body style of a custom car that became popular in the USA in the 1950s such as the Mercury; the term derives from the fact that large amounts of body lead are required to achieve the smooth body lines desired

lead sulphate: Chemical compound; poisonous white crystals found in discharged batteries

lead tolerance: Resistance to leaded fuel

lead weight: A balance weight on a wheel rim. Also called wheel weight. Also see red lead lead wire: A welding term referring to the electricity carrying wire from the power source to the electrode holder or to the ground clamps.

leaf: also See auxiliary leaf helper leaf leaf spring longitudinal leaf spring quarter-elliptic leaf spring leaf spring: A length of flat spring steel plates bent in an arch usually with curled ends to allow mounting to the frame. Two holes are drilled in the center to mount a u-bolt shackle which surrounds the axle. Some applications need only one leaf spring; but most have several leaves, each smaller than the other, nested together. Only the longest one is mounted to the frame. Also called semi-elliptic springs. Also see longitudinal leaf spring quarter-elliptic leaf spring semi-elliptic leaf spring tapered leaf spring taper leaf spring transverse leaf spring leak: also See

helium leak test slow leak stop-leak leakage: See compression leakage

leak detector: Any device used to detect leaks in an air conditioning system (dye, solutions, electronic, propane, etc)

leak down tester: The leak-down tester is similar to a compression tester, except the engine does not need to be cranked over. Instead, the leak-down tester pressurizes the cylinder and then measures the amount of cylinder pressure lost through worn piston rings. This lost pressure is called blow by and can indicate a defective valvetrain or blown head gasket.

leak-off pressure: Manufacturer-specified pressure used to test injector leakage on a pop tester

leak test: See helium leak test

lean: [1] A weak air/fuel mixture that has less fuel to air ratio. The opposite is rich. [2] A lateral movement where one side lists more than the other.

lean air-fuel mixture: A mixture of air and fuel in which there is more air and less fuel. See air-fuel ratio.

Lean Authority Limit Switch: A device developed by GM to monitor heated carburetor inlet air through an air cleaner tvs and to prevent the control unit from providing the carburetor with too lean a mixture, for better performance when starting from cold

lean-burn engine:

An engine which uses a lean mixture of fuel and air to increase fuel economy and reduce exhaust emissions. Also see CACIS lean mixture: A mixture of air and fuel in which there is more air and less fuel. See air-fuel ratio. The opposite is rich mixture. Also see stoichiometric ratio lease: Form of contract transferring the use of a vehicle in consideration of payment. Also see closed end lease off-lease open end lease subsidized lease subvented lease lease term: The duration of the lease. 24 and 36 month leases are the most common but you can lease a vehicle for 12, 48, or even 60 months if you choose. Remember that your monthly payment will change depending on the length of the lease.

leasing: The financial plan like renting where you pay a sum of money each month in return for the use of a vehicle instead of buying it outright. Open-end leases allow you to pay an additional amount at the end of the term so that you can own the vehicle. Sometimes this is called the buy-back option. Closed-end leases state that at the end of the term the ownership and possession of the vehicle must revert back to the leasing agency. Leasing used to be the domain of businesses; but because of the high cost of vehicles, leasing is now an option for the average consumer.

leather: also See chamois leather full leather upholstery full leather leathers:

Apparel worn by those riding motorcycles. They consist of a leather jacket and leather trousers. Their purpose is to reduce the possibility of injury in the event of a fall; but they also provide warmth when riding because the rushing air will tend to cool off the rider.

leather upholstery: See full leather upholstery

LED: Acronym for "Light Emitting diode." A semiconductor device used for digital displays in the instrument panel

ledballast: See dry ballast.

ledge: also See safety ledge special ledge left: When referring to the side of a unit, the left side is always from the perspective of operation. In other words, when sitting in the driver's seat or when pushing a mower, the left side is the operator's left side.

left-hand drive: (LHD) A steering system where the steering wheel is located on the left-hand side of the vehicle; used for driving on the right, as in most parts of the world, except for the UK, Australia, Hong Kong, and Japan. The opposite is right-hand drive (RHD)

left hand gear lever: A device which is attached to the gear lever on the right side of the steering column which allows those who have no use of their right hand to shift gears. left hand monkey wrench: See left-handed monkey wrench.

left-handed monkey wrench:

See left-handed monkey wrench.

left hand rule: To determine direction of lines of force, grasp conductor with left hand thumb extended in direction of current flow. Fingers indicate direction of lines of force

left hand thread: See left-hand thread.

left-hand thread: Most threads on bolts have right-hand thread meaning that turning the bolt clockwise inserts or tightens the bolt; counterclockwise loosens or removes the bolt. But in left-hand thread the reverse is true. Turning the bolt clockwise loosens or removes the bolt. Left-hand thread is used on applications where the normal turning motion of the object is such that there is a possibility that the object could back out and be removed. For instance, the left pedal of a bicycle turns around the crankarm in a counterclockwise direction. If it had right-hand thread, the pedal could fall off. Thus all left pedals have left hand thread so that the motion of the pedal helps to keep the pedal tight on the crankarm.

left handed monkey wrench: See left-handed monkey wrench.

left-handed monkey wrench: A fictitious tool. A monkey wrench is a pipe wrench, a wrench with an adjustable jaw.

leftward welding: Welding a seam towards the left

leg: See chassis leg

Legere: See voiture Legere

leg of fillet weld:

Distance from point where the base metals touched to toe of the fillet.

Le Grand Livre: Literally "the big book" which lists every Paris-Brest-Paris bicycle finisher going back to 1891.

legroom: The amount of space available to move one's legs in a vehicle

LE-Jetronic: The LE-Jetronic system incorporates the advantages of direct airflow measurement with the enhancements afforded by electronics. Electromagnetically actuated injectors inject fuel onto the intake valves. Each cylinder has its own solenoid injector which is actuated once with every crankshaft revolution. The injectors are opened by control pulses delivered by the ECU; the length of these pulses depend on the quantity of inducted air, engine speed and other parameters. All of these parameters are detected by sensors and processed in the control unit

Le Mans: A model of automobile manufactured by Pontiac division of General Motors lemna: See bridge.

lemon: A new or used car with many defects

length: also See floodable length free length nominal length overall length shank length length between perpendiculars:

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The length of a ship between the forward and after perpendiculars

length, overall: The extreme length of a ship measured from the foremost point of the stem to the aftermost part of the stern

lens: [1] A specially treated glass through which a welder may look at an intense flame without being injured by the harmful rays, or glare, radiating from this flame. [2] A glass or plastic front cover of a headlight through which the light converges or diverges. [3] A glass or plastic covering of a signal light, taillight, backup light, etc. Also see diffusing lens lessee : The individual or party signing the lease contract and taking responsibility for the vehicle and lease payments.

lessor: The individual, dealer, business, manufacturer, or financial institution that owns the vehicle. Also see independant lessor let in: To engage, such as to engage the clutch slowly

let out: To release, such as to let some air out of the tire or to release the clutch by pushing in the clutch pedal.

letter drill: See letter drills.

letter drills: A series of drills in which each drill size is designated by a letter of the alphabet: A, B, C, etc.

LEV: Acronym for Low Emission Vehicle Standards.

level: The condition where an item is perpendicular to the force of gravity. also See acceptable quality level automatic level control bac level blood alcohol level engine oil level warning light float level fluid level warning indicator interior noise level oil level oil level gauge oil level sensor spirit level trim level level control: See automatic level control.

level gauge: See oil level gauge

leveling: also See automatic level control headlight leveling control ride levelling roller levelling leveling control: See headlight leveling control

leveller: A component in continuous sheet galvanizing lines by means of which steel strips are stretched and levelled

level out: To work on a panel to remove irregularities with the use of hammer and dolly or by filling and sanding, etc.

level plug: A threaded plug in the side of a gearbox or rear axle to determine if sufficient oil has been used during filling

levels: See emission levels

level sensor: See oil level sensor

level warning: also See engine oil level warning light fluid level warning indicator level warning indicator: See fluid level warning indicator

level warning light: also See coolant level warning light engine oil level warning light lever: A simple machine comprising an arm and a pivot. Also see actuating lever brake lever clutch lever clutch release lever gear lever gearshift left hand gear lever

parking brake lever strut parking brake lever relay lever release lever roller foot lever selector lever shift lever throwout lever tire lever leverage diagonal cutting pliers: See high leverage diagonal cutting pliers

levering bar: A metalworking tool shaped like a large tire iron with flat hooked ends for levering bent panels back into position

lever lock: See selector lever lock

lever strut: See parking brake lever strut

lever-type shock absorber: A spring damper operated by a lever arm from a chassis-mounted hydraulic damper unit. Also see telescopic shock absorber Lexus: A model of automobile manufactured by Toyota Leyland: See British Leyland

LH: Acronym for "left hand"

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LHD: Acronym for "left hand drive."

L head: See L-head engine engine type.

L-head: also See L-head engine engine type L head engine: See L-head engine.

L-head engine: An engine having both valves in the block and on the same side of the cylinder. The arrangement of the valves in the block and the combustion chamber forms an "L" shape. This type of valve train was used in the early years of automotive engineering and is no longer found - with some minor exceptions - in modern engines. Also called "side-valve engine." See flathead.

LH-Jetronic: Bosch LH-Jetronic system measure air mass (weight of air) with a hot-wire sensor instead of measuring airflow with a vane, or flap, type air volume sensor used on LJet systems. The "H" is short for heiss "hot"

LHM: Acronym for "liquide Hydraulique Minerale"

LI: Acronym for load index

licence: British spelling for license. also See driving licence road fund licence

license: Document giving official permission to do something. Also see personalized license personal license rear license plate lamp rear license plate light license plate: A plate (issued by a government) located on the back (and sometimes also the front) of a vehicle showing its registration. The British term is "number plate."

license plate frame: A metal or plastic cover which surrounds and protects the outside of a license plate. Some of them feature the name of a car dealership, state or province, while others have a series of lights surrounding it.

license plate lamp: See rear license plate lamp

license plate light: See rear license plate light

Licensing Agency: See Driver and Vehicle Licensing Agency

Licensing Center: See Driver and Vehicle Licensing Center

lid: also See deck lid hood skid lid trunk lid lien:

The right to hold another's goods or property until a claim is met. See mechanic's lien.

life: also See service life shelf life lifeboat: A boat which is used when the ship is in danger and has to be abandoned

lift: [1] The action of the rear end of the vehicle to rise during braking. [2] The amount by which a poppet valve rises when opened. See valve lift. [3] The aerodynamic force caused by greater pressure above the car than below it and having the effect of loss of traction and stability; (counteracted by a suitable spoiler). Also see anti-lift fork lift high lift rocker arm hydraulic lift rear end lift suction lift tail lift valve lift wheelchair lift liftback station wagon: Small cars came in station wagon form too. The idea was the same as bigger versions, but the conventional tailgate was replaced by a single lift-up hatch. For obvious reasons, compact and subcompact wagons had only two seats instead of the three that had been available in many full-size models. lifter: also See hydraulic lifter hydraulic valve lifter piston lifter roller lifter roller tappets tappets

valve lifter valve spring lifter lifter foot: The part of the lifter that contacts the camshaft

lift: [1] Maximum distance valve head is raise off its seat. [2] A device for raising equipment into a vehicle, e.g., a scooter lift will raise a scooter from the ground, swing it around and place it in the back of a van.

liftgate: The rear opening of a station wagon or hatchback which opens from the bottom and hinges at the top. The British term is "tailgate."

lifting: Etching in which the paint surface is roughened or disintegrated in small patches or a wide area because of an attack from bird droppings, soap deposits, industrial fallout, etc.

lifting platform take-up point: Any of the lifting points specified by the manufacturer for supporting the car on a lifting platform. Only the points specified provide the rigidity required to lift the car without damaging adjacent components

liftoff effect: In eddy-current testing; severe signal changes associated with small changes in distance between probe and test item

lift pump: See fuel pump

lift rocker arm: See high lift rocker arm

Lift-The-Dot fastener:

A registered trade name for a snap fastener

lift-throttle oversteer: A handling characteristic that causes the rear tires to lose some of their cornering grip when the throttle is released during hard cornering.

lift truck: See fork lift.

light: [1] Something that is easy to operate. [2] Something that has relatively little weight. [3] A vehicle window. See backlight. [4] An illumination device. [5] A British term for window. Also see auxiliary brake light auxiliary driving light back-up light backlight brake light brake warning light check engine warning light coolant level warning light courtesy light daytime running lights direction indicator warning light dome light driving light dummy lights engine oil level warning light fog light gas discharge light gooseneck map light handbrake warning light headlight high-mounted brake light idiot light indicator light interior light switch interior light low oil warning light map light

marker light masthead light oil pressure warning light opera light parkbrake warning light parking light park light pillar light quarter light filler panel quarter light rear fog light rear license plate light rear light surround reversing light seat belt warning light side marker light signal light warning light signal light SRS warning light stop light strobe light tail light test light timing light traffic light trouble-shooting light warning light light-alloy piston: See alloy piston

light-alloy wheel: See alloy wheel

lightbar: A bar with a series of lights (driving lights, fog lights, and/or spot lights) mounted on it. The bar is mounted either on the front of the vehicle or on its roof.

light box: See tail light box

light braking:

The action of applying the brakes gently and intermittently. Opposite to heavy braking

light bulb: See bulb

light cable: Cable which does not require high strength. Opposite to heavy cable

light clutch: Having a smooth or easy operation, e.g., requiring little effort to push down the pedal on cars and trucks; or squeeze the lever on motorcycles. Opposite to heavy clutch

light displacement: The displacement in tons of the ship complete with all outfit, equipment, and machinery on board but excluding all fuel, water in tanks, cargo, stores, passengers, dunnage, and the crew and their effects. The light condition displacement includes the lubricating oil for the machinery and water in the boilers at steaming level. Also called "light weight."

light-duty: Something that is built for light loads or non-severe use. Opposite to heavy-duty

light-duty truck: A vehicle weighing less than 10,000 lbs. Compare heavy-duty truck and mediumduty truck

lightened valve: See lightened valves.

lightened valves: Valves in which all possible metal has been ground away to reduce weight. This will allow higher rpm without valve float.

lighter: [1] An electric, push-button device on the dash which, when depressed, produces a red-hot filament for lighting cigarettes, etc.

Also see cigar lighter [2] A flat-bottomed boat for transporting cargo between ship and shore.

lighter aboard ship: (LASH) small barges for carrying cargo between ship and shore

light-fast: Something unaffected by light

light filler panel: See quarter light filler panel

light-footed: A term used to describe a mode of driving which uses gentle pressure on the accelerator, thus maximizing fuel economy

lighting: See auxiliary lighting.

light-off temperature: The temperature at which a catalytic converter achieves a 50% conversion rate; typically near 250°C

light paint: Thinly coated. Opposite to heavy paint

light panel: See tail light panel

light sheet metal: Thin sheet metal for average use.

lights-on reminder: A buzzer, chime, or voice which alerts you that you have left the car lights on upon shutting the engine off.

light steering: Having an easy operation, e.g., requiring little effort to turn the steering wheel

light surround: also See rear light surround tail light surround light switch: See interior light switch

light traffic: A road with few moving vehicles. Opposite to heavy traffic

light truck: [1] A vehicle weighing less than 14,000 lbs. [2] Typically a vehicle under 3 tons, which includes pickups, passenger vans, and most 4WD vehicles and for which one does not need a special license. Compare HGV

light unit: See lamp unit

light van: Typically a vehicle under 3 tons, which includes pickups, passenger vans, and most 4wd vehicles and for which one does not need a special license. Compare HGV

light vehicles: Passenger cars and light trucks.

light warning light: See signal light warning light

light weight:

See light displacement

limber hole: A small drain hole or slot in a frame or plate for the purpose of preventing water or oil from collecting

limit: The performance limit of a car's chassis, tires, etc.; typically experienced during sharp cornering at high speeds. Also see authority Limit cornering limit fatigue limit knock limit lean Authority Limit Switch particulate emission limit self-cleaning limit speed limit limit cycle control: See closed-loop control

limited grade: See traction limited grade

limited-slip axle/center differential: See variable limited-slip axle/center differential

limited slip differential: An axle differential or central differential incorporating a locking or slip-limiting mechanism to counter wheel spin. Limited slip means that some power is always applied to each of the wheels, even when one of them is on a slippery surface like ice or mud. also See limited-slip differential multiple-disc limited-slip differential torque sensitive limited slip differential limited-slip differential:

A differential unit designed to provide superior traction by transferring driving torque, when one wheel is spinning, to the wheel that is not slipping. A cone or clutch disc locks the two independent axle shafts together so that they both turn at the same time. There is a minimal amount of slippage (thus the name limited-slip) to allow for differential action.

limiter: also See engine speed limiter rev limiter torque limiter limiting valve: See pressure limiting valve

limits of adhesion: [1] A term used by sports car enthusiasts to describe the point of which a car begins to lose grip on the road while making a turn in a curve. [2] The ability of a vehicle to respond to an emergency situation such as roads covered in rain, oil, or ice by steering or braking when needed.

Limit Switch: also See authority Limit Switch lean Authority Limit Switch limo: Abbreviation for "limousine." Also see stretch limo limousine: The literal meaning is "a cloak." In France, "Limousine" means any passenger vehicle. An early dictionary defined "limousine" as an auto with a permanently enclosed compartment for 3-5, with a roof projecting over a front driver's seat. However, modern dictionaries drop the separate compartment idea and refer to limousines as large luxury autos, often chauffeur-driven. Some have a movable division window between the driver and passenger compartments, but that isn't a requirement. Also see

stretch limo limp home: See limp-home mode

limp-home mode: [1] A standby circuit which allows a car with electronic system trouble to be driven home slowly. [2] A feature of Cadillac's Northstar engine that even when it has run out of coolant, the car can be driven at moderate speeds.

limp-in: See limp home

Lincoln: A vehicle brand of which all L, K, KA, and KB, 1941 168H, and 1942 268H models are classic cars. The 1952-54 Capri models are Click for books on Lincoln milestone cars. Lincoln Continental: A vehicle brand of which the 1925-1948 models are classic cars. The 1946-48, 1961-64 models are milestone cars. The 1958-60, Click for books 1965-67 Convertibles are milestone cars. The 1961-67 Custom on Lincoln Continental Limos (Lehman Peterson) models are milestone cars. line: The path through a corner that best accommodates a late braking point, a high cornering speed, and the fastest-possible exit speed out of a corner. Also see airline air line assembly line battery fill line belt line brake line buff line cutting line drive line feed line fuel return line inlet line international load line certificate

load line margin line model line mooring line off-line on-line painting line plan lines production line product line red line sculpture line shut line stress line suction line swage line window line liner blast horn: See ocean liner blast horn

linear lamp: See festoon bulb

linear source lamp: See festoon bulb

linear wiper system: A system in which the wiper arm is attached both at the top and bottom and, instead of describing the usual arc, is guided in a straight line from one side of the windshield to the other

line certificate: See international load line certificate

line pressure: Line pressure is fed to the shifting components when they are to be applied; it increases in proportion to engine speed and is the highest pressure in the hydraulic control system

liner: [1] A thin section placed between two parts, such as a replaceable cylinder liner in an engine. Wet liners are the complete cylinder wall where the outside of the liner makes up part of the cooling system to allow coolant circulation. Dry liners are pressed into the block and are not surrounded by coolant. [2] A cargo ship which sails between regular ports of call on a schedule. Also see bonnet liner cylinder liner hood liner inner liner ocean liner blast horn line spanner: See flare nut wrench

lines, plan: The plans that show the shape or form of the ship

lining: [1] The interior trim, e.g., of doors and convertible tops. [2] A friction material (e.g., on brake shoes, brake discs, clutch disc, and automatic transmission brake bands. also See bonded brake lining brake lining clutch lining friction lining riveted brake lining linishing: Smoothing sheet metal using power tools, e.g., with an angle grinder and emery belt or grinding disk. Typical applications are dressing of weld joints and removal of flaking rust to clean up repair areas prior to welding

link: A suspension member that has a single diagnostic link diaphram link drag link, half link inter-cell link joint at each en also d. See lateral link leading link

master link offset link parallel trailing link suspension semi-trailing link stabilizer link suspension link toe control link trailing link transverse link watts link linkage: Any series of rods, yokes, levers, bars or links used to transmit motion from one unit to another. Also see center steering linkage gearchange linkage parallelogram steering linkage progressive linkage shifter linkage shift linkage steering linkage watt linkage progressive linkage shift linkage steering linkage watt linkage linkage power steering: A linkage-type, power-assisted steering system in which a conventional manual system is assisted by hydraulic or pneumatic effort applied directly to a steering linkage such as a relay lever or track rod

link suspension: See parallel trailing link suspension

lip: The edge of a sheet metal panel folded at right angles to the basic panel contours; often used to mount the panel to an adjacent panel, e.g., for spot welding

lip molding:

The molding connecting the outer edge of the fender to the inner fender panel or fender well

lip seal with garter spring: See radial shaft seal

liquefy: British spelling for "liquify"

liquid: Any substance which assumes the shape of the vessel in which it is placed without changing volume.

liquid ballast: A form of ballasting which uses a liquid -- usually water mixed with calcium chloride to prevent freezing and increase specific gravity. Also see dry ballast liquid-cooled: An engine that is cooled by the passage of water or oil. The opposite is "air-cooled"

Liquide Hydraulique Minérale: (LHM) A green hydraulic fluid used by Citroën for some of their suspension systems

liquid gasket: A room temperature vulcanizing gasket sealer (from a tube)

liquid line: [1] The line between the drier outlet and the expansion valve. [2] Sometimes, the line between the condenser outlet and the drier inlet

liquid paint: Paint which contains solvents and cures at room temperature or by baking

liquid pump:

A machine used to raise liquid from a low to a high energy level by transferring energy to the medium being pumped

liquid traction: A special liquid that is applied to the tires of drag racers to provide superior traction.

liquid withdrawal: Drawing LPG (propane) from the bottom of the tank to insure delivery of liquid LPG (propane). Withdrawal from the top of the tank will deliver LPG (propane) in the gaseous state.

liquid withdrawal system: A method of piping where liquid is taken from bottom of an LP gas tank and converted into gas by a vaporizer

liquified natural gas: (LNG) e.g., methane, possible future alternative fuel for spark ignition engines

liquified petroleum gas: A by-product of oil refining, mainly butane or propane or a mixture of the two gases, used as a fuel for some spark ignition gasoline engines. See LPG.

list: When the centerline plane of a ship is not vertical, the ship is said to list, or to heel

list number: The part number stamped on the body of the carburetor, used for identification and can be cross-referenced to obtain the model number

list price: The price suggested by the factory, as quoted in the price list, as opposed to the actual sales price which would include delivery and set-up charges plus taxes.

liter: Metric measurement of capacity equivalent to 2.11 US pints. Five litres equals 1.32 U.S. gallon or 1.1 Imperial gallon. One Imperial quart equals 1.136 liter and a US quart equals 0.946 liter.

lithium base grease: A chassis and wheel bearing grease using lithium as a base. Not compatible with sodium base grease.

lithium grease: A chassis and wheel bearing grease using lithium as a base. Not compatible with sodium base grease. Also see white lithium grease litre: Metric measurement of capacity equivalent to 2.11 US pints. Five litres equals 1.32 U.S. gallon or 1.1 Imperial gallon.

little end: The small end of the connecting rod. See connecting rod

live axle: A driven axle upon which the wheels are firmly attached. Usually there are two half shafts with a differential in between. Each axle drives the wheel it supports. Live axles are non-independent, i.e., when one wheel moves up or down, it affect the movement of the other. They are used on rear-wheel-drive vehicles. In contrast, a dead axle is not driven. Also see axle live wire: See hot wire.

Lizzie: See tin Lizzie

L-Jetronic: Term by Bosch to describe fuel injection system controlled by the air flowing through a sensor with a movable vane, or flap, which indicates engine load. The "L" is for luft "air." Later versions of L-jet are equipped with a Lambda (oxygen) sensor for better mixture control. Bosch originally used the term Air-Flow Controlled (AFC) Injection to denote L-Jet system in order to differentiate them from pressure

controlled D-Jetronic system

L-Jetronic air flow meter: Airflow meter used on the L-Jetronic system

L-Jetronic fuel injection system: An electronically controlled fuel injection system. Fuel is supplied by an intermittent-action L-Jetronic fuel injection system, which uses engine speed and intake airflow as its main control parameters. Each cylinder has its own solenoid injector, which is opened by control pulses delivered by the electronic control unit; the length of these pulses depends on the control parameters. All of these parameters are detected by sensors and processed in the control unit. This fuel injection system is employed by BMW in the K 75 model

L-Jetronic system: An electronically controlled fuel injection system. Fuel is supplied by an intermittent-action L-Jetronic fuel injection system, which uses engine speed and intake airflow as its main control parameters. Each cylinder has its own solenoid injector, which is opened by control pulses delivered by the electronic control unit; the length of these pulses depends on the control parameters. All of these parameters are detected by sensors and processed in the control unit. This fuel injection system is employed by BMW in the K 75 model

LNG: See liquified natural gas

LNG carrier: Liquefied natural gas carrier.

load: [1] something to be lifted, carried, transported, or accelerated. [2] The amount of material transported. [3] The amount of power carried by an electric circuit. [4] The resistance overcome by an engine when it is driving a machine. Also see axle load axle weight clamping load full load full load enrichment

g-loads international load line certificate negative load base proportional load synchromesh road load horsepower temperature of deflection under load wheel load load alteration effect: The reactions in the drive train or, in FWD vehicles, in the steering, due to sudden load alteration. Compare torque steer

load and inflation table: A chart in the tire manufacturer's data book listing the carrying capacity of a tire at each of several air pressure increments from the lowest range of practical usage to its maximum capacity.

Load at installed height: The specified range of force required to compress a spring to its installed height usually expressed in terms of so many pounds of force at so many inches

load base: Used in calculating load distribution; it is the distance between the center of the rear axle (or center between tandem axles) and the center of payload. Also See negative load base.

load capacity: See carrying capacity.

load-controlled power distribution: A drive torque distribution, as established e.g., by a Torsen differential

load distribution: The distribution of load on truck or trailer chassis. The relationship of the gross load on the front and rear axles to the total gross load.

load distribution calculation: The payload on the front axle is equal to the total payload multiplied by the "load base" (in inches) and divided by the "wheelbase" (in inches). To complete the

calculation of load per axle, it is necessary to obtain the unladen weight of the vehicle and estimate its breakdown by axle.

loaded: See spring loaded

loaded displacement: The displacement of a ship when floating at her greatest allowable draft

loaded radius: Measurement in inches from the wheel axle centerline to the ground when the tire is properly inflated for the load. Also called static loaded radius

loaded tourer: A bicycle whose structure, geometry, and equipment is designed to allow a cyclist to travel with 50 pounds of gear.

load enrichment: See full load enrichment

loader: See low-loader

load floor: [1] The cargo-carrying area of a van or truck. [2] The floor of the luggage area of an station wagon or hatchback

load floor extension: A molded tray that folds out of the rear luggage area and provides an extended load floor which hangs out over the bumper. It can also be used for picnics.

load horsepower: See road load horsepower

load index: (LI) coded number on the sidewall of a tire to indicate the maximum load the tire may carry at a given speed under manufacturer's conditions

loading: The amount with which something is loaded. Also see lead loading load line: The line on a ship which indicates the maximum depth to which it can sink when loaded with cargo. Also known as "marks."

load line certificate: See international load line certificate

load overhang: The distance a load extends beyond the rear of a vehicle. It also requires a red flag or red reflector at the end of the load.

load range: [1] An index of tire strength which replaces the older (discontinued) ply rating system. [2] A discontinued measurement of the number of plies at which a tire is rated. Load range B equals 4 ply rating; C equals 6 ply rating; and D equals 8 ply rating.

load rating: The maximum amount that a vehicle can carry with the tires and springs it has. Also called load index Also see carrying capacity ply rating spring booster load resistor: See ballast resistor

Load Sensing Proportioning Valve: (LSPV) a hydraulic system control valve that works like a proportioning valve, but also takes into consideration the amount of weight carried by the rear axle

load-sensitive proportioning valve: A valve which regulates hydraulic pressure to the rear wheels as a function of chassis height-to-axle distance. A vehicle weight transfer during hard braking increases this distance and, via a spring or rod linkage, will close the valve to reduce braking pressure at the rear wheels; also, a heavily loaded car will have more braking power at the rear wheels

load synchromesh: See proportional load synchromesh

load test: A test applied to a battery. Although the battery indicates 12 volts or more, it may not meet the amperage for which it is rated. A tester with a variety of amperage loads can be applied to determine if the battery is good.

load transfer: See weight transfer

load transference: The changing of the amount of load distributed to each axle while the vehicle is in motion, due to the effects of braking, cornering ascending, or descending grades, etc. See rollsteer.

load waterline: The line on the lines plan of a ship, representing the intersection of the ship's form with the plane of the water surface when the ship is floating at the summer freeboard draft or at the designed draft. Also called marks

lobe: An off-center or eccentric enlargement on a shaft which converts rotary motion to reciprocating. Also called a "cam." See cam lobes.

lobe-type supercharger: A positive displacement compressor with two lobed rotors. Compare lysholm supercharger and roots compressor

local cell: A galvanic cell resulting from differences in potential between adjacent areas on the surface of a metal immersed in an electrolyte

localized corrosion: Rusting occurring at one part of a metal surface at a much higher rate than over the rest of the surface, e.g., pitting corrosion, crevice corrosion. The opposite is uniform corrosion

locating dowel: See dowel pin

locating lug: A projection or pin for holding a part in a specific position. All engine bearings have some means of ensuring that they will not shift or move in the housing bore once installed. Most bearings utilize a locating lug, which is simply a small projection or pin that fits into a recess in the housing bore

locating pin: A projection or lug for holding a part in a specific position. also See dowel pin locating lug locating spring: A steel wire clip in disc brakes that secures the cylinder in a floating frame or caliper frame. Compare spreader spring

lock: [1] A fastening device which closes and opens by the use of a key. [2] A steering term describing the amount by which the wheels of a vehicle are able to turn. See steering lock and lock-to-lock. [3] An obstruction such as a air lock or vapor lock. [4] To close with a key. [5] To fix or become fixed in a certain position such as "the seat belts locked when the brakes were applied suddenly but so did the wheels and the car went into a skid." [6] A gear train term indicating to interlock or couple. Also see angle of lock bonnet lock cable lock childproof lock

differential lock door lock door lock de-icer full lock helical spring lock washer hood lock nylon lock nut opposite lock parking lock selector lever lock shift lock steering wheel and brake lock tire bead lock vapor lock wheel lock lockable differential: A limited-slip differential

lockable wheel: A wheel that can be secured to the hub with a lock

lock angle: See steering angle

lock brakes: See anti-lock brakes

lock buster: lock puller

lock cylinder: A cylinder in the middle of a cylinder lock that is prevented from turning (locked) by a number of pins (typically five) which penetrate down through the wall of the cylinder. The cylinder is turned by inserting a key which pushes the spilt pins up to varying heights so that the edge of the cylinder engages with the gap between the two sections of each pin allowing the cylinder to turn

lock de-icer:

A fluid which is inserted into the key-hole to melt the ice which has bound the tumblers in a door lock. Also see door lock de-icer locker: See chain locker

lock facing: The surface of a door to which the lock is attached

locking: also See action locking central locking parallel action locking pliers remote-control locking locking bar clamp: Locking clamp with sliding jaw providing extended clamping capabilities

locking clamp: Locking pliers with specially shaped jaws for vice work and intricate clamping jobs. Locking clamps include, for example, vice grip C-clamps, vice grip pipe clamps, locking bar clamps, welding clamps, and sheet metal clamps

locking differential: A differential with the ability for locking together the two half shafts, thus putting the differential out of action and greatly improving traction. In a non-locking differential if one wheel was stuck in snow and spinning, the other wheel would be stationary even if it were on dry ground. In a locked differential, both wheels would turn the same amount. Since the dry-ground wheel had traction, it would be able to pull the vehicle out even though the other wheel had no traction.

locking disc: See center locking disc

locking hub:

See central-locking hub

locking lug bolt: An anti-theft wheel lug bolt which requires a special wrench to remove it

locking lug nut: An anti-theft wheel lug nut which requires a special wrench to remove it

locking mechanism: A device which locks the reel of a seat belt when the forward acceleration of the occupant exceeds a certain value

locking pliers: also See action locking pliers parallel action locking pliers locking reel: A device which locks the reel of a seat belt when the forward acceleration of the occupant exceeds a certain value

locking pliers: A type of pliers with locking jaws that can be used as pliers, wrench, clamp, or small vice. Closing the handles locks the jaws into position. The jaws are released by pulling a special release lever. Locking pliers with specially shaped jaws for vice work and intricate clamping jobs are called "locking clamps"

locking synchromesh: A common synchromesh mechanism in which the synchromesh pressure is proportional to the gearchange force, thus preventing overriding of the synchromesh action due to hasty operation of the lever; the gear and gearchange sleeve are prevented from engaging until rotational speeds are synchronized

lock nut: See locknut

locknut:

A nut used in conjunction with a washer or a second nut to lock a mechanism in place, such as the nut found at the upper end of a headset and in front of the calipers on many caliper brakes. Also see center lock nut nylon lock nut lock-out: also See power window lock-out switch starter lockout lock-out switch: See power window lock-out switch

lock picker set: A set of special tools designed for opening locked cars, especially used by professional locksmiths

lock pillar: See b-pillar

lock pin: See locating pin

lock puller: A special door lock picker; attached to the outside of a car door lock, the lock puller rips out the entire lock cylinder

lockring: [1] The notched ring that fits on the left side of a bottom bracket of a bicycle and prevents the adjustable cup from turning. [2] A metal ring which snaps into the rim gutter, holding the side ring in place.

lock ring pliers: Tool for removing and installing heavy-duty circlips, used e.g., on brakes, transmissions, pedal shafts, and clutch shafts

lock striker: See striker

lock-to-lock: A steering designation which describes the distance created by the steering wheel when it is fully to the left and then moved fully to the right.

lockup: The moment when a tire begins to skid during braking. A tire's maximum braking force occurs when it is on the verge of lockup. Ideally all four tires should approach lockup simultaneously to give a vehicle the best braking. Because this ideal is hard to create in the real world, one end tends to lock up before the other. Front-wheel lockup is inherently more stable than rear-wheel lockup. Anti-lock brakes provide the best type of braking because it rapidly releases pressure on the brakes to prevent lockup.

lock-up clutch: Automatically engaged clutch in a lock-up torque converter which prevents slipping losses. Also see torque converter lock-up clutch lockup differential: A differential whose two outputs can be locked together, eliminating any differential action but maximizing traction under slippery conditions.

lockup torque converter: A torque converter fitted with a lockup clutch that can be engaged to eliminate the slip between the torque converter's input and output, thereby improving fuel efficiency and performance because it is now in direct drive mode

lock-up torque converter: Torque converter in which the pump can be mechanically locked to the turbine, eliminating any loss through the fluid because it is now in direct drive mode

lockwasher: There are several types of lockwashers which are designed to be placed between a flat washer and the securing nut in order to keep the nut from backing out or loosening. One type is a split ring. Another looks like a star with prongs or tangs coming out from the outer circumference. Also called a "star washer." Another type

has prongs coming out of the inner circumference of the washer.

locktite: Brand name for a type of liquid which is applied to the threads of a bolt and/or nut to secure them to various degrees of strength.

lock washer: also See helical spring lock washer spring lock washer Locomobile: A vehicle brand of which all models 48 and 90; 1927 8-80; 1928 8-80; and 1929 880 are classic cars.

locut nut: A fastener used to enable sheet metal screws to be used for relatively large holes in panels

loft: See mold loft

log manifold: A special intake manifold generally designed to accept four or more carburetors. Each side has bases for the carburetors set on a pipe-like log area.

logo: See company logo

long and short arm suspension: A suspension system using an upper and lower control arm. The upper arm is shorter than the lower. This is done so as to allow the wheel to deflect in a vertical direction with a minimum change in camber.

long arm suspension: See short arm/long arm suspension

long block: A long block consists of the short block plus the oil pump and sump, cylinder head(s), camshaft(s) as well as the complete valve train. The opposite is short block

long block engine: An engine with a relatively long crankshaft. The opposite is short block engine. Also compare big-block engine. Normally, the term long block engine means a 6cylinder in-line engine which has a longer block than a 4-cylinder or V-8 engine

longeron: The main side member

long-haul: A long distance which a trucker drives

longitudinal: Lengthways. The opposite is lateral

longitudinal engine: A traditional engine layout used on most RWD vehicles with the cylinders lying lengthways from the front to the back. Also called north-south layout. The opposite is transverse engine

longitudinal girder: See side member

longitudinal member: See side member

longitudinal tire clearance: The distance between the tread and the closest point forward or rearward, reduced by increase in tread depth and rearward movement of the axle under load (1/3 of the distance between shackle pin centers).

longitudinal leaf spring: A leaf spring that is mounted so that it is parallel to the length of the vehicle.

longitudinals: Fore-and-aft structural shape or plate members attached to the underside of decks, flats, or to the inner bottom, or on the inboard side of the shell plating.

long-nose pliers: Pliers with half round and tapered jaws, often with a wire cutter and used for electrical work. Also called snipe-nose pliers or needle-nose pliers

long-nose self-grip pliers: Locking pliers with extra long reach jaws

long-reach C-clamp: Self-grip locking clamp with extra long C-shaped jaws

long stroke engine: An engine where the length of the piston stroke is greater than the diameter of the bore of a cylinder. A relatively long stroke produces higher low-end torque at the cost of increased piston speeds and reduced revving ability. The opposite is short stroke engine

long ton: 2240 pounds. Also called "gross ton."

loom: A harness covering. Older vehicles used woven-cloth loom; most modern vehicles use a corrugated-plastic loom or split loom also See spark plug cable loom spark plug wire loom wire loom wiring harness wiring loom loom tape: A non-adhesive tape used as a harness wrap. Adhesive-type tapes, including electrical tapes, are not recommended for wrapping harnesses. Often a piece of shrink wrap is used at tape ends to keep the tape from unravelling

loop:

also See closed loop open-loop open loop system phase-locked loop circuitry loop circuitry: See phase-locked loop circuitry

loop frame: Early motorcycle frame design in which the downtube curves underneath the engine cases to become the seat post

loop scavenging: A method of scavenging used on two-stroke motorcycle engines. The entering gas streams travel across the piston, up the far side of the barrel and curl over and down to complete the scavenging process; loop scavenging is sometimes used to refer specifically to a special variant of this type of scavenging: Schnürle scavenging

loop system: also See closed loop system open loop system loose: [1] Not tight. [2] A colloquial term for oversteer.

loosen: To make something less tight; to slacken

loping: Action of the engine when the mixture of gasoline and air to the carburetor is too lean.

lorry: A British term for truck.

losses: also See charge losses evaporative losses friction losses pumping losses scavenging losses loss leaders: Products whose prices are cut with the idea that they will attract customers to the store.

lost-core technique: A method of producing thermoplastic inlet manifolds

lost-foam casting: A casting method using foamed plastic cores, giving the surface of the castings the appearance of styrofoam; used for engine blocks

lost-foam casting process: A casting method using foamed plastic cores, giving the surface of the castings the appearance of styrofoam; used for engine blocks

lost motion: Motion between a driving part and a driven part which does not move the driven part. Also see backlash lot: also See car lot inspection lot parking lot Lotus: A vehicle brand of which the 1958-63 Elite models are milestone cars.

Click for books on Lotus

loud pedal: A colloquial term for accelerator pedal

louver: The ventilation slots such as sometimes found in the hood of an automobile or in the dash. They let air come into the engine compartment to cool the engine or into the passenger compartment. Sometimes they are merely decorative with no cooling function. Also see rear window louvres louvre: Canadian and European spelling for louver

low: (L) A driving gear ratio in automatic transmissions for climbing hills (to prevent lugging or for going down steep hills so that it acts as a compression brake. also See bull low four-wheel-drive low low-bake booth: A closed section in painting lines in a paint shop, in which coats of paint are dried at low temperatures

low-bake equipment: Equipment for drying coats of paint at low temperatures

low-bake paint: Respray paint baked at 80°C, giving a high-quality finish but requiring suitable lowbake spray booths/ovens

lowball: A car sales practice of stating a very low price for a new car to a customer who is known or expected to be comparison shopping or calling over the phone. Compare highball. When the customer finds that other dealers cannot match this price, he will return to the original dealer, only to be told that the price was a mistake; many customers will then accept a new, higher price because they are tired of shopping around

low battery: A battery with less than acceptable voltage and should be charged or replaced.

low beam: The outboard headlights in a four-light system or the main lights in a two-light system. The low beam is used for most applications of night driving. For those cars without day-time running lights, the low beam should be turned on. In fog and heavy snow, the low beam can provide more light on the road because the high beam reflects light back to the driver. The British term is "dipped beam."

low bed: A low platform trailer for heavy equipment hauling, usually on 15" diameter tires. Also called low boy.

low boy: A low platform trailer for heavy equipment hauling, usually on 15" diameter tires. Also called low bed.

low brake pedal: A condition where the brake pedal approaches too close to the floorboard before actuating the brakes.

low-carbon steel: steel containing 0.03 to 0.3 per cent carbon (typically 0.2%). Used for machine screws, wood screws, etc., and similar products without critical strength requirements. It cannot be heat treated for greater strength. Sometimes called "Mild Steel." The tensile strength is around 54M psi.

low carbon steel: See low-carbon steel

low crown panel: The predominant shape of modem body panels, e.g., on most side panels such as door skins. The opposite is high crown panel

low-density polyethylene:

(LDPE) a relatively soft, flexible polyethylene, used mainly for plastic film and sheet

low-emission: A condition of a vehicle which releases relatively few pollutants into the environment. Compare zero emission vehicle. In some countries tax relief is available for low-emission cars

Low Emission Vehicle Standards: (LEV) State and federal governments set standards for automakers developing vehicles that will produce emission. Each state determines its own levels as does the federal government. California and New York have some of the most stringent laws. Once the requirements are met for a specific vehicle, the automaker may call that car or truck a Low Emission Vehicle. Also see ultra Low Emission Vehicle Standards lower back panel: The body sheet metal between the trunk lid and the rear bumper

lower bending die: A lower tool insert of the press brake

lower dead center: (LDC) See bottom dead center

lower front panel: See front apron

lowering kit: A set of springs and other suspension parts to reduce ground clearance.

lowers: The bottom part of a motorcycle fairing to protect the rider's legs from wind and provide a more aerodynamic configuration

low fuel indicator:

A warning light which glows when fuel is getting low and flashes (on some models) when it is very low.

low gear: The lowest gear in a transmission, usually called first gear.

low geared: A transmission which has a small drive gear and a large driven gear. On a bicycle, for instance, the chainwheel gear (by the pedals) is the smallest (usually called a granny gear and the freewheel gear (at the center of the wheel) is the largest. This arrangement gives the slowest speed but the best torque.

low head pressure: Lower-than-normal-high side pressure caused by a system malfunction

low-head pump: A pump used for low total heads; in the case of centrifugal pumps the low-pressure pump has a nominal total head not exceeding 80 m

low-loader: A truck for heavy loads with a low-level loading platform and often an extension ramp or lift-operated tailgate which can be lowered to street level

low-maintenance battery: A battery that rarely requires topping-up. Compare maintenance-free battery

low oil sensor: See oil level sensor

low oil warning light: See engine oil level warning light

low pedal: A condition where excessive clearance at some point in braking system causes full pedal movement for application of brakes

low pivot swing axle:

A rear axle setup that attaches the differential housing to the frame via a pivot mount. A conventional type of housing and axle extend from the differential to one wheel. The other side of the differential is connected to the other driving wheel by a housing and axle that is pivoted at a point in line with the differential to frame pivot point.

low-pressure cut-out: A device which protects the air conditioning system by switching the compressor off when a pressure loss occurs

low-pressure cut-out switch: A device that disengages the compressor clutch when the system pressure drops below a predetermined level

low-pressure foaming: A process in which plastics are foamed under low pressure (1-5 bar). The opposite is high-pressure foaming

low pressure indicator: A unit or combination of units which provides a visible or audible warning signal whenever the system pressure is below a predetermined value.

low-pressure pump: A pump used for low total heads; in the case of centrifugal pumps the low-pressure pump has a nominal total head not exceeding 80 m

low pressure tire: A tire with a large cross-section for operation at lower pressure. Increased air capacity permits lower pressure. ATV tires, for example, have only 3 or 4 psi.

low profile: A tire with a low aspect ratio of a tire (i.e., the section height is smaller than section width).

low-profile air cleaner: A circular, flat, chrome-plated air cleaner, mounted on top of the carburetor

low-profile tire:

A tire with a wide tread but a low height. A tire with a height that is 70% or less of its width would be described as low-profile, as opposed to an average tire of 80%

low-refrigerant protection system: A system which interrupts the electrical current to the compressor clutch in the event of refrigerant loss. A typical exhaust is the GM superheat switch and thermal limiter low side: suction side -- the low pressure part of the system between the expansion valve outlet and the compressor inlet

low rider: A customized car which is extremely lowered through body and suspension modifications

low side: An air conditioning term describing the side between the expansion valve or orifice tube and the compressor; includes the evaporator -- called the low pressure portion

low side gauge: A gauge that can indicate both pressure and vacuum. Also called a compound gauge

low-side service valve: A device, located on the suction or low side of the compressor, at which low side pressure can be checked and other service operations can be performed

low speed: Gearing provided in an automobile which causes greater number of revolutions of engine as compared to driving wheel

low spot: An indentation on a panel surface

low-suction pressure: Condition of lower than normal high side pressure caused by system malfunction

low temperature activity: A description of the ability of a catalytic converter to purify exhaust gases in the warm-up phase following a cold start. This phase is included in most of the current exhaust emission test procedures, as CO and HC concentrations are particularly

high when engines are operated below normal operating temperatures

low temperature fouling: See carbon fouling

low temperature phosphating: Phosphating at temperatures around 20° C

low tension: See low voltage

low tension lead: See low tension leads.

low tension leads: The wiring in the ignition system that is distinguished from the high tension wiring. The low tension leads carry only 6 or 12 volts. Includes the battery cables, the coil connections (but not the high tension wire going to the distributor), the wiring to the ignition switch, and the non-high tension wires going to the distributor.

low speed circuit: See idle circuit.

low-speed circuit: See idle circuit.

low speed traction control: See low-speed traction control.

low-speed traction control: A system that helps prevent front-wheel spin on slippery or gravel surfaces during acceleration at speeds up to 40 kph (25 mph).

low voltage circuit: See primary circuit

low zinc technology: A technology used in present-day phosphating processes. Normal zinc phosphating baths used as pre-treatment for painting contain approximately 2-4 grams-per-liter (g/l) zinc and approx. 5-10 grams-per-liter (g/l) phosphorus pentoxide. In low-zinc baths, the corresponding values amount to approx. 0.4-1.7 g/l zinc and 12-16 g/l phosphorus pentoxide

lozenged: A car chassis which, as the result of an accident, no longer holds its true shape but is rather pushed into the shape of a rhombus or diamond

LPG: Acronym for "liquified petroleum gas" or bottled gas or a mixture of butane and propane. In Canada, propane is the recognized term, not LPG as used in the U.S.A. Volatile petroleum gases are compressed to a liquid form. It must be kept under pressure or at a low temperature to keep it in a liquid form. It is generally less expensive than gasoline yet has high octane. It also does not create as much carbon deposit in the engine or dilute engine oil as gasoline does thus reducing the need to change spark plugs and other components as frequently. However, if not serviced and maintained properly, it can result in leakage and possible explosion. Most underground parking facilities will not accept propane powered vehicles.

L-section ring: A special piston ring characterized by its L-shaped cross-section. It is used mostly in high-performance two-stroke engines. The L-section ring allows combustion gas to penetrate behind its vertical section and thus uses the gas pressure to increase the pressure of the ring against the cylinder wall

LSPV: Acronym for load Sensing Proportioning Valve

L/T: Long tons (2,240 lb.).

LT circuit: See primary circuit

LTD:

An abbreviation for Limited

lube: A colloquial term for "lubrication"

lube grease: A very thick lubricating oil that has a paste-like consistency. Used to lubricate the steering linkage, the suspension system, and other moving parts outside the engine. Also see gear grease lube job: The greasing and lubrication of the suspension system, the drive train, and other parts of the vehicle which need it. A grease gun is applied to zerk or grease fittings and the grease is forced into the component. It should be done professionally once or twice a year. It can be done regularly when you change your oil.

lube oil: See lubricating oil

lubricant: Any material, usually of a petroleum nature such as grease, oil, etc., that is placed between two moving parts in an effort to reduce friction. Lubricant can also protect a part from dirt and moisture. Also see extreme pressure lubricant Grease oil lubricate: To cover or treat with a lubricant. Also see ep lubricant extreme-pressure lubricant lubricate beads: In order to mount a tire on a rim, the bead of the tire is coated with a vegetable base lubricant. In this way, the tire slides on easily. A petroleum base lubricant must never be used.

lubricating oil: A refined crude oil used as a lubricant

lubricating pressure: The pressure of a lubricating oil

lubrication: A type of friction reducing agent like oil or grease. Also see central chassis lubrication chassis lubrication clean oil lubrication dry sump lubrication forced-feed lubrication petroil lubrication pressure lubrication pump-fed lubrication separate lubrication splash lubrication total-loss lubrication wet sump lubrication lubrication film: A coat of lubricant to reduce the friction created when two surfaces move on one another

lubrication point: A place lubricant is applied

lubrication pump: A pump used to supply oil to lubricating points, particularly for plain bearings

lubrication system: The system which stores, cleans, cools, and recirculates oil in an engine to lubricate its moving parts and bearings. It includes the oil pump, oil pan or sump, oil coolers, tubing, filters, oil passages in the block, and dashboard oil gauge. Checking the level of oil is accomplished with the oil dipstick.

lubricator: See cam lubricator

Lucas Bosch: This system, used in Jaguars and Triumphs, is a Bosch L-Jetronic system licensed for production by Lucas

lug: [1] To cause the engine to labor by failing to shift to a lower gear when necessary. The British term is "labour." [2] A protrusion on an object. Also see dog [3] An external metal sleeve that holds two or more tubes together at the joints of a frame. [4] A device mounted on a rotating shaft or component that engages in a recess of a component to be driven. [5] A solid block of tread on a tire. Also see ford-type lug helmet lug locating lug locking lug bolt locking lug nut towing lug lug bolt: Bolts which secure the wheel to the hub. Also called "wheel lug bolt." Also see locking lug bolt luggage: Travelling bags or suitcases. In some luxury vehicles, the luggage is shaped to fit the trunk.

luggage carrier: A rack which is bolted on top of the trunk lid for taking luggage or the spare wheel (often seen on old sports cars where space was at a premium). In modern vehicles it is only decorative rather than functional.

luggage rack: A trunk which fits on the back of a motorcycle behind the rear passenger.

lugging: A condition of an engine having difficulty in turning because the transmission is in a higher gear than the road speed requires. The British term is "labouring."

lug nut: One of several nuts which hold the wheel and tire assembly on the car and are screwed on the studs. The inner face of the lug nut is a tapered (conical) nut to help center the wheel. On modern wheels for passenger cars, lug nuts and corresponding studs are less frequently used than bolts. On commercial vehicles, however, lug nuts are very common. A lug wrench is necessary to remove the nuts. The British term is wheel nut. Also see locking lug nut lug wrench: A wrench used to remove the lug nuts which secure the wheels to the vehicle. Some are L-shaped while others are X-shaped. They are usually found in the trunk of the car with the tire jack. Also see cross-shaft lug wrench lumbar support: A feature in an automobile seat which allows the driver or passenger to increase the pressure in the small of the back and thus provide more comfort.

luminance: The luminous intensity of a surface in a given direction per uatt of projected area of the surface, in candela per square meter; not the same as the apparent brightness

luster: Reflected light; sheen or gloss

lustre: British and Canadian spelling of luster

luxe:

(L) Although the word means luxury, on its own it is often used to denote a rather basic model. Compare CL and GL. Also see comfort Luxe grand Luxe luxury car: A well-appointed, well-equipped, well-designed and constructed vehicle varying in size from a compact to a large sedan.

Lysholm supercharger: A lobe-type supercharger similar to the Roots compressor, but more efficient and much more expensive

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A] [B][C] [D][E] [F][G] [H][I] [J][K] [L][M] [N][O] [P][Q] [R][S] [T][U] [V][W] [X][Y] [Z] [Ma] [Mc] [Me] [Mg] [Mi] [Mm] [Mo] [Mu]

M+S: Acronym for "mud and snow," as in M+S tire. A tire with a tread design which gives the maximum traction in mud and snow.

M+S tire: Acronym for "mud and snow tire," as in M+S tire. A tire with a tread design which gives the maximum traction in mud and snow.

MAC: Acronym for "motor assisted bicycle" -- usually an electric motor

machine: also See injection molding machine milling machine perpetual motion machine wheel balancing machine wheeling machine machined surface: A smooth surface of metal such as the top of a cylinder block. machinery spaces: See unmanned machinery spaces

machine screw: A screw with thread running the length of the shank and available with a variety of different heads

machining:

an operation which shapes metal parts by carving away excess material as chips produced in a sequential process of turning, milling and grinding operations.

machinists' caliper: A measuring tool with two curved arms for inside or outside measurement; the reading taken with the arms is transferred to a steel rule or micrometer to attain the exact value

machinists' hammer: A ball pien hammer

MacPherson strut: A suspension piece which employs a coil spring and shock absorber attached to the lower A-arms and the top of the front body structure. Originally it had a lateral link with an anti-roll bar instead of the lower A-arm. It was first invented by a Ford of England engineer, Earle S. MacPherson.

MacPherson strut tower: A sheet metal panel surrounding the upper mount of the MacPherson strut at the side panels of the engine compartment; it may be a separate panel fitted by spotwelding or a deep-drawn section of the side panel shaped to take the upper strut end. Also called "suspension leg turret"

MacPherson suspension: A suspension layout incorporating macpherson struts

macromolecule: Any very large molecule, such as a synthetic polymer used in the manufacture of plastic

macromolecular: with very large molecules

MAF: Acronym for mass airflow

MAFTS:

Acronym for "manifold air/fuel temperature sensor"

MAG: Swiss engine makers, the initials stand for Motosacoche Acacias Geneva. The company also produced complete Motosacoche motorcycles

mag: [1] Abbreviation for "magneto." [2] Abbreviation for "magnesium," as in mag wheels." Also see mags mag alloy: Magnesium alloy, a strong lightweight metal used for many components, particularly wheels

magnaflux: A special chemical process, used to check parts for cracks.

magnesium wheel: An alloy wheel. See mag wheel

magnet: A piece of magnetized steel that will attract all ferrous material. The permanent magnet does not need electricity to function and will retain its magnetism over a period of years. Often shaped into the letter "U." Also see alnico magnet permanent magnet magnetically controlled electronic ignition: See electronic ignition system.

magnetic clutch: A coupling device used to turn the compressor off and on electrically. See electromagnetic clutch

magnetic drain plug:

A plug or bolt fitted in the sump or oil pan to collect metal filings

magnetic field: The area encompassed by the magnetic lines of force surrounding either a bar magnet or electromagnet. The flow of magnetic force between the opposite poles of a magnet. Also see field primary magnetic field magnetic pick-up: [1] A pulse generator consisting of a stator with a permanent magnet and a rotor, which induces an AC voltage in the inductive winding by the periodic change of the air gap between stator and rotor. Magnetic pick-ups attached to the distributor for ignition triggering have as many teeth on the pole piece (stator) and on the trigger wheel (rotor) as the engine has cylinders. Some magnetic pick-ups have a bowl-like rotor with ferrite rods inserted in the walls. Magnetic pick-ups on the crankshaft flywheel act as reference mark sensors. [2] A tool with flexible or rigid shaft and magnetic tip used to retrieve dropped nuts, bolts, and other metal parts from hard-to-reach places. Also see pick-up tool transistorized ignition with magnetic pick-up magnetic pick-up assembly: A pulse generator consisting of a stator with a permanent magnet and a rotor, which induces an AC voltage in the inductive winding by the periodic change of the air gap between stator and rotor. Magnetic pick-ups attached to the distributor for ignition triggering have as many teeth on the pole piece (stator) and on the trigger wheel (rotor) as the engine has cylinders. Some magnetic pick-ups have a bowl-like rotor with ferrite rods inserted in the walls. Magnetic pick-ups on the crankshaft flywheel act as reference mark sensors

magnetic pick-up tool: A tool with flexible or rigid shaft and magnetic tip used to retrieve dropped nuts, bolts, and other metal parts from hard-to-reach places. Also see pick-up tool magnetic plug:

A plug or bolt fitted in the sump or oil pan to collect metal filings

magnetic screwdriver: [1] A screwdriver with a magnetized shank. [2] A screwdriver tool with hexagon socket end to accept and operate hex bits and hold them securely by magnetism. Some also have a hollow handle for storing the bits

magnetized: made magnetic

magneto: An electrical device which generates electrical current when it is rotated by an outside source of power. It needs no outside source of power such as a battery. It may produce either low or high tension current. Also see flywheel magneto magneto file: A tool for filing ignition points and other small objects

magneto ignition: A compact assembly of a magneto generator, an ignition coil, and a distributor. Ignition voltage is induced within the magneto by the movement of a coil relative to the poles of a permanent magnet. Because it needs no battery, the system is particularly suited for small engines, e.g., motorcycles, outboard engines, etc.

magneto puller: A tool which screws into the center of the magneto to force the magneto away from the shaft on which it rides.

magnet sensor: See Hall vane switch

mags: See mag wheel.

mag wheel:

Lightweight, sporty wheels made of magnesium. The term mag is often applied to aluminum and aluminum and steel combination wheels. Also see alloy wheels main bar: The bar on a convertible top which carries the main load when the top is raised and taut, and defines the hinge point for the folding motion. Also called "main bow"

main beam: British term for high beam

main beam indicator: British term for high beam indicator

main bearings: The bearings in the engine block that support the crankshaft.

main bearings: See main bearing

main bearing support: See main bearing supports.

main bearing supports: A steel plate that is installed over the main bearing caps to increase their strength for racing purposes.

main bow: The bar on a convertible top which carries the main load when the top is raised and taut, and defines the hinge point for the folding motion. Also called "main bar"

main combustion chamber: with diesel engines, the fuel may be injected in three different locations: in the prechamber, the swirl chamber, or the main combustion chamber (for direct injection engines), depending on the process used

main deck: The continuous deck of a ship running from fore to aft. The freeboard is measured from this deck.

main jet: The primary, large fuel orifice in a carburetor through which most of the fuel flows.

mainline pressure: See line pressure

main member: The primary chassis rail

main metering circuit: The cruising circuit or the high speed circuit. It supplies the correct air/fuel mixture to the engine during cruising and high-speed conditions. Also called main metering system

main mixing well: Main well main nozzle: Main delivery tube

main mixture discharge nozzle: The jet through which the gasoline and air is fed into the carburetor barrel where it becomes the air/fuel mixture

main petal: The primary petal of a dual-stage reed valve. The opposite is subsidiary petal. In dual-stage reed valves, the subsidiary petal opens first

main pressure: See line pressure

main regulating system: The carburetor components are divided into the fuel intake control, the main regulating system, the idle system, and the staring aids. The main regulating system includes the main jet, jet needle, needle jet, and throttle valve, whose purpose it is to provide an appropriate amount of fuel and air to the carburetor

mains: See four bolt mains

main shaft: The transmission output shaft

main sun visor: In dual visor systems, the main visor is moved sideways and the secondary visor is flipped down, thus shielding the driver from the sun from both the front and side

maintenance: The work undertaken by a car owner to keep his vehicle in good working order; typically checking the tires, lights, oil and coolant levels, windscreen wipers, and seat belts. Compare service

maintenance-free: Something that requiring no work in order to be kept operational

maintenance-free battery: A battery with a permanently sealed top, thus requiring no topping-up

maintenance manual: A book of instructions detailing routine maintenance

main triangle: See front triangle.

main venturi: Large venturi cast into the carburetor main body

main well: The reservoir in which fuel for the main system is stored. The main well is located in the main body casting. It is connected to the venturi area by the discharge nozzle

main-well tube:

A perforated tube which extends from an air bleed in the top of the air horn down into the main well. Admits air from the air bleed into the main well to emulsify the fuel in the main well. Improves idle response and stability when the engine is hot and prevents fuel percolation and general hot-starting problems. Also improves response in the main metering circuit during part throttle conditions. Also called emulsion tube

major diameter: On a bolt or screw, the diameter measured from the crest of a thread to the corresponding crest on the opposite side of the bolt or screw

make: brand name of a car or truck (i.e., Chevrolet, Ford, Dodge, Honda).

male end: A plug, pin, or protrusion which fits into a receptacle (female end).

male thread: Something with external threads like a bolt or screw. Female threads are found in nuts.

malfunction: Problem in system that affects normal operation

malfunction indicator light: (MIL) an electric circuit between the computer and the "check engine" or "service engine soon" light on the dash panel of a computer equipped vehicle

malleable castings: [1] Cast forms of metal which have been heat-treated to reduce their brittleness. [2] A casting which has been toughened by annealing

mallet: also See bossing mallet rubber mallet wood mallet

man: Short form for manual transmission

management system: See engine management system

mandrel: A round shaft used to mount a stone, cutter, saw, etc.

maneuver: to drive or steer a vehicle around obstacles or in a confined space

maneuverability: The ease with which a vehicle can be steered around objects

Manganese: See methylcyclopentadienyl Manganese Tricarbonyl

manganese bronze: An alloy of copper, zinc, and manganese

manganese phosphate coating: A phosphate coating with added manganese to increase resistance to wear and fatigue

Manganese Tricarbonyl: See methylcyclopentadienyl Manganese Tricarbonyl

Manhattan: See Frazer.

manifold: A pipe or number of pipes connecting a series of holes or outlets to a common opening. also See air injection manifold

exhaust manifold high-rise manifold induction manifold inlet manifold intake manifold heater intake manifold log manifold ram intake manifold split manifold variable intake manifold manifold absolute pressure: (MAP) manifold pressure measured on the absolute pressure scale, an indication of engine load. At sea level, MAP = 1 bar (14.5 psi)

manifold absolute pressure sensor: (MAP) A sensor which monitors the engine's intake manifold pressure and transmits the data to the engine controller. A pressure-sensitive disk capacitor used to measure air pressure inside the intake manifold. The Map sensor sends a signal to the computer which uses this information to determine load conditions so it can adjust spark timing and fuel mixture. Also called manifold pressure sensor or pressure differential sensor

manifold air temperature sensor: (MAT sensor) sensor that monitors the temperature of the air entering the intake manifold

manifold charge temperature sensor: (MCT) same as the air charge temperature sensor (ACT)

manifold control valve: (MCV) a thermostatically operated valve in the exhaust manifold for varying heat to the intake manifold with respect to the engine temp. Also called "exhaust heat control valve"

manifold gauge set: A complete, testing assembly consisting of a high side gauge, a low side gauge and a high side gauge, a test manifold, and a set of service or charging hoses. Also, can be used to discharge refrigerant, evacuate air and moisture, and charge air conditioning system with refrigerant

manifold heat control valve: A valve placed in the exhaust manifold, or in the exhaust pipe, that deflects a certain amount of hot gas around the base of the carburetor to aid in warmup.

manifold heater: A system used to improve the cold start behavior of an engine, consisting of heating ducts incorporated into the intake manifold that are connected to the water cooling system of the engine; alternatively, an electric heater may be used. Also see inlet manifold heater intake manifold heater manifold pressure controlled: (MPC) a fuel injection system which determines engine load based on intake man pressure

manifold pressure sensor: A sensor that reads pressure changes in the intake manifold in relation to barometric pressure. Also known as manifold vacuum sensor, manifold absolute pressure sensor, pressure differential sensor, or vacuum sensor

manifold runners: Single passage in a manifold from one cylinder to the major manifold opening

manifold vacuum: As the pistons move down on the intake stroke, they create a suction or vacuum in the intake manifold. This vacuum reading can be used to determine how well the engine is running.

manifold vacuum sensor: A sensor that reads pressure changes in the intake manifold in relation to barometric pressure. Also known as manifold pressure sensor, pressure differential sensor, or vacuum sensor

manoeuvrability: British spelling of maneuverability

manoeuvre: British spelling of maneuver

manometer: A device for measuring a vacuum, consisting of a "U" shaped tube partially filled with fluid. One end of tube is open to air, the other is connected to a chamber in which vacuum is to be measured. A column of mercury 30 in. high equals 14.7 psi, which is atmospheric pressure at sea level. Readings are given in inches of mercury (Hg)

manual: [1] Something done by hand. also See manual choke manual steering manual transmission [2] A colloquial term for a vehicle with manual transmission. [3] A book of instruction. also See flat rate manual maintenance manual owner's manual repair manual service manual manual choke: A linkage system which begins with a knob on the dash which can be pulled to activate and pushed to de-activate. The knob is attached to a cable and the other end of the cable is attached to a the butterfly valve on the carburetor. Because many drivers had difficulty knowing when to use the choke knob, manufacturers developed the automatic choke system which decides this information for the driver.

manual-crank window: See manually operated window

manual gearbox: See manual transmission

manually operated window:

window operated by turning a lever by hand. Compare electric window

manual panel cutter: cutting tool drawn manually across a panel surface to cut to the desired shape

manual steering: A steering system that does not have a power booster to reduce the effort of steering changes especially during slow movements such as parallel parking.

manual transmission: A transmission system in which gears are selected by the driver by means of a handoperated gearshift and a foot-operated clutch. In a motorcycle the clutch is handoperated and the gearshift is foot-operated. Contrasts with an automatic transmission. Also called a "standard transmission."

manual valve: (MV) A control in an automatic transmission which distributes line pressure to the various control valves and pistons which operate the multi-plate or band brakes or the clutches; operated by the driver via the selector lever

manual version: A passenger car with a manual transmission

manufacturer: See automobile manufacturer

manufacturer discounts: In some leases, particularly subvented leases, the manufacturer reduces the MSRP which lowers the purchase price of the vehicle, which the lease is based on. This is a form of capitalized cost reduction.

manufacturer's performance ratings: The performance data as specified by the car manufacturer

manufacturer's suggested retail price: (MSRP) The suggested retail price the dealer is asking. Generally the same as the "sticker price." Dealers typically sell at a discount to this price.

manufacturing: process technology (i.e., metal forming, machining, injection molding, blow molding, die casting, forgings, electronics/electrical, assembly, coating/plating); capacity utilization (in percent); production volumes; strategic alliances (e.g., joint ventures, technology agreements).

MAP: See manifold absolute pressure

map: A pictorial representation of a series of data points stored in the memory of the control unit of system with complete engine management. The control unit refers to the map to control variables such as fuel injection pulse width and ignition timing also See characteristic map dwell-angle map engine map ignition map spark-angle map spark map map-controlled ignition: A microprocessor-controlled ignition system with electronic ignition timing by means of an ignition map stored in the control unit memory. The engine speed is sensed by Hall generators at the distributor or magnetic pick-ups on the crankshaft, the load signal being given by pressure sensors which measure the air mass or air per unit of time

map light: An interior light to facilitate, for example, map reading. Also see gooseneck map light MAPP: A stabilized methyl acetylene-propadiene fuel gas. It is a Dow Chemical Co. product.

mapped ignition:

A microprocessor-controlled ignition system with electronic ignition timing by means of an ignition map stored in the control unit memory. The engine speed is sensed by Hall generators at the distributor or magnetic pick-ups on the crankshaft, the load signal being given by pressure sensors which measure the air mass or air per unit of time

mapping: See characteristic map

MAP sensor: Manifold absolute pressure system sensor tells computer how much pressure is in the intake manifold

Maquila: Mexican assembly plant located near the U.S.-Mexican border where most production is exported to the United States.

Maquiladora: Mexican assembly plant located near the U.S.-Mexican border where most production is exported to the United States.

marbling: A special decorative painting effect with rotating brushes

margin: [1] The return an intermediary achieves on the selling price of the article. That is, if the intermediary buys a product for $1 and sells it for $1.50, the margin is calculated. For example, .50 (i.e., $1.50 - $1) divided by $1.50, or 33%. See gross margin [2] Also see valve margin margin bracket: A bracket connecting a side frame to the margin plate at the bilge

margin line: A line, not less than 3 inches below the top of the bulkhead deck at side, defining the highest permissible waterplane in the final condition of sinkage, trim and heel

mark: also See draft marks reference mark sensor skid mark swirl marks timing mark tracking mark witness mark marker lamp: [1] A light which is mounted on the extreme edges of the roof of a truck to show the maximum height and width of a vehicle. Also called "clearance lamp." [2] A side marker light

marker light: A side marker light

market: also See aftermarket do-it-yourself market grey market mechanic installed market replacement market gray Market Vehicles market share: The percentage of total sales represented by an individual manufacturer/importer, make or nameplate.

Market Vehicles: See gray Market Vehicles

marking: also See size marking water marking wheel marking

marks: See mark

mark sensor: See reference mark sensor

mark-up: the return an intermediary achieves on the cost price of an article. Using the same example described above, mark-up is .50 divided by $1, or 50%.

Marles steering: A form of cam-and-roller steering

Marmon: A vehicle brand of which all 16-cyl.; 1925 74; 1926 74; 1927 75; 1928 E75; 1930 Big 8; 1931 88 and Big 8 models are classic cars.

marque: A particular brand name of a vehicle. Also spelled "marquee"

marquee: A particular brand name of a vehicle. Also spelled "marque"

martin: Aston Martin.

mascot: also See Emily Rolls Royce mascot Maserati: A vehicle brand of which the 1925-1948 models with required application are classic cars. The 1957-64 3500/3700 GT models are milestone cars.

Click for books on Maserati

mask: to cover the surrounding area when paint spraying to protect it from splashes

masking tape: An adhesive tape used to cover surfaces that border an area to be painted, so as to protect them

mass: The quantity of matter a body contains. Mass is measured in kilograms (and often incorrectly called weight). The mass of a body does not change if, for example, it is moved to the Moon where the force of gravity is less. also See sprung mass unsprung mass weight mass airflow meter: (MAF) device for measuring the mass flow of air into an engine. Also see airflow sensor hot-wire airflow meter mass damper: A device which reduces or prevents vibrations or oscillations, usually a weight which counteracts (balances) undesirable motions; used on drive shafts of some FWD cars

mass-produced car: A car which is manufactured in great numbers to a standard pattern and with extensive mechanization

mass tone: The tone of a paint as it appears from the color of the paint in the can; this is required for formulating the ingredients of a paint tone. Also see tint tone mass transit system:

A system designed to transport large numbers of people or goods

mast: A tall vertical or raked structure, usually of circular section, located on the centerline of a ship and used to carry navigation lights, radio antennas and cargo booms

master: The primary or controlling device. A secondary or dependent device is called a "slave." also See brake master cylinder dual-piston master cylinder master link master brake cylinder: See brake master cylinder.

master con rod: In a two-stroke dual piston engines, the connecting rod that is articulated directly on the crankshaft. Also see slave con rod master cylinder: The primary component for pressurizing fluid in a hydraulic system. Used in the braking system, it supports a reservoir for holding brake fluid and is activated each time the driver depresses the brake pedal. Also see brake master cylinder dual-piston master cylinder slave cylinder split-system master cylinder tandem master cylinder master link: A special link on a chain that can be opened by flexing a plate, removing a screw, or some other means besides driving out a rivet. The retaining spring clip is shaped like a fish with a round head and twin tails. This illustration helps to determine the position of the clip because the "fish" moves in the direction of chain movement. When installed in reverse, the clip may come off.

master model: The first precision model of an automobile based on a clay model or CAD-data; essential for the manufacture of prototypes

master pattern: The first precision model of an automobile based on a clay model or CAD-data; essential for the manufacture of prototypes

master switch: See battery master switch

master vac: See vacuum brake booster

master vac servo unit: See vacuum brake booster

masthead light: A white light situated on the fore and aft centerline of a ship

mastication: The reduction of rubber to a pulp preparatory to making tires

mastic seam sealant: soft waterproof sealant for joints

mat: [1] A dull, not shiny, paint finish. Also spelled "matt." [2] A covering. also See bead seat mat fibreglass mat matched:

See color-matched

matching: also See color matching paint color matching mate: to fit together

material: also See base material bearing material molding material performance characteristics of materials piston material soundproofing material viscoelastic materials material safety data sheets: Sheets that contain information on the handling of hazardous wastes, the use of protective equipment and the procedures to follow in case of an accident

mating: Fitting together; matching

mating gears: gears which mesh together

mating surface: A surface which interacts perfectly with another

mating thread: A thread which engages with a corresponding thread, such as the male and female threads of a nut and bolt

MAT sensor:

Acronym for manifold air temperature sensor

matter: See particulate matter

matrix: That portion of the mold which surrounds the tire transferring heat to the uncured rubber and forming the tread pattern.

matt: A dull, not shiny, paint finish. Also spelled "mat"

Maxima: A model of automobile manufactured by Nissan in Japan

Click for books on Maxima

maximum brake power: The maximum power of an engine as measured by a dynamometer

maximum power: The maximum power of an engine as measured by a dynamometer

maximum trailer weight: Also known as towing capacity; the heaviest trailer the vehicle is rated to tow. Towing capacity is typically based on the vehicle plus a driver of 150 pounds. The weight of additional passengers and/or cargo should be deducted from the maximum trailer weight.

Maybach: A vehicle brand of which the 1925-1948 models are classic cars.

Mays: See Raymond-Mays

Mazda: A model of automobile manufactured in Japan

Click for books on Mazda Mazda RX: A model of automobile with a rotary engine manufactured in Japan

Click for books on Mazda RX

McFarlan: A vehicle brand of which the 1925-1948 models are classic cars.

McPherson strut: See MacPherson strut

M/C solenoid: Acronym for mixture control solenoid

MCT: Acronym for manifold charge temperature sensor

MCU: Acronym for microprocessor control unit

MCV: Acronym for manifold control valve

mean: See indicated mean effective pressure

mean distance to the sun: 240 million miles; used to specify the headroom in convertibles

mean effective pressure: (MEP) The pressure of the burning fuel (average) on the power stroke subtracted by the average pressure on the other three strokes. Pressure is in pounds per square inch. Also see brake mean effective pressure

indicated mean effective pressure mean indicated pressure: A mathematical value that indicates the relation between the effective area of the work diagram of the two-stroke engine and the movement of the piston

measuring: See ionic-current measuring technique pushrod measuring tool measuring method: See ionic-current measuring method

measuring technique: See ionic-current measuring technique

measuring tool: See pushrod measuring tool

mechanic: A person who works on engines or machines. Also see automobile mechanic car mechanic DIY mechanic do-it-yourself mechanic motor mechanic mechanical advance: See centrifugal advance mechanism

mechanical brake: See mechanical brakes.

mechanical brakes: Service brakes that are actuated by a mechanical linkage (rather than hydraulic lines) connecting the brakes to the brake pedal. The parking brake on most vehicles

is mechanical.

mechanical efficiency: An engine's rating as to how much of the potential horsepower is wasted through friction within the moving parts of the engine. The ratio between the indicated horsepower and the brake horsepower of an engine.

mechanical face seal: A shaft seal consisting of two highly polished mating surfaces, one surface being connected to the shaft (rotating element) and the other to the casing (stationary element)

mechanical galvanizing: See mechanical plating

mechanical ignition timing: Centrifugal and vacuum advance

mechanical plating: A deposition of zinc on another material by a cold-peening process, such as tumbling

mechanical seal: A shaft seal consisting of two highly polished mating surfaces, one surface being connected to the shaft (rotating element) and the other to the casing (stationary element)

mechanical stress: A force acting across a unit area in solid materials in resisting the separation, compacting, or sliding that tends to be induced by external forces

mechanical surface treatment: A production of a dull or rough surface or a decorative finish by grinding, brushing, polishing, or abrasive blasting

mechanic installed market: (MIL) Vehicle maintenance and repair conducted by a mechanic/professional at a service outlet.

mechanic's creeper: See creeper

mechanic's elbow: A shallow dent in body panels, usually on the top of a fender near the engine compartment; caused when leaning over into the engine compartment and supporting the body with elbows on the fender

mechanics lien: When you take your vehicle to a shop to be repaired and you fail to pay your repair bill, the repair shop has a lien on your vehicle and can confiscate and sell your vehicle to pay for the work on your vehicle.

mechanic's stethoscope: See sonoscope

mechanism: See gearchange mechanism locking mechanism shifter mechanism vacuum advance mechanism MECP: Acronym for "Mobile Electronics Certification Program."

median: See center median

medium: See aggressive medium

medium carbon: A type of carbon steel used extensively for sheet metal screws and grade 2 hex head bright cap screws.

medium-duty truck: vehicle weighing from 10,001 to 25,000 lbs.

megajoule: (MJ) An SI measurement of energy (= l000 joules)

MEMA: Acronym for "Motor and Equipment Manufacturers Association."

member: A general term that refers mainly to the side rails and crossmembers but also to any structural hollow-section part on a vehicle. Also see box member cross member frame member longitudinal member main member reaction member side member member of the gear train: sun gear, internal gear, and planet carrier are the members of a planetary gear train

membrane: See sill membrane

memory: See alive memory fault memory keep alive memory last station memory memory button: A button which operates the position of electric seats, mirrors, etc. and which stores the requirements of a particular driver in its memory

MEP:

Acronym for "mean effective pressure."

MERA: Acronym for "Mobile Electronics Retailers Association."

Mercedes: A vehicle brand of which the 1925-1948 models with required application are classic cars.

Click for books on Mercedes

Mercedes-Benz: A vehicle brand of which all 230 and up, and K, S, SS, SSK, SSKL, Grosser and Mannheim models with required application are classic cars. The 1955-61 190 SL models are milestone cars. The 1951-54 220A Coupe and Convertible are milestone cars. The 1956-65 220S/220SE Coupe and Convertible are milestone car. The 1963-67 230SL Coupe and Convertible are milestone cars. The 1965-67 250SE Coupe and Convertible are milestone cars. The 1965-67 250 SL models are milestone cars. The 1969-70 280 SL models are milestone cars. The 1965-67 300 SE Coupe and Convertible are milestone cars. The 1952-64 300 S, SL, SE, 300 Coupe and Convertible are milestone cars. The 1964 600 model is a milestone car. The 1965-70 SWB-LWB 600 models are milestone cars.

Click for books on MercedesBenz

Mercer: A vehicle brand of which the 1925-1948 models are classic cars.

Mercosur: the southern zone common market of Argentina, Brazil, Paraguay, and Uruguay. Mercosur enacted a common external tariff on January 1, 1995 for almost 85 percent of tariff items of the four countries; most trade among members will be duty-free.

Mercury: A vehicle brand of which the 1967-68 Cougar XR-7 models are milestone cars. The 1946 Sportsman is a milestone car. The 1954- Click for books on Mercury 55 Sun Valley models are milestone cars. mercury column: A reference term used in connection with a manometer

mercury switch: safety switch to prevent erroneous deployment of the air bag. Due to ecological problems associated with mercury in automobile waste, mercury switches are being replaced by suspended-mass switches, e.g., a Hamlin switch

Merkur: A model of automobile manufactured by Ford of Europe Click for books on Merkur mesh: to engage, especially gears. The opposite is disengage. Also see constant-mesh gearbox metal mesh stainless-steel mesh wire mesh mesh gearbox: See constant mesh gearbox constant mesh gears meshing drive: A device for engaging the starter pinion with the flywheel ring gear

meshing spring: A component of a pre-engaged starter which ensures that the shift lever will move to its final position and that the starter current will be switched on in case of tooth abutment

message center: usually a multifunctional display of a diagnostic system. A typical messages are: "NORMAL," "DOOR AJAR," "TAILGATE OPEN," "LAMP OUT," "WASHER FLUID LOW," etc.

metacenter: The intersection point of a vertical line drawn through the line of buoyancy of a slightly listed vessel which intersects the centerline plane

metacentric height:

The distance from the metacenter to the center of gravity of a ship. If the center of gravity is below the metacenter the vessel is stable

metal: See babbitt metal base metal burned metal ferrous metal heavy sheet metal light sheet metal noble metal nonferrous metal pedal to the metal platinum metals pot metal scrap metal sheet metal sound metal weld metal white metal metal-arc: See gas metal-arc welding

metal-arc welding: See gas metal-arc welding

metal blank: See sheet metal blank

metal brake pad: See sintered metal brake pad

metal catalyst: A catalyst whose active phase is supported by a metal substrate, i.e., sheet steel. Compare metal monolith

metal clamp:

See sheet metal clamp

metal conditioner: An acid-based metal cleaner that removes rust and corrosion from bare metal, etches it for better adhesion and forms a corrosion resistant film

metal cutter: A bench tool for cutting sheet metal. Also see sheet metal cutter metal fatigue: A crystallizing of the metal due to vibration, twisting, bending, etc. The unit will eventually break. Bending a piece of wire back and forth to break it is a good example of metal fatigue. See fatigue.

metal folder: See sheet metal folder

metal forming: solid metal and molten metal process such as casting, forging, stamping, and machining.

metal inert gas welding: See MIG welding

metallic: referring to or consisting of metal

metallic drive screw: A British term for a self-tapping screw

metallic finish:

metallic paint:

A finish paint colors that contain both pigment and small metallic flakes which reflect light. The opposite is solid paint. The flakes are often of different sizes. When the surface is viewed from different angles, the color shade seems to vary, since the flakes are all oriented at different angles in the paint and consequently reflect the light differently. Japanese motorcycles used a different size of flakes than was common in the USA. As a result, repainted tanks in the USA did not have the same "look."

metallize: To coat or impregnate a metal or non-metal surface with metal, as by metal spraying or by vacuum evaporation

metallographic examination: A test to determine the structural composition of a metal as shown at low and high magnification and by X-ray diffraction methods. Tests of this type include macroexamination, micro-examination, and X-ray diffraction analysis

metal mesh: See wire mesh

metal monolith: See metal support

metal remains: See sheet metal remains

metal roller: See sheet metal roller

metal shears: A scissor-like hand tool for cutting sheet metal. Also called "snips"

metal spraying: A coating of surfaces with droplets of molten metal or alloy by using a compressed gas stream

metal support:

A thin corrugated strips of steel alloy rolled up into a tight coil as a support for the catalyst in a catalytic converter. Also see ceramic honeycomb metalworking: forming and shaping metal

metalworking spoon: See body spoon

METC: Acronym for "Mobile Electronics Technical Center."

meter: [1] A device for measuring the quantity of a substance passing through it. [2] To measure with a meter. [3] to supply at a measured rate. [4] A distance of about a yard (actually a little over 39.37"). Also spelled "metre." Also see airflow meter CO meter dwell meter hot-wire airflow meter L-jetronic air flow meter mass airflow meter newton meter parking meter smoke meter trip meter metering jet: A small hole or orifice used to control the flow of gasoline in various parts of the carburetor.

metering orifice: A small hole that restricts the flow of liquid -- usually coolant or oil

metering port:

A part of the metering unit in the fuel distributor

metering rod: A thin, movable rod which varies the opening area in a carburetor jet. As the rod is raised it permits more fuel to enter the jet.

metering signal: A (relative) vacuum signal generated by the pressure differential that occurs at the venturi. The strength of the metering signal determines how much fuel is pulled from the main circuit into the venturi. The smaller the venturi the greater the pressure drop and the stronger the metering signal; the larger the venturi, the smaller the pressure drop and the weaker the metering signal

metering slits: In Bosch CIS, the narrow slits in the control-plunger barrel of the fuel distributor. Fuel flows through the slits in accordance with the lift of the control plunger and the pressure drop at the slits

metering unit: A unit which regulates the quantity of fuel injected in the K-jetronic system. A lever connected to the sensor plate raises or lowers a stepped control plunger in the metering unit. The position of the control plunger relative to the metering ports in the metering unit varies the flow of fuel to the fuel injectors

metering valve: A valve positioned in the hydraulic line to the front brakes, on some cars with front disc and rear drum brakes. It prevents the disc brakes from applying until after the rear brake linings contact the drum. The metering valve closes off pressure to the front disc brakes until a specified pressure level is generated in the master cylinder. This allows pressure in the rear brake circuit to overcome return spring force and an gap before the hydraulic pressure is admitted to the front disc brakes

methacrylate: A polymer used in toughening rubber. Also see polymethyl methacrylate methanol: An alcohol that is occasionally blended with gasoline (typically 3%) to raise octane levels, it is poisonous to humans and causes trouble with rubber and plastic parts of

the fuel system not designed to handle alcohol-blended fuels. Also called "methyl alcohol" or "wood alcohol."

methyl alcohol: See methanol.

methylated spirits: Almost pure alcohol (which has wood alcohol and coloring added to make it unfit for human consumption); used for cleaning

Methylcyclopentadienyl Manganese Tricarbonyl: (MMT) An organic manganese compound. It is used as a fuel additive designed to enhance octane levels in gasoline.

metre: See meter

metric century: A bicycle ride of 100 kilometers (62.14 miles). See century.

metric size: Units made to metric system measurements.

metric thread: The threads of metric nuts, bolts, and screws. Two primary styles were common: ISO (International Standardization Organization) and JIS (Japanese Industrial Standard) which is no longer used. UNC thread and UNF thread cannot be interchanged with any metric nut or bolt. Width across flat Pitch Nominal diameter ISO JIS ISO JIS 3

5.5

6

0.5

0.6

4

7

8

0.7

0.75

5

8

9

0.8

0.9

6

10

10

1.0

1.00

8

12

14

1.25

1.25

10

14

17

1.25

1.25

12

17

19

1.25

1.5

14

19

21

1.5

1.5

16

22

23

1.5

1.5

18

24

26

1.5

1.5

20

27

29

1.5

1.5

metro driving: An American term for driving exclusively in the city rather than on the highway. The British term is "urban driving."

MEWA: Acronym for "Motor and Equipment Wholesalers Association."

MF: Acronym for multi-focal

MF headlight: A conventional headlight with a multiple-focus parabolic reflector

MFN: Acronym for " Most-Favoured-Nation Treatment."

MG: A vehicle brand (Morris Garages) of which the 1935-39 SA, 1938-39 WA, and (1925-1948 models with required application) are classic cars. The 1946-49 Series TC models are milestone cars. The 1950-53 Series TD models are milestone cars.

MIC: Acronym for "Microvan" (e.g., Suzuki Carry).

Michelin "X": Registered trademark for Michelin's steel belted radial cord tire.

mickey mouse: A trivial thing. In automotive usage it means something that is simplistic and worthless.

microbial corrosion: Corrosion associated with the action of micro-organisms present in the corrosion system

microcar: small car, popular in the 1950s, that featured a body offering full-weather protection and mechanics often derived from motorcycle technology, e.g., Goggomobil, BMW Isetta, etc. Also see bubble car micro finish: Degree of surface roughness, measured with a profilometer

microgalvanic cell: local cell

micrometer: [1] A precision measuring tool that will give readings accurate to 0.002 mm or 0.0001 of an inch. Sometimes called inside micrometer or outside micrometer. Also called a "mike." Also see air micrometer depth micrometer external micrometer internal micrometer [2] A unit of measurement of thickness which is equal to one thousandth of a millimeter. Also called "micron."

micrometre: See micrometer

micron: See micrometer

micro oil filter: A special oil filter designed to trap particles down to 1 micrometer in order to allow extended oil change intervals in the order of 60,000 miles (100,000 km) without affecting engine life

microprocessor control unit: (MCU) an integral part of an electronically controlled feedback carburetor using a TWC catalyst. Various sensors monitor conditions. MCU is widely used on Ford vehicle for the control of air-fuel ratios

microprocessor spark timing system: (MSTS) See mapped ignition system

midbed: In dual bed catalytic converters with air injection, the plenum between the threeway catalyst and the conventional oxidation catalyst, into which secondary air is injected

middle body: See parallel middle body

mid-engine: A chassis layout that positions the engine behind the passenger compartment but ahead of the rear axle. Also see underfloor mid-engine front engine rear engine mid-engine chassis configuration: The engine is located in the center of the chassis directly behind the passenger compartment (normally these are only 2-seater vehicles) but ahead of the center line of the rear wheels. In most cases, the fuel tank is directly in front of the passengers. This provides much better weight distribution and handling. There are three basic chassis configurations used today. The front engine configuration with the engine in the front, the passenger compartment in the middle and the trunk in the back. There are rear-engineered cars (like the Volkswagen Bug and the Porsche 911) where the trunk is in the front, the passengers are in the middle and the engine is in the back, behind the center line. And the mid-engine configuration described above. See midengine.

mid-range:

The middle of the rev range, around 3000 rpm

midrange torque: The pulling power of the engine in the middle of the rev range

midship section: A drawing showing a typical cross section of the hull and superstructure at or near amidships and giving the scantlings of the principal structural members

mid-size car: At one time (during the 1960s) a mid-size car was between the large full-size car (like Cadillac, Lincoln, and Imperial) and the compact cars (like Nova, Falcon, and Valiant). They included the Chevelle, Torino, and Coronet. However, with the fuel shortage of the mid-1970s, many models shrunk. For example, the full-size Mercury and Ford became about the size of the previous Torino. The Nova, et al, were called mid-sized in the '80s, especially with the introduction of the Chevelle, Escort, and Colt. By the close of the '80s, even Cadillac DeVille was smaller than the 1969 Chevelle.

MIG: Acronym for "metal inert gas." A term used to describe gas metal arc welding

migrate: When electrophoretic paint is attracted to car bodies when they are immersed in a bath of paint with an applied polarity across the bath and the bodies

MIG welding: An arc welding method in which the electric current is provided by the filler metal wire which is cooled and shielded from the access of air by a stream of chemically inert gas, thus preventing oxidation of the joint. Compare TIG welding

mike: [1] A micrometer. [2] The use of a micrometer to measure an object.

MIL: Acronym for malfunction indicator light

mild steel: A type of steel with a low carbon content (0.1-0.25%), widely used in vehicle construction. See low-carbon steel

mileage: [1] The distance measured in miles, as by a mileometer. [2] The total number of miles a motor vehicle has travelled. [3] The number of miles a motor vehicle travels on one gallon of fuel. Also see delivery mileage only fuel mileage mileage allowance: Mileage Allowance Lease agreements usually establish the average miles per year that the car may be driven during the lease. This is often between 12,000 and 15,000 miles. The lease contract also establishes the amount you'll have to pay for every mile driven over the allowance. This mileage fee is usually 15 cents per mile. You can often purchase additional miles at the start of the lease at a discounted rate. If you're sure you're going to drive more than the number of miles allowed, then your best option is to negotiate for a higher allowance on the lease.

mileage counter: See trip mileage counter

mileage tire: See special mileage tire.

mileometer: A device that records the number of miles travelled. Compare odometer. Also spelled "milometer."

miles per hour: See mph.

Milestone Car Society: P.O. Box 50850, Indianapolis, IN, 46250.

milestone cars: Great cars of the post-war era, 1946-70 which include the following:

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

AC Ace (1954-61) AC Aceca (1955-61) AC Buckland Open Tourer (1949) AC (Shelby) Cobra (1962-67) Alfa Romeo Giuletta Spider (1956-64) Alfa Romeo Giuletta/Giulia Sprint Speciale (1959-61) Alfa Romeo 6C 2500 Super Sport (1949) Allard Series J2, K2, K3 (1946-56) American Motors AMX (1968-70) Apollo (1963-66) Arnolt Bristol (1952-62) Aston Martin (1948-63) Aston Martin DB4, DB5, DB6 (all) (1964-67) Austin Healey 100-6 (1956-59) Austin Healey 3000 (1959-67) Austin Healey 100/100M (1953-56) Bentley (1946-67) BMW 507 (1957-59) Bugatti Type 101 (1951) Buick Riviera (1949, 1963-70) Buick Skylark (1953-54) Cadillac Eldorado (1953-58, 67-70) Cadillac Eldorado Brougham (1957-58) Cadillac 60 Special (1948-49) Cadillac 61 Coupe Fastback (1948-49) Cadillac 62 Sedanet, Convertible DeVille (1948-49) Cadillac 75 Sedan/Limo (1946-70) Chevrolet Bel Air V-8 Hardtop and Convertible (1955-57) Chevrolet Camaro SS/RS V-8 and Z-28 (1967-69) Chevrolet Corvette (1953-70) Chevrolet Nomad (1955-57) Chrysler 300 Hurst (1970) Chrysler 300 Letter Series (1955-65) Chrysler Town and Country (1946-50) Cisitalia GT (Pininfarina) (1946-49) Citroën D8 and ID 19 (1955-64) Continental Mark II (1956-57) Corvair Monza (1960-64) Corvair Monza Spyder (1962-64) Corvair Monza/Corsa (1965-69) Crosley Hotshot/SS (1950-52) Cunningham (1951-55) Daimler DE-36 Custom Built (1949-53) Daimler 2.5 Special Sport Convertible (1949-53) Delage D-6 Sedan (1946-49) Delahaye Type 135, 175, 180 (1946-51) DeSoto Adventurer (1956-58)

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

Devon S/S (1958-62) Dodge Coronet R/T (1967-70) Dodge Charger R/T and Daytona (1968-70) Dual Ghia (1956-58) Excalibur II Series I (1965-69) Facel Vega V-8 (1954-64) Ferrari V-12 (All Front Engined) (1947-70) Ford Mustang GT/GTA V-8 (1965-67) Ford Mustang Boss 302/Mach 1 (1969-70);Ford Crestline Skyliner (1954) Ford Skyliner Retractable (1957-59) Ford Crown Vic Skyliner (1955-56) Ford Sportsman (1946-48) Ford Thunderbird (1955-57, 1958-60) Frazer Manhattan (1947-50) Gaylord (1955-57) Healey Silverstone (1949-50) Hudson (All) (1948-49) Hudson Hornet (1951-54) Imperial (1955-56) Jaguar XK 110 (1945-54) Jaguar Mark V Drophead (1951) Jaguar Mark VII and '54 Mark VII M (1951-54) Jaguar KX 140 (1954-57) Jaguar Mark VIII (1956-57) Jaguar Mark IX (1958-61) Jaguar Mark X (1962-64) Jaguar XK 150 (1958-61) Jaguar 3.4/3.8 Sedans (1957-64) Jaguar E Type (1961-67) Kaiser Darrin 161 (1954) Kaiser Deluxe/Deluxe Virginian (1951-52) Kaiser Dragon (1951-53) Kaiser Manhattan (1954-55) Kaiser Vagabond (1949-50) Kaiser Virginian (Hardtop) (1949-50) Lagonda V-12 (1948-49) Lagonda 2.5 Liter Drophead Coupe (1949-53) Lancia Flaminia Zagato (1959-64) Lancia Flaminia GT Two Passenger Coupe or Convertible (1961-63) Lancia Flavia Coupe (1962-66) Lancia Aurelia B.20 and B.2O Coupe (1951-59) Lancia Aurelia B.24 Spyder and Convertible (1953-59) Lea Francis 2.5 Liter Eighteen Sports (1950-54) Lincoln Capri (1952-54) Lincoln Continental (1946-48, 1961-64) Lincoln Continental Convertible (1958-60, 1965-67) Lincoln Continental Custom Limos (Lehman Peterson) (1961-67)

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

Lotus Elite (1958-63) Maserati 3500/3700 GT (1957-64) MG Series TC (1946-49) MG Series TD (1950-53) Mercedes-Benz 190 SL (1955-61) Mercedes-Benz 220A Coupe and Convertible (1951-54) Mercedes-Benz 220S/220SE Coupe and Convertible (1956-65) Mercedes-Benz 230SL Coupe and Convertible (1963-1967) Mercedes-Benz 250SE Coupe and Convertible (1965-1967) Mercedes-Benz 250 SL (1965-67) Mercedes-Benz 280 SL 1969-70 Mercedes-Benz 300 SE Coupe and Convertible (1965-67) Mercedes-Benz 300 (S, SL, SE, 300 Coupe and Convertible) (1952-64) Mercedes-Benz 600 (1964) Mercedes-Benz SWB-LWB 600 (1965-70) Mercury Cougar XR-7 (1967-68) Mercury Sportsman (1946) Mercury Sun Valley (1954-55) Morgan Plus Four (1950-64) Muntz Jet (1950-54) Nash Healey (1951-54) NSU Wankel Spyder (1964) OSCA MT-4 (1948-56) Oldsmobile 88 (Coupe, Convertible, Holiday) (1949-50) Oldsmobile 98 Holiday HT (1949) Oldsmobile Fiesta (1953) Oldsmobile 442 (1964-70) Oldsmobile Toronado (1966-67) Packard Caribbean (1953-56) Packard Custom (Clipper and Custom Eight) (1946-50) Packard Pacific/Convertible (1954) Packard Panther Daytona (1954) Packard Patrician/400 (1951-56) Panhard Dyna (1946-67) Pegaso (All) (1951-58) Plymouth Fury (1956-58) Plymouth Satellite SS and GTX (1965-70) Plymouth Barracuda Formula S (1965-69) Plymouth Roadrunner and Superbird (1968-70) Pontiac Safari (1955-57) Pontiac GTO (1964-69) Porsche Series 356 (1949-64) Porsche 356C (1965) Riley 2.5 (RMA, RME) (1945-55) Rolls-Royce (All) (1947-67) Shelby 350GT and 500 GT (1965-67) Sunbeam Tiger Convertible (1965-67)

• • • • • • • • • • •

Studebaker Avanti (1963-64) Studebaker Gran Turismo Hawk (1962-64) Studebaker Starlight Coupe (1947-49) Studebaker Starliner Hardtop (Six and V-8) (1953-54) Studebaker President Speedster (1955) Talbot Lago 4.5 (All) (1946-54) Triumph TR2/TR3 (1953-63) Tucker (1948) Volvo P.1800S, 2-door Coupe (1961-67) Willys Overland Jeepster (1948-51) Woodill Wildfire (1952-58).

mill: [1] Often used to refer to the whole engine. [2] To remove metal through the use of a rotating toothed cutter. [3] to grind, press or reduce to powder. [4] to shape or cut metal. [5] A milling cutter [6] A milling machine

milled glass fiber: Chopped strands of glass fibre which vary in length from 3 mm to about 50 mm

Miller cycle: A type of engine developed by Ralph Miller in the 1940s. It differs from a standard engine in that it has a supercharger. During the compression stroke, the intake valve remains open so that compression is against the supercharger instead of against the walls of the cylinder. The efficiency of the engine is increased by up to 15%.

milliampere: One thousandth of an ampere. With figures it is usually written mA

milliammeter: An ammeter with a milliampere scale

milligram: A unit of measurement of weight. A thousand milligrams equal one gram. With figures usually written mg

milliliter: A unit of measurement of liquid or volume where a thousand milliliters equal one liter. Also, one milliliter equals one cubic centimeter. With figures usually written ml.

millilitre: British spelling of milliliter

millimeter: A unit of measurement of distance where a thousand millimeters equal one meter. 25.4 millimeters equal an inch. With figures usually written mm.

millimetre: British spelling of millimeter. A metric measurement equivalent to about 0.039370 of an inch.

milling cutter: A rotating, toothed cutter in a milling machine, used to cut or shape metal

milling machine: [1] A machine that uses a variety of rotating cutter wheels to cut splines, gears, keyways, etc. [2] A machine tool with a table on which rests material which is cut by a rotating cutting tool held by a horizontal arbor or vertical spindle

millsaw file: A flat hand file with round or square edges for sharpening saw blades or machinecutting knives

milometer: A device that records the number of miles travelled. Compare odometer. Also spelled "mileometer."

MIL: Acronym for "Mechanic Installed Market."

mineral oil: A light lubricating oil refined from crude oil

Minerva: A vehicle brand of which all 1925-48 models except 4-cyl are classic car.

Mini: A small British front-wheel drive car designed in 1959 by Sir Alec Issigonis (190688)

miniature offset open-end wrench: A very small, open-ended wrench with two jaw openings of the same size set at different angles to the handle, e.g., 15° at one end and 60° at the other. Also called electrical wrench

minibus: small, single-decker bus designed to carry around 12-20 people

minicar: A very small sedan carrying no more than four adults

mini catalytic converter: A small but usually a primary catalytic converter which is installed close to the engine in the headpipe

miniframe: See suspension subframe

mini-grinder: See angle grinder

Minilite: A true magnesium wheel, developed for the mini in 1962 by nuclear engineer Derek Power on the basis of experience gathered with magnesium components in nuclear power plants. The Minilite started the boom in alloy wheels

Minilite alloy wheel:

A true magnesium wheel, developed for the mini in 1962 by nuclear engineer Derek Power on the basis of experience gathered with magnesium components in nuclear power plants. The Minilite started the boom in alloy wheels

mini-motorhome: See type C motorhome

mini spare wheel: See space saver spare.

mini tube cutter: A compact tube cutter for cutting brass, copper, plastic, or thin steel tubing in confined areas

minivan: [1] minibus-sized van with no side windows, used to transport goods instead of people. [2] A smaller van, with windows, which became popular with the VW van and its GM copy Greenbrier (based on the Corvair). Later, Chrysler produced its Magic Wagon series (also copied by GM and Ford) which has almost eliminated the station wagon.

Minlon: A mineral-fiber-reinforced polyamide, used for alloy wheels as a rim trim cover that protects the balancing weights

min/max governor: Controls the idle speed and prevents overspeed

minor diameter: The diameter measured from the thread valley to the corresponding valley on the opposite side of the bolt or screw

mint condition: A colloquial term for a vehicle that has been kept in, or restored to, perfect condition. Also called "cherry condition."

mirror:

A reflective device which is located in one of several positions: between the two Aposts within the passenger compartment (called the rearview mirror); behind either/both sunvisors (vanity mirror); on either side of the outer A-posts; on the forward or leading edge of the front doors; or on the front fenders. Also see anti-dazzle mirror day-night mirror dimming mirror dipping mirror driving mirror electric mirror exterior mirror external mirror inspection mirror interior mirror remote mirror vanity mirror wing mirror mirror control: See remote mirror.

misalignment: [1] general term referring to all types of frame damage caused by accidents. [2] The condition of two mating parts which are not placed in proper alignment

misfire: The failure of the fuel charge in one or more engine cylinders to fire or ignite at the proper time. It can be due to poor compression caused by worn or improperly adjusted valves, worn piston rings, a faulty head gasket, or in the case of a twostroke engine leaking crank seals. It can also be caused by poor ignition due to worn or dirty spark plug electrodes, worn or improperly gapped points or spark plugs, poor fuel delivery, faulty ignition wiring, or faulty distributor components. An easy way to detect the problem is to put a stiff piece of paper at the end of the tail pipe and listening for an irregular puffing sound. Also called "missing" or "backfiring." See engine misfire

misfiring: Failure of an explosive to occur in one or more cylinders while engine is running. This may be a continuous or intermittent failure

miss:

See misfire

missing: See misfire.

mist: See spray mist

mist action: An action of intermittent wipers which will make one or two swipes to clear away any mist from the windshield.

mist coat: Usually the final color coat, produced by over-reducing with a slow evaporating thinner. It is generally used to blend in the final overlap areas.

Mitsubishi: A model of automobile manufactured in Japan

Click for books on Mitsubishi

mix air cap: See external mix air cap internal mix air cap mixed-flow impeller: A pump impeller which combines radial and axial-flow principles, i.e., liquid flows both along the drive shaft and out through the impeller; pump impellers are classed as mixed-flow when the specific speed is 2,000 to 6,000 rpm

mixed-flow pump: A centrifugal pump which develops its head partly by centrifugal force and partly by the lift of the vanes on the liquid

mixing chamber: [1] That part of the welding torch where the welding gases are intimately mixed, prior to combustion. [2] that part of a carburetor distinct from the float chamber both in function and layout, in which the air and the fuel mix as they meet.

[3] The midbed of a catalytic converter

mixing head: The head of an oxyacetylene torch by which the mixture of oxygen and acetylene can be adjusted

mixing rolls: A machine designed for the mixing and mastication of the materials from which tires are made

mixte frame: A bicycle frame that replaces the top tube with twin lateral tubes that run all the way from the head tube back to the rear dropouts.

mixture: [1] A substance made up of two or more chemicals in some proportion. [2] A fuel-air mixture in an internal combustion engine. [3] The combination of oil and gasoline in the fuel tank of a two-stroke engine, e.g., 1:50, i.e., one part of oil is added to every 50 parts of fuel. Also see air-fuel mixture air mixture fuel-air mixture fuel mixture idle mixture adjustment screw idle mixture screw idle mixture lean air-fuel mixture lean mixture main mixture discharge nozzle rich air-fuel mixture rich mixture mixture adjustment screw: See idle mixture adjustment screw

mixture control knob: See choke

mixture control screw:

See idle mixture screw

mixture control solenoid: (M/C) [1] A device, installed in carburetor, which regulates the air/fuel ratio by oscillating the metering rods. [2] A computer-controlled device in a feedback carburetor that alters the mixture adjustment by moving the carburetor's metering rod in and out of the metering jet. Also called a duty-cycle solenoid

mixture control unit: [1] A unit in the K-jetronic fuel injection system which combines the fuel distributor and the airflow sensor; it monitors the rate of airflow and meters the fuel supplied to the injectors. [2] In Bosch CIS, the collective term for the airflow sensor plate and the fuel distributor, which are integrated into a single component

mixture discharge nozzle: See main mixture discharge nozzle

mixture screw: See idle mixture screw.

mixture volume: The quantity of air/fuel mixture

ML oil: Motor Light oil used in engines that work under ideal conditions of light loads, moderate speeds, and clean conditions.

mm: Millimeter. 25.4 mm = 1 inch.

MM oil: Motor Medium oil used in engines that work under moderate conditions where there is moderate loads, occasional high speeds, and a normal amount of dust.

MMT:

Methylcyclopentadienyl Manganese Tricarbonyl.

mobile home: A large home which can be hauled to its location (it does not have an engine). Once in place, the wheels are removed. In most cases, the home is never moved again. A motor home, in contrast, keeps its wheels and has its own engine.

mobile phone: A cellular telephone (i.e, cell phone)

mobile two-way radio: A receiver/transmitter used for CB communication

mock-up: A full-size model of a vehicle made of wood and clay, used for design studies. Also see prototype.

mode: [1] A way of operating. [2] A particular state of operation. Also see hump mode limp-home mode viscous mode mode door: A device which directs the flow of air through the heater/evaporator box

model: [1] A vehicle can be designated by a number of parameters: manufacturer, make, model, series, engine size, etc. For example: GM, Cadillac, DeVille, Concours, Northstar 4.5 engine. [2] A miniature representation of a full-size vehicle. Also see base model clay model entry model flagship model master model

production model top-of-the-line model top-of-the-range model trunk model model designation: A shortened description of a particular model

model line: A group of motor vehicles having the same platform or model name.

model name: word, group of words, letter, number or similar designation assigned to a motor vehicle by a marketing division of a motor vehicle assembler.

model year: (MY) A new model year starts after the summer break of the car production plant, during which the assembly lines are altered to accommodate the changes introduced in the cars of the next model year. A model year and year of manufacture can, therefore, differ.

modifications: See engine modifications

modifier: See friction modifier

mods: Abbreviation for "modifications" to refer to changes made in the appearance or performance of a vehicle.

modular air strut: See self-levelling suspension strut

modulated: See back pressure modulated

negative back pressure modulated valve modulated EGR: See vacuum modulated EGR

modulated valve: See back pressure modulated valve negative back pressure modulated valve modulation: Variation of a wave. See amplitude modulation frequency modulation modulator: A pressure control or adjusting valve used in the hydraulic system (i.e., hydraulic modulator) of the automatic transmission. When the vehicle is under heavy load or full throttle, the modulator increases the pressure to hold the clutches in place. In a light load situation, the modulator reduces pressure to give smoother shifts. If the vehicle tends to stay in low gear, shifts with difficulty, or produces a white smoke, and has low transmission fluid or has leaked transmission fluid, you have a transmission problem. It may be cured by an expensive repair or by simply replacing the modulator. Also called "vacuum modulator."

modulator pressure: Pressure controlled by the actuator valve and thus directly related to inlet manifold vacuum

modulator valve: A valve operated by the modulator to create modulator pressure by means of inlet manifold vacuum

module: A packaged functional assembly of wired electronic components for use with other such assemblies. Also see airbag module drive module

electronic control module hall module ignition module nox-control module pick-up module transmission control module modulus in shear: A measure of a material's resistance to shearing stress equal to the shearing stress divided by the resultant angle of deformation expressed in radians

mold: [1] A hollow form, matrix, or cavity, into which molten metal or plastic is poured to form a casting or product in the desired shape. [2] A device, that includes a matrix, enclosing the tire and supplying heat and pressure to cause curing. [3] To shape something into the desired form.

moldability: The capacity for being molded into a particular form

molded: See injection-molded integral molded seat molded beam: The maximum breadth of a hull measured between the inboard surfaces of the side shell plating of flush-plated ships

molded depth: The vertical distance from the molded baseline to the top of the freeboard deck beam at side, measured at midlength of the ship

molded part: A plastic part produced by injection molding etc.

molded seat:

See integral molded seat

molding: A plastic part produced by injection molding etc. Moldings are parts which have been produced from molding materials (compounds) by shaping in molds closed on all sides (e.g., by compression molding, transfer molding, or injection molding). Also see body side molding compression molding injection molding machine injection molding plastic molding powder slush molding reaction injection molding reinforced reaction injection molding slush molding transfer molding molding compound: See sheet molding compound

molding machine: See injection molding machine

molding material: Molding materials are products which can be molded permanently by a shaping process employing mechanical forces within a given temperature range into molded parts or semi-finished articles; in some cases molding materials are used in a preformed state (e.g., pelleted or granulated) without their plastic moldability being appreciably impaired by such preforming

mold loft: A floor space used for laying down the full size lines of a ship for making templates for construction

mold shrinkage: In thermoplastics, the difference in dimension between the cold mold and the cooled molded part, expressed in percent relative to the dimension of the cold mold

molecular weight:

The mass of a molecule that may be calculated as the sum of the atomic weights of its constituent atoms

molecule: The smallest portion that matter may be divided into and still retain all the properties of the original matter.

mole grips: locking pliers

mole wrench: locking pliers

moly: Abbreviation for "molybdenum" which is a lightweight metal which is often combined with chromium. It is used in piston rings (chrome moly rings) and even bicycle frames (chrome moly frames).

molybdenum: A hard white metallic element (symbol Mo; atomic number 42; atomic mass 95.94) which forms hard steel and/or chromium alloys to make piston rings and bicycle frames. See moly.

molybdenum piston ring: A piston ring with a molybdenum coating

moly ring: A piston ring with a molybdenum coating

moment of inertia: This is similar to inertia except that it relates to rotating movement rather than linear movement. Linear movement is the tendency of an object to remain motionless if at rest and to keep moving in a straight line if already in motion. The moment of inertia, however, is the tendency of an object to resist being accelerated when it is rotating. The polar moment of inertia is the rotating movement around a vertical axis through the center of rotation. It greatly affects steering and handling response in an automobile. The greater the length of the axis the greater the polar moment of inertia. By having the heavy components of a vehicle such as the engine and

transmission between the two front wheels, the polar moment of inertia is low so that the tires can easily change the direction of the vehicle. Also see polar moment of inertia momentum: A measure of a body's motion. It can be calculated from the product of the body's mass and velocity.

MON: Acronym for "Motor Octane Number." See octane number.

monel metal: Corrosion resistant alloy of nickel, copper, iron, and manganese

money factor: [1] When purchasing a vehicle, the characteristics of its engine, appearance, and appointments may be very appealing, but the money factor (i.e., its cost) may be prohibitive. [2] The most common way to express the base interest rate of a lease is as a money factor. If you multiply a money factor by 2400, the result will be equivalent to the base interest rate. The money factor of most leases is known by a dealer's sales staff. The money factor measures the cost of money, just like an interest rate. However, money factors are used almost exclusively in leases, whereas interest rates are used everywhere else.

money metal: Corrosion-resistant alloy of nickel, copper, iron, and manganese

monitoring: Maintaining a continuous control of an operation or function, varying control as required by specific conditions

monkey wrench: A tool which is similar to a pipe wrench. While a pipe wrench has teeth and a loosly mounted head that allows it to "bite" into the pipe and tighten as a strain is put on the handle, a monkey wrench has adjustable, smooth jaws that always remain parallel. The money wrench is used for turning pipe unions, the heads of bolts, and other flat surfaced object. The monkey wrench has pretty much been replaced by the Cresent wrench and other more modern adjustable wrenches. Monkey wrenches are

still used on old steam engines (not necessarily locomotives) and boiler fittings. Some call it a "steamboat" wrench. (definition submitted by George King III). The expression "throw a monkey wrench" into something generally means to sabotage something or to cause a problem or delay in performing repairs. Also see left-handed monkey wrench monobloc: All cylinders cast as one unit.

monobloc casting: A type of engine construction where the cylinders are cast in a single block which incorporates the crankcase

monobloc construction: A type of engine construction where the cylinders are cast in a single block which incorporates the crankcase

monoblock: All cylinders cast as one unit.

monocoque: [1] A design of a vehicle's body where a single shell has the engine and suspension attached to it in various places to spread the load evenly over the whole shell. Holes are cut only to install the engine and allow the driver to get into it. Otherwise it is completely closed. Also called "unit" or "unitized construction" or unitary construction. [2] A motorcycle frame in which the structure is made as one unit from a sheet material (i.e., alloy or steel). It may also include bodywork or fuel containers in the structure. The Vespa scooter and the F750 Norton of c.1973 are among the rare examples in motorcycles

Monodex-type cutter: See nibbler

Mono-Jetronic: A single point injection system developed by Bosch

monolith:

A single block of material; used to describe the (ceramic) base for the catalyst in one type of catalytic converter. Also see metal monolith monolithic converter: catalytic convener with a catalyst-coated, ceramic honeycomb monolith through which the exhaust gases pass

monolithic substrate: The ceramic honeycomb structure as a base to be coated with a metallic catalyst material for use in the catalytic converter

monomer: A relatively simple compound which can react with itself to form a polymer or with other monomers to form a copolymer

monotube damper: See single-tube shock absorber

monotube shock absorber: See single-tube shock absorber

monoxide: See carbon monoxide.

Monroney sticker: A window sticker. A US federal law requires that all cars sold in the USA display a Monroney sticker which is required to specify the manufacturer's suggested retail price for the vehicle and all its factory-installed options, a destination charge for shipping from final assembly point (or port of importation) to the dealer, and EPA fuel economy estimates; most dealers add a second window sticker that lists accessories installed at the dealership, as well as other charges

monster: A type of vehicle, usually a truck, which has very large tires.

Monte Carlo: A model of car produced by Chevrolet

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monthly payment: [1] The amount that must be paid each month to satisfy the lease contract. It is common for the monthly payment shown in lease advertisements to exclude applicable taxes, which will add to the amount paid each month. [2] The amount that is paid on a vehicle loan. <>Moon: [1] An automobile make of which only the Custom bodies with required application are classic cars. [2] A type of hubcap which does not cover the whole wheel and is perfectly smooth and dome shaped.

moon key: See half moon key

mooring: Securing a ship at a dock or elsewhere by ropes or cables

mooring line: A cable or rope used in securing a ship

Mopar: Trade name of Chrysler Corp for its motor parts (i.e., MOtorPARts). Chrysler also uses the name Autopar to indicate its automobile parts (i.e., AUTOmobilePARts).

moped: A two-wheeled motorized bicycle (short for motorized pedal bicycle) with an engine of less than 50cc

moquette: A thick, velvety upholstery fabric often used as weatherstrip

Morgan: A vehicle brand of which the 1950-64 Plus Four models are

milestone cars.

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Morris: A model of automobile manufactured in England

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Morris Garages: See MG

Most-Favoured-Nation Treatment: (MFN) one country's commitment to extend to another country the lowest tariff rates that it applies to any third country.

MOT: Acronym for the British "Ministry of Transport"

MOT certificate: A certificate awarded when a vehicle passes an mot test

mothball: A substance that was used to increase the octane rating in gasoline. It had a marginal effect in increasing octane.

motion: Also see angular motion lost motion perpetual motion machine perpetual motion rotation motion shaft: See third motion shaft

motocross: Off-road racing over a rough circuit. Formerly known as scrambling

motor: [1] An electrically driven power unit (electric motor). This term is often incorrectly (but commonly) applied to an internal combustion engine. [2] An engine [3] An automobile. [4] Attaching a generator to a battery in such a way it revolves like an electric motor. [5] A starting motor. See starter. [6] To travel by automobile, as in "Let's motor down the road." Also see compound motor cranking motor drive motor electric motor inboard motor outboard motor radiator fan motor servo motor starter motor stepper motor synchronous motor wet motor motorbike: A motorcycle.

motor car: A British term for a car or automobile (a 4-wheel road vehicle)

motor caravan: A British term for motor home

motorcycle: A two-wheeled motorized vehicle where the two wheels are not side-by-side but in line. Most have the fuel tank ahead of the saddle and the engine just below the tank. The engine size usually ranges from 50cc to 1500cc. Also called "motorbike" or just "bike." Also see cafe racer chopper cruiser scooter

sportbike touring bike trike wing motorhome: A motorized recreational vehicle that looks something like a bus. also See mini-motorhome type A motorhome type B motorhome type C motorhome motor insurance: Insurance against damage to or damage caused by a vehicle. Also see automobile insurance comprehensive insurance motorist: Someone who drives an automobile

motorized: A wheeled vehicle with a motor or engine.

motor mechanic: See mechanic

motor mount: The rubber-covered bracket that hold the engine and transmission to the frame of the vehicle and cushions vibrations.

motor mounts: The rubber-covered brackets that hold the engine and transmission to the frame of the vehicle and cushions vibrations.

motor octane number: (MON) See octane number

motor oil: engine oil or gear oil

motor pump: See canned motor pump

motor scooter: A lightweight motorcycle with small wheels, an enclosed engine, open foot platform, and leg shields. Also called "scooter."

Motorsports Association: See international Motorsports Association

motor vehicle: Any automotive vehicle that does not run on rails; usually with rubber tires; such as cars, vans, trucks, lorries, scooters, and motorcycles

Motor Vehicle Safety Act: (MVSA) Act which regulates the manufacture and importation of motor vehicles and motor vehicle equipment to reduce risk of death, injury and damage to property and the environment.

motorway: A multi-lane, main road for fast-moving traffic with speed from 55 mph to 70 mph (90 - 110 kph) with a center median, and few exit and entry points

motor wheel type: (Spoke steel type) -- A type of dual mounting wheels similar to the Chevrolet type using single cone locking nuts on each stud, however, the conical washer which forms the base of the cone is loosely attached to the nut and swivels independently.

Motronic: Bosch term to denote its engine management systems. The original Motronic system combined L-Jetronic with electronic ignition timing control in one control unit. Most Motronic-equipped engines also have electronic idle stabilization. Around 1986, Motronic system got knock regulation by ignition timing of individual cylinders; adaptive circuitry, which adapts fuel delivery and ignition timing to actual conditions; diagnostic circuitry which enables the control unit to recognize system faults and store fault information in its memory. Motronic has also

been integrated with KE-Jetronic system and is referred to as KE-Motronic

MOT test: An annual roadworthiness test for all vehicles in Britain over two years old, undertaken by a garage approved by the (currently named) Department of Transport. Parts covered by the MOT test are: steering, suspension, transmission, lighting, brakes, tires and wheels, seat belts, horn, exhaust system (including a metered emission check), and vehicle structure

mottling: spotty, non-uniform, blotchy appearance of metallic paint, characterized by small, irregular areas darker in color, or spots in solid color paint -- caused by the flakes flowing together

mould: British term for "mold"

mouldability: British term for moldability

moulded part: British term for molded part

moulding: British term for molding

moulding material: British term for molding material

mould shrinkage: British term for mold shrinkage

Moulton Hydragas suspension: hydropneumatic suspension developed by Leyland

Moulton Hydrolastic suspension:

Hydrolastic suspension developed by Leyland

mount: [1] to attach something to a support. [2] A device for attaching something. Also see motor mounts transverse mount mountain bike: A bicycle with straight handlebars, sturdy fat tires, and wide-range gearing designed for off-road use. Also called "All-Terrain Bike" or "ATB."

mounted speaker: See flush mounted speaker

mounting: A support to which or by means of which something is attached. Also see anti-vibration mounting belt anchorage belt mounting budd mounting din mounting dual mounting engine mounting fender mounting headlight mounting panel inner mounting face panhard rod mounting box spigot mounting spring mounting suspension mounting wheel mounting wing mounting mounting bolt: A bolt upon which some component is secured. See pivot bolt.

mounting box:

See panhard rod mounting box

mounting face: See inner mounting face

mounting flange: See windshield mounting flange

mounting frame: A floating-frame disc brake in which the floating frame is held by a casting which is bolted to the steering knuckle or other suspension part

mounting panel: See headlight mounting panel

mouse: See mickey mouse

movement: See bead movement

move off: to start from rest; to begin to drive away

moving contact: A component of a solenoid switch; in a starter motor it is designed for switching on the electric circuit in the excitation and armature windings. Also see contact breaker MPC: Acronym for manifold pressure controlled

MPFI: Acronym for multi-point fuel injection

mpg: Abbreviation for "miles per gallon," as a measure of fuel consumption. The U.S. gallon is 3.785 liters. The Imperial gallon is 20% larger (4.546 liters). When a vehicle gets 30 mpg (US), he will get 36 mpg (Imperial). The metric system calculates fuel consumption as the number of liters per 100 kilometers. The same vehicle will be giving 7.8 l/100 km.

mph: Abbreviation for "miles per hour." The metric equivalent is Kilometers per hour (kph). To convert Miles to Kilometers, multiply by 1.609344. It may be easier to divide the miles by 10 (i.e., knock off a zero) and then double it four times. Thus 60 mph divided by 10 is 6. Doubled is 12, doubled is 24, doubled is 48, doubled is 96. The accurate figure is 96.56, but 96 is probably close enough. To convert from Kilometers to Miles, divide by 1.609344. It may be easier to multiply is by 10, then chop it in half four times. Thus 70 kilometers becomes 700. Chopped in half it is 350, chopped again is 175, again is 87, and one more time is 43.5. Accurately it is 43.49.

MPI: See multi-point injection

MPV: Acronym for "Multi-Purpose Vehicles" (like Ford Villager and Windstar, and Daimler-Chrysler Voyager).

MR2: A model of automobile manufactured by Toyota

Click for books on MR2

MS oil: Motor Severe oil used in engines that operate under heavy loads and at high speeds. MS oil is required for automotive engines.

MSRP: Acronym for "Manufacturers Suggested Retail Price."

MSTS: See microprocessor spark timing system

M/T:

Metric ton (2,250 lbs.).

mud and snow: (M+S) A type of tire tread which gives maximum traction in mud and snow.

mud and snow tire: (M+S tire) winter tire with a deep tread

mud flap: A rubber or plastic shield which is positioned behind a wheel (usually the rear wheels) to prevent mud and small rocks from being thrown up against the body of the vehicle or from being thrown at a following vehicle. Also called "splash guard"

mudflap: See mud flap

mudguard: curved part over the wheels of a motorcycle to minimize splashing

muffler: A unit through which the exhaust gases are passed to quiet the sounds of the running engine. The British term is "silencer." Also see glass pack muffler gutted muffler steel pack muffler Multec: A combined fuel injection and ignition system

Multec system: A combined fuel injection and ignition system

Multicon connector system: A 13-pinned electrical connection system for trailers

multi-cut file:

See multipurpose file

multi-disc: See multi-plate

multi-entry: See multi-suction pump

multi-focal: (MF) multiple-focus

multi-focal headlight: A conventional headlight with a multiple-focus parabolic reflector

multi-function control stalk: A rod-shaped control mounted on the steering column near the steering wheel. A unit could operate the signal lights, headlight dimmer switch, wipers, windshield washer, cruise control, and horn

multigrade oil: An engine oil that meets the viscosity requirements of several different single-grade engine oil types. Also called multi-viscosity oil

multigrip pliers: Pliers with an adjustable head allowing different jaw widths

multi-hole nozzle: A two-hole, three-hole, or four-hole injector nozzle in a direct injection engine. Also see pintle nozzle multi-inlet pump: See multi-suction pump

multileaf spring:

A leaf spring with several flat leaves bundled together by steel bands.

multi-link independent rear suspension: A special multi-link rear suspension design, developed by Mercedes-Benz for the W 201 series

multi-link rear suspension: A general term for independent rear suspension layouts incorporating several control arms. Also see four-link rear suspension five-link rear suspension multilink suspension: A rear suspension consisting of at least four links, or "arms," and no struts. Because multilink suspensions assign specific wheel-locating duties to each element, they provide great flexibility for optimizing both ride and handling.

multi-piece rim: A rim type incorporating at least one demountable bead seat and/or rim flange to allow tire mounting. The opposite is a one-piece rim. The bead seats of all multipiece rims (except flat base rims) have a 5° taper; rims incorporating the semi-drop center, the tapered bead seat or the flat base design are multi-piece rims

multi-plate clutch: British term for multiple-disc clutch

multiplate clutch: A clutch with several friction and drive plates. Its compact size makes it ideal for motorcycles

multiple disc: See multiple disc clutch.

multiple disc clutch: A clutch which has several clutch discs in its construction. The greater number of discs allows the size of the bell housing to be smaller in diameter and still maintain efficiency. A clutch with more than one driven plate, usually of the oil-immersed type; frequently used in motorcycle drive trains, in automatic transmissions of cars,

in power distribution systems of 4WD vehicles, and as locking elements in limitedslip differentials. Also see viscous coupling multiple-disc limited-slip differential: limited-slip differential incorporating multiple discs as locking or slip-inhibiting devices

multiple-plate clutch: British term for multiple-disc clutch

multiple-point injection: See multi-point injection

multiple-spark coil: See multi-spark ignition coil

multiple-spark ignition coil: See multi-spark ignition coil

multiplex technology: In cars, connecting lamps, wipers, horn, etc. to a single power cable via electronically controlled modules, making it easier to diagnose faults and to service the problem

multi-point fuel injection: (MPFI) a fuel injection system that uses one injector per cylinder, mounted on the engine to spray fuel near the intake valve are or the combustion chamber. Also called multi-port injection

multi-point injection: (MPI) Gasoline fuel-injection system in which only air enters the inlet manifold; as the air approaches the inlet valve, an injection valve opens in the valve port, spraying fuel into the airstream. Also see SPI

multi-port injection: A fuel injection system that uses one injector per cylinder, mounted on the engine to spray fuel near the intake valve are or the combustion chamber. Also called multipoint fuel injection

multi-purpose file: A flat file with faces featuring different cuts, e.g., coarse cut on one side and smooth cut on the other

multipurpose ship: A ship designed for carrying different types of cargoes requiring different methods of handling. See OBO ship

multi-reed cage: A reed valve in a two-stroke induction control which consists of several petals

multi-spark coil: A type of ignition coil used in static high-voltage distribution, designed as a doublespark or four-spark coil

multi-spark ignition coil: A type of ignition coil used in static high-voltage distribution, designed as a doublespark or four-spark coil

multi-stage pump: A pump with two or more stages (impellers/diffusers or other pumping elements) operating in series. Multi-stage centrifugal pumps are employed to operate against higher pressures, where several impellers are built onto one shaft in the same casing

multi-storey car park: A car park with many levels

multi-suction pump: A centrifugal pump with several impellers connected in parallel; i.e., the flow is separated into two or more partial flows. Multi-suction usually means double suction in practice

multi-viscosity oil:

Oil meeting SAE Requirements for both low temperature requirements of a light oil and the high temperature requirements of a heavy oil. Example: (SAE 10W-30). Also called Multiweight.

multi-viscosity oils: Oils meeting SAE Requirements for both low temperature requirements of a light oil and the high temperature requirements of a heavy oil. Example: (SAE 10W-30). Also called Multiweight.

multiweight: See multi-viscosity oils.

Muntz: A vehicle brand of which the 1950-54 Jet models are milestone cars.

mural: A customized designed air-brushed paintwork on the side panels of vans, cars, and motorcycles

mush pot: A container used to keep body lead bars in a semi-liquid state to enable them to be spread directly onto the car body

mushroom-shaped dolly: A dolly with a shank to allow it to be hand-held or clamped in a vice; a more or less rounded head may be fitted to one or both ends of the shank

mushroom tappet: A tappet shaped like a mushroom located on the underside of a pushrod operating the valves of a four-stroke engine. Also see flat tappet mushroom valve: See poppet valve

Mustang:

A vehicle brand of which the 1965-67 GT/GTA V-8 models are milestone cars. The 1969-70 Boss 302/Mach 1 models are milestone cars.

Click for books on Mustang

muting: See automatic muting

mutual inductance: A condition that takes place when the current in one winding induces an EMF in another winding in the same magnetic circuit

M.V.: Motor Vessel or Diesel Engine driven ship

MV: Acronym for manual valve

MVAN: Acronym for "Medium Van" (e.g., Toyota Hiace).

MVMA: Acronym for "Motor Vehicle Manufacturers Association."

MVSA: Acronym for "Motor Vehicle Safety Act.

MX: Abbreviation for "Motocross"

MY: Acronym for model year

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DICTIONARY OF AUTOMOTIVE TERMS "N" [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Na] [Ne] [Ni] [No] [Ns] [Nu]

N: A gear selection indication for neutral

NAAMSA: Acronym for "National Association of Automobile Manufacturers of South Africa"

NACA duct: This is an air opening which was named after the National Advisory Committee for Aerodynamics. It was the American organization which developed the kinds of designs for low drag air ducts for jet engines. NACA ducts are used on cars to force air for engine breathing and cooling, for forcing air through the radiators, and for providing fresh air for the passenger compartment.

nacelle: A plastic or metal covering. A headlight nacelle on a motorcycle is the bucket surrounding the headlight.

NADA: Acronym for "National Automobile Dealers Association"

NAFTA: Acronym for "North American Free Trade Agreement" on http://strategis.ic.gc.ca/SSG/am00635e.html.

N.A.G.: A vehicle brand of which these models, with required application, are classic cars.

NAICS:

Acronym for "North American Industrial Classification System."

nail hammer: A hammer designed to hit the head of nails and usually has a claw device which allows for the removal of nails.

nail punch: See drift punch

name: See model name

nameplate: See import nameplate

NAPA: Acronym for "National Automotive Parts Association"

NASCAR: Acronym for "National Association for Stock Car Auto Racing" or "North America Stock Car Auto Racing" or

Nash: A vehicle brand of which the 1930 Twin Ignition 8; 1931 Series 900; 1932 Series 990, Advanced 8, and Ambassador 8 with required application are classic cars. The 1951-54 Healey models are milestone cars. See Frazer Nash.

Click for books on Nash

national coarse thread: (NC) A standard for the threads of nuts and bolts in which the number of threads per inch is much fewer than a fine (NF) nut or bolt. Observe the difference in the number of threads per inch (TPI) of the NF and NC in the following chart. Also called unified National Coarse thread WIDTH NF TPI NC TPI #10

32

24

#12

28

24

1/4

28

20

5/16

24

18

3/8

24

16

7/16

20

14

1/2

20

13

9/16

18

12

5/8

18

11

3/4

16

10

7/8

14

9

1

14

8

1-1/8

12

7

1-1/4

12

6

1-3/8

12

6

1-1/2

12

5

1-3/4

n/a

4

2

n/a

4.5

2-1/4

n/a

4.5

2-1/2

n/a

4

2-3/4

n/a

4

3

n/a

4

national fine thread: (NF) A standard for the threads of nuts and bolts in which the number of threads per inch is much greater than a coarse (NC) nut or bolt. Also called unified National Fine thread. Observe the difference in the number of threads per inch (TPI) of the NF and NC in the following chart WIDTH NF TPI NC TPI #10

32

24

#12

28

24

1/4

28

20

5/16

24

18

3/8

24

16

7/16

20

14

1/2

20

13

9/16

18

12

5/8

18

11

3/4

16

10

7/8

14

9

1

14

8

1-1/8

12

7

1-1/4

12

6

1-3/8

12

6

1-1/2

12

5

1-3/4

n/a

4

2

n/a

4.5

2-1/4

n/a

4.5

2-1/2

n/a

4

2-3/4

n/a

4

3

n/a

4

national flag: The flag flown by a ship to show her nationality.

natural frequency: The frequency at which an object, circuit, or system oscillates or vibrates when set in free vibration

natural gas: An alternative, environmentally friendly fuel (mainly methane) which can be stored under pressure in the trunk as compressed natural gas (CNG). Also see compressed natural gas liquified natural gas naturally aspirated engine: A conventional engine that takes in air at normal pressure, i.e. not turbocharged or supercharged. The opposite is forced-induction engine

natural oxide film: A transparent film which forms naturally on an aluminum surface due to oxidation

natural oxide skin: A transparent film which forms naturally on an aluminum surface due to oxidation

natural rubber:

(NR) An elastomer produced from latex, a milky sap, obtained from the rubber tree (Hevea brasiliensis) and other plants. An elastic and porous form of rubber. Also see synthetic rubber natural weathering: A corrosion test by means of which the corrosion resistance of a material is tested in the open air

nave: A wheel hub

nave plate: A hub cap

navigating bridge: The command post of a ship.

navigator: See electronic navigator

NC: Acronym for :normally closed"

NCM: Acronym for NOx-control module NCS: See noise cancellation system

NDIR analyzer: A non-dispersive infrared analyzer, used for analyzing concentrations of carbon monoxide and carbon dioxide in an exhaust gas sample

NDS:

Acronym for neutral drive switch

NDT method: A non-destructive testing method, such as ultrasonic testing, X-ray testing, dyepenetrant testing

Neader-pattern: A motorcycle frame and fork design by Neader using pressed steel or Duralumin

nearside: (n/s) the side of a vehicle nearest the curb (when driving)

neck: See filler neck fuel filler neck necking: When ductile test specimens are subjected to a tensile test, they exhibit necking when the tensile force exceeds the yield strength of the material; necking results in a reduction of area, measured in percent after break of the specimen

needle: [1] An indicator on a dial, instrument, or gauge. [2] A thin rod or small tapered rod used to open or close a hole. See bury the needle float needle jet needle metering rod needle and seat needle bearing needle cage. needle and seat: A pair of items in a carburetor. The seat is usually a brass plug with a specially shaped hole to accommodate the needle which is a shaft with a pointed end. When the needle is fully seated in the seat, no gasoline can enter the float bowl. As the needle is lifted off the seat some gas pours into the float bowl. The needle moves when the float in the float bowl drops below a set height.

needle bearing: A roller type bearing in which the many rollers have a very narrow diameter in relation to their length. The design makes them particularly useful in situations where there is limited space such as the rod bearings on some pistons. Also called "Quill-type bearing." needle cage: In a needle bearing, there are many rollers within a holder or cage.

needle-flame test: A test to assess fire hazard by simulating the effect of small flames, which may result from faults within the equipment

needle-nose pliers: See long-nose pliers thin needle-nose pliers needle valve: [1] A valve with a needle-shaped pin that can be moved to control the flow of a fluid. [2] The valve, in a carburetor, which controls the amount of gasoline flowing from the pump to the float chamber

neg: Abbreviation for "negotiable," as in the price is neg. Also it may refer to the negative terminal of a battery, or negative ground.

negative back pressure valve: See EGR negative transducer EGR valve

negative back pressure modulated valve: See EGR negative transducer EGR valve

negative camber:

See camber.

negative caster: See caster.

negative connections: Connections in an electric circuit through which the current flows back to its source.

negative electrode: See negative plate

negative ground: An electrical system where the chassis is the negative side of the circuit and a separate wire to each component is the positive (hot) line. See ground positive ground negative load base: If the center of the payload is behind the rear axle, it is negative and takes load off the front axle. See load base.

negative offset: [1] A steering geometry layout where the steering axis cuts the wheel axis above the wheel center plane. Compare center point steering, positive offset, and scrub radius. [2] The distance between the mounting face of the disc and the rim centerline; the offset is referred to as negative when the inner attachment face of the wheel disc is shifted towards the inner side of the wheel. Opposite to positive offset.

negative offset steering: A steering system which indicates the placement of the wheels. From the back of the vehicle, it appears as though the tires are tucked in where they contact the road. Although this system may appear strange, it actually does provide the benefit of helping a vehicle to stop in a straight line when the brakes are weak or the road friction is different on one side than the other.

negative plate: The grey plate which acts as anode during battery discharge. Opposite of positive plate

negative pole: The point toward which an electrical current flows through the circuit. It is designated by a minus sign (-).

negative spark: A spark that jumps from the negative center electrode to the positive ground electrode of the spark plug, allowing a reduction in the high voltage required

negative suction head: See suction lift

negative temperature coefficient: (NTC) a special type of thermistor whose resistance decreases as the temperature increases. Nearly all coolant temperature sensors are NTC thermistors

negative terminal: That terminal (such as that on the battery) from which the current flows on its path to the positive terminal. It is usually marked with a minus symbol and is attached with the black cable.

negative transducer EGR valve: A valve used on engines with a relatively low back pressure to provide the desired opening point and exhaust gas recycling rate

negative wheel dish: See negative offset

negative wheel dishing: See negative offset

negative wheel offset: See negative offset

Nelson:

See Piquet, Nelson

neon tube: An electric "bulb" or tube filled with a rare gas, used on ignition test instruments like timing lights.

neoprene: A hard plastic like substance.

nerf bar: A type of front bumper guard, typically made of chrome-plated steel tubing; extends horizontally from below front end and is curved upward; a pair of nerf bars is usually braced by a horizontal crossbar. In Australia it is called a roo bar. Also see bull bar Nernst equation: A relationship showing that the electromotive force developed by a dry cell is determined by the activities of the reacting species, the temperature of the reaction, and the standard free-energy change of the overall reaction

net: See bungee net cargo net tonnage net net bhp: See sae net bhp

net capacity: The weight of cargo which a vessel can carry when loaded in salt water to her summer freeboard marks. Also called cargo carrying capacity, cargo deadweight, useful deadweight.

Net cap cost: The price of the vehicle after deducting any dealer participation, manufacturer discounts, and cap cost reduction ("down payment") from the MSRP.

net capitalized cost: The price of the vehicle after deducting any dealer participation, manufacturer discounts, and cap cost reduction ("down payment") from the MSRP.

net horsepower: See SAE net horsepower.

net interest rate: The total interest rate for the lease. It represents the lease's true cost, similar to an APR for a bank or credit union loan. The lower the net interest rate, the lower the cost of the lease.

net sales value: the selling price received by the manufacturer for the vehicle including the cost of transporting the vehicle in Canada (includes mark-up).

net tonnage: See tonnage, net

neutral: [1] (N) The neutral position of a transmission is the gear position where the engine is unable to drive the wheels. It is usually placed between reverse and one of the forward gears in automatic transmissions; and is located centrally in manual transmissions. [2] Something that does not have any distinctive characteristics. [3] A charactristic of handling where both front and rear wheels have the same amount of traction so that neither one has a tendency to slide. [4] Something that is neither an alkaline nor acid, usually with a pH of 7.

neutral drive switch: (NDS) a sensor that provides information on transmission status to the computer

neutral flame: Flame which results from combustion of perfect proportions of oxygen and the welding gas.

neutral handling:

A vehicle with neither oversteer nor understeer

neutralizer: See rust neutralizer

neutral safety switch: A switch which allows the starter to be engaged only when the automatic shift lever is in either park or neutral

neutral steer: The characteristic of a vehicle's slip angles where both front and rear are the same. In slippery conditions, both the front and rear tires will break loose at the same time so that the vehicle slides sideways rather than the rear end swinging around (oversteer) or the front end wanting to move to the rear (understeer). A cornering condition in which the front and rear slip angles are roughly the same. Although seemingly an ideal state of balance, perfect neutral steer is not as stable as slight understeer.

neutron: A neutral charge particle forming part of an atom.

new car dealer: major car dealership with a parts and service operation.

new-old-stock: (NOS) New genuine parts for older models, referring mostly to spare parts that are normally no longer produced

new-old-stock part: (NOS) New genuine parts for older models, referring mostly to spare parts that are normally no longer produced

newton: A unit of force. One newton is the force which acts on a mass of 1 kilogram to produce an acceleration of 1 metre per second per second.

newton meter:

See newton metre as the standard spelling.

newton metre: (Nm) A unit of torque. One pounds-force feet (lb-ft) equals 1.356 Newton metres. One Newton metre equals 0.7375 lb-ft.

newton's law: For every action there is an equal, and opposite reaction.

new tread: A term used by some tire companies to denote a retreaded tire. Also called "nutread."

New Werner frame: A motorcycle frame design first used on the 1901 Werner, the engine was mounted between the front downtube and the bottom bracket

NIASE: National Institute for Automotive Service Excellence (usually referred to as ASE)

nibbler: A tool used to cut sheet metal without deforming the sheet or causing a burr; works upwards, leaving the hands above the material; allows circular and straight cuts

nibbling: The jerking action which occurs in a vehicle, due to the distortion within some tires as they are forced to traverse pavement ridges at a slight angle.

NiCaSil: Nickel-silicon plating used, for example, on the cylinder walls of certain lightweight high-performance engines to reduce weight and friction and improve heat transfer. May be spelled "nikasil." Also see scanimet nichrome: A metallic compound containing nickel and chromium, used in making high resistances

nickel plating: thin coating of nickel deposited on a surface by electrolysis

nickel steel: Nickel is alloyed with steel to form a heat and corrosion resistant metal

nikasil: See NiCaSil

nipple: [1] A small metal piece that fits through a wheel rim of a bicycle or motorcycle and is threaded inside to receive the end of a spoke. [2] A small, one-way valve used for injecting grease into a bearing. Also see grease nipple [3] A short, steel tube holding a thin rubber or plastic tube used for bleeding hydraulic fluid

nippy: A small and relatively powerful motor vehicle.

Nissan: A model of automobile manufactured in Japan

Click for books on Nissan

Nissan Altima: A model of automobile manufactured by Nissan in Click for books on Nissan Japan Altima Nissan Maxima: A model of automobile manufactured by Nissan in Click for books on Nissan Japan Maxima Nissan Pathfinder: A model of SUV manufactured by Nissan in Japan

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Nissan Pulsar: A model of automobile manufactured by Nissan in Japan

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Nissan Sentra: A model of automobile manufactured by Nissan in Japan

Click for books on Nissan Sentra

Nissan Stanza: A model of automobile manufactured by Nissan in Japan

Click for books on Nissan Stanza

Nissan SX: A model of automobile manufactured by Nissan in Japan

Nissan Z: A model of automobile manufactured by Nissan in Japan

Click for books on Nissan SX

Click for books on Nissan Z

nitriding: The hardening of steel by heating it for several hours in ammonia gas. Used on crankshafts

nitrocellulose paint: A paint which gives a deep, lustrous finish. It is used on old Jaguars but was prone to crazing and checking. Because spraying with nitrocellulose paints creates environmental problems, they are no longer used for volume cars

nitrogen: See oxides of nitrogen

nitrogen oxide: See nitrogen oxides.

nitrogen oxides:

(NOx) In the combustion process, nitrogen from the air combines with oxygen to form nitrogen oxides such as nitric oxide and nitrogen dioxide. Nitric oxide is the main oxide of nitrogen emitted in raw exhaust gas, typically 90%; nitric oxide and nitrogen dioxide are severely toxic gases: without emission controls, the exhaust of an spark ignition engine contains 0.3-1.5 kg of NOx per 100 liters of gasoline consumption

nitrophyl: A closed cell material that's impervious to gasoline and fuel additives; used as a float material

nitrous oxide: (NOx) One of the three basic pollutants found in the exhaust emission of an internal combustion engine. The amount of NOx usually varies in an inverse proportion to the amount of HC and CO.

nitrous oxide system: A performance system that injects nitrous oxide into the inlet manifold at the press of a button, thereby introducing a quick dose of extra energy and a burst of power. On a 6-cylinder or V-8 engines, the nitrous oxide system is intended to add up to 250 HP; it consists basically of a pressurized nitrous oxide bottle as used for welding, solenoids, an injector base plate for the carburetor, and steel pipes; the low vaporization temperature of nitrous oxide (-130°F, -90°C) cools the A/F charge, dampening detonation and minimizing stress caused by increased load

Nm: Acronym for "newton metre.

NMA: Acronym for "The National Motorists Association"

NO: Acronym for "normally open"

noble metal: A rare or precious metal (such as gold, silver, mercury, platinum) which conducts electricity very well, resists corrosion, and is inert; some are used as catalysts in catalytic converters

no-claims bonus: A reduction in insurance premiums because no claims have been made

no-cost option: An optional extra for a new car at no extra cost

no fault insurance: A form of vehicle accident insurance in which the insurance company of each driver pays for the damages of its own driver regardless of who is at fault. So if you and I have an accident, my insurance company will pay for my damaged car and your insurance company will pay for your damages. If you don't have insurance, my insurance company will pay for my damages even if I think you are at fault.

noise: See engine noise induction noise interior noise level tappet noise noise cancellation: (NCS) The reduction of noise by means of anti-noise loudspeakers. Compare soundproofing material

noise control: See anti-noise system

noise control system: See active noise control system

noise level: See interior noise level

noise reduction: The reduction of noise by means of anti-noise loudspeakers

noise system:

See anti-noise system

nomad: See Chevrolet Nomad.

nominal capacity: See rated capacity

nominal diameter: A characteristic value used for pipeline systems to identify parts which belong together such as pipes, pipe joints, fittings, etc.; a nominal size for the inside diameter

nominal engine speed: See rated speed

nominal length: [1] The length of the shank of screws/bolts with flat bearing faces. [2] The length of shank plus height of head of countersunk bolts/screws. [3] The overall length of a stud minus the length of the stud end

nominal pressure: See rated pressure

nominal rim diameter: A measurement from one bead seat to the opposite bead seat 180° away.

nominal rim width: A measurement between the flanges at the bead seat.

nominal thread diameter: See major diameter

nominal voltage: See rated voltage

non-destructive testing: (NDT) See NDT method

non-directional tread: An arrangement of bars, grooves and ribs in a manner that gives equal traction in forward or reverse direction. Also see directional tire directional tread non-dispersive infrared analyzer: See NDIR analyzer

nonferrous metal: A metal which contains no iron (except in very minute quantities). Thus it is not subject to rusting, e.g., aluminium, copper, magnesium, etc.

nonferrous metals: All metals containing no iron (except in very minute quantities). Thus they are not subject to rusting.

non-self-priming pump: A centrifugal pump which is unable to evacuate and prime the suction line without external assistance. The opposite is self-priming pump. Most centrifugal pumps are non-self-priming and require a flooded suction line

non-servo brake: A drum brake design; each brake shoe is anchored, therefore no one shoe can assist in the application of the other; one shoe is self-energizing, the other is not

non-staged carburetor: A 4-barrel carburetor that has secondary throttle plates which open at the same time as the primary throttle plates, or a two-barrel carburetor with only one throttle shaft (both throttle valves open simultaneously)

non-woven abrasive: A grinding disc which is made of very hard material used primarily for cutting.

Nordberg key: A round key

Nordic Anti-Corrosion Code: A code developed by the Scandinavian automobile and consumer associations which stipulates that, as of January 1983, all cars must be free of surface corrosion for three years and free of perforation and weakening damage for six years

no rinse treatment: An application method of chemical conversion coatings by means of a roll coating system whereby no rinsing treatment is required

normally aspirated: An engine that intakes air or "breathes" without the assistance of a supercharger or turbocharger. normally aspirated engine: An engine which uses the factory installed carburetor or fuel injection system with its normal air filter, etc. It does not use modified air flow systems which pump more air into the engine. Usually this expression is used as comparison as in My modified intake puts out more horsepower than a normally aspirated engine. Also called naturally aspirated engine or a "free breather."

normal zinc technology: See low zinc technology

NORS: Acronym for "new old replacement stock," or "new old reproduction stock." These are parts that were aftermarket replacements, usually of the same quality, for the manufacturer's parts. Or, they are parts that were reproduced by an aftermarket supplier using the same quality of materials and manufacture as the original manufacturer, but now are "old."

North American Free Trade Agreement: (NAFTA) Agreement creating free trade among the United States, Canada, and Mexico. The NAFTA went into effect on January 1, 1994.

North American Industrial Classification System: (NAICS) Industry Classification between Canada, the United States and Mexico to increase compatibility of data with these countries. The classification is based on establishment rather than commodity. This classification system will be

implemented with reference to year 1997 and data will be available in 1999.

North American produced: motor vehicles assembled in Canada, the United States or Mexico.

north pole: The magnetic pole in a magnet from which the lines of force emanate; travel is from North to South pole.

north-south layout: An engine layout with the cylinders lying lengthways from the front (north) to the back (south). Also called longitudinal engine. Compare east-west layout

NOS: Acronym for "new old stock." These are parts that originally were available from the manufacturer of an automobile. They have never been used, thus are "new." But they also may have been on the shelf for decades, thus are "old."

nose: The front end of a vehicle. Also see front nose section insulator nose projected core/insulator nose nose section: See front nose section

nose-to-tail: A driving mode in rush-hour traffic. Also called bumper-to-bumper

nose-up: A description of the towing vehicle if the vehicle being towed is too heavy

nose dive: See brake dive

nosepiece: An insert for pop-rivet pliers that is used to allow various pop-rivet diameters to be used

nose protector: A cover, usually of black soft plastic sheeting with flannel-like backing, that fits around the front end of a car. Also called nose bra. Compare stealth bra. It protects the front portion of hood and fenders against damage caused by flying rocks, road debris and insects; attaches to car with bendable plates, straps, or hooks and grommeted edges; sometimes personalized with a vehicle logo; relatively common in the USA, but rarely found in Europe

noseweight: A vertical weight on the center of the towing ball exerted by the vehicle being towed (on level ground). This must be within certain limits; generally between 110165 lbs (50-75 kg) for car and trailer

nosing: See shaving

no-spin differential: See limited-slip differential

notch: A V-shaped or U-shaped indentation cut into a test piece, test bar, or into a molded part

notchback: A classical sedan shape which is sometimes called a three box design. When you look at the side of the car, the front section in front of the windshield is one box; the section with the doors and windows is the second box; and the third box is the trunk. Because the third box starts just below the back window, it is called a notchback.

notched rocker arm stud: A rocker arm stud with a notch worn in its side; a notched stud is more likely to break

notchy:

The action of changing the gears in a rough way which causes a slight crashing of gears. It is often caused by the clutch failing to disengage fully

note: See exhaust note

NOx: Oxides of nitrogen. They are at their worst when combustion is most efficient. They are produced because the air is 78 percent nitrogen. Combines with HC in sunlight to form photochemical smog. NOx emissions can be reduced by lowering peak combustion temperatures through lowering compression ratios and by recirculating exhaust gases.

NOx-Control module: (NCM) A digital ignition control module for retrofitting to cars with Motronic engine control; modifies ignition timing characteristics for lower NOx emissions

nozzle: A thin hollow tube; a jet or hole at the end of a pipe. See fuel injector nozzle injector nozzle main mixture discharge nozzle multi-hole nozzle pintaux nozzle pintle nozzle nozzle cleaning unit: See spray gun nozzle cleaning unit

nozzle drip: Air rushing by the venturi at idle can cause fuel to drip from the discharge nozzle for the main metering circuit

nozzle restrictor: A restrictor in the fuel filler neck of cars fitted with catalytic converters that prevents filling from leaded petrol pumps, which have larger pump nozzles

notchback:

A body shape which differs from a fast back. When a fastback is observed from the side, there is a smooth line (curve) along the roof from the A-pillar to the back of the car. In a notchback, the roof is abruptly dropped down to the leading part of the rear deck (or trunk).

Nova: An automobile model produced by Chevrolet

Click for books on Nova

NPN: Three-element transistor made of two types of semi-conductor metals

NR: See natural rubber

NRT: Net registered tons. See tonnage, net

n/s: Abbreviation for "nearside"

NSPA: National Standard Parts Association.

NSU: 1906 saw the launch of the "Sulmobil," a three-wheeled vehicle with a 3.5 hp motorcycle engine. However, the "Sulmobil" was not a success. As a result, the first "Original Neckarsulm Motor Car," with a 1308 cc four-cylinder engine and 10 hp, went into production the same year. The 1964 Wankel Spyder models are milestone cars.

NTC: Acronym for negative temperature coefficient

NTF: Acronym for "notify." When a mail order seller does not have the merchandise in stock, but expects to get it in the future, he tells a customer the item's status with "NTF," which means he will notify the buyer when it is in stock.

nuclear: Involving the inner part of an atom, the nucleus. Changes in the nucleus can release a lot of energy which can be used in the generation of power.

nucleation site: A location where nucleation, i.e., the formation of new crystal nuclei in supersaturated solutions, starts

nudge bar: See nerf bar

number drill: See number drills.

number drills: A series of drills in which each size is designated by a number (0-80).

number one diesel fuel: Used in cold climates; sometimes blended with number two diesel fuel to increase number one's energy and two's cold weather performance

numberplate: A British term for license plate

numberplate lamp: British term for license plate light

number two diesel fuel: Diesel fuel used in moderate climates

nut: [1] A fastening device that is somewhat doughnut shaped with a number of flat surfaces on the outer rim and threads on the inner hole. Also see ball and nut

ball worm and nut bolt and nut butterfly nut cap nut captive nut castellated nut castle nut center lock nut cylinder head nut double cap nut flare nut flare nut spanner flare nut wrench fly nut inner cap nut jam nut knurled nut locking lug nut lock nut locut nut lug nut nyloc nut nylon lock nut octagon nut outer cap nut recirculating ball and nut steering recirculating ball worm and nut rudge nut self-locking nut sleeve nut speed nut staked nut stiff nut thumb nut union nut wheel nut wing nut [2] A person who is greatly interested in a field such as "Jim is a car nut." Also see buff.

nut cover: A cap or covering over a nut to protect it or to improve appearance.

nut cracker:

A tool used to crack open stubborn nuts without damaging the bolt or stud thread

nut driver: A shaft with a handle on one end (like a screwdriver) and a socket on the other. Also see tubular nut driver nut end: The end of a stud on which a nut is screwed. The opposite is the stud end

nu-tread: See new tread.

nut spanner: See chainring nut spanner flare nut spanner nut spinner: A shaft with a handle on one end (like a screwdriver) and a socket on the other

nut splitter: A tool used to crack open stubborn nuts without damaging the bolt or stud thread

nut starter: A tool used to hold a nut for easy placement in tight locations

nut steering: See recirculating ball and nut steering

nut thread: The internal thread of a nut

nut wrench: See flare nut wrench

wheel nut wrench NVH: Acronym for "Noise, Vibration, and Harshness." Every vehicle has some degree of NVH. It is the task of the manufacturer to reduce them as much as possible. The comfort of vehicles can be compared based on their NVH. For example, some vehicles may have more noise but less vibration or harshness than another.

nyloc nut: A self-locking nut with nylon insert. Also called "nylon lock nut"

nylon: A synthetic fiber which is stronger than vinyl. It can be used in sheet, fiber, or solid form

nylon hammer: A soft face hammer with a nylon face

nylon lock nut: A self-locking nut with nylon insert. Also called "nyloc nut"

nylon ties: See harness ties

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Ob] [Oc] [Od] [Of] [Oh] [Oi] [Ol] [On] [Op] [Or] [Os] [Ot] [Ou] [Ov] [Ow] [Ox] [Oz]

O2 sensor: A device that detects the amount of oxygen in the exhaust stream and sends that information the ECM. Also called an oxygen sensor or an exhaust oxygen sensor

O3: See ozone

OAC: Acronym used by car dealers to indicate "on approval of credit."

OBD: Acronym for "On-Board Diagnosis."

objectives: See program objectives

oblique crash test: You have seen crash tests where the vehicle slams into a brick wall, but what happens if your vehicle is hit on the front corner. Do you still have the same kind of protection? The oblique crash test determines a vehicle's ability to withstand crashes which may occur to any of its four corners.

OBO: Acronym for "or best offer" which indicates that the seller is willing to negotiate. If you offered $10 for a vehicle and you were the only one who made an offer, technically your offer is the best. However most sellers understand "$3000 obo" as meaning "about $3000, maybe less." Some think it means "I'll sell it for $3000; but if someone offers $4000, I will take that instead."

OBO ship:

A multipurpose ship that can carry ore, dry bulk goods and oil.

OBRO: Acronym for "or best reasonable offer."

obsolescence: See planned obsolescence.

obstruction wrench: A bent ring wrench for reaching around manifold and other obstacles to work on parts with difficult access, such as starters or alternators

OC: [1] Acronym for overhead camshaft. [2] Acronym for oxidation catalyst

ocean liner blast horn: A horn which imitates the deep bellow of an ocean liner horn

octagonal bolt: A bolt with an eight-sided head

octagonal head bolt: A bolt with an eight-sided head

octagon nut: A nut with eight sides

octane: An amount of anti-knock compound in gasoline. See iso-octane motor octane number research octane number octane number:

Every brand of gasoline has an octane rating or number which indicates its ability to resist knocking. When the numbers were first developed, the researchers found that normal heptane (a hydrocarbon) had almost no ability to resist knocking so they gave it an octane number of zero. Then they found that isooctane (also a hydrocarbon) was very resistant to knocking so they gave it the octane number of 100. To measure a particular sample of gasoline they discovered when it began to create detonation. Then they mixed isooctane to heptane to find out what percentage of isooctane created the same results as the sample of gasoline. In United States, there are two methods for determining the octane number depending upon operating conditions. The Research Octane Number (RON) is obtained when conditions are somewhat mild. The Motor Octane Number (MON) is obtained when conditions are somewhat severe and give a much lower number than the RON. The numbers on the gasoline pumps are usually an average of the RON and MON. Usually the pump number is about four numbers less than the RON. Thus if the automobile manufacturer recommends using gasoline with a RON of 91 or more, it would be acceptable to use pump gas rating of 87. The pump number is the anti-knock index which is half the sum of the RON and the MON. See motor octane number research octane number octane rating: See octagon number

OD: Acronym for outside diameter, outer diameter, or overdrive.

odometer: An instrument which measures and registers the number of kilometers or miles a vehicle travels. In automobiles, it is usually located in the same housing as the speedometer. Bicycles do not generally come with odometers as standard equipment. Motorcycles usually have the odometer in an instrument housing along with the speedometer for measuring and registering the miles and tenths of a mile (or kilometers and tenths of a kilometer) that the vehicle is driven. Some cars and motorcycles also have an additional trip odometer that can be reset to zero for conveniently measuring the miles or kilometers driven during trips or between fuel fillups.

OE: Acronym for "original equipment."

OECD:

Acronym for " Organization for Economic Co-operation and Development."

OEM: Acronym for "original equipment manufacturer." Products supplied by the company which first created the product.

off-boost: The condition that exists when a turbocharger is not producing power. If exhaust pressure is not sufficient to spin the turbine, the turbocharger goes off boost.

off-car balance: A procedure of removing a wheel from a vehicle and balancing the assembly. This is the most common form of wheel balancing and is done either statically or dynamically. The preferred method of off-car balancing is dynamic.

off color: A color mismatch (though very close to the correct color) due to wrong paint mixing or application

offer up: To bring a part close to or in contact with another, ready to fit the pieces together

off-highway vehicle: Vehicle intended for operation on unmade surfaces or rough terrain (i.e., for construction or agriculture).

off-idle discharge ports: The holes that deliver fuel from the idle circuit during the transition from curb-idle to the main metering circuit. Located just above the throttle plates. At curb idle, offidle ports function as an extra air bleed for further emulsification of the idle mixture; but as vacuum moves up the carburetor bore when the throttle plates are opened, they become fuel discharge ports. Either one or more holes, or a single slot (slots are usually used because they are cheaper to manufacture). Also called transfer ports

off-lease: A vehicle which was once leased, but now has been returned after the lease has expired.

off-line: Something that is independent of the main production process line which is characterized by a separate operation

off-line painting: The painting of parts, mostly plastic parts, outside the actual painting line

off-road tire: (OTR) A tire that is used on vehicles designed for operation on unmade surfaces or rough terrain (i.e., for construction or agriculture or recreation). See A-2 tire.

off-road vehicle: Vehicle intended for operation on unmade surfaces or rough terrain (i.e., for construction or agriculture).

offset: [1] Something set at an angle or to one side. [2] See scrub radius. [3] The distance between the centerline of the rim and the attachment face of the wheel disc at the wheel hub; this dimension can either be positive, negative, or zero. An important measurement for positioning the tire to insure proper tracking of the vehicle and adequate dual spacing. See caster offset kingpin offset miniature offset open-end wrench negative offset steering negative offset negative wheel offset positive offset rim offset wheel offset zero offset offset angle: The angle of the offset crankpins in V-engines

offset crankshaft:

A crankshaft layout whereby the axes of the crankshaft and the piston pin do not intersect. They do not intersect because the forces acting on the piston do not act uniformly on the walls of the cylinder through the skirt of the piston but much more on the side affected by the thrust of the con red during the power stroke. The crankshaft is thus offset, so that the con rod is less inclined during the power stroke than during the compression stroke

offset dish: A wheel with a hub which is not in the same plane as the rim.

offset handle: A drive handle for use with sockets, with one end set at 90° to the handle

offset link: A link in a chain which is often called a "half-link." An offset link increases the number of links by one.

offset open-end wrench: See miniature offset open-end wrench

offset screwdriver: A screwdriver with either straight or Phillips (cross-head) tips or a combination of both, and the two ends set at right angles to the shank, somewhat in the shape of the letter "Z"

offset steering: See negative offset steering.

offset twin: A typical motorcycle engine with the two crankpins offset by 180°

offset wrench: An L-shaped tool for turning recessed screws

off shade: A color mismatch (though very close to the correct color) due to wrong paint mixing or application

offside: (o/s) The side of the vehicle farthest away from the curb (when driving)

off-the-car balancing: balancing the wheel after it has been removed from the car. The opposite is on-thecar balancing

off-the-dolly panel beating: A metalworking technique used to hammer out dents in the bodywork. If the panel has a depression on one side, the dolly is held behind the depression, and the hammer blows are directed on the ridge away from the dolly, i.e., on the other side of the dolly. This causes a reaction by the dolly, producing an alternating impact on the dent from both sides

OHC: Acronym for "overhead camshaft."

ohm: A unit of measurement used to indicate the amount of resistance to the flow of electricity in a given circuit.

ohmmeter: An instrument used to measure the amount of electrical resistance in a given unit or circuit (in ohms).

Ohm's law: Mathematical relationship between voltage, resistance, and amount of current in an electrical circuit. It states: E=IxR; I=E/R; R=E/I

OHV: Acronym for "overhead valve" -- valve-in-head engine in which the valves are directly above the piston.

OHV engine: See OHV

OICA: Acronym for "Organisation Internationale des Constructeurs d'Automobiles" (i.e., International Organization of Motor Vehicle Manufacturers)

oil: A substance that lubricates and cools the moving parts of the engine and reduces the formation of rust and corrosion. It contains additives which fights the corrosion of bearings, keeps small particles in suspension, reduces engine wear, and reduces oxidization, minimizes carbon, lacquer, and gum formation. Oil comes in varying viscosity weights suitable for efficient operation in cold and hot weather and for engines in varying states of wear. See bedding-in oil break-in oil change the oil check the oil clean oil crude oil detergent oil diesel oil engine oil engine oil level warning light engine oil pan EP gear oil flushing oil full-flow oil filter gear-type oil pump gear oil hypoid gear hypoid oil hypoid oil low oil sensor low oil warning light lube oil lubricating oil micro oil filter mineral oil ML oil MM oil motor oil MS oil multi-viscosity oils multigrade oil oil filter oil filter bypass valve penetrating oil piston ring, oil control pumping, oil

single-grade oil straight-weight oil straight weight engine oil synthetic engine oil synthetic oil viscosity oil additive: Any one of a variety of chemicals added to engine oils to improve their performance. They include additives to increase viscosity at high and low temperatures; to inhibit corrosion, wear, and foaming; to prevent the formation of breakdown products caused by oil oxidation and to keep these in suspension

oil and water extractor: See air transformer

oil bath air cleaner: An air cleaner that uses a pool of oil to insure the removal of impurities from the air entering the carburetor.

oil bleed line: An external oil line which circumvents the evaporator pressure regulator or bypass valve to ensure positive oil return to the compressor when rpm are high and the system is under a low charge or clogged

oil bleed passage: An internal orifice which bypasses the evaporator pressure regulator, the bypass valve or the expansion valve to ensure positive oil return to the compressor

oil breather: Ventilated cap on oil filler pipe for allowing fumes to escape from the crankcase.

oil breather pipe: A crankcase breather pipe used prior to engine emission control systems to remove fumes and pressure from the engine crankcase. Also called road-draft tube. The tube, which was connected to the crankcase and suspended slightly above the ground, depended on venturi action to create a partial vacuum as the vehicle moved. The method was ineffective below about 20 mph

oil burner: An engine that consumes an excessive quantity of oil.

oil can: [1] A container with a long, thin nozzle for lubricating machinery. [2] A shallow dent in a panel that causes the panel to warp. The dent will spring back into its original shape with a characteristic sound if light pressure is applied but will not retain its normal shape once the pressure is released. It must therefore be straightened with body tools

oil change: The act of draining and replacing the engine oil at regular intervals

oil circulation: The passing of oil throughout the engine. The engine oil circulation is maintained by a gear-type pump with an output of up to 35 litres per hour

oil-combination splash and pressure system: An engine oiling system that uses both pressure and splash oiling to accomplish proper lubrication.

oil consumption: The amount of oil an engine uses

oil control: See piston ring, oil control

oil control orifice valve: A valve located in the feed line between cylinder and cylinder head

oil control ring: A piston ring designed to scrape oil from the cylinder wall, the ring is of such a design as to allow the oil to pass through the ring and then through holes or slots in the groove. In this way the oil lubricates the cylinder walls and is returned to the pan rather than getting into the combustion chamber where it might foul the spark plugs and create carbon on the head of the cylinder. There are many shapes and special designs used on oil control rings. Often it is the third or fourth ring from the top. Also called oil scraper ring

oil cooler: This looks like a small radiator used to cool off the engine oil or the automatic transmission fluid. As air passes through the cooler, the temperature of the oil in the cooler is reduced. Some units reduce the temperature of the manual gearbox and differential lubricants in racing cars.

oil cooler bypass valve: An oil-temperature-controlled valve which closes the oil circuit through the oil cooler when the oil is still cold; similar function as the thermostat in the engine cooling system. Engine oil is heated to a considerable temperature in engines subject to a high thermal load. This in turn greatly reduces the lubricating ability and the cooling capacity of the oil. Thermostats control the oil volume to the oil cooler, thus ensuring constant temperature of the oil

oil dipstick: See dipstick.

oil drain plug: The large bolt or plug that secures the drain hole in the oil pan. It is fitted with a gasket or o-ring to prevent leakage. Often the drain plug is magnetized so that any stray particles of iron will stick to it rather than lodge in some vital orifice. Also called "sump drain plug"

oil drain valve: A valve in an upright oil filter housing which lets oil drain into the oil pan when the filter element is removed. It prevents oil spill

oil duct: A pipe or passage through which oil flows under pressure. Also called "oil passage" or "oil way."

oiler: [1] A cam lubricator. [2] An oil can

oil filler cap:

A cap covering the oil filler hole

oil filter hole: A hole at the top of the engine (usually the rocker cover) through which new oil can be added after the oil filler cap is removed.

oil filter: A device used to strain the oil in the engine thus removing abrasive particles. Some filters are a can-like container, others look like small air filters which fit into a canister. Most manufacturers recommend that the oil filter should be replaced at least every second oil change. See centrifugal oil filter filter full-flow oil filter micro oil filter oil filter oil filter bypass valve oil filter bypass: See oil filter oil filter bypass valve

oil filter bypass valve: A valve in or near the oil filter which routes the oil unfiltered directly to the lubricating points; it comes into operation when the oil filter is clogged so that pressure across the filter is higher than the pressure needed to overcome the oil filter bypass valve spring

oil filter cartridge: [1] The type of oil filter usually used on automotive engines which comes complete with filter and housing, and where both components are replaced together. [2] A paper or textile insert for the oil filter housing (quite commonly used on motorcycle engines where e.g., the main filter is a disposable cartridge, while a filter screen is located on the bottom of the oil pump)

oil filter housing: A case surrounding an oil filter

oil filter wrench: A special automotive tool for the removal and installation of oil filters; they come in a variety of shapes, e.g., as strap wrenches, chain wrenches, or special cup-style end

cap oil filter wrenches

oil full pressure system: See oil-full pressure system.

oil-full pressure system: An engine oiling system that forces oil, under pressure, to the moving parts of the engine.

oil gage: See oil gauge.

oil gallery: A pipe or drilled passageway in the engine that is used to carry engine oil from one area to another.

oil gauge: An instrument on the dashboard which indicates the oil pressure as the oil is pumped through the engine. If this gauge shows a sharp drop, reads low, or lights up, it is possible that there is no oil in the engine. Stop the vehicle and turn off the engine. Check the oil level and replenish it as necessary. A vehicle with no oil in the engine could destroy an engine within a kilometer (or a mile). Also called oil pressure gauge

oil grade: A rating of an oil according to its viscosity

oil groove: recess designed to either accommodate or transport lubricant

oil-immersed clutch: See wet clutch

oil level: The depth of oil in the oil pan, gearbox, transmission, power steering reservoir, or rear axle. Also see engine oil level warning light

oil level gauge: A dial on the instrument panel that indicates the oil level; operates when the ignition is switched on and stops shortly after the engine starts to run

oil level sensor: A sensor mounted in the oil pan that supplies information on the engine oil level to the corresponding gauge

oil level warning light: See engine oil level warning light

oil lubrication: See clean oil lubrication

oil-ML: Engine oil designed for light duty service under favorable conditions.

oil-MM: Engine oil designed for moderate duty service with occasional high speeds.

oil-MS: Engine oil designed for high speed, heavy duty operation or for a great deal of stop and go driving.

oil pan: The removable metal chamber or bowl (usually of sheet steel or cast alloy) at the bottom of the crankcase into which the oil drains to be stored. The oil drain plug is found at the bottom of this pan and can be removed to allow the old oil to flow out of the vehicle during an oil change. The British term is "sump." Also see engine oil pan

oil pan drain plug: short fat bolt for draining the sump (when removed)

oil pan gasket: A gasket fitted between the cylinder block and the oil pan

oil pan guard: A shield fitted under the engine to protect the oil pan

oil passage: A pipe or passage through which oil flows under pressure. Also called "oil duct" or "oil way"

oil pick-up: A pipe or tube from the strainer to the oil pump in the oil pan

oil pick-up pipe: A pipe or tube from the strainer to the oil pump in the oil pan

oil pressure: The lubrication points of the engine will be lubricated sufficiently only if, in addition to the oil quantity required, the oil pressure is also sufficient; the oil pressure is maintained by the oil pump

oil pressure gage: See oil pressure gauge.

oil pressure gauge: An instrument on the dashboard which indicates the oil pressure as the oil is pumped through the engine. If this gauge shows a sharp drop, reads low, or lights up, it is possible that there is no oil in the engine. Stop the vehicle and turn off the engine. Check the oil level and replenish it as necessary. A vehicle with no oil in the engine could destroy an engine within a kilometer (or a mile).

oil pressure sensor: A sensor mounted above the oil filter that supplies information on the engine oil pressure to the corresponding warning light

oil pressure switch: A switch which indicates a drop to below the minimum permissible oil pressure by illuminating the oil pressure warning light

oil pressure warning light:

An instrument panel light that illuminates when oil pressure falls below a certain level

oil pump: The device located in the crankcase used to force oil, under pressure, to various parts of the engine, it is driven by a gear on the camshaft. There are two types: gear pump and rotor-type pump. Also see gear-type oil pump

oil pumping: A condition where an excessive quantity of oil passes the piston rings and is consumed in the combustion chamber.

oil pump strainer: A coarse-mesh metal screen on the bottom of the pick-up pipe that prevents foreign matter (such as lost washers, nuts and bolts) from entering the oil pump

oil rail: The part of the oil ring responsible for the seal between piston and cylinder wall and thus for the actual "scraping off" of the oil

oil ring: The lowermost piston ring that scrapes off excess oil from the cylinder walls and returns it to the oil pan via vents in the ring and piston. The oil ring consists of up to three separate pieces. The two outside pieces are thin rings (rails), and the inner section of the ring is called the expander ring. The oil ring is also called the "oil scraper ring"

oil screen: See oil pump strainer

oil seal: A device used to prevent oil leakage past a certain area. See grease seal valve oil seal oil sensor:

See low oil sensor

oil separator: A wire-mesh filter used to trap oil in the fumes drawn out of the engine by the crankcase ventilation system

oil slinger: A cone-shaped collar attached to a revolving shaft so that any oil passing that point will be thrown outward where it will return to the point of origin.

oil splash system: See oil-splash system.

oil-splash system: An engine oiling system that depends on the connecting rods to dip into oil troughs and splash the oil to all moving parts.

oil sludge: A thick deposit in the oil pan and elsewhere, of dirt and the products of combustion, partial combustion and oxidation of the oil (e.g. carbon particles, unburned hydrocarbons and oxides)

oil sump: See oil pan

oil tanker: A ship designed for transporting oil in bulk

oil temperature gauge: A gauge which indicates the temperature of the engine oil

oil thermal vacuum switch: (OTVS) a switch used by some GM vehicle to shut off vacuum to the early evaporation (EFE) valve when oil temperature reaches 150° F

oil trap:

See oil separator

oil warning: See low oil warning light

oil warning light: See low oil warning light

oil way: A pipe or passage through which oil flows under pressure. Also called "oil duct" or "oil passage"

Oldsmobile: A vehicle brand of which the 1949-50 88 Coupe, Convertible, and Holiday are milestone cars. The 1949 98 Holiday Hardtop is a Click for books milestone car. The 1953 Fiesta is a milestone car. The 1964-70 on Oldsmobile 442 models are milestone cars. Oldsmobile 88: A model of automobile manufactured by General Motors

Click for books on Oldsmobile 88

Oldsmobile Ciera: A model of automobile manufactured by General Click for books on Oldsmobile Motors Ciera Oldsmobile Omega: A model of automobile manufactured by General Click for books on Oldsmobile Motors Omega Oldsmobile Toronado: A vehicle brand of which the 1966-67 Toronado models are milestone cars. old-stock: See new-old-stock

Click for books on Toronado

oleopneumatic suspension: See hydropneumatic suspension

Oldsmobile Omega: A model of automobile manufactured by General Motors Click for books on Omega ON: See octane number

on-board computer: An electronic component used to control vehicle electrical circuits, etc. and to process data for instrument panel gauges

on board diagnostics: (OBD) A unit that monitors the Electric Control Unit and system responses for errors during normal vehicle operations. When the vehicle is serviced, this information on the errors can be down loaded and displayed to the service personnel which will facilitate the trouble shooting process.

on-board diagnostic system: An indicating device on the car that alerts the driver when something is wrong in the system

on boost: The condition that exists when a turbocharger is producing power. When exhaust pressure is sufficient, the turbine spins, and the turbo is on boost.

on-car balance: In contrast with off-car balancing (which removes a wheel from the vehicle) on-car balancing leaves the wheel on the vehicle and a special machine is used to balance the tire, wheel and brake assembly making adjustment for all of these components. Obviously this is the best (and most costly) procedure in obtaining balance.

on-center feel: The responsiveness and feel of the steering when the wheel is approximately centered. In a car with good on-center feel, the steering wheel tends to return to center when slightly deflected, assisting straight-line stability.

One: See formula One

one-coat finish: A finish consisting of a single coat of paint

one-groove track: Regardless of the width of a track, going into and coming out of a tight turn causes the track to have room for only one line of race cars rather than two.

one-off: A car or spare part of which only a single unit is made

one off: A car or spare part of which only a single unit is made

one-piece rim: A wheel rim consisting of one part, designed for tubeless tire mounting. The opposite is a multi-piece rim

one-piece rim designation: A coded description of a one-piece wheel rim.

one-piece wheel: A wheel with a rim constructed in one piece incorporating a well formation at or near its center to enable the tire beads to be mounted over the rim flanges. A cast wheel, a one-piece forged wheel, and a steel wheel have either a 5° drop center rim, 15° drop center rim, wide base rim, or double wide base rim are one-piece wheels. The opposite is a multi-piece wheel

one price selling: published fixed price displayed on a new vehicle eliminating need for negotiation.

one-way: See reactor one-way clutch

one way clutch:

A mechanical clutch which transmits power in one direction of rotation only; when torque is not applied, the driven member rotates freely; used in automatic transmissions and the old freewbeel. See freewheeling sprag clutch reactor one-way clutch one-way clutch: See oneway clutch

one-way valve: See check valve

on-line: A state in which a piece of equipment or subsystem is directly connected with or incorporated into the main system

on-line painting: A painting of components within the actual painting line. This is especially relevant for plastic moldings, which are fitted to the metal car body after the welding assembly operation. On-line painting means that such plastic parts are painted together with the body and must withstand the bake-in temperatures of about 150°C

ONO: Acronym for "or nearest offer" as a term of negotiation which indicates that the seller is not too flexible in his price.

on/off delay: See headlight on/off delay system

on-the-car balancing: Balancing the wheel while it is still attached to the car. The opposite is off-the-car balancing

on-the-dolly panel beating: A metalworking technique used to tap out dents in the bodywork. The dolly is held directly under the ridge in the panel so that the dolly contour closely matches that of the original panel shape. Hammering is then directed at the peak of the ridge,

working along the ridge from end to end in a progressive manner to push the area down gradually to its original shape

on-the-road charges: Extra charges, in addition to the list price of a new car, to cover delivery, license, etc.

opacimeter: An instrument for measuring the content of particulate suspended in a fluid

opacity: See poor opacity

Opel: A model of automobile manufactured by General Motors in Click for books on Europe Opel open car: Another name for convertible

open circuit: A circuit in which a wire is broken or disconnected.

open coil glow plug: See wire glow plug

open cradle frame: A motorcycle frame without tubes running under the engine. The engine unit bolts into place between the front downtube and the swingarm pivot area as a semistressed or stressed member

open-deck design: A design in which there is no metal at the cylinder head joint face between the cylinder walls and the outer block

open differential:

Common to all conventional motor vehicles, performing the basic drive axle differential function. Unlike a limited-slip or locked differential, an open differential is unable to compensate for traction distinctions from one side of the vehicle to the other, and will thus spin the wheel with the least available grip.

open element glow plug: See wire glow plug

open-end: See miniature offset open-end wrench

open-ended wrench: A wrench with openjaws

open end lease: With an open-end lease, there is still a residual value set at the beginning of the lease. However, if the car is worth less than the residual value at the lease's end, the lessee must pay the difference. In other words, the lessee assumes the risk for depreciation with an open-end lease.

open-end wrench: See miniature offset open-end wrench

open face helmet: A motorcycle helmet which does not wrap around the chin to protect the whole face.

open frame: A step-through motorcycle/scooter frame

opening angle: The angle of the timing diagram that indicates how long the port remains open

opening cam/rocker: With desmodromic engines, the cam/rocker responsible for opening the intake or exhaust valve

openings: See tonnage openings

open loop: An operating condition or mode based on programmed instructions and not modified by a feedback system

open-loop: Without feedback from e.g., oxygen-sensor control systems

open-loop catalytic converter: A preset converter which does not use an oxygen-sensor control system and thus operates without feedback. The opposite is computer-controlled catalytic converter. Certain engine management systems deactivate emission control systems (such as EGR and/or oxygen sensor control) under certain operating conditions (e.g., fullthrottle driving); i.e., the electronic control module operates in the open-loop mode

open-loop fuel control: A non-feedback mode of operation which a feedback system resorts to when the engine is started while it is still cold. During this period, the oxygen sensor isn't yet able to supply reliable data to the computer for controlling the air/fuel mix ratio because the engine isn't yet warmed up. So mix control is handled by a program stored in computer memory

open loop mode: Mode in which the computer operates without feedback from the oxygen sensor while the engine is in the cold running condition

open loop system: A control system which operates by feeding in instructions at the beginning of a process and they are followed to complete the process.

open registry: See flag of convenience flag of necessity opens:

See exhaust valve opens inlet valve opens intake valve opens open system: Term for a crankcase emissions control system which vents to the atmosphere

open throttle: See wide open throttle

open tourer: See AC Buckland Open Tourer.

opera light: A light mounted on the outside of the B-pillar or C-pillar

operated absolute: See pilot operated absolute

operated window: See manually operated window

operating costs: The costs of running a vehicle. It includes insurance premiums, tax, depreciation, fuel, oil, maintenance, repairs, etc.; usually expressed in dollars per mile or kilometer

operating piston: A piston in an automatic transmission which causes its respective clutch(es), band, or multi-disc brakes to be applied by converting fluid pressure into mechanical force and movement

operating profit: pre-tax earnings after deducting all operating expenses from gross margin.

operation:

See interval operation part-load operation part-throttle operation operational test: A check of temperature, pressure, and other conditions under controlled circumstances to determine whether an air conditioner or some other system is operating optimally

opportunity cost: The cost of what you didn't do. For instance, if you have the cash to buy a car, the opportunity cost of the purchase is the interest lost on the cash you used for the car. One of the often-cited advantages of leasing is that it frees up your money to invest elsewhere.

opposed engine: See horizontally opposed engine.

opposite lock: The act of turning the wheels to avoid a skid by steering in the opposite direction to which the vehicle is going. If the tail of the vehicle swings out to the left in a skid, you should correct the problem by turning the steering fully to the left. Some people express it by saying, steer in the direction of a rear-wheel skid. Others say, counter steer to straighten out the vehicle. If you have never experienced a skid, you might consider taking a course designed to give you the skill. Otherwise, practice in an unoccupied snow-covered parking lot.

opt: Abbreviation for "options" or optional equipment.

optical check: [1] A cursory visual inspection. [2] an examination with optical instruments

optics: See fiber optics

optimize:

To set at the best possible value

option: See cost option no-cost option purchase option factory options optional equipment: Any equipment or feature of a new vehicle which is not included in the basic price and is provided only if the purchaser requests it. Also see extras. The opposite is standard equipment

options: Extra features which may be purchased or may be included in the normally standard list of features and appointments of a vehicle.

OPUS: See oscillating pick-up ignition system

orange peel: A rough paint surface, resembling the skin of an orange caused by the paint spray failing to flow together.

orbital sander: A flat, cushioned plate covered with abrasive paper, rotated with an elliptical motion by an electric motor and used for fine sanding work like feather edging. Also see disc sander

order: See firing order

ore-bulk-oil carrier: See OBO ship

ore carrier:

A large ship designed for the transportation of ore.

organic: Something of chemical compounds that are based on carbon chains or rings and containing hydrogen with or without oxygen, nitrogen, or other elements. The opposite is inorganic

organic linings: Brake lining material using asbestos as its main ingredient

Organization for Economic Co-operation and Development: (OECD) An organization whose purpose is to provide its 29 Member countries with a forum in which governments can compare their experiences, discuss the problems they share and seek solutions which can then be applied within their own national contexts. Each member country is committed to the principles of the market economy and pluralistic democracy.

orientation: The tendency of plastic molecules if stretched, to align themselves in the direction of the stress. Molecular orientation leads to anisotropy of mechanical properties (i.e., having different mechanical properties in different directions). This can be used to advantage in the production of fibers and film or may be the undesirable result of a molding process

orifice: Opening through which gases flow. It is usually the final opening, or any opening controlled by a valve. See atomization orifice lateral atomization orifice orifice spark advance control: (OSAC) a device used by Chrysler to apply vacuum advance over a period of time. By limiting the timing advance rate, NOx is reduced

orifice valve: See oil control orifice valve

orig:

Abbreviation for "original," as in orig. owner.

original condition: An older vehicle that has all of its original paint and equipment and has not been restored or modified.

original equipment: These are the items on a vehicle which came from the manufacturer. It does not include accessories produced by "aftermarket" companies (sometimes called "jobber"). Generally original equipment parts are the best for the vehicle. Although it must be admitted that some aftermarket products are better quality and may be less money; however the opposite is also true.

original finish: The paint applied to vehicle when it is built by the manufacturer.

o ring: See O-ring.

o-ring: An o-ring is a doughnut shaped (annular) rubber or plastic ring which is placed in a groove and compressed to seal fluid or gas from passing a particular point.

o-ring chains: A drive chain (usually used on motorcycles) which has small neoprene o-rings within the exposed rollers to encircle the pins. The o-rings help to prevent dust from getting in and thus the chain lasts much longer.

o/s: Abbreviation for offside

OSAC: Acronym for orifice Spark advance control

OSCA: A vehicle brand of which the 1948-56 MT-4 models are milestone cars.

oscillate: To swing back and forth like a pendulum.

oscillating action: A swinging action such as that in the pendulum of a clock.

oscillating pick-up ignition system: (OPUS) An ignition system where the contact breaker and cam are replaced by a timing rotor, a pick-up module, and an amplifier module

oscillation: A swinging action such as that in the pendulum of a clock.

oscilloscope: A testing unit which projects visual reproduction of the ignition system spark action onto screen of cathode-ray tube. Also see ignition oscilloscope

OSD: Acronym for "Otomotiv Sanayii Dernegi" (i.e., Automotive Manufacturers Association) (Turkey)

OSHA: Acronym for "Occupational safety and health administration"

otg: Abbreviation outdoor or outside temperature gauge

OTR: Acronym for off-road tire. Also see A-2 tire.

otto cycle: Four-stroke cycle consisting of the intake, compression, firing, and exhaust strokes. Also see four-stroke cycle engine. It was named after the German engineer Dr. Nikolaus Otto (1832- 1891) who first patented the design in 1876

OTVS:

Acronym for oil thermal vacuum switch

ounce: See troy ounce

ounce inches: An expression of the force exerted by a heavy spot (or counterbalance weight) on a tire. Multiply the weight times its distance from the axle center, i.e., 3 oz. x 7" = 21 ounce inches.

outboard: [1] Something away from the center of a vehicle. [2] Away from the centerline and towards the side. Outside the hull

outboard contre pente: Safety contour for tubeless passenger car wheel rims, featuring a contre pente on the outer bead seat

outboard flat hump: A safety contour for tubeless passenger car rims, featuring a flattened hump on the outer bead seat

outboard flat pente: A safety contour for tubeless passenger car rims, featuring a flattened contre pente on the outer bead seat

outboard motor: A boat motor which is attached to the rear of a small boat

outboard round hump: A safety contour for tubeless passenger car rims, featuring a round hump on the outer bead seat

outdoor temperature gauge: (otg) A gauge which indicates the ambient air temperature outside the vehicle

outer bulb:

See outer envelope

outer cap nut: A securing device on a dual mounted disc wheel type where it threads directly on the inner cap nut and holds the outer wheel in place against the hub.

outer dead center: See bottom dead center

outer diameter: (OD) The external diameter of a cylinder or tube

outer electrode: [1] The outer terminal. [2] The ground electrode

outer envelope: The bulb of a gas discharge lamp which protects and supports the arc tube; either filled with gas or evacuated to avoid oxidation of the arc tube

outer headlight: On a headlight system where there are four lights (two on each side), the outer headlights (low beam) are at the extreme outside (i.e., the furthest away from the center of the car). Also see inner headlight

outer sill: A ledge below the doors visible from the outside; often referred to as the sill, whereas the inner sill is actually the side member

outer terminal: The electrode on the inside of the distributor cap, one outer terminal being assigned to each spark plug; the distributor rotor distributes the firing voltage from the central electrode to the outer terminals. The opposite is center electrode

outer tower: A socket on the distributor cap corresponding to the outer terminal, one per cylinder, to connect the spark plug leads

outer wrap: Something that surrounds the converter shell of a catalytic converter and serves as a retainer and provides mechanical protection for the insulation

outlet: [1] synonymous with vehicle dealership. [2] The exhaust port of 4-stroke engine. [3] The rear opening of a catalytic converter or muffler. [4] The last pipe of an exhaust system (i.e., the tailpipe). See air outlet HT outlet outlet pipe: A pump discharge pipe

outlet side: That side of the pump or pumping system on which the liquid pumped leaves the pump or system. The opposite is suction side

outlet valve: [1] See exhaust valve. [2] See discharge valve

outline: To mold plastic material around something. Compare insert

Out-Of-Pocket Cost: See total Out-Of-Pocket Cost

out of round: Something that is not completely circular. For instance a wire wheel may be true in that it does not wobble from side to side, but it may have a flat spot. A condition where engine cylinder bore has grater war at one diameter than another

out of true:

Something inaccurately made or incorrectly adjusted, e.g., of a wheel with side-toside deviation or wobble

out of tune: An engine which is not running ideally and needs a tune up

output: See gearbox output shaft pump power output output driver: A transistor in the output control area of the computer that is used to turn various actuators on and off

output shaft: The shaft delivering power from within a mechanism. The shaft leaving the transmission, attached to the propeller shaft or driveshaft, is the transmission output shaft. See gearbox output shaft transmission output shaft output speed: The speed of the transmission output shaft which is transmitted to the driven wheels via the final drive; as the final drive provides a constant gear ratio, output speed is proportional to vehicle road speed

out-rigger: [1] A device with retractable mechanical legs used to stabilize equipment such as cranes, ditch diggers, etc., while working. [2] A short angle or box section member that runs across part of the car. On cars with separate frames, outriggers are used to link the main chassis or the longitudinal members with the sill or running board area. An outrigger is far shorter and often of a smaller section than a crossmember

outrigger: [1] A device with retractable mechanical legs used to stabilize equipment such as cranes, ditch diggers, etc., while working.

[2] A short angle or box section member that runs across part of the car. On cars with separate frames, outriggers are used to link the main chassis or the longitudinal members with the sill or running board area. An outrigger is far shorter and often of a smaller section than a crossmember

outside caliper: A machinists' caliper used to check outside dimensions. See caliper.

outside calipers: See caliper.

outside corner weld: Fusing two pieces of metal together, with the fusion taking place on the underpart of the seam.

outside diameter: The external diameter of a cylinder or tube

outside spring caliper: An outside caliper with a spring for accurate setting

outside temperature gauge: (otg) A gauge which indicates the ambient air temperature outside the vehicle

oval piston: A special piston developed by Honda, able to accommodate eight valves and two spark plugs

oval track: A race course which is shaped like an oval rather than a circle. Sometimes used to describe any race track, other than a road race.

ovals: See wide ovals

oven:

See drying oven primer oven top coat oven overall gear ratio: The ratio of engine revolutions to road wheel revolutions, producing road speed as a ratio of engine speed (sometimes expressed as mph per 1000 rpm)

overall length: the extreme length of a ship measured from the foremost point of the stem to the aftermost part of the stern

overall ratio: See steering overall ratio

overall repainting: A type of paint job that involves the entire vehicle

overall rim diameter: A measurement from the top of the flange to opposite top of the flange 180° away.

overaxle pipe: See kick-up pipe

overcapacity: the situation where maximum global production of automobiles exceeds the total global demand for automobiles.

overcure: Vulcanizing a tire longer than necessary. It can result in the deterioration of certain physical properties.

overdrive: [1] A unit with a planetary gearset which turns the driveshaft faster than the transmission output shaft. [2] An additional gearbox which is mounted in the driveline. Normally the final drive ratio is 1:1; but the overdrive makes it less (e.g., 0.87:1). The overdrive can

reduce gas consumption at sustained high-speed driving, engine noise, and engine wear. Also called "overdrive transmission." Also see aftermarket overdrive

overdrive transmission: A transmission with a high gear which acts as an overdrive.

overflow: To spew out tread compound at the mold parting line or at the edge of the matrix skirt. This excess material should be trimmed or buffed off the finished product.

overflow hose: A tube located in the radiator fill hole that allows excess liquid to escape from the cooling system under conditions of extreme heat, pressure, or overfilling. Also see coolant recovery system.

overflow pipe: A tube located in the radiator fill hole that allows excess liquid to escape from the cooling system under conditions of extreme heat, pressure, or overfilling. Also see coolant recovery system.

overhang: The distance between the outermost front or rear point of a vehicle and the wheel centers of the respective axle. Also see load overhang

overhaul: See rebuild engine overhaul overhead cam: (OHC) See overhead camshaft double overhead cam dual overhead cam engine single overhead cam overhead cam engine:

See dual overhead cam engine

overhead camshaft: (OHC) The camshaft that activates the valves is mounted above the head and driven by a long timing chain or cam chain. In contrast, a pushrod engine has the camshaft below the cylinders so that thin rods (pushrods) are moved by the camshaft and activate the valves. An engine with an overhead cam means that the distance between the cam and the valves is much shorter, so the valves respond quicker and valve adjustment can be more accurate. Also this system allows for higher engine speed because of fewer moving valvetrain parts. A system with only one cam is called "Single Overhead Cam" (SOHC). In some instances there are two camshafts above the heads (one for the intake valves and the other for the exhaust) and called "double overhead cam" (DOHC). See single overhead camshaft twin overhead camshaft overhead position: A weld made on the underside of the joint with the face of the weld in a horizontal plane.

overhead valves: (OHV) Valves located in the head. A four-stroke engine with the intake and exhaust poppet valves located in the cylinder head and not at the side of the cylinder as in a side-valve engine. The valve stems are either at an angle or parallel and the valve discs face the piston, valve actuation pushrod and swing arm. Also see I-head engine.

overheat: To make or become too hot. Engine overheating could be caused by a fault in the cooling system caused by a leak, blockage, slipping or broken fan belt; lack of engine oil; or an over-lean mixture. Brake overheating can be caused by prolonged use (e.g., when going downhill) leading to brake fade, binding brake shoes, or seized disc pads or pistons

overinflated tire: A tire which has too much air in it, causing premature wear in the tread center. The opposite is underinflated tire

over inflation:

Excessive tire pressure in relation to the tire size and load carried. It will generally result in wear at the center of the tire tread rather than the outer sides.

overlap: [1] The part of the spray band that covers the previous application of paint. A 50% overlap on each stroke is generally recommended. [3] Extension of the weld face metal beyond the toe of the weld. [2] The number of degrees of crankshaft rotation where the both the intake and exhaust valves are open at the same time. This situation will occur only at the end of the exhaust stroke and the beginning of the following intake stroke. Also see valve overlap.

overlay: The upper layer of a plain bearing insert. If the overlay is worn, the bearing material beneath it will still allow for a certain emergency operation of the component supported in the plain bearing

overlay paint: A special type of custom paint where a design on the painted surface is embedded below a coat of translucent paint, giving the impression that two paints are applied to the car. Compare candy paint

overload: Carrying more weight on a tire than its listed maximum carrying capacity or carrying excessive loads on a tire in relation to its inflation (esp. if underinflated).

overload spring: A chassis spring which acts only under heavy load and prevents bottoming

overrev: To run an engine above the maximum recommended rpm. To exceed the redline on the tachometer

override button: See ABS override button.

overrider: A short, vertical attachment to the bumper, to prevent interlocking with other bumpers

overrun: [1] A vehicle travelling with no throttle and the engine acting as a brake is said to be "on the overrun" or "overrunning." [2] The action of a trailer when it travels faster than the towing vehicle See coast deceleration overrun control valve: A valve in a crossover pipe between the compressor suction and discharge sides of some turbocharger systems. When the manifold pressure drops, as during deceleration, the overrun control valve opens and allows compressed air to circulate through the compressor again; this maintains turbo speed on the overrun, minimizing turbo lag when the throttle is re-opened; not to be confused with a safety-relief valve in the compressor discharge line or with a wastegate valve

overrun cut-off/shut-off: See deceleration fuel cut-off

overrunning clutch: [1] A clutch mechanism that will drive in one direction only. If driving torque is removed or reversed, the clutch slips. [2] A part of a starter motor designed to avoid armature damage caused by severe overrevving. [3] A device in an automatic transmission that disengages the engine on overrun See freewheeling one-way clutch overrunning clutch starter: See pre-engaged starter

overrunning clutch starter drive: A starter drive that is mechanically engaged. When the engine starts, the overrunning clutch operates until the drive is mechanically disengaged. Also see freewheeling.

overrunning coupling:

See freewheeling

oversize: Installing a tire larger than needed to carry the load. A common (though not always beneficial) practice on passenger vehicles to increase one size when replacing OEM tires.

oversize piston: A piston with a diameter slightly larger than that of the standard piston, used in order to allow for a honing of the cylinder walls

oversize valve guide: A valve guide with a slightly larger outside diameter than the standard valve guide, used to repair worn valve guides after their bores have been reamed

overspray: The fine mist of paint on areas where it is not wanted (glass, moldings, other painted surfaces, etc). The distinguishing mark of a vehicle that has been painted or had body work done. Compare spray mist

oversquare: An engine where the cylinder bore diameter is greater than the length of the stroke.

over square engine: An engine in which the bore diameter is larger than the length of the stroke.

oversteer: The tendency for a vehicle, when negotiating a corner, to turn more sharply than the driver intends. The rear end of the vehicle wants to swing toward the outside of a turn. It is generally a sign that the suspension roll resistance is too hard in the rear or too soft in the front. A rear-engine vehicle has a natural tendency to want to swap ends, or oversteer, unless its suspension is adjusted to counteract it. A handling condition in which the slip angles of the rear tires are greater than the slip angles of the front tires. An oversteering car is sometimes said to be "loose," because its tail tends to swing wide. See lift-throttle oversteer power oversteer roll oversteer

tire deviation angle overtake: To pass another vehicle going in the same direction

overtaking: The action of your passing a vehicle which is going in the same direction you are.

overthin: To add too much thinner to paint

overtime: includes pay received for the number of hours worked in excess of the standard workday or workweek.

owner: Someone who actually owns something, i.e., has the title of property. Also see registered owner

owner's handbook: A booklet provided with a new car which briefly describes the position and operation of the various instruments and switches, as well as technical specifications and some maintenance information. Also called owner's manual

owner's manual: Every new vehicle is supplied with an owner's manual which gives the basic instructions for operating the controls. It includes a maintenance schedule and specifications such as the type and quantity of fluids. For instruction on repair work, you will need a service manual which may be ordered from the dealership which sold you your vehicle.

oxalic acid: An acid used as an electrolyte for anodising

oxidation: [1] One of the processes by which enamel paint cures, by combining oxygen in the air with the paint film. This process dries and continues to harden enamel for several weeks. Oxidation also results in chalking in older paint.

[2] A chemical reaction which increases the oxygen content of a compound or in which a compound or radical loses electrons, i.e., in which the positive valence is increased. Compare reduction

oxidation catalyst: (OC) type of bead material in catalytic converter which aids in oxidation of CO and HC

oxide: A chemical compound of oxygen with another element. See aluminum oxide natural oxide skin nitrogen oxides nitrous oxide system nitrous oxide polyphenylene oxide oxide film: See natural oxide film

oxide layer: See anodic coating anodic oxide layer oxides: See nitrogen oxides

oxide skin: See natural oxide skin

oxides of nitrogen: See nitrogen oxides

oxide system: See nitrous oxide system

oxidize: Action where surface of metal is combined with oxygen in the air to produce rust, scale, etc.

oxidizer: A compound which gives up oxygen easily, removes hydrogen from another compound, or attracts electrons. Also see trap oxidizer

oxidizing: The combining of oxygen with any other substance. For example, a metal is oxidized when the metal is burned, i.e., oxygen is combined with all the metal or parts of it.

oxidizing agent: A compound which gives up oxygen easily, removes hydrogen from another compound, or attracts electrons

oxidizing catalyst: A catalyst which decreases CO and HC levels using excess air. Compare reducing catalyst

oxidizing converter: A converter with a conventional oxidation catalyst that needs a secondary air supply to convert hydrocarbons and carbon monoxide to carbon dioxide and water; does not control NOx. Compare single-bed oxidizing converter oxidizing flame: Flame produced by an excess of oxygen in the torch mixture, leaving some free oxygen which tends to burn the molten metal.

oxyacetylene welding: See oxygen-acetylene welding. Also called gas welding

oxygen: A gas formed of the element oxygen. When it very actively supports combustion it is called burning; when it slowly combines with a substance it is called oxidation.

oxygen acetylene cutting:

Cutting metal using the oxygen jet which is incorporated with an oxygen-acetylene, preheating flame or flames.

oxygen-acetylene welding: A method of welding, using as a fuel a combination of the two gases - oxygen and acetylene.

oxygenated gasoline: Any fuel with a mixture of ethyl or methyl alcohol. The addition of oxygen causes a slightly leaner fuel-air mixture which is especially beneficial with older cars.

oxygenated gasolines: See oxygenated gasoline.

oxygenates: An oxygen-enriched fuel or anti-knock additive

oxygen corrosion: An electrochemical corrosion caused by neutral or alkaline electrolytes in which, during the cathodic reaction, oxygen is reduced to hydroxide

oxygen cylinder: A specially built container manufactured according to I.C.C. Standards and used to store and ship certain qualities of oxygen.

oxygen-hydrogen flame: The chemical combining of oxygen with the fuel gas hydrogen.

oxygen-LP gas flame: Chemical combining of oxygen with the fuel gas LP (liquefied petroleum).

oxygen regulator: An automatic valve used to reduce cylinder pressures to torch pressures and to keep the pressures constant. They are never to be used as acetylene regulators.

oxygen sensor:

A pollution control device which measures the amount of oxygen in the exhaust stream and sends that information the ECM. It controls the fuel-air mixture entering the engine. Also called a lambda sensor, exhaust oxygen sensor, or an O2 sensor

oxygen sensor system thermo-switch: A sensor of a fuel injection system that is usually located in a coolant hose to provide a coolant temperature signal to the ECM

oxyhydrogen gas: A highly explosive mixture of oxygen and hydrogen, generated during charging of lead-acid batteries. Compare gassing

ozone: A faintly blue form of oxygen produced by the silent discharge of electricity into the air. Ozone is very harmful to tires.

ozone checking: Cracks or hard spots usually found on the sidewalls of tires. Caused by the action of the ozone in the air on the rubber. This condition is normal, but could be dangerous on tires that are more than 65,000 km (40,000 miles) old or have been exposed to the ozone created by electrical machinery.

ozone compound: Rubber compounded with certain chemicals to retard ozone damage. Properly this should be called anti-ozone compound.

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DICTIONARY OF AUTOMOTIVE TERMS P [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Pa] [Pc] [Pe] [Ph] [Pi] [Pl] [Pn] [Po] [Pr] [Pu] [Py]

p: [1] A tire designation for "Passenger," as used in rating tires such as P185R13. [2] A tire designation for speeds up to 150 kph (95 mph) as in P195PR78 (the first P is passenger, but the second P is the speed rating. [3] The designation for "park" on the gear selector of an automatic transmission. See PRNDL

PA: Acronym for "power antenna."

p/a: An abbreviation for power-assisted

pace car: A vehicle which leads the pack of racers during the first part of the race (usually one lap) so that the racers can warm up their engines, etc. The pace car never runs the actual race. They also lead during parade, pace lap, caution periods, and restarts.

pace lap: The warm-up part of the race before the actual race begins.

Pacific Economic Cooperation: See Asia Pacific Economic Cooperation

pack: See See glass pack muffler rectifier pack

package: See accessory package equipment package trailer-towing package Packard: A vehicle brand of which all sixes and eights 1925-34; all 12-cyl. models; 1935 Models 1200-1208; 1936 Models 1400-1408; 1937 Models 1500-1508; 1938 Models 1603-1608; 1939 Models 1703-1708; 1940 Models 1803-1808; 1941 Models 1903-1908; 1942 Models 2004Click for 2008 plus 2023; 1946-47 Models 2106 and 2126; all Darrin-bodied books on with required application are classic cars. The 1953-56 Caribbean models are milestone cars. The 1946-50 Clipper and Custom Eight are Packard milestone cars. The Pacific sedan and convertible for 1954 are milestone cars. The 1954 Panther Daytona is a milestone car. The Patrician 400 for 1951 to 56 are milestone cars. packed gland: A cylindrical recess that accommodates a number of rings of packing around the shaft or shaft sleeve of a pump. Pumps used for high-temperature fluids are provided with jacketed, water-cooled packed glands. Also called "stuffing box."

packing: See stuffing-box packing

pack muffler: See glass pack muffler steel pack muffler PAD: Acronym for "Program Associated Data."

pad: See backing pad brake pad ceramic brake pad friction pad

pillion pad sintered metal brake pad skid pad padding disc: An insert in the crankcase area designed to reduce the internal volume of the crankcase and thus to increase the precompression ratio; this helps to increase the output of a two-stroke engine

paddle: See solder paddle stirring paddle paddling the lead: The act of filling repair areas by smoothing the body lead layer until a smooth surface is achieved

pad retainer: A pin which locates the brake pad in a disc brake

pad retainer pin: A pin which locates the brake pad in a disc brake

pad wear indicator: See brake pad wear indicator

pagoda roof: An unusual roof design, introduced on the Mercedes-Benz SL Hardtop, which was slightly lower in the center than at the sides

pagoda-style roof: An unusual roof design, introduced on the Mercedes-Benz SL Hardtop, which was slightly lower in the center than at the sides

paid value:

See duty paid value

Paige: See Graham-Paige

paint: [1] A liquid or paste consisting of a suspension of a pigment in oil or water, etc. When spread over a surface, it dries to form a hard, thin covering colored by the pigment. The primary purpose of paint is to help in the preventing of rusting. A secondary purpose is to provide a variety of color. See acrylic paint barrier paint bituminous paint candy apple paint candy paint job candy paint coach paint dust-free paint finishing paint flame paint heavy paint light paint liquid paint low-bake paint metallic paint nitrocellulose paint overlay paint polyurethane paint pyroxylin paint refinishing paint soft paint solder paint solid paint tire paint two-pack paint two-tone paint zinc-rich paint [2] The act of spray painting a surface.

paint booth:

A closed area where coats of paint are applied

paint chip book: A color chart

paint color matching: The process of determining the correct paint shade with the aid of color charts and special mixing devices and through spectral analysis

paint film: The actual thickness of the paint on a surface.

paint gun: See spray gun

painting: See cataphoretic painting electrophoretic painting electrostatic painting off-line painting on-line painting painting line: The route taken by the bodywork of a newly manufactured vehicle on its way through the paint shop

painting robot: A robot used for paint application

paint refinishing: The various steps involved in repainting a secondhand car

paint shop: [1] The production stage in an automobile manufacturing plant during which the bodywork is treated with paint. [2] A separate paint repair shop, usually near a body repair shop (i.e., for damaged vehicles)

paint stripper: A liquid paint remover

paint system: The sum of all coats of paint on a work

paintwork: The overall result of painting; the paint coating or finish

PAIR system: See pulse air system

palladium: A white, ductile, malleable, noble metal of the platinum family; atomic number 46, atomic weight 106.4; resembles platinum and together with other platinum metals is used as a catalyst in automotive exhaust converters. Compare platinum metals

palletized construction: The process of building a vehicle where the workers assemble a complete chassis at a comfortable workbench height, in a well-lighted area, away from the main line -not underneath a moving body. Working conditions and product quality are vastly improved.

palm spinner: A device which is attached to a steering wheel to allow disabled people to insert a hand into its bracket in order to steer a vehicle. pan: A thin stamped cover that is bolted to the bottom of the crankcase, it forms a sump for the engine oil and keeps dirt, etc. from entering the engine. See engine oil pan floor pan oil pan seat pan panamax:

A water-borne vessel (i.e., ship) designed small enough for passage through the Panama Canal

pancake engine: An engine in which the cylinders are on a horizontal plane, this reduces the overall height and enables them to be used in spots where vertical height is restricted. Also see flat engine.

pan drain plug: See oil pan drain plug

pane: A sheet of window glass

panel: [1] A flat piece of metal that is stamped to create a body component such as a door panel. [2] A plastic molding; e.g., interior trim of doors. See a-panel access panel aperture panel back panel body panel bonnet landing panel closing panel cluster panel corner panel cowl panel cowl side panel dashboard dash panel deck panel door panel front panel full panel grille face panel grille panel header panel headlight mounting panel high crown panel hinge panel

hood landing panel inner fender panels instrument panel kick panel lamp panel low crown panel lower front panel manual panel cutter off-the-dolly panel beating on-the-dolly panel beating parent panel part panel patch panel pattern panel pressed panel quarter light filler panel quarter panel quarter window filler panel radiator support panel rear corner panel rear deck panel rear panel replacement panel replica panel reproduction panel rocker panel roof panel sacco panels scuttle panel scuttle side panel shelf panel side aperture panel side bumper panels side panel splash panel squab panel straightened panel sunroof aperture panel tail light panel trim panel under seat panel under sill panel wheel house panel wheel panel windshield corner panel windshield header panel

windshield panel windshield support panel panel beater: [1] A person who beats out the dented bodywork of a damaged vehicle. [2] A panel hammer

panel beating: beating out the dents in damaged bodywork. See off-the-dolly panel beating on-the-dolly panel beating panel bonding: A new repair process using a special adhesive to glue body panels in place instead of spot-welding them

panel contour: The normal shape of a new, undented body panel as produced by the factory

panel cutter: An air-operated tool used to cut out old panels. It is a relatively coarse tool and is thus suited mainly for cutting sheet metal in areas where minor distortion along the cutting lines does not matter. Also see manual panel cutter

panel file: See body file

panel flanger: See joggler

panel hammer: A special hammer for metalworking that has two different fly-shaped heads for different purposes, e.g., cross-pein and shrinking hammer

panelling: [1] A combination of separate sheet metal panels to form a complete assembly, e.g., the outer panels of the body or even the panels surrounding the engine

[2] A plastic molding; e.g., interior trim of doors. See cladding underside panelling panel picking: The act of straightening very fine indentations or marks of very small diameter on a panel surface with a pick hammer

panel puller: A tool with a slide hammer and hook or self-threading screw tip to pull dented doors, fenders, and other sheet metal panels back into place. After drilling a hole in the deepest part of the dent, the hook or screw tip is inserted to pull out the dent by means of slide hammer impact. Also called knocker

panel release tool: See trim panel release tool

panel repair: A type of repainting job involving an entire panel but not the entire vehicle

pan gasket: See oil pan gasket

pan guard: See oil pan guard

Panhard: A vehicle brand of which the Dyna for 1946-67 models are milestone cars.

panhard rod: A rod or linkage on the axle which runs from side to side. Usually one end is attached to the body and the other end is connected to the axle. Also called a "track bar."

Panhard rod mounting box:

box section used to mount the Panhard rod of the rear axle

pannier: A luggage bag used in pairs and fastened alongside one or both wheels of a bike. Saddlebag.

panniers: Luggage bags used in pairs and fastened alongside one or both wheels of a bike. Saddlebags.

p. ant: Abbreviation for "power antenna."

panoramic windshield: A windshield style popular in the 1950s and '60s that featured recessed screen pillars, giving a wide, unobstructed view of the road; entry for the front passengers was awkward, since the screen pillar comers projected into the door opening

pantechnicon: A British term for a large van or truck, especially one for moving furniture

Pantera: A model of automobile manufactured in Italy

Click for books on Pantera

panting: The pulsation in and out of the bow and stern plating as the ship alternately rises and plunges deep into the water

panting frame: The frames in the forward and after portions of the hull framing to strengthen against shell panting

paper: See abrasive paper

paper air cleaner:

An air cleaner that makes use of special paper through which the air to the carburetor is drawn.

parabolic reflector: An old headlight reflector in the shape of a parabola, now replaced by ellipsoidal reflectors

parabolic spring: A leaf spring tapered in the shape of a parabola

paraffin: A British term for kerosene a solvent for removing grease

parallel: [1] The same distance apart at every point. [2] Two or more electrical components each receiving the same voltage resistors connected in parallel. Opposite to series. [3] To connect in parallel

parallel action locking pliers: A locking pliers with parallel action jaws, e.g., for pinching off hoses when servicing cooling systems

parallel circuit: An electrical circuit with two or more resistance units so wired as to permit current to flow through both units at the same time. Unlike the series circuit, the current in the parallel circuit does not have to pass through one unit to reach the other. A method or pattern of connecting units in an electrical circuit so that they are connected negative-to-negative and positive-to-positive. In a parallel circuit, current can flow independently through several components at the same time. Also see series parallel circuit

parallelism: [1] The same thickness of brake discs all the way around. [2] See axle parallelism.

parallel key:

See feather key

parallel middle body: The amidships portion of a ship in which the contour of the underwater hull form is unchanged

parallelogram steering: See parallelogram steering linkage

parallelogram steering linkage: A steering system using two short tie rods connected to the steering arms and to a long center link. The link is supported on one end on an idler arm and the other end is attached directly to the pitman arm. The arrangement forms a parallelogram shape.

parallelogram steering system: See parallelogram steering linkage

parallelogram suspension: See double wishbone suspension

parallel parking: The action of bringing a vehicle to a stop behind another vehicle (or between two vehicles) so that your front bumper is right behind the rear bumper of the vehicle in front of you. The technique of parallel parking involves driving beside the other vehicle and then backing up while turning the steering first to the right and then at the correct time turning it to the left. It is one of the testing requirements for obtaining a licence.

parallel trailing link suspension: A front suspension layout used primarily by Volkswagen on rear-engined cars

parallel twin: A type of engine usually found on two-cylinder motorcycles where the cylinders are beside each other and on the same side of the crankshaft. An opposed twin has two cylinders that are on either side of the crankshaft.

parallel valves:

The intake and exhaust valves with parallel valve stems

parameters: See engine parameters

parent panel: The panel left in place on the car to which a new panel is welded after all the rusted metal has been cut out

park: (P) [1] One of the positions of the gear selector for an automatic gearbox; when engaged (after the vehicle has come to a complete standstill) the driving wheels are locked. [2] To leave a vehicle in a particular place. [3] A parkade. See car park multi-storey car park parkade: A place where vehicles can be parked on one of several levels. Also see See car park multi-storey car park Park Avenue: A model of automobile manufactured by Buick

Click for books on Buick Park Avenue

park brake: See parking brake

park brake extension: A device which is attached to the parking brake to help disable people to operate the parking brake more easily. parkbrake warning light:

A light on the instrument panel that illuminates when the parkbrake is applied; on most new cars it has been superseded by a multifunction brake warning light

parking: The action of placing a vehicle at a full stop out of the flow of traffic. See angle parking attendant parking echelon parking parallel parking self-parking valet parking parking brake: Hand or foot operated brake which prevents vehicle movement while parked by locking rear wheels, or transmission output shaft. One type applies the rear brake shoes by mechanical means and the other type applies a brake band to a brake drum installed in the drivetrain. Also see emergency brake.

parking brake console: The reinforcing member incorporated in the center tunnel area of the floorpan to provide the mounting support for the handbrake

parking brake lever: [1] A lever inside the drum brake which spreads the brake shoes outward; the long end is connected to the parking brake cable, the opposite end to one brake shoe and to a push bar which acts on the other shoe. [2] A lever inside the passenger compartment attached to the end of the parking brake rod and which activates the parking brake cable.

parking brake lever strut: A push bar between the shoes in a drum brake

parking brake pedal: foot-operated pedal for the parking brake

parking disc: A marker displayed on the inside of a parked car showing time of arrival or latest permitted time of departure in a British parking lot

parking heater: An air heating system which operates independently of the engine

parking interlock: See parking lock

parking lamp: An energy-saving vehicle illumination mode on British cars for long-term roadside parking; includes only one front sidelight and one taillight; the parking light can be switched to illuminate the left side or the right side

parking light: An energy-saving vehicle illumination mode on British cars for long-term roadside parking; includes only one front sidelight and one taillight; the parking light can be switched to illuminate the left side or the right side

parking lock: (PL) A lock gear and pawl that lock the transmission mechanically

parking lot: A ground level, outdoor area where vehicles can be left temporarily.

parking meter: A coin-operated timing device that indicates how long a vehicle may legally remain parked

parking space: A parking place reserved for a particular vehicle

parking ticket: A written fine for a parking offence, especially where a vehicle has exceeded the time limit for parking

park light: A low intensity light which is often incorporated into the front signal lights. The park lights are to be illuminated when the vehicle is still running, but pulled off the

road. However, many people drive with them on -- an action which is illegal in some parts of North America.

park safety switch: A switch which allows the starter to be engaged only when the automatic shift lever is in either park or neutral

part: A component of a vehicle. See aftermarket part identical part molded part new-old-stock part spare part structural part partial flow filter: A bypass filter

partial respray: A respraying of only part of the bodywork, opposite to full respray or complete respray

participation: See dealer participation

particulate: See diesel particulate filter

particulate catalyst: A pellet catalyst

particulate emission: An emission of solid particles of carbon and unburnt hydrocarbons from the exhaust system

particulate emission limit:

The weight of particulate emissions in the exhaust of diesel engines, specified in grams per mile

particulate filter: See diesel particulate filter

particulate ignition temperature: In diesel filtration tests, the exhaust gas temperature at which there is an equilibrium between particulate burn-off and deposit build-up

particulate matter: (PM) Suspended solids of carbon and unburnt hydrocarbons from the exhaust system

particulates: (PM) Suspended solids of carbon and unburnt hydrocarbons from the exhaust system

part-load: The throttle opening between idle and fully open

part-load enrichment: Extra fuel injected during throttle opening to enrich the mixture during transition. Usually occurs during closed-loop operation

part-load operation: The operation of systems and components under conditions below full load

partnership: Business owned by at least two people

Partnership for a New Generation of Vehicles: (PNGV) established in 1993, this partnership, between the United States Federal Government and the Automotive industry, was founded to establish global technical leadership in the development and production of affordable, fuel-efficient, low emission vehicles that meet today's performance standards.

part number: (p/n, PN) A reference number attributed to a particular part. Each company uses its own system of numbering the parts.

part out: To dismantle a vehicle and sell the parts. British term is "break up"

part panel: See patch panel

parts car: A vehicle that has been damaged beyond repair or restoration, or that has deteriorated badly. It is useful only as a source of parts. It may be drivable though unsafe, but it usually is not in drivable condition.

parts catalog: A directory listing available parts for a particular product

parts store: See auto parts store

part-throttle operation: Driving without using full throttle

part-time four-wheel drive: A manually selectable four-wheel drive

PAS: Acronym for power-assisted steering

pascal: (pa) SI measurement of pressure, it equals one newton per square meter

pascal's law: A principle which states that when pressure is exerted on a confined liquid, it is transmitted undiminished. The law is particularly valid for hydraulic systems.

pass: [1] The act of overtaking a vehicle which is travelling in the same direction you are. [2] The act of going past a vehicle which is travelling is the opposite direction from you. [3] Weld metal created by one progression along the weld. Also see bypass

passage: See air passage lateral air passage oil passage relief passage scavenging passage transfer passage water passage passenger capacity: The maximum number of people that a vehicle can carry.

passenger car: A four-wheeled motor car powered by an engine and designed for passengers

passenger car wheel: A one-piece wheel made of sheet steel. The rim and disc are welded together or made of light-alloy (cast or forged), and designed for tubeless tires. Rims for passenger cars are almost exclusively designed as 5° drop center rims incorporating a safety bead seat (double hump and combination hump are most common; flat hump designs are less common) and a J-flange. The B-flange type is reduced in height and used on passenger cars with small rim diameter and rim width

passenger cell: That part of the vehicle in which the driver and passengers sit

passenger compartment: That part of the vehicle in which the driver and passengers sit

passenger ship:

A ship authorized to carry more than twelve passengers.

passenger-side air bag: An air bag restraint system designed to protect the front passenger; introduced on some cars in the early 1990s, it usually occupies the space normally provided for a glove compartment

passenger vehicle: four wheeled motor vehicle that also includes mini-vans and sport utility vehicles.

passing: [1] The action of overtaking another vehicle going in the same direction you are. [2] The action of going past another vehicle which is going in the opposite direction you are.

passing gear: An automatic transmission gear that shifts a vehicle into a lower gear for a short burst of extra power to pass other cars on the highway. The gear is engaged by sharply depressing the gas pedal. When the pedal is released, the vehicle returns to normal to normal driving gear. See forced downshift.

passing lane: The outside lane (far left lane in North America, etc. or the far right lane in Britain, Australia, etc.). Also called the "fast lane"

passivate: To reduce the reactivity of a chemically active metal surface by electrochemical polarization or by immersion in a passivating solution

passive restraint system: See airbag restraint system.

passive safety: Any device which automatically provides protection for the occupants of a vehicle such as the bumpers, seat belt, padded dash, laminated windshield, head restraints, collapsible steering column, air bags, etc. In contrast with active safety.

passive safety features:

Items in a vehicle which do not require action on the part of the driver to avoid a hazard, e.g., crumple zones, bumpers, side impact beams, and roll-over bars. See passive safety.

Passport: A model of automobile manufactured by Honda Click for books on Honda Passport paste: See glass reinforced filler paste grinding paste patch: [1] To repair a component. [2] The added part used to repair a component, e.g., a rubber disc glued to a tube to cover a nail hole. [3] The footprint of a tire in its contact with the ground. See contact patch balance patch plug patch patching: [1] A repair method for welding up local corrosion damage by using smaller panels made up from sheet metal. [2] A repair method for gluing a rubber patch to a tube which has a hole in it.

patch panel: A small sheet metal panel that is usually made up specially to repair minor rust holes

path: See heat path

Pathfinder: A model of SUV manufactured by Nissan in Japan patter:

Click for books on Pathfinder

See wheel patter

pattern: See contact pattern heavy side pattern ignition pattern master pattern primary pattern reference ignition pattern secondary pattern spray pattern tread pattern wear pattern pattern panel: A body panel made by somebody other than the original manufacturer, usually for repair purposes; this also includes panels remanufactured after the factory has discontinued making and supplying those parts.

pattern percentage: See tread pattern percentage

pattern snips: See straight pattern snips

pawl: [1] A bar, pin, or stud that can be moved, pivoted, or slid into engagement with teeth cut on another part, such as the parking pawl on the automatic transmission that can be slid into contact with teeth on another part to lock the rear wheels. [2] A catch at the bottom of a lever which connects with a toothed rack to hold the lever in position (e.g., with a handbrake lever or in ratchets). [3] An arm pivoted so that its free end can fit into a notch, slot, or groove at certain times in order to hold a part stationary

payload: [1] The actual weight of cargo being carried, including packaging, etc. (GVW -Unladen weight = payload). [2] The revenue-earning cargo of a commercial vehicle. Also see interior payload

payment: See monthly payment

PB: Acronym for "power brakes" or for "pushbutton" as in PB radio.

PC: Acronym for pitch circle or polycarbonate

PCB: Acronym for printed circuit board

PCD: Acronym for pitch circle diameter

PCI: Acronym for program comparison and identification

PCV: Acronym for "positive crankcase ventilation."

PCV system: Abbreviation for "positive crankcase ventilation system." A system which prevents crankcase vapors from being discharged directly into the atmosphere. Also see closed crankcase ventilation.

PCVV: Acronym for positive crankcase ventilation valve

PCV valve: (PCVV)Part of the positive crankcase ventilation system, which reroutes crankcase blowby to the intake manifold and back to the engine, where it is reburned in the cylinders as part of the fuel-air mixture. This cuts emission pollution and improve fuel economy because unburned fuel in the blowby is consumed the second time around. It also keeps the blowby and water vapor from fouling the oil in the crankcase, thus reducing the formation of engine sludge.

PDA: Acronym for "Personal Digital Assistant."

PDB: Acronym for "power disc brakes."

PDL: Acronym for "power door locks."

PDLR: Acronym for "power deck lid release."

PDR: Acronym for "power deck release."

PE: Acronym for polyethylene or polyellipsoidal

peaking: A condition, usually in the cushion rubber, resulting from local material starvation and excessive flow from adjacent areas.

peak inverse voltage: Amount of voltage a diode can take in reverse direction without being damaged

peak power: The point of maximum torque

peak pressure period: The phase of diesel combustion lasting from about five degrees before top dead center to about 10 degrees after top dead center, the majority of diesel fuel burns during this period

peak revs: The point of maximum engine speed

peaky: An engine that is able to deliver useful power only at high revs and needs frequent shifting. Compare flexible

peanut: A small motorcycle fuel tank which holds about five litres (one gallon). See chopper.

pedal: A lever operated by the foot. See accelerator accelerator pedal brake pedal clipless pedal clutch pedal dead pedal depress the gas pedal depress the throttle pedal ease up on the throttle pedal ease up on the gas pedal foot pedal free pedal play gas pedal loud pedal low brake pedal parking brake pedal pumping the gas pedal pumping the throttle pedal pump the gas pedal pump the throttle pedal quill pedal spongy brake pedal spongy pedal step on the gas pedal step on the throttle pedal throttle pedal. pedal clearance: The distance between the pedal and the floor, when the pedal is folly depressed; reference points may vary

pedal free play:

The distance a pedal moves until a slight resistance is felt. See clutch pedal free travel free pedal play pedal free travel: See clutch pedal free travel free pedal play free travel pedal play: See free pedal play

pedal pulsation: The vibration of the brake pedal when depressed, caused by a defective disc or drum (or when ABS is activated)

pedal to the metal: To fully apply the accelerator for a fast take-off.

pedal travel: The total stroke of a pedal, i.e., the distance the pedal moves

pedestal pivot: A semi-cylindrical (half-round) pivot used with pivot guided rocker arms. A pedestal pivot restricts the rocker arm so it pivots around one axis or in a single plane-the plane of the valve stem and pushrod

peel: [1] The action of rapid acceleration so that the tires slip on the road surface (i.e., the wheels are turning, but the vehicle is not moving very much) which may result in a strip of rubber on the road surface. See peel rubber. [2] The action of paint coming off. See orange peel.

peel rubber: Rear wheels slipping on the highway during acceleration. Also called "burn rubber."

peen: Also spelled "pein" [1] To flatten out the end of a rivet, etc., by pounding with the round end of a hammer. [2] The ball-shaped, or narrow wedge-shaped end of a hammer head opposite the flattened striking face. See ball peen hammer wide-nose peen hammer peen hammer: Also spelled "pein hammer." A body hammer with a peen of triangular section with a fairly sharply shaped end. Compare ball pein hammer

peening: The flattening or shaping with a peen hammer

Peerless: A vehicle brand of which the 1926-28 Series 69; 1930-31 Custom 8; and 1932 Deluxe Custom 8 are classic cars.

peg: See highway peg

pegs: [1] Studs or nipples which may be used for alignment of parts or the placement of a part. [2] Footpegs, often called pegs, are where the motorcycle rider's feet rest. Some motorcycles have floorboards instead of pegs. With pegs, the rider usually rests the balls of his feet on the peg, whereas a floorboard is large enough to accommodate the whole foot.

Pegaso: A vehicle brand of which all models from 1951-58 are milestone cars.

PE headlight: A headlight with a gas discharge lamp and a polyellipsoidal reflector

pein:

Also spelled "peen" [1] To flatten out the end of a rivet, etc., by pounding with the round end of a hammer. [2] The ball-shaped, or narrow wedge-shaped end of a hammer head opposite the flattened striking face

pein hammer: Also spelled "peen hammer." A body hammer with a pein of triangular section with a fairly sharply shaped end. Compare ball pein hammer

peining: The flattening or shaping with a pein hammer

pellet catalyst: See pellet-type catalytic converter

pellet-type catalytic converter: The first type of automotive catalytic converter, introduced in the USA in 1975. It consisted basically of a sheet steel catalyst container surrounded by thermal insulation and a sheet steel outer shell. The catalyst container was fitted with one or two beds of ceramic pebbles (pellets) coated with a catalyst. This type of catalytic converter suffered from poor service life due to vibration-induced attrition of the catalytic coating; this also produced additional particulate emissions and the pellet bed caused high exhaust back pressure, resulting in poor engine performance. Pellet-type catalytic converters have been superseded by monolithic converters

penalty: See residual penalty stop-and-go penalty pencil: See glow pencil grease pencil pencil-type glow plug: See sheathed-type glow plug

pencil-type injector: An early GM injection nozzle

pendulum impact test: The standard test methods are the Izod and Charpy tests; the specimens have a standard notch machined in them, and the impact energy absorbed in breaking the specimen is recorded

penetrating oil: A special oil with very thin viscosity that is used to free rusted parts (esp. nuts and bolts) so that they can be removed.

penetration: The extent that the fusion goes into the base metal as measured from the surface of the base metal.

penny-farthing: An early bicycle which had a large front wheel (which was both the driving wheel and the steering wheel) and a smaller rear wheel. Its name comes from two British coins -- the large penny and the small farthing.

pent crown piston: A piston design with a sloping, pent-roof shaped piston crown to improve the flow of the fuel/air mixture and to increase engine compression

pente: See contre pente flat pente outboard contre pente outboard flat pente pent-roof: A combustion chamber whose upper surface resembles a shallow peaked roof. Usually used with four valves per cylinder.

pent-roof combustion chamber:

A combustion chamber whose top is angled like a roof

percolation: A condition in which the fuel actually boils due to excess heat. Percolation prevents proper atomization of the fuel causing rough running. Also see anti-percolation valve.

percussion welding: The type of resistance welding in which the heating comes from an arc produced by an electrical discharge and instantaneous pressure applied during or immediately following the heating.

perf: See hi Perf.

perfect scavenging: The scavenging parameter of two stroke engines. In an ideal scavenging process, the fresh mixture is considered to push the combustion products out of the cylinder without mixing or exchanging heat. This process continues until all burnt gases have been expelled and the cylinder is completely filled with a fresh mixture

performance: [1] The general way a vehicle, machine, or material is able to accomplish its purpose. [2] The ability of a vehicle to accelerate and reach top speed. See engine performance tester high-performance manufacturer's performance ratings performance characteristics of materials: The specific values for materials, obtained by standard test methods and available for the selection of appropriate materials

performance handling system: A suspension system that can be improved by adding appropriate front and rear anti-roll bars, nitrogen-filled gas shock absorbers, and special springs

performance ratings:

See manufacturer's performance ratings

performance tester: See engine performance tester

performance tuning: The act of improving a vehicle's performance in general or engine performance in particular, such as upgraded suspension, higher engine output and/or torque, or drag-reducing measures, such as the addition of spoilers

perimeter frame: Sometimes called a "Space Frame." A steel frame making up the chassis of a vehicle. The engine, transmission, body panels, and interior are all attached to the frame. Most cars today do not use a frame but are instead made with unibody construction.

period: See blowdown period dwell period induction period injection period saturation period period of roll: The time occupied in performing one complete roll of a ship as from starboard to port and back to starboard

periphery: The outside edge or circumference.

permanent four-wheel drive: A British term for full-time four-wheel drive. A permanently engaged four-wheel drive (with lockable or limited-slip differentials).

permanent magnet: The permanent magnet does not need electricity to function and will retain its magnetism over a period of years.

peroxide: See lead peroxide

perpendiculars: See after perpendiculars between perpendiculars fore perpendiculars forward perpendiculars length between perpendiculars perpetual motion: A situation where a device will turn forever because there is no friction between the moving part and the stationary part. Although friction can be greatly reduced, it can never be eliminated. Thus a perpetual motion machine is impossible.

perpetual motion machine: a device which will turn forever because there is no friction between the moving part and the stationary part. Although friction can be greatly reduced, it can never be eliminated.

personalized license: A license plate chosen (at a cost) by a vehicle's owner, rather than one allocated by the agency giving out the license. The letters and numbers may spell out a person's name or occupation or even some cryptic reference.

personal license: A license plate chosen (at a cost) by a vehicle's owner, rather than one allocated by the agency giving out the license. The letters and numbers may spell out a person's name or occupation or even some cryptic reference.

Perspex: See polymethyl methacrylate

petal: See main petal

subsidiary petal petcock: A small valve or tap which is used to control the flow of liquid. You may find one at the bottom of a radiator to permit draining the radiator. A petcock may also be found on the line coming from the fuel tank in small engines and motorcycles. It allows you to cut the flow of gasoline going to the carburetor. On some motorcycles, the position of the petcock lever may permit draining the last part of the fuel tank as a reserve position. In units where the carburetor is fed by gravity feed from a fuel tank, turning off the petcock when the unit is not in operation may prevent gasoline from leaking past the carburetor's needle and seat and into the crankcase to dilute the oil.

petroil lubrication: A lubrication method for two-stroke engines where the oil is added to the fuel and lubricates the moving engine parts as the air/fuel mixture passes through the crankcase

petrol: A British term for gasoline. See lead-free petrol leaded petrol petroleum: Raw material from which gasoline, kerosene, lubricating oils, propane, diesel fuel, etc. are refined. Consists primarily of hydrogen and carbon; but also contains other elements. Its source is decomposed organic matter which has been buried. Some used to think that the action of ice ages moved soil over great forests of tropical vegetation. The current suggestion is that great bodies of water flooded tropical vegetation in a cataclysmic event. Also see liquified petroleum gas

petroleum gas: See liquified petroleum gas

petroleum jelly: A whitish jelly-like substance obtained from petroleum, used as a lubricant and as a protection against corrosion

petrol pump:

A British term for gas pump. A pump which dispenses gasoline at a gas station

petrol station: A British term for a gas station or service station

petrol tanker: A British term for a tanker truck -- a specially equipped truck for transporting gasoline and other fuels

Peugeot: A vehicle brand of which the 1925-1948 models, with required application, are classic cars. Click for books on Peugeot PFI: Acronym for port fuel injection

PG: Acronym for "powerglide" automatic transmission.

PGM-FI: Acronym for programmed Fuel Injection

P grit numbers: A standard system of grit numbers applied to sandpapers to ensure identical properties in products made by different manufacturers

pH: See pH value

phaeton: An open-type body with two cross seats, it usually accommodates five passengers. A folding windshield, folding weatherproof fabric top and removable side curtains

are usually standard equipment. The four-seater was called a double phaeton, and the six-seater or seven-seater was called a triple phaeton. Also see sport and Imperial phaeton.

phase-locked loop circuitry: See PLL circuitry

phase pressure forming: See solid phase pressure forming

phenolic spacer: A carburetor base gasket made from a thermosetting resin used specifically for heat insulation between the carburetor and the intake manifold

phillips head screw: A screw having a fairly deep cross slot instead of the single slot as used in conventional screws.

Phillips screw: A common type of cross-head screw

phillips screwdriver: A screwdriver with a pointed tip that is shaped to fit the crossed slots in the heads of Phillips screws.

phone: See car phone cell phone cellular phone mobile phone phosphate: See manganese phosphate coating

phosphate coating: A special conversion coating produced by phosphating. It is applied to camshafts which promotes oil retention.

See manganese phosphate coating zinc phosphate coating phosphate section: A section in a painting line in which phosphate treatment is performed

phosphate treatment: A treatment of metals with a phosphating solution to produce a phosphate conversion coating on the surface

phosphating: See heavy phosphating low temperature phosphating phosphate treatment phosphating solution: A solution of phosphoric acid, often enriched with zinc, used during the bodywork production process for cleaning and rust prevention

phosphor-bronze: Bearing material composed of tin, lead, and copper.

photochemical: Relates to branch of chemistry where radiant energy (sunlight) produces various chemical changes.

pH value: A measure of the concentration of hydrogen ions in a solution, which shows the strength of acid or alkaline. The pH value of an aqueous solution is a number describing its acidity or alkalinity. The pH of a neutral solution is 7.0 at 25°C

pick: See prospector's pick

pick and finishing hammer:

A widely used type of body hammer with a pointed end on one side and a shallow domed end for finishing on the other side

picker: See electro picker

picker set: See lock picker set

pick hammer: A hammer with a round head for conventional planishing and a small pick-shaped head for working away in sharp or tight corners. It should not be confused with a bullet-point pick hammer, which has a more blunt pick, nor with a pein hammer

picking: See panel picking

pickling: The removal of oxide or mill scale from the surface of a metal by immersion, usually in an acidic or alkaline solution

pickling attack: The initial chemical reaction between phosphating solutions and metal surfaces in phosphate treatment

pickup: [1] A utility truck with a closed cab and an open box. In Australia it is called a "utility" or "ute." [2] The transfer of material, as between bearing and shaft, caused by friction and heat due to lack of oil; can lead to seizure. [3] A pick-up coil or yoke.

pick-up: [1] A utility truck with a closed cab and an open box. In Australia it is called a "utility" or "ute." [2] The transfer of material, as between bearing and shaft, caused by friction and heat due to lack of oil; can lead to seizure. [3] A pick-up coil or yoke.

See inductive pulse pick-up magnetic pick-up magnetic pick-up assembly magnetic pick-up tool oscillating pick-up ignition system transistorized ignition with inductive pick-up transistorized ignition with magnetic pick-up pick-up assembly: See magnetic pick-up assembly

pickup coil: See pick-up coil.

pick-up coil: The coil in which voltage is induced in an electronic ignition.

pick-up ignition: See oscillating pick-up ignition system

pick-up ignition system: See oscillating pick-up ignition system

pick-up module: A trigger-activated device which sends a signal to the ignition unit of an electronic ignition system

pick-up pipe: See oil pick-up pipe

pick-up screen: See oil pump strainer

pick-up tool: A tool with a flexible or rigid shaft and a claw type pick-up end; used to retrieve small objects from hard-to-reach areas. Compare magnetic pick-up tool

picture: See scavenging picture

piece: See blanking piece distance piece extension piece pole piece sill end piece pien hammer: See ball pien hammer

Pierce-Arrow: A vehicle brand of which the 1925-1948 models are classic cars.

piezoelectric ignition: A system of ignition that employs the use of a small section of ceramic-like material. When this material is compressed, even a very tiny amount it emits a high voltage that will fire the plugs this system does not need a coil, points or condenser.

pig iron: Produced in blast furnaces, pig iron is the raw material for practically all iron and steel products; contains about 3-5 % carbon

pigment: Finely ground powders in the paint that give it its color.

pigtail: See wiring pigtail

pile: This is a steel or concrete bar which is driven into the ground to form part of the foundations for a building. Also see scrap pile

piling: The build-up of metal on a contact breaker point. The opposite is pitting

pill: A jet in the fuel-return line which establishes the mixture

pillar: A shaft or upright member or support holding up the roof. Also called a post. The A-post holds up the windshield. The B-post is behind the front door about in the middle of the side of the roof. The C-post holds up the rear window. In station wagons, another post is placed between the B-post and the last post so that it becomes the C-post and the last post is the D-post. See A-pillar B-pillar C-pillar cabin pillar center pillar D-pillar dogleg pillar dogleg pillar door pillar switch door pillar front pillar hinge pillar reinforcement hinge pillar latching pillar latch pillar lock pillar rear cabin pillar pillared hardtop: See four-door pillared hardtop

pillar jack: See tower jack

pillar light: A courtesy light mounted on the central pillar within the passenger compartment

pillar reinforcement:

See hinge pillar reinforcement

pillars: See roof pillars windshield pillars pillar switch: See door pillar switch

pillion pad: A backrest pad which is mounted behind the seat on a motorcycle.

pilot bearing: A small bearing in the center of the flywheel end of the crankshaft, which carries the forward end of the clutch shaft. The British term is "spigot bearing." See clutch pilot bearing.

pilot hole: When using a large drill bit, it is sometimes hard for the drill to cut through the metal and do it evenly in a straight line. A pilot hole is first made with a small bit. Then, when you use the large bit, the drilling is much easier.

pilot house: The enclosed space on the navigating bridge from which a ship is controlled when under way. See bridge

pilot jet: A jet in the idling circuit of a fixed jet carburetor which measures and admits fuel

pilot operated absolute: See POA suction throttling valve

pilot operated absolute valve: (POA) the POA valve is a suction throttling device used on some GM and Ford air conditioner system.

pilot shaft: A dummy shaft that is placed in a mechanism as a means of aligning the parts. It is then removed and the regular shaft installed.

pilot valve: A small valve used to control action of a larger valve

pin: A small cylinder used for fastening something or as a pivot. See bonnet pin carbon pin cotter pin dowel pin floating piston pin fulcrum pin gudgeon pin boss gudgeon pin circlip gudgeon pin end gudgeon pin hair pin hitch pin hood pin kit hood pins kingpin knuckle pin locating pin lock pin pad retainer pin pawl piston pin piston pin boss piston pin circlip piston pin end pivot pin roll pin shear pin spiral wrapped pin split pin swivel pin tri pin worm and taper pin wrist pin

pin boss: See gudgeon pin boss piston pin boss pinch-off pliers: See hose pinch-off pliers

pin circlip: See gudgeon pin circlip piston pin circlip wrist pin circlip pin end: See gudgeon pin end piston pin end wrist pin end ping: See pinging.

pinging: A metallic rattling sound produced by the engine during heavy acceleration when the ignition timing is too far advanced for the grade of fuel being burned. The noise is caused by vibrations in the cylinder walls, head, and piston. When an engine pings, the normal, controlled even spread of the flame front is disrupted by the spontaneous combustion of pockets of fuel. Their collision sets off the pressure waves that result in the pinging sound. Pinging can be caused by bad timing, inadequate octane rating, incorrect fuel-air mixture, a hot spot in the combustion chamber caused by a glowing piece of carbon, or an overheat condition. Also called "knocking." Also see detonation.

pinhole: See rust pinhole

pinholing: Tiny bubbles in the paint finish that are often grouped together. It is caused by trapped solvents, moisture or air released from the film. Compare solvent pop

pinion: A small, tapered gear which meshes with a larger gear or rack. It is found in two primary places in an automobile: the differential pinion and the rack and pinion steering. See crown wheel and pinion drive pinion inertia pinion planet pinion rack and pinion gearbox rack and pinion ring and pinion pinion carrier: That part of the rear axle assembly that supports and contains the pinion gear shaft.

pinion gear: Pinion Gear: The smaller of two meshing gears. A pinion gear is used in a starter motor to engage the flywheel ring gear and also rides along the surface of the steering rack (a rod with grooves cut in it to mesh with the gear) See rack and pinion gearbox.

pinion gearbox: See rack and pinion gearbox

pinion shaft: A short drive shaft in the rear axle connecting the prop shaft to the crown wheel via the final drive pinion

pinion steering: See rack and pinion steering

pinking: A British term for pinging

pin kit: See

bonnet pin kit hood pin kit pinned piston ring: A steel pin, set into the piston, is placed in the space between the ends of the ring. The ring is thus kept from moving around in the groove.

pinned ring: A steel pin, set into the piston, is placed in the space between the ends of the ring. The ring is thus kept from moving around in the groove.

pinning: Procedure for repairing cracks in the combustion chamber using threaded pins

pin punch: A tool with a parallel shaft for use with a hammer to drive out pins, shafts, rivets, etc. Compare drift punch)

pin slider caliper disc brake: A disc brake design with a sliding caliper. The major components are: caliper (a casting with one cylinder and piston), caliper frame (casting), guide pins, Teflon or rubber sleeves/bushings. The caliper floats on the sleeves over the guide pins. The guide pins are threaded or riveted to the caliper frame. The caliper frame is bolted to the suspension

pin spanner: A wrench with pins on forked ends, used to turn an adjustable cup on a bottom bracket of a bicycle.

pinstripe: A thin, precisely contoured lines along certain body features; they may extend along the whole car and finish off in elaborate, bouquet-like designs. Striping usually refers to simple decorative lines, e.g., on motorcycle tanks, while pinstriping mostly refers to custom work, i.e., more elaborate and sharply curved lines

pinstriping: A thin, precisely contoured lines along certain body features; they may extend along the whole car and finish off in elaborate, bouquet-like designs. Striping usually refers to simple decorative lines, e.g., on motorcycle tanks, while pinstriping mostly

refers to custom work, i.e., more elaborate and sharply curved lines

pinstriping tool: A painting tool used to apply thin, precise lines on the body, e.g., on motorcycle tanks and to enhance car body contours.

pintaux nozzle: A pintle-type diesel fuel injector nozzle with a hole in the side through which a very small amount of fuel is sprayed when the needle valve is partly opened at low pressure, before the main hole comes into use

pintle: [1] The needle of the injection valve in a diesel fuel injector. [2] A vertical bolt or pin in a towing bracket, to which the towbar is attached. [3] The pins or bolts that hinge the rudder to the gudgeons on the rudder post or sternpost

pintle nozzle: An injector nozzle containing the pintle

pin wrench: A wrench with a pin that can be fitted into a hole in a nut to exert extra pressure

PIP: Acronym for profile ignition pickup

pipe: A tube used to transfer liquid or gas. See air pipe balance pipe brake pipe breather pipe chain pipe discharge pipe downpipe exhaust pipe feed pipe flexible brake pipe

front pipe hawse pipe heater air pipe impact pipe induction pipe inlet pipe intake pipe kickup pipe oil breather pipe oil pick-up pipe outlet pipe overaxle pipe overflow pipe pick-up pipe side pipe sounding pipe suction pipe tail pipe twin front pipe Y-pipe pipes: See exhaust system lake pipes lakes pipes pipework: A system of pipes

pipe wrench: An adjustable wrench with serrated jaws. The most common type of pipe wrench is the so-called "Stilison wrench." Also called a "monkey wrench." Also see chain pipe wrench

piping: [1] A system of pipes. [2] A rubber or plastic strip inserted between two removable panels, i.e., between a bolt-on fender and the body, to cover up the joint and to prevent water getting in; with the piping inserted, only the round bead along the upper edge of the piping is visible

pip mark: A little dot or indentation which indicates the top side of compression ring

Piquet, Nelson: A three-time, World Driving Champion from Brazil and is considered one of the alltime great Formula One drivers

piston: A round or cylindrical plug, which closed at one end and open at the other. It slides up and down in the cylinder. It is attached to the connecting rod and when the fuel charge is fired, will transfer the force of the explosion to the connecting rod then to the crankshaft. See accumulator piston alloy piston autothermic piston belted piston brake piston cam-ground piston charging piston collapsed piston damper piston deflector piston flat-topped piston flat-top piston floating piston pin floating piston full-skirt piston light-alloy piston molybdenum piston ring operating piston oval piston oversize piston pent crown piston pinned piston ring primary piston secondary piston slipper piston slotted piston split skirt piston stepped piston piston bore:

The diameter of the hole in the cylinder block in which the piston moves back and forth between top dead center (TDC) and bottom dead center (BDC)

piston boss: The built-up area around the piston pin hole. Also see boss.

piston charging pump: [1] The function of the piston of the two-stroke engine to pre-compress the fresh charge induced into the crankcase. [2] A separate piston used in earlier two-stroke engine designs to provide a supercharging effect

piston collapse: A reduction in the diameter of the piston skirt caused by heat and constant impact stresses. Also see collapsed piston.

piston compressor: A compressor in an air-conditioning system with one or more pistons arranged in either an in-line, axial, radial, or V-configuration

piston crown: The very top of the piston. The piston crown transmits the pressure created during the ignition of the air/fuel mixture to the piston pin, then to the connecting rod, and from there to the crankshaft. The diameter of the piston crown is slightly smaller than the piston skirt. Also called piston dome.

piston damper: A small damper piston in an SU or Stromberg carburetor which reduces the movement of the large air piston in the venturi

piston diaphragm: A flexible membrane which displaces under pressure, imparting movement to the piston in a Stromberg carburetor

piston displacement: Amount (volume) of air displaced by a piston when moved through the full length of its stroke. Also see displacement.

piston dome: The top surface of a piston. It is often shaped for better combustion and to prevent a valve from contacting the surface. Also called piston crown. See piston head.

piston engine: A form of internal combustion engine. It is a heat engine in which the expansion of gas causes (by the explosion or a fuel and air mixture or the introduction of steam) a piston inside a cylinder to move and turn a crank shaft.

piston expansion: Because pistons are usually made of aluminum and the cylinder walls are made of iron, the piston will expand more rapidly than the cylinder when they get hot. Some type of compensation needs to be made for this expansion or the piston will seize in the cylinder. See split skirt T-slot steel strut cam-ground piston piston extension screw: A stroke limiting screw between the primary piston and secondary piston stop

piston head: That portion of the piston above the top ring. See piston dome piston crown piston land: That portion of the piston which is between the ring grooves.

piston lands: That portion of the piston which is between the ring grooves.

piston lifter: A pin in the base of the piston chamber in an SU or Stromberg carburetor, used to check the strength of the mixture and the free movement of the piston

piston material: The materials from which pistons are made are grey cast or light alloys; most light alloys consist of an aluminium-silicon alloy

piston pin: A steel pin that is passed through the piston, it is used as a base upon which to fasten the upper end of the connecting rod. It is round and may be hollow. Also called "wrist pin" or "gudgeon pin." See floating piston pin.

piston pin boss: See piston boss.

piston pin circlip: A circlip which is used on either end of the piston pin to hold the pin in place.

piston pin end: The small end of the connecting rod through which the piston pin is inserted

piston ring: A metal, split ring installed in the groove on the outside wall of the piston. The ring contacts the sides of the ring groove and also rubs against the cylinder wall thus sealing the space between the piston and the wall. Poor rings can cause poor compression and severe blowby. Often seen as blue smoke out the exhaust pipe. See compression ring dykes ring molybdenum piston ring oil control ring pinned piston ring piston ring, chrome: A piston ring which has a thin layer of chrome plate on the outer edge.

piston ring clamp: A special automotive tool used for installing pistons. The clamp is slipped over the piston and when tightened, compresses the piston rings into the piston grooves. With the piston rings compressed, the piston can be installed into the cylinder by light tapping

piston ring, compression: See compression ring.

piston ring end gap: The distance left between the ends of the ring when installed in the cylinder.

piston ring expander: A spring device placed under a piston ring to hold it snugly against the cylinder wall. Also see expander.

piston ring flutter: The oscillations of a piston ring which mainly occur at high engine speed and thus can cause breakage

piston ring gap: See piston ring end gap.

piston ring groove: One of the channels into which the piston rings reside.

piston ring groove cleaner: A special automotive tool to remove carbon and varnishes from piston grooves before installing piston rings

piston ring job: Reconditioning the cylinder and installing new rings.

piston ring, oil control: See oil control ring.

piston ring, pinned: A steel pin, set into the piston, is placed in the space between the ends of the ring. The ring is thus kept from moving around in the groove.

piston ring pliers: A pliers-like special automotive tool used to spread and slip piston rings over a piston for removal and installation

piston ring ridge: That portion of the cylinder above the top limit of ring travel. In a worn cylinder, this area is of a smaller diameter than the remainder of the cylinder and will leave a ledge or ridge that must be removed.

piston ring side clearance: The space between the sides of the ring and the ring lands.

piston ring stop: A pin pressed into the ring grooves of a two-stroke engine in order to prevent the rings from rotating, which would allow the open ends to become jammed in the ports

piston rocking: See piston slap

piston rod: A shock absorber rod which operates the piston in a telescopic damper

piston seal: A fluid seal on a disc brake caliper piston

piston seizure: A sudden stalling of the engine, caused by the piston becoming stuck in the bore; this is often caused by overheating or lack of lubrication and often leaves severe score marks in the cylinders and on the skirt of the piston.

piston skirt: That portion of the piston below the rings and bosses. (Some engines have an oil ring in the skirt area.).

piston skirt expander: A spring device placed inside the piston skirt to produce an outward pressure which increases the diameter of the skirt.

piston skirt expanding:

Enlarging the diameter of the piston skirt by inserting an expander, by knurling the outer skirt surface, or by peening the inside of the piston.

piston slap: The condition caused by too much clearance between the piston and the cylinder walls. The piston rattles or slaps against the wall of the cylinder. It makes a hollow, muffled, bell-like sound.

piston speed: The speed of the piston for a given engine rpm

piston spring: A coil spring in an SU carburetor which counteracts the upward movement of the piston

piston thrust: The pushing action of the piston which occurs at the sides of the piston 90° away from the piston pin as it pushes against the cylinder wall.

piston top: See piston crown

piston-type compressor: A compressor in an air-conditioning system with one or more pistons arranged in either an in-line, axial, radial, or V-configuration

piston-valve engine: A two-stroke engine that relies on the ports in the cylinder walls to control admission and exhaust of the air/fuel mixture; it is not equipped with other control elements such as rotary valves

pit: [1] Area at a race track for fuelling, tire changing, making mechanical repairs, etc. [2] Small craters in the surface of metal. See cockpit inspection pit

pitch: [1] The back and forth rocking motion of a vehicle which compresses the front springs and extends the rear springs so that the nose of the vehicle is down while the tail is up. Then the action reverses so that the nose is up and the tail is down (i.e., dive and squat). [2] The distance between two threads on a bolt or screw. [3] The distance between a point on one gear tooth and the same point on the next gear tooth. [4] The quality of sound with respect to the frequency of vibration of the sound waves. [5] The angle at which something is tilted. See variable pitch stator. [6] In Britain, a parking space or site for a trailer, camper, etc. See coarse pitch height hamper pitch control thread pitch pitch circle: (PC) the circumference on which the centers of the wheel bolt holes are located

pitch circle diameter: (PCD) The diameter of the stud holes/bolt holes for fixing the wheel to the hub. The pitch circle (PC) is usually shown as a double number, e.g., 5-5.5. The first number indicates the number of holes, and the second, the diameter of the PC

pitch control: See height hamper pitch control

pitch diameter: On a straight thread the diameter of the coaxial cylinder the surface of which would pass through the thread profiles at such points as to make the width of the groove equal to one-half of the basic pitch. Approximately half way between the major and minor diameters.

pitch gauge: See screw pitch gauge thread pitch gauge pitch stator:

See variable pitch stator

pitman arm: A short lever arm splined to the steering gear cross shaft, the pitman arm transmits the steering force from the cross shaft to the steering linkage system. In this way rotary motion of the steering wheel is turned to lateral movement of the arm. The British term is "drop arm." Also see idler arm.

pitman shaft: See rocker shaft

pitot tube: A tube for measuring the pressure and velocity of a fluid flow; in some CVTs, used in conjunction with a valve arrangement to control ratio changes

pit road: The paved roadway that leads into the pit area from the racetrack.

pits: [1] Area at a race track for fuelling, tire changing, making mechanical repairs, etc. [2] Cavities extending from the surface into the metal as a result of pitting corrosion. Also see shallow pits

pit stop: [1] A stop at the pits by racer, for fuel, tires, repairs, etc. [2] Colloquial term for going to the toilet.

pitted: Eroded contact breaker points

pitting: Surface damage to a metal in the form of pits or holes. The opposite is piling

pitting corrosion: A corrosion process resulting in pits

pitting factor:

The ratio of the depth of the deepest pit to the average penetration as calculated from weight loss

pivot: A pin or shaft about which a part moves. The place at which a lever swivels. A lever cannot work without a pivot. Also see low pivot swing axle

pivot axis: See swivel axis

pivot bolt: A bolt on which the arms of caliper brakes pivot and which also serves as the means for mounting the brakes on the bike frame. Also called "mounting bolt."

pivot pin: See kingpin

pivot ring: See fulcrum ring

pivot swing axle: See low pivot swing axle

PL: Acronym for parking lock

PL&PD: Acronym for "Public Liability and Property Damage" as a form of basic car insurance

plain bearing: A cylindrical sleeve friction bearing; most commonly used type of bearing. See ball bearing needle bearing roller bearing

plain disc wheel: A type of wheel without holes or slots in the wheel disc

plain gage tubing: See plain gauge tubing.

plain gauge tubing: Tubing whose thickness remains constant over its entire length.

plan: See body plan capacity plan lines, plan plane: A flat surface. See inclined plane.

plane sailing: A method of navigation which ignores the earth's curvature, treating its surface as a plane. Colloquially it indicates travel or procedure without difficulty or obstruction.

planetary gear: A gear used in some starters as an intermediate transmission

planetary gear differential: A planetary gear set used as a differential with asymmetric torque distribution, as used in 4WD vehicles

planetary gears: See planetary gearset.

planetary gearset: A gearing unit consisting of a ring gear with internal teeth, a sun or central pinion gear with external teeth, and a series of planet gears that mesh with both the ring and the sun gear. Frequently used in overdrives and automatic transmission. Also called epicyclic gearbox.

planetary gear set: A central externally toothed sun gear, an internally toothed outer ring gear, and several intermediate planet gears which are evenly spaced and supported by a planet carrier; they are in constant mesh with the sun gear and the internal gear

planetary transmission: A form of gear used by Benz in which small pinions revolve around a central or sun gear and mesh with an outer ring gear called the annulus. Type used in the Ford Model T. Also called epicyclic gearbox and "sun-and-planet gears."

planet carrier: That part of a planetary gearset upon which the planet gears are affixed. The planet gears are free to turn on hardened pins set into the carrier. The planet carrier revolves around the central axis of a planetary gear set and supports the planet gears

planet gear: See planet gears stepped planet gear sun and planet gears planet gears: Those gears in a planetary gearset that are in mesh with both the ring and the sun gear. They are referred to as planet gears in that they orbit or move around the central or sun gear. See stepped planet gear sun and planet gears planetary gear set: See ravigneaux planetary gear set simpson planetary gear set planetary set: See ravigneaux planetary gear set

planet pinion:

See planet gear

planets: See twin planets

planet spider: A common type of planet carrier with a spider or web-style design

planet wheel: See planet gear

planishing: The final panel hammering stage for lifting out minor imperfections in a panel surface. Part of the panel finishing process

planishing hammer: A panel beater's hammer

plan lines: the plans that show the shape or form of the ship

planned obsolescence: A policy of manufacturers that encourages motorists to become dissatisfied with their cars so that they are eager to buy the latest model.

planning: See product planning

plant: See pressing plant

plaque: See dashboard plaque

plasma:

Temporary physical condition of a gas after it has been exposed to and has reacted to an electric arc.

plasma arc cutters: Cutting equipment that makes clean, fast cuts without destroying the properties of high-strength steels

plasma spray process: The process in which a very high temperature flame is produced by blowing gas through an electric arc. Metal wire or powder is melted by passage through the flame and is projected on the surface to be coated

plastic: A material that contains as an essential ingredient one or more organic polymeric substances of large molecular weight. It is solid in its finished state and, at some stage in its manufacture or processing into finished articles, can be shaped by flow. See glass reinforced plastic hydrocarbon plastics plastic deformation: A permanent change in the shape or size of a solid body without fracture resulting from the application of sustained stress beyond the elastic limit

plastic engine: An automobile engine whose bulk is made of plastic components (e.g., engine block, inlet manifold, water-pump housing, valve covers, oil pan), the use of metal being limited to parts subjected to extreme mechanical or thermal loads (e.g., combustion chamber, exhaust manifold, pistons, cylinder liners, valve train, etc.)

plastic filler: See polyester filler

plasticize: To soften a material to make it plastic or moldable by heating, kneading, or adding a plasticizer

plasticizer:

An additive that gives flexibility to an otherwise rigid plastic

plastic molding: a process that converts organic-based materials, by means of a general-purpose press and purpose-built tooling under controlled heat and pressure, and injects the hot material into a die cavity shaped in the final form of the intended part.

plastics welding: A uniting of thermoplastic, i.e., non-setting plastics of similar or different type using heat and pressure and with or without the addition of plastic of a similar kind (filler material). The welding proceeds within the temperature range of thermoplasticity of the contact surfaces on the parts to be welded; the freely mobile molecular chains in the marginal areas flow together and become interlaced

Plastigage: A soft plastic that flattens out to predetermined widths when subjected to torque; these widths equal a specific clearance. It is normally used to check main and rodbearing clearance. It is sold in a paper sleeve that also doubles as the scale on which it is measured (in thousandths of an inch)

plate: [1] The action of coating a material with some metal. Also called "electroplate" or anodize. [2] A flat piece of material. [3] Two lead-alloy plates in each cell where the positive plate is made of lead peroxide and the negative plate is made of spongy lead. Separators are placed between the plates of different polarity. [4] Clutch discs See adapter plate backing plate baffle plate blanking plate brake backing plate breaker plate center drive plate chafing plate clutch plate clutch pressure plate contact breaker plate driven plate drive plate

end cover plate flitch plate friction plate governor plate gusset plate heel plate hinge plate hinge tapping plate hub plate intel-plate intermediate drive plate intermediate plate keel, flat plate license plate frame license plate nave plate negative plate positive plate pressure plate rear license plate lamp rear license plate light registration plate restrictor plate retainer plate scuff plate sensor plate skid plate spacer plate step plate stopper plate striker plate swash plate tapping plate thrust plate torque converter drive plate transfer plate valve body separator plate valve plate vanity plate wobble plate plated: See armor-plated cadmium-plated

chrome-plated chromium-plated plate frame: See license plate frame

plate grid: See grid

plate group: An assembly of plates of identical polarity (positive or negative) used in a battery cell

plate keel: See flat plate keel

plate lamp: See rear license plate lamp

plate light: See rear license plate light

plates: [1] Thin sections of lead peroxide or porous lead in a battery. There are two kinds of plates -- positive and negative. The plates are arranged in groups, in an alternate fashion, called "elements," they are completely submerged in the electrolyte. [2] Any basically flat surface often used to mount another device. See baffle plate brake backing plate breaker plate clutch pressure plate plate strap: The conducting connection between the lugs of battery plates of like polarity and the cell terminal

plate support:

The support at the bottom of a battery case on which the elements rest. It provides space for the sediment chamber

platform: primary load-bearing structural assembly of a motor vehicle determining the basic size of the motor vehicle, and is the structural base that supports the driveline and links the suspension components of the motor vehicle. Also see lifting platform take-up point

platform frame: The underbody construction consisting of a reinforced and fairly flat section that forms the entire lower portion of a vehicle. It includes the floorpans and is bolted to the body; (e.g., Volkswagen Beetle)

platform take-up point: See lifting platform take-up point

plating: The coating of metal usually by electrolysis. See black chromium plating chromium plating copper plating gold plating hard chromium plating mechanical plating nickel plating shell plating silver-plating zinc plating platinum: A precious light-grey, heavy, ductile, noble metal, atomic number 78, atomic weight 195.09; melting point at 1769°C. It is the main member of the so-called platinum metals. Together with other platinum metals, it is used as a catalyst in automotive exhaust converters. It is used in the construction of breaker points. It conducts electricity well and is highly resistant to burning.

platinum electrode: A spark plug electrode made of platinum which lasts longer than one of nickel alloy because it can better withstand high temperatures

platinum metals: A generic term for a family of noble metals found with and resembling platinum. It includes ruthenium, rhodium, palladium, osmium, iridium, and platinum. They are used as catalysts in catalytic converters. Less than a tenth of a troy ounce is required per converter to produce acres of catalytically active catalyst surface

platinum spark plug: A spark plug with a platinum center electrode

play: Movement between two parts. See camshaft end play end play free pedal play free play pedal free play radial play player: See cassette player CD player plenum: [1] A chamber, located between the throttle body and the runners of an intake manifold, used to distribute the intake charge evenly and to enhance engine breathing. [2] An enclosure containing air or gas at a higher pressure than exists outside. Also see intake plenum

plenum chamber: [1] A large cast alloy body in an induction system which connects the throttle body or inlet tube to the cylinder head(s) or inlet manifold. [2] The air compartment in a car body formed between the scuttle and the bulkhead, providing a basis for the interior air supply

plexiglas:

A trade name for an acrylic plastic, made by the Rhom and Haas Co.

plexiglass: See plexiglas.

pliers: A gripping tool with two hinged arms and serrated jaws. See action locking pliers angle-nose pliers bending pliers circlip pliers clamp pliers clip pliers combination pliers crimping pliers end cutting pliers eyelet pliers flat-nosed pliers flat-nose pliers general purpose pliers half-moon slip joint pliers heavy-duty diagonal cutting pliers heavy-duty end cutting pliers high leverage diagonal cutting pliers high leverage end cutting pliers hose clamp pliers hose clip pliers hose pinch-off pliers internal circlip pliers locking pliers lock ring pliers long-nose pliers long-nose self-grip pliers multigrip pliers needle-nose pliers parallel action locking pliers piston ring pliers radiator hose shark tooth pliers shim pliers snipe-nose pliers spark plug pliers thin needle-nose pliers valve shim pliers

valve stem seal pliers plies: See ply stabilizing plies tire plies PLL circuitry: A phase-locked loop circuitry in a radio which "locks" the station frequencies to ensure utmost frequency stability

plug: A removable "cork" or stopper which fills a hole. See blanking plug coil glow plug cold plug core hole plug core plugs drain plug drain plug key drain plug spanner drain plug wrench expansion plug fill plug flame glow plug freeze plug glow plug glow plug indicator glow plug starter switch heater plug hot plug hot spark plug level plug magnetic drain plug magnetic plug oil drain plug oil pan drain plug open coil glow plug open element glow plug pencil-type glow plug platinum spark plug

radiator drain plug resistor spark plug RFI suppressed spark plugs rubber plug self-regulating sheathed-type glow plug sheathed-type glow plug sooted plug sooty plug spark plug spiral-type glow plug split electrode spark plug SR sheathed glow plug sump drain plug sump plug surface discharge plug surface gap spark plug welch plug wire glow plug [2] A spark plug. [3] A male electrical connector. [4] To seal with a stopper

plug body: See spark plug body

plug boot: See spark plug boot

plug boot puller: See spark plug boot puller

plug brush: See spark plug brush

plug cable: See spark plug cable

plug cable cover strip: See spark plug cable cover strip

plug cable loom: See spark plug cable loom

plug cable marker: See spark plug cable marker

plug cable separator: See spark plug cable separator

plug caddy: A special box which can hold spare spark plugs and is especially used by snowmobilers.

plug cap: The device on the end of the high tension wire coming from the coil and mounted on the spark plug. Also called spark plug cap

plug condition: See spark plug condition

plug electrode: See spark plug electrode

plug gap: See spark plug gap.

plug gapping: Adjusting the side electrode on a spark plug to provide the proper air gap between it and the center electrode.

plug gauge: See spark plug gauge

plug ignition: See twin plug ignition

plug-in diagnosis: On-board computer provides means for special test equipment to be plugged in for making a series of programmed tests to check condition of various units and systems on the vehicle

plug indicator: See glow plug indicator

plug insert tap: See spark plug insert tap

plug insulator: See spark plug insulator

plughole: The hole in a tank or cistern, which can be closed with a rubber plug

plug key: See drain plug key

plug lead: See spark plug lead

plug patch: A tire repair material which is forced into a nail hole to fill it. The plug is attached at one end to a patch that seals the hole and then expands to fill the hole. Although a common procedure, it is not the most satisfactory method of repair

plug pliers: See spark plug pliers

plug repair: The filling of a nail hole by forcing repair material into the damaged area, often while the tire is mounted and containing air. It is not a satisfactory method of repair.

plug shell:

See spark plug shell

plug socket: See spark plug socket

plug spanner: See drain plug spanner spark plug spanner plug starter switch: See glow plug starter switch

plug tester: See spark plug tester

plug weld: A weld which holds two pieces of metal together and made in a hole in one of metal which is lapped over the other pieces. Also called "rosette weld."

plug welding: A number of holes are punched along the edge of the repair section to be welded in; the section overlaps the damaged area to be repaired and is welded to the base metal at the punched boles. This is a convenient way of duplicating the spot welding process used by manufacturers, as spot welding equipment is usually too expensive and cumbersome for repair purposes

plug whiskering: See gap bridging spark plug whiskering plug wire: See spark plug wire

plug wire cover strip:

See spark plug wire cover strip

plug wire loom: See spark plug wire loom

plug wire marker: See spark plug wire marker

plug wire separator: See spark plug wire separator

plug wrench: See drain plug wrench spark plug wrench plunger: [1] Any immersing type of piston. [2] A hydraulic tappet component (e.g., in a valve). [3] An actuating element in an ignition lock. [4] A piston in a starter solenoid. Also see control plunger

plunger principle: A new ABS control system which offers improved pressure modulation with very small amplitudes even at pressures close to zero. Compare valve principle

plunger pump: An oil pump consisting of a reciprocating plunger in a ported chamber

plunger suspension: A suspension system in which the vertical movement of the axle is controlled by springs mounted above and below the axle.

plunging joint: A slip joint which is a connection in the drive train, of variable length, which permits the drive shaft to change in effective length. The British term is "sliding joint"

ply: A layer of rubber-coated parallel cords which forms a unit of a tire carcass. The plies are made of cord, fiberglass, steel, or structural fabric. See bias tire conventional cross ply radial ply tire plies tire ply Plymouth: A vehicle brand of which the Fury for 1956-58 are milestone cars. The Satellite SS and GTX for 1965-70 are milestone cars. The Barracuda Formula S for 1965-69 are milestone cars. The Roadrunner and Superbird for 1968-70 are milestone cars.

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ply rating: (PR) An indication of tire strength and load carrying capacity. It does not necessarily indicate actual number of plies. A two-ply four-ply rating tire would have the load capacity of a four-ply tire of the same size but would have only two actual plies. This system of measurement has been replaced by the term "load range."

ply separation: A breakdown of the bonding compounds resulting in the plies detaching from each other. Usually as a result of excessive heat.

ply tire: See bias ply tire

ply turnup: The extension of a carcass ply to its end after wrapping around the bead. Also called "flipper strip"

PM: See particulate matter

PM trap:

A diesel particulate filter

PMMA: See polymethyl methacrylate

p/n: Abbreviation for part number

PN: Acronym for part number

pneumatic suspension: See air suspension.

pneumatic tire: A flexible, hollow rubber forming the outer part of the vehicle wheel and inflated by air pressure. Originally rubber tires were solid core. Dunlop was the first to invent a tire with an air-filled tube for bicycles. Later, tubeless tires were invented. The tire is filled with enough compressed air to support the weight of the vehicle and cushion road impacts. The opposite is solid tire

pneumatic trail: The distance between a vertical line through the center of the wheel and the center of pressure of the tire contact patch; most apparent during cornering. See selfaligning torque.

pneumatics: The study of pressure and flow in gases. A pneumatic drill is operated by compressed air; a pneumatic tire contains compressed air.

PNGV: Acronym for "Partnership for a New Generation of Vehicles."

PNP: Three element transistor made of two layers of semi-conductor materials

POA:

Acronym for pilot operated absolute valve used in some air conditioning systems

POA suction throttling valve: A term standing for "pilot operated absolute" and is a modification of a suction throttling valve which has a metal bellows with a vacuum instead of a diaphragm; it provides more accurate evaporator pressure control, allowing for lower evaporator temperatures without cone icing

pocket: See door pocket still-air pocket gas pockets pocket caliper: A small slide-type caliper for inside and outside measurement up to about 100 mm or 4 inches

pocket slide caliper: A small slide-type caliper for inside and outside measurement up to about 100 mm or 4 inches

pod: A housing for a gauge mounted on the dash. See induction pod sidelight pod pod filter: A foam filter which is like a sock (open at one end and closed at the other) and is clamped on the horn of a carburetor

point: See bead point boiling point breaker point breaker points brittle point

charging point check point cloud point contact breaker point contact point contact points coupling point dew point dry boiling point dual breaker points fire point flash point ignition point file ignition point ignition points jacking point lifting platform take-up point lubrication point point gap points pour point shift point vacuum runout point wet boiling point point file: See ignition point file

point gap: The space between the contact points when they are fully open. The distance of the gap will determine the effectiveness of the points.

point gauge: See sighting point gauge

point injection: See single point injection

points: See boiling point

breaker points contact breaker points contact points dual breaker points ignition points point points file: A thin, fine-toothed file for cleaning and smoothing off the piles on contact breaker points

points gap: A gap between the contact breaker points when fully open; measured with a feeler gauge

point steering: See center point steering

poke: A colloquial term for power or acceleration

polarity: [1] Indicates if the pole shoes are so magnetized as to make current low in a direction compatible with the direction of flow as set by the battery. [2] Indicates if the end of a magnet is the North or South pole (N or S). [3] Indicates if the battery terminal (either one) is positive or negative (plus or minus) (+ or -). See direct polarity reversed polarity straight polarity polarization resistance: The transition resistance between the electrodes and the electrolyte; part of the internal resistance of a battery. Compare internal resistance

polarizing: The process of sending a quick surge of current through the field windings of the generator in a direction that will cause the pole shoes to assume the correct polarity. This will insure that the generator will cause current to flow in the same direction as

normal.

polar moment of inertia: The resistance of an object to rotational acceleration. When the mass of an object is distributed far from its axis of rotation, the object is said to have a high polar moment of inertia. When the mass distribution is close to the axis of rotation, it has a low polar moment of inertia. A mid-engined car has most of its mass within its wheelbase, contributing to a low polar moment of inertia, which, in turn, improves cornering turn-in. See moment of inertia.

pole: [1] One end, either North or South, of a magnet. See negative pole north pole positive pole south pole [2] A post or long shaft. [3] The best starting position in an auto race. It is the inside space on the first row of drivers. Most races begin with the cars in a formation of rows of two. Most events begin with a standing start or a rolling start.

pole piece: A soft magnetic core of the inductive winding in a magnetic pick-up assembly; stator

pole position: The best starting position in an auto race. It is the inside space on the first row of drivers. Most races begin with the cars in a formation of rows of two. Most events begin with a standing start or a rolling start.

pole shoe: See pole shoes.

pole shoes: Metal pieces about which the field coil windings are placed, when current passes through the windings, the pole shoes become powerful magnets, example: Pole shoes in a generator or starter motor.

polish: [1] A substance like wax used to make the exterior paint shine or gloss. See automobile polish car polish [2] The act of making the paint shine. [3] To remove the minor obstructions in the exhaust flow. A term sometimes coupled with porting, as in porting and polishing or "port and polish." This is generally a process of blueprinting a two-stroke engine so that the intake and exhaust ports are polished and have no obstructions in the flow of fuel-air mixture or exhaust gases. In this way the engine generally has more performance. A problem may arise when an individual port has been polished too much. Also see ground and polish

polishing: See chemical brightening chemical polishing polishing barrel: A barrel used for a polishing process in which the aluminum surface is smoothed in the presence of metallic or ceramic shot by a rotating movement of the barrel

pollutant: Hydrocarbons, carbon monoxide, and nitrogen oxides. See exhaust emissions exhaust pollutants pollution: See air pollution.

polycarbonate: (PC) A polyester polymer in which the repeating structural unit in the chain is of the carbonate type; used for bumpers, body and roof panels

polyellipsoidal: A curve which is an ellipse in every direction so that the light of the bulb which is positioned at the focal point will bounce into the same forward direction.

polyellipsoidal headlight: A headlight with a gas discharge lamp and a polyellipsoidal reflector

polyester: A synthetic fiber.

polyester filler: A body repair material for smoothing dents in body panels; includes a resin base filler paste and a catalyst which is added to the base filler and hardens by chemical reaction

polyester powder: A powder used for electrostatic powder coating

polyethylene: (PE) A polymer prepared by the polymerization of ethylene as the sole monomer; very resistant to chemical attack. High-density polyethylene (HDPE) is used, e.g., for blow-molded parts such as tanks for fuel, coolant, washer and brake fluid; lowdensity polyethylene (LDPE) is used for plastic film and sheet

poly-glycotes: See glycote.

polymer: A material consisting of large units (molecules) made by joining many smaller building blocks (simple molecules). Usually used to describe synthetic rubber.

polymer alloy: A mixture of two or more different compatible polymers

polymer coating: A coating that prevents paint from oxidizing and so protects a vehicle from premature fading and rusting. Professionally applied, it will last up to three years.

polymerization:

The bonding of two or more monomers (by chemical reaction) to produce a polymer. Plastic parts produced from specific polymer alloys usually give better performance in respect to thermal and mechanical properties as compared to those of parts consisting of the respective individual components

polymethyl methacrylate: (PMMA) A thermoplastic polymer derived from methylacrylate; transparent solid with excellent optical qualities and weather resistance; typical automotive applications are the lenses of rear lights. Also called Perspex

polyphenylene oxide: (PPO) The characteristics of this plastic are high impact strength, good thermal and dimensional stability as well as excellent flame-resistance

polypropylene: (PP) An extremely versatile plastic, available in many grades and also as a copolymer (ethylene/propylene). PP has the lowest density of all thermoplastics (900 kg per cubic meter) and is characterized by excellent strength, stiffness, fatigue, and chemical resistance

polytetrafluoroethylene: (PTFE) The major advantages of this material are its excellent chemical resistance and its extremely low coefficient of friction; automotive uses are parts where these characteristics are relevant, such as in valve stem seals, friction bearings, and joints

polyurethane: (PUR) A thermoplastic material with high strength, good chemical and abrasion resistance; used mainly for foamed reaction injection moldings and for adhesives, such as for flush-bonded body glass

polyurethane paint: A type of two-pack paint based on polyurethane substances

polyurethane powder: A powder used for electrostatic powder coating

poly-V-belt: A drive belt with multiple Vs; flat, similar to the toothed belts used as timing belts, but with lengthwise V-shaped ribs rather than transverse cogs; used increasingly on

new engines instead of conventional V-belts

polyvinyl chloride: (PVC) Both plasticized and unplasticized PVC types are marked by good weathering resistance, excellent electrical insulation properties, and good surface properties; they are self-extinguishing

poop: A superstructure fitted at the after end of the upper deck of a ship

Pontiac: A vehicle brand of which the Safari for 1955-57 are milestone cars. The GTO for 1964-69 are milestone cars.

Pontiac Fiero: A model of automobile manufactured by Pontiac division of General Motors

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Pontiac Firebird: A model of automobile manufactured by Pontiac division of Click for books on General Motors Firebird Pontiac Grand Am: A model of automobile manufactured by Pontiac division of General Motors

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Pontiac Grand Prix: A model of automobile manufactured by Pontiac division of General Motors

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Pontiac GTO: A model of automobile manufactured by Pontiac division Click for books on of General Motors Pontiac GTO Pontiac Le Mans: A model of automobile manufactured by Pontiac division of General Motors

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Le Mans Pontiac Sunbird: A model of automobile manufactured by Pontiac division of General Motors

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Pontiac Tempest: A model of automobile manufactured by Pontiac division of General Motors

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Pontiac Trans Am: A model of automobile manufactured by Pontiac division of General Motors

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pony car: Small, sporty car along the lines of the Mustang, Firebird, Camaro, etc.

poor opacity: A paint fault in which the color of underlying coats or fillers remains visible through the topcoat; may be caused by insufficient paint thickness, overthinning, etc.

pop: See solvent pop

pop-off valve: A one-way valve that opens to the atmosphere above a certain set pressure to relieve excessive internal pressure buildup; often used with a turbocharger installation to limit boost pressure to the engine.

popper: See snap fastener

poppet valve: A valve structure consisting of a circular head with an elongated stem attached in the center, very much like the shape of a mushroom with a flat top. It is designed to open and close a circular hole or port. Its name comes from the fact that it pops up and down. In engines, it is the valve used to open and close the valve port entrances

to the engine cylinders.

popping: See solvent pop

popping back: See blowback

pop rivet: A type of tubular rivet which initially has a hard steel pin (like a nail) passing through it; when the pop rivet is fitted with a pop rivet gun, the head of the pin expands the inner end of the tubular rivet, closing it; the head of the pin then snaps off; used when a joint can be accessed from only one side

pop tester: An injector testing tool used for measuring opening pressure, leakoff pressure, and spray patterns of injectors

populaire: A randonneur bicycle event under the regulations and pace of a standard brevet which is less than 200 kilometers.

pop-up: A towable tent that pops up when parked to expand its space. These types have a furnace, three way refrigerator, a/c, and more options.

pop-up headlights: See concealed headlights

porcelain: The material used to insulate the center electrode of a spark plug, it is hard and resistant to damage by heat.

porcelain enamel: A glassy material obtained by melting a mixture of inorganic materials; this can then be applied in one or more layers on a metal surface to which it is firmly bonded after firing; typical automotive applications are for badges and trim. The British term is "vitreous enamel"

pore: A small opening in a surface

porosity: Presence of gas pockets or voids in the metal.

porous: permeable to air or fluids

Porsche: A vehicle brand of which the Series 356 for 1949-64 are milestone cars. The 356C for 1965 is a milestone car.

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Porsche-type synchromesh: A sophisticated synchromesh technology depending on the frictional forces created by a spreading synchronizer ring

port: [1] An opening in an engine cylinder block for exhaust and intake valves and water connections. See adjustable variable exhaust port cargo port compensating port exhaust port freeing port inlet port intake port metering port replenishing port third scavenging port transfer port valve port variable exhaust port vent port [2] To smooth out, align, and somewhat enlarge the intake passageway to the valves or intake chambers (especially in two-stroke engines). [3] A small hole in the master brake cylinder to permit fluid to return to the reservoir. See compensating port.

[4] The left-hand side of a ship when facing forward.

port area: The cross-section area of the port of a two-stroke engine; this value is one of the factors determining the gas flow and the power of a two-stroke engine

port bar: If the ports of the two-stroke engine have to be exceptionally wide, as in the case of the exhaust, a port bar is sometimes formed vertically across the port to give support to the rings, which might otherwise expand into the port and be jammed and broken

port bridge: If the ports of the two-stroke engine have to be exceptionally wide, as in the case of the exhaust, a port bar is sometimes formed vertically across the port to give support to the rings, which might otherwise expand into the port and be jammed and broken

port cover: See transfer port cover

ported EGR valve: Operated by a vacuum signal from the carburetor EGR port. The port signal actuates the valve diaphragm. As vacuum increases, spring pressure is overcome, opening the valve and allowing EGR flow. The amount of the flow is dependent on the position of the tapered pintle or poppet whose position reflects the strength of the vacuum signal

ported vacuum: A slot-type port located right at the throttle plates, used for controlling various devices that must work in proportion to throttle plate opening, such as the EGR valve. When the throttle plates are closed at idle, there is virtually no vacuum signal at this slop. But as the throttle plates open during acceleration, they expose the slot to a progressively increasing amount of intake manifold vacuum

ported vacuum advance: (PVA) A series of restriction devices between the distributor advance unit and the carburetor advance port to ensure that there is no vacuum advance during idle, but increasing ignition advance as the throttle opens

ported vacuum switch:

(PVS) a temperature actuated switch that changes vacuum connections when the coolant temperature changes (originally used to switch spark port vacuum; now used for any vacuum switching function that requires coolant temperature sensing)

port fuel injection: (PFI) A type of fuel injection with at least one injector mounted in the intake port(s) of each cylinder. Usually the injector is mounted on the air intake manifold close to the port. Port fuel injection improves fuel distribution and allows greater flexibility in intake-manifold design, which can contribute to improved engine breathing. Also called multi-point injection

porthole: A styling accessory popularized by the Buicks of the early 1950s where two or three round chrome surrounds were fitted to the sides of both fenders for decorative purposes; this trim detail was soon imitated by other manufacturers and was offered as an option for many models, even in Europe. The T-bird had a porthole window on each the rear sail panels.

port induction: See third port induction

port timing: In 2-stroke engines the critical moment when ports are covered or uncovered by the piston

pos: Abbreviation for "positive ground."

position: See driving position flat position welding flat position horizontal position overhead position pole position projected spark position recessed spark position spark position vertical position

position sensor: See crankshaft position sensor throttle position sensor position welding: See flat position welding

Positioning Satellite: See global Positioning Satellite

positive camber: See camber.

positive caster: When an imaginary line extending through the steering axis cuts the wheel axis ahead of the extended vertical axis through the wheel center. See caster.

positive clutch: See dog clutch

positive connections: Connections in an electric circuit out of which electricity constantly flows. The positive connections out of which electricity flows may also be termed that into which electrons flow; and the negative connection into which electrons flow; and the negative connection into which the electricity flows may be considered that pole out of which the electrons flow.

positive crankcase ventilation: (PCV) A process introduced in 1963 for preventing the buildup of harmful acidproducing combustion gases within the crankcase. See closed crankcase ventilation.

positive crankcase ventilation system: (PCV) A process for preventing the buildup of harmful acid-producing combustion gases within the crankcase. See closed crankcase ventilation.

positive crankcase ventilation valve:

(PCVV) a one-way valve which controls the flow of vapors from the crankcase into the engine

positive displacement compressor: A pump which provides a measured amount of gas or liquid per stroke or cycle and requires some form of mechanical drive arrangement, usually a belt drive from the crankshaft; typical positive displacement compressors are piston compressors, roots compressors and vane-type compressors

positive electrode: The positive plate of a battery

positive ground: An automotive electrical system where the negative post of the battery was the hot wire and the positive post was connected to the frame of the vehicle. Opposite to negative ground.

positive offset: [1] A steering geometry layout where the steering axis cuts the wheel axis at or below the wheel center plane. [2] The distance between the mounting face of a disc and the wheel centerline; the offset is referred to as positive when the inner attachment face of the wheel disc is shifted towards the outer side of the wheel. The opposite is negative offset

positive plate: The chocolate-colored plate during battery discharge which acts as cathode. The opposite to negative plate

positive pole: The point away from which an electrical current flows through the circuit. It is designated by a plus sign (+).

positive temperature coefficient: (PTC) a thermistor (temperature sensor) whose resistance increases as the temperature increase. The opposite of a negative temperature coefficient (NTC) thermistor

positive terminal:

The terminal (such as that on the battery), to which the current flows. It is usually marked with the letters "pos" or a plus sign (+) and is usually red.

post: [1] The round, tapered lead posts protruding above the top of the battery to which the battery cables are attached. See terminal. [2] The pillars which support the roof on a car. See A-post B-post battery post C-post D-post door post hardtop hinge post pulling post terminal post [3] The insert tube to which the seat of a bicycle is attached. See seatpost.

postheating: [1] Temperature to which a metal is heated after an operation has been performed on the metal (welding, cutting, forming, etc.). [2] The heating of glow plugs after the engine is started to prevent blue smoke and misfiring during the warm-up phase

post-ignition: The ignition of the air-fuel mixture after the electrical ignition has been shut off

pot: [1] A colloquial term for "carburetor." [2] An abbreviation for a "potentiometer." [3] A cylinder. [4] A dashpot. Also see mush pot

pothole: A deep hole in the surface of a road.

pot joint:

A universal joint in which the rollers or balls can move freely in an internally grooved cylinder. See constant velocity joint slip joint pot metal: An alloy that is cast as a unit. It is relatively inexpensive to make, but is easily subject to breakage.

potential: An indication of the amount of available energy.

potential energy: The mechanical energy possessed by a body due to its position. For example, water in a reservoir above a hydro-electric power station has high potential energy which is converted to work when it drives the turbines of the power station.

pound: See foot-pound

pound foot: The unit of measurement for torque. One pound-foot is equal to the twisting force produced when a one-pound force is applied to the end of a one-foot-long lever.

pour point: The lowest temperature at which oil will pour, a test of its ability to flow and lubricate in cold weather.

powder: See electrostatic powder coating polyester powder polyurethane powder powder coating: See electrostatic powder coating

powder slush molding: A processing technique applied to produce PVC skins. In a preheated rotating mold, a thin layer of PVC dry blend is evenly spread across the mold surface. The mold is transferred to an oven to fuse the PVC skin and is finally cooled in a water-bath

power: [1] The rate of doing work. It is expressed in mass times distance over a period of time. See candle power constant power distribution equal power distribution equal power split fifty-fifty power split four-stroke power cycle horsepower hydro-electric power in-line power steering integral-type power assisted steering integral-type power steering linkage power steering load-controlled power distribution maximum brake power maximum power peak power propelling power propulsive power pump power output rated power [2] To provide power to something.

power antenna: (PA) or (P.Ant) A radio antenna which automatically moves up and down whenever the radio is turned on or off. It is a telescoping antenna driven by an electric motor. See antenna.

power assisted brake: See power brakes.

power assisted brakes:

See power brakes.

power-assisted steering: (pas) A steering system in which a hydraulic pump powered by the engine helps the driver to turn the steering wheel. Compare power steering. Also see integral-type power assisted steering

power band: The subjectively defined rpm range over which an engine delivers a substantial fraction of its peak power. The power band usually extends from slightly below the engine's torque peak to slightly above its power peak.

power booster: A device that uses engine vacuum to assist you in braking the vehicle. Helps the brake pedal to activate the hydraulic pistons in the master cylinder.

power brake: See power brakes.

power brakes: (PB) A conventional hydraulic brake system that uses engine vacuum to operate a vacuum power piston, the power piston applies pressure to the brake pedal, or in some cases, directly to the master cylinder piston. This system reduces the amount of pedal pressure that the driver must exert to stop the vehicle. Also called "vacuum-assisted brakes" or "hydraulic-assisted brakes." Also see brake booster.

power closing: See automatic closing system

power cut-off: A battery master switch

power cut-off switch: A battery master switch

power cycle:

See four-stroke power cycle

power distribution: A specific drive torque distribution between front and rear axles in a 4WD system. Compare asymmetric power distribution equal power distribution load-controlled power distribution

powerglide: (PG) A two-speed automatic transmission offered by General Motors.

power hood: British term for electric top

power output: See pump power output

power oversteer: In a rear-wheel-drive vehicle, power oversteer creates a skid when too much power is applied and the rear wheels spin.

powerplant: The automobile engine regardless of its type.

power seat: (P.seat) The cushions upon which the driver and or passengers sit which is adjusted by a control switch connected to a small electric motor so that the seat can be moved forward or back, up or down, or be tipped forth and aft. See also seat.

powershift transmission: A transmission which can be shifted without declutching or decelerating

power split: See asymmetic power distribution equal power split fifty-fifty power split

power steering: (PS) A steering system using hydraulic pressure to increase the driver's turning effort. As the driver turns the steering wheel, steering effort is reduced. The pressure is used either in the gearbox itself or in a hydraulic cylinder attached to the steering linkage. Also called "power-assisted" or "assisted steering." See in-line power steering integral-type power steering linkage power steering speed-sensitive steering variable assist power steering variable ratio steering power steering pump: A pump which supplies hydraulic pressure for the power steering system

power stroke: The third stroke of the four-stroke cycle. The piston moves downward from top dead center to bottom dead center as a result of the force of combustion acting on the top of the piston. power take off: (PTO) The end of the crank (usually on the other side from the magneto or starter) where the motion of the crank is transferred to the transmission or power output.

power to weight ratio: See power-to-weight ratio.

power-to-weight ratio: The relationship of a vehicle's horsepower to the weight of a vehicle. The greater the horsepower is in relation to the weight of the car, the faster the car will go and the faster it will accelerate.

power train: See powertrain.

powertrain: An engine and transmission combination. Sometimes includes the drive shaft, and drive axle. See

drivetrain direct drive powertrain power valve: An enrichment unit in a carburetor that is operated by vacuum or mechanical linkage to provide more fuel at wide open throttle.

power window: A side window which is raised and lowered by an electric motor which is operated by a switch. The British term is "electric window"

power window lock-out switch: A switch that renders inoperable all electric window controls on the individual windows, except for the master controls on the driver's door

power windows: Side windows which are raised and lowered by an electric motor which is operated by a switch. The British term is "electric windows"

Pozidriv screwdriver: A proprietary type of screwdriver whose tip resembles the Phillips cross-head configuration but with four additional wedges, making eight flanks altogether, which allows a more positive drive and a higher torque.

PP: Acronym for polypropylene

PPM: Acronym for "parts-per-million." Term used in determining extent of pollution existing in given sample of air.

PPO: Acronym for polyphenylene oxide

PR: Acronym for ply rating

Pratt and Whitney key: (P&W) A bar like a flat key except the ends are oval shaped.

prechamber: A small upper chamber in the cylinder head of a diesel engine, connected to the main combustion chamber by a narrow passage; fuel is injected into the prechamber (also called swirl chamber) where it is ignited before spreading to the main chamber. See pre-combustion chamber.

pre-chamber: See pre-combustion chamber.

precision insert bearing: A very accurately made replaceable type of bearing, it consists of an upper and lower shell, the shells are made of steel to which a friction type bearing material has been bonded, connecting rod and main bearings are generally of the precision insert type.

precombustion chamber: See pre-combustion chamber.

pre-combustion chamber: A small chamber located outside the combustion chamber of some cars in which a small amount of rich fuel-air mixture can be ignited to increase fuel efficiency and cut emissions. Found principally on diesel engines and stratified charge engines. Also called "pre-chambers."

pre-combustion engine: A diesel engine using indirect injection. The British term is indirect injection engine

pre-compounding: A process of mixing plastic raw materials with additives

pre-compress: To compress the fuel-oil mixture first

pre-compression:

See crankcase pre-compression

pre-compression chamber: A chamber below the pistons in a two-stroke engine in which the fuel-oil mixture is initially compressed in order to enable more fresh charge to be fed into the cylinder

pre-converter vehicle: A car built prior to the enforcement of emission control standards requiring a catalytic converter to be fitted to every new car

precured tread rubber: Pre-cured rubber, usually of high density and available in various tread designs, is lined with cushion gum before applying to a buffed casing using the cold cap method of retreading. Recently it has been applied in some hot cap molds employing a smooth matrix or other modifications.

pre-engaged Bendix starter: A combination of Bendix and pre-engaged starter drives

pre-engaged starter: A starter motor in which the solenoid-operated pinion engages with a flywheel ring gear before the full electric current flows; an overrunning clutch enables the pinion to freewheel before disengaging, once the engine has fired

Preferential Tariff: See generalized Preferential Tariff

preheater system: A cold starting aid for diesel engines, consisting of glow plugs, a glow-control unit, and a glow plug and starter switch, for preheating the combustion chamber or the intake air up to auto-ignition temperature

preheating: [1] Temperature to which a metal is heated before an operation is performed on the metal (welding, cutting, forming, etc.). [2] The application of some heat prior to the later application of more heat, cast iron is preheated to avoid cracking when the welding process is started. A coil (ignition) is preheated prior to testing. Also see converter preheating.

preheating zone: A section in hot-wax flooding units, in which body shells are preheated to 60°C

preignition: The fuel charge being ignited before the proper time. Sometimes causes pinging or detonation. This is the combustion of the fuel-air mixture that is not a result of the spark plug's firing, but by high pressure, a flame, or a hot surface.

preloading: Adjusting an antifriction bearing, ball joint, or spring so that it is under mild pressure, this prevents bearing looseness under driving stress.

prelubricator: A lubrication system consisting mainly of an electronically controlled pump that circulates pressurized engine oil to an engine's vital parts for about six seconds when the ignition is switched on prior to starting the engine; reduces friction during cold starts and prolongs engine life

premium: See insurance premium

premium gasoline: Gasoline with a high amount of octane.

pre-owned vehicle: A used vehicle.

prepreg: The reinforcing or molding material already impregnated with a synthetic resin

pre-selector gearbox: An arrangement that enables the driver to select a gear speed before he needs it and then depress the clutch pedal when he desires to use the selected gear.

preselector gearbox:

See pre-selector gearbox.

preset station button: A button for tuning a radio automatically to a preset frequency, i.e., one radio station can be allocated to each button

press: See drill press

press brake: A large type of sheet metal folder, built to handle larger panels and thicknesses

press, drill: See drill press.

pressed panel: A panel produced with special press tools and dies, as opposed to a hand-made panel

pressed steel: Sheet steel made into curved sections by press forming. It is often used in the construction of the frame and forks

press fit: An interference fit. A fit so tight that an object must be removed with a puller or a press. See drive fit interference fit force fit pressing plant: A factory specializing in the manufacture of automobile bodies

pressure: The force due to the weight of a substance exerted over the area the substance occupies. In metric measure, it is the force acting on each square metre. To calculate pressure, divide the force (in newtons) by the area (in square metres). It is measured

in newtons per square metre (N/m²). In Imperial (U.S.) measure, it is measured in pounds per square inch (lb/in.²) (psi). See absolute pressure air pressure atmospheric pressure atomizing pressure back pressure boost pressure brake mean effective pressure center of pressure charging pressure clutch pressure plate combustion pressure control pressure discharge pressure effective pressure exhaust back pressure extreme pressure lubricant fuel pressure governor pressure high pressure foaming high pressure relief valve high pressure hydraulic pressure pump indicated mean effective pressure inflation pressure line pressure low pressure indicator low pressure tire lubricating pressure mainline pressure main pressure manifold absolute pressure sensor mean effective pressure mean indicated pressure modulator pressure negative back pressure modulated valve negative back pressure valve nominal pressure oil-combination splash and pressure system oil-full pressure system oil full pressure system oil pressure gauge oil pressure sensor oil pressure switch

oil pressure warning light oil pressure pressure bleeder pressure cap pressure radiator cap pressure relief valve radiator pressure cap ram pressure rated pressure residual pressure valve safety pressure cap solution pressure static pressure tire pressure pressure accumulator: A spherical pressure tank of about 10 mm diameter in an hydraulic brake booster. A diaphragm separates the pressure accumulator into two chambers, one contains pressurized nitrogen, the other contains hydraulic fluid supplied by the hydraulic pump; pressure inside the accumulator is in the order of 60 bar

pressure bleeder: A device that forces brake fluid under pressure, into the master cylinder so that by opening the bleeder screws at the wheel cylinders, all air will be removed from the brake system.

pressure buildup: As a tire heats up as it travels on the road, the air inside the tire expands and thus increases the air pressure. Any increase exceeding 15% above starting cold pressure should be investigated. The practice of bleeding the excess or hot pressure should be avoided.

pressure cap: A special cap for the radiator, it holds a predetermined amount of pressure on the water in the cooling system, this enables the water to run hotter without boiling. In this way, the engine can operate at a higher and a more efficient temperature without danger of overheating. The cap also has a vacuum valve that lets air into the cooling system if the pressure falls too low to prevent outside air pressure from causing a partial collapse of the radiator. See radiator pressure cap safety pressure cap

pressure differential sensor: A sensor that reads pressure changes in the intake manifold in relation to barometric pressure. Also called a manifold pressure sensor, manifold vacuum sensor, or vacuum sensor

pressure differential switch: A hydraulic pressure-operated switch (often included in a combination valve) which activates the "brake failure" warning light when one of the brake circuits (in a dualcircuit system) falls due to a system leak and associated pressure drop

pressure differential valve: Senses unbalanced hydraulic pressure between two halves of the split brake system

pressure drop: The difference in pressure between two points in the system, usually caused by a restriction device. Specifically the difference in pressure where fuel metering occurs. In electronic injection system, this is the difference between fuel system pressure and intake manifold pressure. In Bosch CIS, it is the difference between system pressure inside the control plunger and the pressure outside the slits, in the upper-chamber of the differential-pressure valves

pressure-feed spray gun: A type of spray gun with a separate paint container (pressure-feed tank). It is used mostly for spraying highly viscous materials such as spray putty

pressure foaming: See high pressure foaming

pressure forming: See solid phase pressure forming

pressure gage: See oil pressure gauge

pressure gauge: See oil pressure gauge

tire pressure gauge pressure indicator: See low pressure indicator

pressure limiting valve: A British term for a proportioning valve

pressure lubrication: [1] Forced-feed lubrication. [2] Lubrication system with crankcase scavenging. Fresh oil is supplied from a separate container and lubricates the engine components as it passes through the crankcase. The oil is ignited along with the air/fuel mixture. With this system, it is no longer necessary to add oil to the fuel when filling up

pressure modulated: See back pressure modulated negative back pressure modulated valve pressure modulated valve: See negative back pressure modulated valve back pressure modulated valve pressure plate: [1] The plate that carries the brake pad in a disc brake. Also called backplate. [2] The part of the clutch assembly which is pressed against the clutch plate by the clutch springs to transmit the drive. Also see clutch pressure plate.

pressure pump: See hydraulic pressure pump

pressure radiator cap: See pressure cap.

pressure regulating valve:

[1] any valve which maintains pressure at or under a certain pressure; specifically the pressure relief valve of the oil pump. [2] In a continuous injection system, part of the fuel distributor, consisting basically of a spring-loaded steel diaphragm which serves to keep the pressure drop across the metering ports at a constant 0.1 bar

pressure regulator: A spring-loaded diaphragm-type pressure-relief valve which governs the pressure of the fuel delivered to the fuel injectors by the fuel pump and returning the excess to the tank. Also see system pressure regulator

pressure regulator valve: A valve which releases hydraulic fluid if pressure exceeds a preset value

pressure relief: What you must do to all fuel injection system before cracking a line and opening up the system

pressure relief valve: A one-way valve designed to open at a specific pressure to prevent pressures in the system from exceeding certain limits. In an engine's lubrication system, a pressurerelief valve opens to relieve excessive pressure that the oil pump might develop. See blowoff valve high pressure relief valve safety valve wastegate pressure ridge: A work-hardened edge of a damaged panel area that will often remain, even after the area has been smoothed with hammer and dolly; it must then be dressed with hammer and body spoon

pressure sensing line: Connects the remote bulb to the expansion valve. Also called capillary tube

pressure sensing switch: Device, used on some late model GM and Ford vehicle, which cycles compressor operation in accordance with pressure changes sensed at the accumulator

pressure sensor: See absolute pressure sensor barometric pressure sensor manifold absolute pressure sensor oil pressure sensor pressure switch: See oil pressure switch

pressure system: See oil-combination splash and pressure system oil-full pressure system oil-combination splash and pressure system oil full pressure system pressure tap: Also called a fuel-injection system test port

pressure tire: See low pressure tire

pressure-vacuum cap: Fuel tank filler cap designed to prevent loss of fuel or vapor from tank

pressure valve: See back pressure valve negative back pressure valve residual pressure valve pressure warning light: See oil pressure warning light

pressure wave:

Pulsations or oscillations in the induction and exhaust systems caused by the opening and closing of the valves

pressure wave supercharger: A supercharger using the pressure waves created by the expanding exhaust gases to compress the inlet charge. Also called "Comprex supercharger." See comprex pressure wave supercharger

pressurized: working under pressure

Presta valve: A bicycle tube valve whose stem has a small nut on top, which must be loosened during inflation, instead of a spring such as is found on the Schrader valve.

pretensioner: A device that retracts the seat belt to tighten or take up slack in the wearer's belt. When a collision occurs or when brakes are applied, a seat belt with a pretensioner detects the stopping action and tightens the belt before the wearer is propelled forward. This holds the occupant more securely in the seat.

preunit: An engine and gearbox that are not built together in the same casing. Preunit construction was common on earlier motorcycles

prevention: See corrosion prevention

Previa: A model of automobile manufactured by Toyota price: See basic price end-of-lease purchase price final purchase price fixed price selling list price

Click for books on Previa

manufacturer's suggested retail price one price selling purchase price sticker price trade-in price price selling: See fixed price selling one price selling prick punch: Small, sharp punch used to make punch marks on a metal surface

primary battery: A non-rechargeable battery consisting of one or more primary cells, used e.g., in portable radio receivers. Opposite to secondary battery or storage battery

primary brake shoe: The brake shoe that is first to press against the brake drum. The other shoe is the secondary shoe. When both shoes are pressing against the drum, the amplification of forces is called "servo action."

primary catalytic converter: A small converter positioned close to the engine which quickly achieves the necessary operating temperature to reduce exhaust emissions during the warm-up period

primary cell: An electric cell that converts chemical energy into electrical energy in an irreversible process: unlike a secondary cell, it cannot be recharged

primary chain: The chain of a primary drive

primary circuit: The low voltage (6 or 12 volts) path of the ignition system which goes from the positive pole of the battery to the primary windings of the coil, through the breaker points, and into the ground which leads back to the negative pole of the battery.

primary compression: A term that is used in two-stroke engines. Primary compression takes place in the crankcase and is then pushed up into the combustion chamber where secondary compression takes place as the piston squeezes the mixture. If the crankcase seals are poor, primary compression will be reduced resulting in reduced secondary compression so that it may be difficult to start the engine.

primary compression ratio: The degree of compression achieved in the crankcase area below the piston of a two-stroke engine when the piston moves down and compresses the mixture supplied into the crankcase

primary forward brake shoe: The brake shoe that is installed facing the front of the vehicle, it will be a selfenergizing shoe.

primary key: A key which operates all the locks of the car. Also see secondary key

primary magnetic field: A magnetic field of the primary winding

primary pattern: The oscilloscope pattern of the primary circuit

primary piston: The main piston in a tandem master cylinder

primary pressure: Also known as system pressure in Bosch continuous injection system

primary pull-off diaphragm: Device that partially opens the choke when vacuum develops (i.e., when the engine starts), allowing more air to pass through the carburetor, thinning out the excessively rich idle mixture

primary pump: An engine-driven oil pump feeding pressurized oil to the transmission and hydraulic control system

primary seal: The primary piston seal in a tandem master cylinder

primary shaft: See clutch shaft

primary shoe: The shoe of a brake drum system which pivots outwards into the approaching drum. The British term is leading shoe

primary structure component: Any structural component which, if it collapsed, could make the car uncontrollable or would seriously reduce occupant safety in a crash

primary terminal: The clip found inside the distributor which allows electric current to pass from the points to the condenser and provides the insulation to keep the current from contacting other metal parts.

primary valve: The valve which controls the primary V-pulley

primary V-pulley: (CYT) The pulley which is driven by the engine via a clutch; one of its halves can be slid hydraulically, thus varying the diameter of the steel thrust belt track and changing the transmission ratio

primary winding: The low voltage (6 or 12 volt) windings in ignition coil, the primary winding is heavy wire; secondary winding uses fine wire.

primary windings: The low voltage (6 or 12 volt) windings in ignition coil, the primary winding is heavy wire; secondary winding uses fine wire.

primary wire: See primary wires.

primary wires: The wiring which serves the low voltage part of the ignition system. Wiring from battery to switch, resistor, ignition coil, distributor points.

prime: [1] To paint bare metal with primer to prevent rusting. A second color (often different from the prime color) is painted over the primer. [2] Pronounced PREEM, a stage in a bicycle race. [3] To fill a machine (e.g., a pump) with the necessary fluid before starting, in order to improve its sealing qualities. [4] To put fuel in the float chamber of a carburetor to ease the starting of an engine

prime coat: A primer or surfacer applied to the old paint or bare metal before the finish coat is applied.

primer: The surfacer that acts as a bond between the bare metal surface or old paint and the color coat and designed to give rust protection. See anti-chipping primer electrophoretic primer etching primer etch primer factory primer shop primer weld-through primer zinc-rich primer primer bath: A container filled with primer into which a metal object is submerged. This painting procedure is faster than spray painting and will cover better. The disadvantage is that a lot of primer is required and the metal must be bare of anything else (i.e., glass, rubber, cloth)

primer filler:

A special primer used to cover fine cracks

primer oven: A painting oven used to dry the coats of primer

primer surfacer: The material for the resilient coating underneath the top paint coat which provides corrosion protection, protects the paint system from chipping caused by gravel, provides a smooth surface for the top paint coat, and serves as an adhesion promoter. A primer that contains a lot of solid material to fill small imperfections in the substrate (primer-surfacer must be sanded before applying paint over them)

principal: See dealer principal

principle: See air principle plunger principle pulse air principle Ricardo principle valve principle printed circuit: An electrical circuit made by connecting the units with electrically conductive lines printed on a panel, this eliminates actual wire and the task of connecting it.

printed circuit board: (pcb) A thin plastic insulating board on one or both sides of which the components and connections of an electronic circuit are formed by etching in a metallic coating or electrodeposition

prise off: To remove a stubborn object with a lever

Prix: See grand Prix

PRND: Acronym for the order in which an automatic transmission is displayed to the driver and stands for "Park," "Reverse," "neutral," and "Drive." Sometimes, two or more drive positions will be displayed as D1 and D2.

PRNDL: Acronym for the order in which an automatic transmission is displayed to the driver and stands for "Park," "Reverse," "neutral," "Drive," and "Low." Sometimes, the Low may be divided into 3, 2, 1.

probe: [1] A pointed tool, like an icepick. It is used to determine the extent of injuries during the tire inspection. [2] An awl. Click for books on [3] A measuring sensor, usually long and thin to gain access to Ford Probe narrow cavities. Also see lambda probe. [4] A model of automobile manufactured by Ford process: See alfin process casting process cbr process jet process lost-foam casting process plasma spray process reverse process sendzimir process vertac-process Procon-ten: A safety system developed by Audi which makes use of the relative displacement of the engine during a frontal collision; steel cables pull the steering wheel away from the driver and increase the seat belt tension

produced: See american produced north American produced product:

See care product corrosion product product carrier: A tanker used to carry refined oil products. Normally four different grades of oil can be handled simultaneously.

product design: the process of planning the product's specifications.

production: See cost of production

production car: A vehicle model that has been assembled for sale to the general public as opposed to a concept vehicle that is not available to be purchased. Also called "production model."

production engineering: planning and control of the mechanical means of changing the shape, condition of materials toward greater effectiveness and value.

production line: A system of assembly in which the parts of an end product are transported by a conveyor past a number of sites where the parts are modified without stopping the conveyor

production model: A vehicle manufactured by a mass-production process. A vehicle model that has been assembled for sale to the general public as opposed to a concept vehicle that is not available to be purchased. Also called "production car."

production retread shop: A shop which schedules its production not on the basis of day-to-day orders but rather on long runs of purchased tire casings in order to secure the lowest cost per unit.

production vehicle: A vehicle manufactured by a mass-production process. A vehicle model that has been assembled for sale to the general public as opposed to a concept vehicle that is not available to be purchased. Also called "production model."

productivity: relative measure of output per labour and/or machine output.

product line: A series of different products made by the same company which form a group (such as different models of cars)

product planning: a function whereby an enterprise is responsible for the efficient, planning, scheduling and coordination of production activities.

product range: A series of different products made by the same company which form a group (such as different models of cars)

product testing: rigorous methods whereby a product's quality and durability are measured.

profile: [1] The side view of something. [2] The aspect ratio of a tire. See cam profile low profile tread profile profile depth: See tread depth. Compare aspect ratio

profile ignition pickup: (PIP) a Hall Effect vane switch that furnishes crankshaft position data to the Ford EEC-IV processor

profit: See operating profit

program cars: automobiles sold by manufacturers for fleet use. Usually applies to very large fleets, such as those of car rental companies.

program comparison and identification: (PCI) A system that identifies a radio station and compares stations to find the station which offers the strongest signal

programmable read only memory: (PROM) An electronic component which can be specifically programmed to the design of each car model to control the M/C solenoid. Plugs into the Electronic Control Module (ECM). Also called an engine calibration unit

Programmed Fuel Injection: (PGM-FI) Honda's fuel injection system for the Accord, Civic, Civic CRX, and Prelude

program objectives: A consensus of what has been determined to be the most marketable product for a given model year.

progressive carburetor: See compound carburetor

progressive linkage: A carburetor linkage designed to open the throttle valves of multiple carburetors. It opens one to start with and when a certain opening point is reached, it will start to open the others.

progressively wound valve spring: A valve spring with variable spacing between its coils which helps to improve responsiveness and thus to reduce the load on the valve train

progressive rate spring:

A spring with an increasing spring constant. For example, if the first inch of spring motion requires 100 pounds of force, the second inch would require more than an additional 100 pounds, and the third inch would require still more. Progressive-rate springs become stiffer as they are compressed, unlike single-rate springs, which have a fixed spring rate.

progressive spring: See progressive rate spring.

progressive suspension: A system in which the suspension stiffness changes depending on the amount of change required. On light bumps, the suspension is soft; but on greater bumps, the suspension is stiff.

progressive transmission: An older version of a manual transmission. When you wanted to go from low gear to the highest gear, you had to go through all the gears in between. Likewise when you wanted to go from the highest gear to the lowest, you had to proceed through all the intermediate gears.

progressive valve spring: A valve spring with variable spacing between its coils which helps to improve responsiveness and thus to reduce the load on the valve train

projected core/insulator nose: An insulator tip that extends beyond the end of the spark plug shell

projected spark position: The amount the spark plug gap projects into the combustion chamber: 1 mm for the slightly projected spark position in older engines and 3 mm for the normally projected spark position in modern engines

projection welding: resistance welding method

PROM: Acronym for programmable Read Only Memory. PROM contains permanent information about how components should perform under various operating conditions

promoter: A substance embedded in the washcoat on catalyst substrates that serves to enhance catalytic efficiency

prony brake: A device using a friction brake to measure the horsepower output of an engine.

prop: See gas prop

propane: A colorless, flammable gas which is a petroleum product, similar to and often mixed with butane. It is useful as an engine fuel or for cooking and heating. In Canada this is the term used for LPG.

propellant: See solid propellant

propeller: The impeller of a pump, characterized by a small number of blades of double curvature; propellers are generally axial-flow impellers, seldom mixed-flow ones. Also see divided propeller shaft

propeller pump: The impeller of a pump, characterized by a small number of blades of double curvature; propellers are generally axial-flow impellers, seldom mixed-flow ones

propeller shaft: British term for driveshaft. The shaft connecting the transmission output shaft to the differential pinion shaft. See composite propeller shaft divided propeller shaft propeller shaft safety strap:

See driveshaft safety strap.

propelling power: The force with which a vehicle moves; the pulling force; depends not only on engine power and torque, but also on the amount of friction between driving wheels and road surface

proper proportion of air and fuel: One of the essential factors in a combustion engine (Fuel, Air, Proper proportion of mixture, compression, timing, spark).

properties: See run-flat properties

property: See intellectual property rights

property rights: See intellectual property rights

proportion: See proper proportion of air and fuel

proportional load synchromesh: See locking synchromesh

proportioning: The act of distributing something (e.g., brake fluid) to several components in equal measures. See brake proportioning valve load-sensitive proportioning valve regulated proportioning valve proportioning valve: [1] any valve which limits pressure in a system, e.g., in a hydraulic circuit, in automatic transmissions, in pneumatic suspension systems, etc.

[2] The valve used in the rear brake line of some cars with front disc and rear drum brakes. When braking gently, pressure is about equal front and rear; as pedal pressure is increased, the limiting valve controls and finally limits pressure to the rear wheels to prevent rear wheel lockup during heavy braking. The British term for "proportioning valve" is "pressure limiting valve." See brake proportioning valve load-sensitive proportioning valve regulated proportioning valve propshaft: Abbreviation for "propeller shaft." See divided propshaft driveshaft split propshaft prop shaft: Abbreviation for "propeller shaft." See driveshaft.

propulsion: See hybrid propulsion

propulsive power: The force with which a vehicle moves; the pulling force; depends not only on engine power and torque, but also on the amount of friction between driving wheels and road surface

prop up: To secure the hood, trunk, or liftgate in the open position using the hood support rod.

Prost, Alain: Alain Prost of France is a four-time World Driving Champion. He is the only French Grand Prix driver to win the World Championship in the modern era (1951 through the present). He has won more races than any other driver in Grand Prix racing history. And his 51 wins are a record that will likely stand for a long time.

protection:

See cathodic protection corrosion protection edge protection electrolytic protection energy Protection Agency rust protection sacrificial protection theft protection underbody protection Protection Act: See Canadian Environmental Protection Act

Protection Agency: See Energy Protection Agency

protective coat: A layer or layers applied to a surface to provide corrosion protection

protective coating: A layer or layers applied to a surface to provide corrosion protection

protector: See door protector nose protector wheel arch protector protector washer: A filter disc between the primary piston and primary seal which supports and protects the primary seal when the brake system is under pressure

Protocol: See kyoto Protocol

proton: A positive charge particle forming part of the atom.

prototype: The test model of a new car design that is intended to be produced in quantity. See Camel Grand Touring Prototype concept car Grand Touring Prototype mock-up proud: Something that projects up slightly from the surrounding surface. Something not flush

prospector's pick:

pry: See inside pry spoon

pry spoon: See inside pry spoon

PS: Acronym for "power steering."

p. seat: Abbreviation for "Power seats."

PSI: Acronym for "pounds per square inch." A unit of inflation for a tire, or a unit of measurement for an engine's compression. Normal atmospheric pressure at sea level is 14.7 psi. Metric measurement uses kilopascals.

PSIA: Acronym for pounds per square inch absolute

PSIG:

Acronym for pounds per square inch gauge

PSR: Acronym for "power sun roof."

PTC: Acronym for positive temperature coefficient

PTFE: See polytetrafluoroethylene

PTO: Acronym for "power take off." A device (usually a pulley) on an engine or wheel which drives a secondary device.

puck: See brake pads.

puckering: A paint fault. See wrinkling

pucks: See brake pads.

puddle: Portion of weld that is molten at the place heat is supplied.

puddle jumper: A colloquial term for a small car. It was used in North America when most cars were very large and was representative of the VW, Austin, Nash Metropolitan, etc.

puddle lamp: A lamp in the bottom of a luxury car door which illuminates the area into which a passenger is going to step when the door is opened

puddle welding:

See plug welding

pull: The action of a vehicle to deviate towards the side. There may be various causes for a vehicle pulling to one side or the other, the most common being: the brakes on either side exerting uneven pressure, incorrect wheel alignment, uneven tire tread, or a defect in the steering system. See door pull rim pull pull away: to drive away from a standing start

puller: A device for separating two components which are secured by press fitting them. See stud puller ball bearing puller bearing puller dent puller flange-type puller flywheel puller gear puller hub puller lock puller magneto puller panel puller reversible gear puller spark plug boot puller stud puller suction cup dent puller tie rod puller pulley: A grooved wheel carrying a string, rope, chain, or belt which turns the wheel. See camshaft pulley crankshaft pulley driven pulley drive pulley fan pulley

idler pulley jockey pulley timing belt pulley V-pulley pull in: To drive to the side of the road or into a rest stop, etc.

pulling: See brake pulling

pulling beam: A hydraulic ram attached securely to the vehicle at strong points; pulling force is then applied to the pulling beam to pull the frame or sheet metal back into place

pulling post: A post bolted to the shop floor or secured in a concrete foundation which forms the anchor for the chain and hydraulic jack assemblies to straighten misaligned bodies

pull-in winding: A winding as used in a starter solenoid that does the heavy pull-in work. Also see hold-in winding

pull it down: A term often used in reference to dismantling and overhauling an engine. Same as "tear it down."

pull off: To drive off a road (and stop)

pull out: [1] To drive away from the side of a road. [2] To drive out from behind a vehicle in front in order to overtake (pass)

pull-out door handle: An outside door handle which is pulled away from the door skin to open the door

pull over: to drive to the side of the road and stop

pullover point: The location of the main circuit discharge in the venturi, which is always higher than the fuel level in the bowl so fuel wont run into the venturi when it shouldn't. Spillover is determined by the size of the venturi and by the displacement of the engine pulling air through the carburetor. Also called spillover point

pull-type clutch: A clutch in which the clutch release bearing is pulled away from the flywheel when the clutch is disengaged. Compare push-type clutch

pull up: To get close to and stop as in "to pull up to the gas pumps."

PULSAIR: A GM system similar to the air Injection Reaction System (AIR) except there is no air pump. Instead exhaust pressure pulses draw air into the exhaust system. Fresh air that is filtered by the air cleaner is supplied to the system on a command from the Electronic Control Module (ECM).

Pulsar: A model of automobile manufactured by Nissan in Japan Click for books on Pulsar pulsation: See pedal pulsation

pulsation damper: A device used to smooth out the pulsations or surges of fuel from the fuel pump to the carburetor. Also see damper.

pulse: See hot-start pulse relay inductive pulse pick-up pulse air principle:

The method, in air induction systems of introducing secondary air into the exhaust system by means of aspirator valves actuated by the pressure pulses of the exhaust gas stream

pulse air system: An air induction system using the pulse air principle. An exhaust emission control system that uses exhaust pulse in a pipe to permit air to be drawn into exhaust system

pulse arc welding: A type of welding arc in which the arc welding current is interrupted or pulsed as the welding arc progressed.

pulsed injection: A system that delivers fuel in intermittent pulses by the opening and closing of solenoid-controlled injectors. Also called electronic fuel injection (EFI)

pulse former: A circuit for changing the waveform of a signal

pulse generator: See pick-up module transistorized ignition with inductive pulse generator pulse period: The time available, depending on engine speed, for opening the solenoid injectors

pulse pick-up: See inductive pulse pick-up

pulser coil: See coil.

pulse relay: See hot-start pulse relay

pulse shaper: A circuit for changing the waveform of a signal

pulse time: The measurement, in milliseconds, of the duration of the signal that activates the fuel injector. In other words, the amount of time that an injector is energized. The duration or pulse width is related directly to the amount of fuel injected into the combustion chamber. Also called pulse width

pulse vacuum hublock: This is a new scheme of switching the hubs in a four-wheel-drive vehicle using a pulse of vacuum rather than electrical solenoids, which are heavier and more prone to failure.

pulse width: The measurement, in milliseconds, of the duration of the signal that activates the fuel injector. In other words, the amount of time that an injector is energized. The duration or pulse width is related directly to the amount of fuel injected into the combustion chamber. Also called pulse time

pump: [1] A device for moving liquid or gas by decreasing or increasing the pressure on it. See accelerator pump air pump canned motor pump cell pump centrifugal pump charging pump circulating pump coolant pump diaphragm pump eccentric rotor pump electric fuel pump external vane pump feed pump foot pump fuel injection pump fuel pump fuel pump shut-off switch fuel pump switch gasoline pump

gas pump gear-type oil pump gear pump hydraulic pressure pump impeller pump in-line pump injection pump internal gear pump internal vane pump jerk pump lift pump liquid pump low-head pump low-pressure pump lubrication pump mixed-flow pump multi-inlet pump multi-stage pump multi-suction pump non-self-priming pump oil pump oil pump strainer petrol pump piston charging pump plunger pump power steering pump primary pump propeller pump radial-flow pump reciprocating pump roller-vane pump roller cell pump rotary pump rotary vane pump rotor-type pump rotor pump scavenging pump secondary pump self-priming pump sliding-vane pump twin diaphragm pump two-stage pump vacuum pump vane-in-rotor pump vane-in-stator pump vane pump

water pump windshield washer pump [2] As a verb, it means to move something energetically up and down. See pumping the gas pedal oil pumping pump down: See evacuate

pump-fed lubrication: See forced-feed lubrication

pump gasoline: Normal gasoline (whether regular or premium) available at service stations in contrast with racing fuel obtained from specialty locations.

pumping: See oil pumping

pumping chamber: See precompression chamber

pumping losses: That part of engine power which is expended on the induction of the fuel and air charge into the engine and the expulsion of combustion gases

pumping, oil: See oil pumping.

pumping the gas brakes: A method of repeatedly applying the brakes so that optimum braking can be established without creating brake fade. In anti-lock brakes, this procedure is unnecessary.

pumping the gas pedal:

Forcing the accelerator up and down in an endeavor to provide extra gasoline to the cylinders, this is often the cause of flooding. It is especially harmful to cars with fuel injection.

pumping the throttle pedal: Forcing the accelerator up and down in an endeavor to provide extra gasoline to the cylinders, this is often the cause of flooding. It is especially harmful to cars with fuel injection.

pump inlet check ball: A steel ball located in the plunger head or in the bottom of the accelerator pump well. The pump inlet check ball prevents fuel from escaping from the well when the throttle is opened and pressure is exerted on the fuel in the pump well by the accelerator pump piston

pump power output: the energy transferred by a pump to the liquid pumped

pump rotor: A centrifugal pump assembly consisting of the pump shaft, impeller and further rotating components, such as rotating hearing and shaft sealing parts

pump sag: A hesitation in carburetor performance between the time the accelerator pump squirts fuel into the venturi and the point at which the main fuel circuit is activated

pump shaft: A shaft which transmits the driver torque to the impeller(s) of centrifugal pumps or to the displacement element(s) of rotary pumps

pump shut-off: See fuel pump shut-off switch

pump shut-off switch: See fuel pump shut-off switch

pump strainer:

See oil pump strainer

pump switch: See fuel pump switch

pump the brakes: See pumping the brakes.

pump the gas pedal: See pumping the gas pedal.

pump the throttle pedal: See pumping the gas pedal.

punch: A tool for making holes or driving out bolts, rivets and pins. See aligning punch brass punch center punch drift drift punch fender punch gasket punch hole punch nail punch pin punch starter punch tapered punch wad punch wing punch puncture: A penetration of a tire's air chamber by a foreign object, nail, glass, etc. resulting in loss of air. Such loss can be rapid with the collapse of the innertube, or relatively slow in the case of tubeless tires.

punt chassis:

See backbone chassis

PUP: Acronym for "Pick-ups" (like Ford Blackwood or GM Sierra).

PUR: Acronym for polyurethane

purchased: Component supplied by an outside manufacturer

purchase option: Most closed-end leases grant the lessee an option to purchase the vehicle at the end of the lease. The end-of-lease purchase price is usually the same as the stated residual value. Check your lease contract before signing to ensure that there is a purchase option. The lessor must disclose the purchase option price prior to your signing the lease contract.

purchase price: The price of a vehicle that the consumer pays. Start with the MSRP and subtract any manufacturer discount and dealer discount you negotiate. Purchase price is a key determinant of the true cost of a lease. Purchase price less your down payment and dealer participation equals the net capitalized cost. See end-of-lease purchase price final purchase price purchasing: total materials purchased for manufacturing/assembly into auto parts (i.e., steel, plastics, rubber, textiles, etc.).

pure: See layer of pure zinc

pure zinc: See layer of pure zinc

purge:

to get rid of impurities

purge control valve: (PURGE CV) used to control the release of fuel vapors from the charcoal canister into the engine

PURGE CV: Acronym for purge control valve

purge solenoid: A device used to control the operation of the purge valve in an evaporative control emission system

purification: See exhaust gas purification system

purification system: See exhaust gas purification system

purpose lacquer: See general purpose lacquer thinner

purpose lacquer thinner: See general purpose lacquer thinner

purpose pliers: See general purpose pliers

purpose: See general purpose pliers

purpose ship: See dual purpose ship

push:

A colloquial term for understeer.

push bar: A bar between the shoes in a drum brake

push button: See pushbutton.

push-button: A switch which is engaged by pushing a button in. In most cases there are several button options so that when one is selected, the previously selected button is pushed back out (de-selected).

pushbutton: A switch which is engaged by pushing a button in. In most cases there are several button options so that when one is selected, the previously selected button is pushed back out (de-selected).

pushrod: See push rod

push rod: The rod that connects the valve lifter to one end of the rocker arm. Used on valvein-head installations where the cam is below the piston and the valves are above the piston. The rods are moved by the cam and activate the valve lifter. Engines with overhead cams do not need push rods because the camshaft connects to the valves directly.

pushrod engine: See push rod engine

push rod engine: An engine configuration where the camshafts are located lower in the engine. Connecting rods and other components are used to operate the valves at the top of the cylinder heads

pushrod measuring tool:

A tool which measures the length of pushrod needed in an engine; a pushrod of proper length is vital to keep the rocker in the center of the valve, minimize the risk of breakage and extend the valve guide life

push start: A procedure of starting a vehicle with a manual transmission by pushing the vehicle with another vehicle or by the power of several strong people or by coasting downhill. Once sufficient speed is obtained and the clutch is disengaged (the pedal or lever is pushed in) and the transmission in second gear, then engaging the clutch. At this point, the engine will turn over and start. This procedure will not work with a vehicle with an automatic transmission. The British term is "bump start"

push-type clutch: A conventional clutch in which the clutch release bearing is pushed towards the flywheel when the clutch is disengaged. Compare pull-type clutch

putty: A malleable cement or paste used for repairing minor panel imperfections, e.g., chips or scratches on the filled surface; it is used after normal filling and gives an extremely smooth surface. See body putty cellulose putty putty knife: A tool for scraping off dirt, carbon, and paint or for applying putty

PVA: Acronym for ported vacuum advance

PVC: Acronym for polyvinyl chloride

PVC seam sealing: The sealing of seams with PVC sealant to prevent the penetration of corrosive agents

PVC tape:

See insulating tape

PVC underbody treatment: A treatment of the underbody of a vehicle to protect it from chipping due to gravel or stones and corrosive agents

PVC underseal: A protective PVC coating applied to the underbody of a vehicle

PVC underseal coating: A protective PVC coating applied to the underbody of a vehicle

PVS: Acronym for ported vacuum switch

PW: Acronym for "power windows."

P&W key: See pratt and Whitney key

pylon: A highly visible marker for controlling traffic.

pyrometer: A device which determines the temperature in various parts of a tire.

pyroxylin paint: An early type of quick drying synthetic paint.

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [Qua] [Que] [Qui]

Q: [1] The letter on the sidewall of a tire denoting the maximum speed for which it is designed (160 kph or 100mph). See speed rating. [2] A symbol for "throughput." [3] A symbol for the quantity of water discharged, usually in m3s-1. [4] A symbol of merit, often called the Q-factor, for an energy-storing device, resonant system, or tuned circuit. [5] A symbol for "charge."

QAM: Acronym for "quadrature amplitude modulation"

Q-band: The frequency band mostly in radar, 36-46 GHz which has now been superseded by Ka-band.

QCD: Acronym for "quantum chromodynamics"

Q-code: A telecommunications code using three letter groups: QAA-QNZ for aeronautics; QOA-QQZ for Maritime uses; QRA-QUZ for all other services.

QDC: Acronym for "quick die change."

QED: Acronym for "quantum electrodynamics"

Q-factor:

A symbol of merit, often abbreviated "Q", for an energy-storing device, resonant system, or tuned circuit.

q-feel: A term given to a device which applies an artificial force on the control column of a power-controlled aircraft proportional to the aerodynamic loads on the control surfaces, thereby simulating the natural "feel" of the aircraft throughout its speed range.

Q-gas: One based on helium (98.2% He, 1.8% butane) widely used in gas-flow counting.

Qiana: A trade name for a special nylon with silken properties when spun into fiber.

QIC: Acronym for "quarter-inch cartridge"

Q-meter: A laboratory instrument which measures the Q-factor of a component

QPP amplifier: Abbreviation for "quiescent push-pull amplifier"

QPSK: Acronym for "quaternary phase-shift keying"

QS: An acronym for "quick sweep" or "quantity surveyor"

Q-shell: The electron shell in an atom corresponding to a principal quantum number of seven. It is the outermost shell for heavy radioactive elements.

Q-signal: [1] The signal, in the NTSC color system, that corresponds to the narrow-band axis of the chrominance signal.

[2] The first of three-letter code kfor standard messages in international telegraphy. See Q-code

Q-switching: A means of producing high instantaneous power from a laser.

QTS: Acronym for quartz tuning system

quad: [1] A four-wheeled off-road ATV which is generally designed for one rider. [2] Either four insulated conductors twisted together (star-quad) or two twisted pairs (twin-quad). Normally a single structural unit of a multiconductor cable. [3] A prefix to denote a paper size whch is four times the area of that of the basic size (broadsize), i.e., both dimensions of the basic size are doubled. [4] A piece of metal less than type height, for spacing. Also called "quadrat"

quad-cam engine: An engine with four camshafts

quad fork: A steering device which attaches to the rim of the steering wheel to assist disabled drivers in handling the steering. quadrant: [1] The gearshift selector indicator marked PRNDL. [2] The V-shaped toothed section of a worm-and-sector steering box. [3] A slotted segmental guide through which an adjusting lever works. It is provided with means for locating the lever in a number of angular positions. See link motion. [4] A quarter of a circle. [5] In cartesian mathematics, two intersecting lines divide a plane (e.g., a sheet of paper) into four sections called quadrants.

quadrantal diviation: Those parts of the deviation which vary as sine and cosine of twice the compass course, thus changing their sign quadrantally with change in direction of the ship's head

quadrantal point:

One of the four points of the compass which in moving from north correspond to the headings NE(45°), SE(135°), SW(225°), and NW(315°)

quadrant dividers: A form of dividers in which one limb moves over an arc fixed rigidly to the second limb and may be secured to it by tightening a binding screw

quadrant electrometer: See Dolezalek quadrant electrometer

Quadrantids: A major meteor shower which shows maximum activity on January 3 with a rate of around 110 per hour

quadraphonics: See quadrophonics

quadrat: A piece of metal less than type height, for spacing. Also called quad

quadratic equation: An algebraic equation of the second degree (ax2 + bx + c = 0), whose solution is

quadratic system: See tetragonal system

quadrature: The relation between two waves of the same frequency but one-quarter of a cycle (90°) out of phase, as in TV color difference signals

quadrature amplitude modulation: A modulation system involving phase and amplitude modulation of a carrier, used in microwave and satellite communication links.

quadrature component:

See reactive component

quadrature reactance: A term used in the two reaction theory of synchronous machines to denote the ratio which the synchronous reactance drop produced by the quadrature component of the armature current bears to actual value of quadrature component.

quadrature transformer: A transformer designed so that secondary emf is 90° displaced from primary emf

quadric: The three-dimensional surface represented by a general second-degree equation in three variables. By a suitable choice of co-ordinates sucha an equation can be reduced to one of the following standard equations: If all of the ± are "+" then it describes an ellipsoid; if there is one "-" it is a hyperboloid of one sheet; if two "-" then a hyperboloid of two sheets; and if three "-" then an imaginary (virtual) quadric An elliptic paraboloid (a and b of the same sign), a hyperbolic paraboloid (a and b of opposite sign) A cone A cylinder quadricycle: An early type of lightweight, four-wheeled automobile using bicycle wheels and a frame of steel tubes.

quadrilateral: A four-sided polygon

quadrilateral speed-time curve: A simplified form of speed-time curve used in making preliminary calculations regarding energy consumption and average speed of railway trains. The acceleration and coasting portions of the curve are sloping straight lines and the braking portion is neglected, so that the curve becomes a quadrilateral

quadripole:

A network with two input and two output terminals. A balanced wave-filter section

quadrivalent: A term describing an atom with four electrons in its valency shell

quadrophonics: A system of sound transmission using a minimum of four speakers fed by four, or sometimes three, separate channels.

quadruple-expansion engine: A steam engine in which the steam is expanded successively in four cylinders of increasing size, all working on the same crankshaft

quadruple point: A point on a concentration-pressure-temperature diagram at which a twocomponent system can exist in four phases

quadruplex: Videotape recording and reproduction system using four rotating heads to produce transverse tracks on two-inch wide magnetic tape

quadruplex system: A system of Morse telegraphy arranged for simultaneous independent transmission of two messages in each direction over a single circuit

quadrupole: A collection of charges such that the potential at a point distance r from their center of mass may be expressed by an infinite series of terms in inverse powers of r. The inverse third power term is the quadrupole potential

quadrupole moment: The moment derived from the series expansion (see quadrupole) of charges multiplied by space co-ordinates. The sum of the quadratic terms is the quadrupole moment, which is possessed by most metals.

quadrupoles: Radiator producing a sound field of two adjacent dipoles in antiphase. the eddies in a subsonic jet of gas are quadrupoles

qualification test: An evaluation of a flight article or its equivalent to verify that it functions correctly under the specified conditions of space-flight; normally the test condidtions are more severe than those expected

qualifying diaphragm: See vacuum-break diaphragm

qualitative analysis: Identification of the constituents of a sample without regard to their relative amounts. It often refers to elemental analysis, but may also refer to the detection of acid-base or redox properties in a sample

quality: [1] Conformance to requirements in relation to a degree of excellence. [2] In sound reproduction, the degree to which a sample of reproduced sound resembles a sample of the original sound. The general description of freedom from various types of acoustic distortion in sound-reproducing systems. [3] The timbre or quality of a note which depends upon the number and magnitude of harmonics of the fundamental. [4] The condition of a saturated vapor, particularly steam, expressed as the ratio per cent of the vaporized portion to the total weight of liquid and vapor. [5] In radiography, an indication of the approximate penetrating power. Higher voltages produce higher quality X-rays of shorter wavelength and greater penetration. The term dates from before the nature of X-rays was completely understood. See build quality

quality control: A form of inspection involving sampling of parts in a mathematical manner to determine whether or not the entire production run is acceptable, a specified number of defective parts being permissible

quality factor: A measure of relative biological effectiveness.

quality grading: Department of Transportation requirements for labelling of various tire safety and performance criteria by the manufacturer.

quality level: See acceptable quality level

quality management: See total quality management

quality of service: The overall performance level of a network connection as perceived by its users, covering such aspects as speech quality, digital error rate and delay jitter.

quality systems: Ways of managing materials, components and products so as to ensure high-quality control of manufactured products at all levels

quantile: The argument of the cumulative distribution function corresponding to a specified probability; (of a sample) the value below which occur a specified proportion of the observations in the ordered set of observations.

QuantiMet: A trade name for a machine which analyses material surfaces for microstructural variables such as grain size diameter, orientation etc. Based originally on the optical microscope, extended to electron optical examination. Uses computer techniques to perform statistical analyses based on stereological methods.

quantitative analysis: Identification of the relative amounts of substances making up a sample. It usually refers to elemental analysis, but may refer to any constituent of the sample. In addition to chemical methods, virtually every physical property can be a basis for some analytical method, and spectroscopic and electrochemical techniques are particularly often employed.

quantity of electricity: A product of the flow of electricity (current) and time during which it flows. The term may also refer to a charge of electricity.

quantity of light:

A product of luminous flux and time during which it is maintained; usually stated in lumen-hours.

quantity of radiation: Product of intensity and time of X-ray radiation. Not measured by energy, but by energy density and a coefficient depending on ability to cause ionization.

quantity surveyor: One who measures up from drawings and prepares a bill (or schedule) of quantities showing the content of each item. This is then used by contractors for estimating. The quantity surveyor also periodically measures and assesses the value of the work done.

quantization: [1] See digitize. [2] In quantum theory, the division of energy of a system into discrete units (quanta), so that continuous infinitesimal changes are excluded. [3] In pulse-code modulation, the division of the amplitude range of a continuously variable signal, e.g., speech or video, into discrete levels for the purposes of sampling and coding.

quantization distortion: The distortion that arises in the mapping of a continuous signal on to a number of discrete levels so that it may be coded for digital transmission.

quantization distortion unit: A measure of quantization distortion equivalent to the transition from analogue to 64 Kbits--1 A-law digital code and back again.

quantization noise: Noise introduced into a circuit using pulse-code modulation because there are too few levels of quantitation to describe the waveform accurately.

quantometer: An instrument showing by spectrographical analysis the percentages of the various metals present in a metallic sample.

quantum:

[1] A general term for the indivisible unit of any form of physical energy; in particular the photon, the discrete amount of electromagnetic radiation energy, its magnitude being hv where v is the frequency and h is Planck's constant. See graviton magnon phonon roton [2] An interval on a measuring scale, fractions of which are considered insignificant.

quantum chromodynamics: (QCD) The theory of strong interactions between elementary particles including the interaction that binds protons and neutrons to form a nucleus. It assumes that strongly interacting particles are made of quarks and that gluons bind the quarks together.

quantum efficiency: The number of electrons released in a photocell per photon of incident radiation of specified wavelength.

quantum electrodynamics: (QED) A relativistic quantum theory of electromagnetic interactions. It provides a description of the interaction of electrons, muons and photons and hence the underlying theory of all electromagnetic phenomena.

quantum electronics: The study of the amplification or generation of microwave power in solid crystals, governed by quantum mechanical laws.

quantum field theory: The overall theory of fundamental particles and their interactions. Each type of particle is represented by appropriate operators which obey certain commutation laws. Particles are the quanta of fields in the same way as photons are the quanta of the electromagnetic field. So gluon fields and intermediate vector boson fields can be related to strong and weak interactions. Quantum field theory accounts for the lamb shift.

quantum gravity:

The theory that would unify gravitational physics with modern quantum field theory.

quantum Hall effect: The effect in which Hall resistivity changes by steps so that it is a fraction of h/e2 where h is planck's constant and e is the electronic charge. Observed in twodimensional semiconductors (e.g., metal-oxide-silicon) at high magnetic fields and ultra-low temperatures. Also see Hall effect.

quantum mechanics: A generally accepted theory replacing classical mechanics for microscopic phenomena. Quantum mechanics also gives results consistent with classical mechanics for macroscopic phenomena. Two equivalent formalisms have been developed: matrix mechanics (developed by W. Heisenberg) and wave mechanics (developed by E. Schrödinger). The theory accounts for a very wide range of physical phenomena. See correspondence principle statistical mechanics

quantum number: One of a set of numbers describing possible quantum states of a system, e.g., nuclear spin. See principal quantum number spin

quantum statistics: Statistics of the distribution of particles of a specified type in relation to their energies, the latter being quantized. See Bose-Einstein statistics Fermi-Dirac statistics

quantum theory:

The theory developed from Planck's law to account for black-body radiation, the photoelectric effect and the Compton effect and to form the Bohr model of the atom and its modification by Sommerfeld.

quantum tunnelling: See potential barrier tunnel effect

quantum voltage: Voltage through wich an electron must be accelerated to acquire the energy corresponding to a particular quantum

quantum wire: A nano-structure proportioned like a wire so that electron behavior is strongly constrained by quantum mechanical effects in two dimensions.

quantum yield: The ratio of the number of photon-induced reactions occurring to the total number of incident photons.

quaquaversal fold: A dome-like structure of folded sedimentary rocks which dip uniformly outward from a central point.

quark: A type of fundamental particle that forms the constituents of hadrons. There are currently believed to be six types (or flavours) of quarks (and their antiquarks): up, down, charm, strange, top, bottom. In quark theory, the baryon is composed of three quarks of different colour, an antibaryon is composed of three antiquarks, and a meson is composed of a quark and an antiquark. No quark has been observed in isolation.

quarl: See burner firing block

quarrel:

The diamond-shaped pane of glass used in fret-work

quarries: Same as quarry tiles

quarry: [1] An open working or pit for granite, building-stone, slate or other rock. [2] An underground working in a coal mine for stone to fill the goaf. Distinction between quarry and mine is somewhat blurred in law, but usage implies surface workings.

quarry-faced: A term applied to a building-stone whose face is hammer-dressed before leaving the quarry.

quarry-pitched: A term applied to stones which are roughly squared before leaving the quarry.

quarry stone bond: A term applied to the arrangement of stones in rubble masonry.

quarry tile: The common unglazed, machine-made paving tile not less than .75" (20 mm) in thickness, Also called "promenade tile."

quart: One-quarter of a gallon, or two pints (UK 1.14 liter, US 0.946 liter in liquid measure, 1.1 liter in dry measure).

quartation: See inquartation

quarter: [1] The phase of the Moon at quadrature. The first quarter occurs when the longitude of the Moon exceeds that of the Sun by 90°, the last quarter when the excess is 270°. The two other quarters are the new Moon and full Moon. [2] The fourth part of a hundredweight, equivalent to 28 (or in US 25) pounds avoirdupois.

[3] A unit equal to 8 bushels. See hinged quarter window rear quarter valance

quarter bend: A union connecting two pipes at 90°

quarter bond: The ordinary brickwork bond obtained by using a 2.25" (57 mm) closer.

quarter-bound: A term applied to a book having its back and part of its sides covered in one material and the rest of its sides in another.

quarter bumper: A type of shortened bumper designed to give a car a sporting image. Instead of extending around the full width of the car, short bumper sections around the lefthand and right-hand corners leave the center unprotected. This type of bumper was popular on certain sports models manufactured by Opel and Ford in the 1970s

quarter-chord point: The point on the chord line at one quarter of the chord length behind the leading edge. Sweepback is usually quoted by the angle between the line of the quarterchord points and the normal to the aircraft fore-and-aft center-line.

quarter-elliptic leaf spring: A cantilevered half of a semi-elliptic leaf spring, rigidly attached to a vehicle at its major section and carrying the axle at its end section

quarter-inch cartridge: (QIC) A standard for computer tapes.

quartering: A method of obtaining a representative sample for analysis or test of an aggregate with occasional shovelsful, of which a heap or cone is formed, This is flattened out and two opposite quarter parts are rejected. Another cone is formed from the

remainder which is again quartered, the process being repeated until a sample of the required size is left.

quarter light: [1] A small, roughly triangular, front-door window that swings out on fixed hinges; situated in front of and separate from the main window. [2] A small, roughly triangular window situated behind the main rear-door window

quarter light filler panel: A relatively small, roughly triangular panel, usually black, inserted into the rear side-window's rear bottom corner

quarter lines: The aggregation of waterlines, buttocklines, sections and diagonals indicative of a ship's form, drawn on a scale of .25" = 1 ft. See fairing

quarter page folder: A supplementary device to give a third fold in line with the run of the paper on webfed presses.

quarter panel: A rear section of the body shell which incorporates the rear fender and usually also the C-pillar. In modern car bodies, the rear fender usually is no longer a separate welded or bolt-on panel, Instead it blends smoothly into the bottom of the rear window frame and the rear panel

quarter-phase systems: See two-phase systems.

quarters: [1] Accommodations (i.e., a place where occupants of a ship can stay). [2] Also see flanks

quarter-space landing: A landing extending across only half the width of a staircase.

quarter turn:

A wreath subtending an angle of 90°

quarter valance: See rear quarter valance

quarter-wave antenna: One whose overall length is approximately a quarter of free-space wavelength corresponding to frequency of operation. Under these conditions it is oscillating in its first natural mode, and is half a dipole.

quarter-wave bar: See quarter-wave line

quarter-wavelength stub: Resonating two-wire or coaxial line, approximately one quarter-wavelength long, of high impedance at resonance. Used in antennas, as insulating support for another line, and as a coupling element.

quarter-wave line: Quarter-wavelength section of transmission line designed to operate as a matching device between lines of different impedance levels.

quarter-wave plate: A plate of quartz, cut parallel to the optic axis, of such thickness that a retardation of a quarter of a period is produced between ordinary and extraordinary rays travelling normally through the plate. By using a quarter-wave plate, with its axis at 45° to the axes of a polarizer, circularly polarized light is obtained.

quarter window: [1] A small, roughly triangular, front-door window that swings out on fixed hinges; situated in front of and separate from the main window. [2] A small, roughly triangular window situated behind the main rear-door window. Also see hinged quarter window

quarter window filler panel: A relatively small, roughly triangular panel, usually black, inserted into the rear side-window's rear bottom corner

quartic equation: An algebraic equation of the fourth degree, i.e., ax4+bx3+cx2+dx+e=0. Its resolution into a pair of quadratic equations, and hence its solution, depends upon the solution of a subsidiary cubic equation.

quartile: The argument of the cumulative distribution function corresponding to a probability of either 1/4 (first or lower quartile) or 3/4 (third or upper quartile); (of a sample) the value below which occurs a quarter (first or lower quartile) or three-quarters (third or upper quartile) of the observations in the ordered set of observations.

quarto: The quarter of a sheet, or a sheet folded twice to make four leaves or eight pages; written 4to.

quartz: Crystalline silica, SiO2, occurring either in prisms capped by rhombohedra (lowtemperature quartz, stable up to 573°C) or in hexagonal bipyramidal crystals (hightemperature quartz, stable above 573°C). Widely distributed in rocks of all kinds; igneous, metamorphic and sedimentary; usually colourless and transparent (rock crystal), but often coloured by minute quantities of impurities as in citrine, cairngorm, etc; also finely crystalline in the several forms of chalcedony, jasper etc.

quartz crystal: A disk or rod cut in the appropriate directions from a specimen of piezoelectric quartz, and accurately ground so that its natural resonance shall occur at a particular frequency.

quartz-diorite: A coarse-grained holo-crystalline igneous rock of intermediate composition, composed of quartz, plagioclase feldspar, hornblende and biotite, and thus intermediate in mineral composition between typical diorite and granite.

quartz-dolerite: A variety of dolerite which contains interstitial quartz usually intergrown graphically with feldspar, forming patches of micropegmatite. A dyke-rock of worldwide distribution, well represented by the Whin Sill rock in N. England.

quartz-fiber balance:

A very sensitive spring balance, the spring being a quartz fiber

quartz-fiber electroscope: A personal radiation monitor whose state can be viewed at any time. The fiber is charged periodically and discharged by radiation.

quartz glass: See vitreous silica

quartz halogen bulb: See quartz-halogen bulb.

quartz-halogen bulb: A bulb with an inner quartz bulb which holds a tungsten filament. Usually the inner bulb contains an inert gas such as iodine or one of the other five halogen gases. The use of a halogen gas prevents the bulb from turning black and thus reducing the amount of light output. Because this type of bulb requires intense heat, a quartz inner bulb is needed instead of glass. As a result, the quartz-halogen bulb produces more light per watt of electrical power. When replacing a quartz-halogen bulb, it is important not to touch the outer bulb with your fingers. The moisture and oils deposited on the glass will cause the glass to break under the high temperature.

quartz-iodine lamp: A compact high-intensity light source, consisting of a bulb with a tungsten filament, filled with an inert gas containing iodine (sometimes bromine) vapor. The bulb is of quartz, glass being unable to withstand the high operating temperature (600°C). Used for car-lamps, cine projectors etc.

quartzite: The characteristic product of the metamorphism of a siliceous sandstone or grit. The term is also used to denote sandstones and grits which have been cemented by silica.

quartz-keratophyre: A type of soda-trachyte carrying accessory quartz.

quartz lamp: One which contains a mercury arc under pressure, a powerful source of ultraviolet radiation.

quartz oscillator: One whose osciliation frequency is controlled by a piezoelectric quartz crystal.

quartz porphyrite: A porphyrite carrying quartz as an accessory constituent; the representative in the medium grain-size group of the fine-grained dacite.

quartz porphyry: A medium-grained igneous rock of granitic composition occurring normally as minor intrusions, and carrying prominent phenocrysts of quartz.

quartz resonator: A standard of frequency comparison making use of the sharply resonant properties of a piezoelectric quartz crystal.

quartz topaz: See citrine

quartz tuning system: (QTS) quartz-controlled tuning system with digital tuning and frequency display; uses microprocessor-controlled PLL circuitry

quartz wedge: A thin wedge of quartz which provides a means of superposing any required thickness of quartz on a mineral section being viewed under a polarming microscope, the wedge being cut parallel to the optic axis of a prism of quartz crystal. It enables the sign of the birefringence of biaxial minerals to be determined from their interference figure in convergent light.

quartz wind: A form of acoustic streaming near ultrasonic transducers operated at high amplitudes

quasar: A distant, compact, object far beyond our Galaxy which looks star-like on a photograph but has a red shift cbaracteristic of an extremely remote object.

quasi-biennial oscillation: (QBO) Alternation of easterly and westerly wind regimes in the equatorial stratosphere with an interval between successive corresponding maxima of from 24 to 30 months. A new regime starts above 30 km and propagates downward at about 1 km per month.

quasi-bistabie circuit: An astable circuit which is triggered at a high rate as compared with its natural frequency.

quasi-duplex: A circuit which operates apparently duplex, but actually functions in only one direction at a time, e.g., a long distance telephone or a radio link, which is automatically switched by speech.

quasi-elastic method: A method of stress analysis for non-linear and/or time-dependent materials, especially polymers, in which elastic moduli in the elastic equations are replaced by the values of the corresponding secant modulus or creep modulus, at the required levels of strain or time, respectively.

quasi-Fermi levels: Energy levels in a semi-conductor from which the number of electrons or holes available for conduction under nonequilibrium conditions; esp. when light is falling on the semiconductor, can be calculated in the same way as from the true Fermi level which applies under equilibrium conditions.

quasi-geostrophic approximation: An approximation to the dynamical equations governing atmospheric flow, esp. the vorticity equation, whereby the horizontal wind is replaced by the geostrophic wind in the term representing the vorticity, but not in the term representing the divergence.

quasi-longitudinal wave: A special type of wave occurring in plates and bars. The particle motion is mainly longitudinal and has a small transverse component caused by lateral contraction.

quasi-optical waves:

Invisible electromagnetic waves with similar wavelength and laws of propagation to visible light.

quasi-stationary front: A weather front which is moving slowly and irregularly so that it cannot be described as either a cold front or a warm front.

quasi S-VHS playback: The facility for playing S-VHS tapes in a VHS video recorder - with VHS resolution.

quaternary: [1] A chemical term consisting of four components etc.; also, connected to four non-hydrogen atoms. [2] The geological period which succeeded the Tertiary. It includes the Pleistocene and Holocene epochs and covers a time span of approx the last two million years.

quaternary ammonium bases: Bases derived from the hypothetical ammonium hydroxide NH4OH, in which the four hydrogen atoms attached to the nitrogen are replaced by alkyl radicals, e.g., (C2H5)4NOH, tetraethyl-ammonium hydroxide. quaternary diagram: Phase diagram of four-component system.

quaternary phaseshift keying: Used in microwave links and satellite communications to double the channel capacity of conventional binary phase-shift keying without changing the bandwidth. The phase of the carrier can be set by modulation to any one of four positions.

quattro: An Italian term for "four" and indicates that a car has four-wheel drive

queen: A slate 36 x 24 in (914 x 610 mm).

queen bolt:

A long iron or steel bolt serving in place of a timber queen-post.

queen closer: A half-brick made by cutting the brick lengthwise.

queen-post: The two spaced vertical ties required for roofs of more than about 30 ft (ca 10 m) span, where the central support of the tie-beam by the king-post is insufficient.

queen post roof: A timber roof having two queen-posts but no king-post.

quench: [1] to damp or suppress a spark. [2] A resistor or resistor-capacitor shunting a contact, to reduce high-frequency sparking when a current is broken in an inductive circuit

quench area: A zone in the combustion chamber where the piston at top dead center is very close to the cylinder head. Because the piston and cylinder head is cooler than the unburned part of the fuel-air mixture (i.e., end gas), they pull the heat from the end gas. Because the end gas is now cooler, detonation is quenched or reduced. However, the process does form unburned hydrocarbons.

quenched cullet: A cullet made by running molten glass into water

quencher: A material introduced into a luminescent substance to reduce the duration of phosphorescence.

quench frequency: The lower frequency signal used to quench intermittently a high-frequency oscillator, e.g., in a super-regenerative receiver.

quenching: [1] Dipping a heated object into water, oil or other substance, to quickly reduce the temperature. Quenching into water gives a more rapid cooling rate than into oil. The

term also applies to cooling in salt and molten-metal baths or by means of an air blast. Applied to steels heated above their upper critical temperature in order to harden them prior to tempering and to other alloys for solution treatment prior to precipitation hardening. [2] A nuclear engineering term to describe the process of inhibiting continuous discharge, by choice of gas and/or external valve circuit, so that discharge can occur again on the incidence of a further photon or particle in a counting tube. [3] A suppression of oscillation, particularly periodically, as in a super-regenerative receiver.

quenching media: See hardening media

quenching oscillator: One with a frequency slightly above the audible limit, and which generates the voltage necessary to quench the high-frequency oscillations in a super-regenerative receiver.

quench oil: Oil injected into the product stream leaving a cracking or reforming heater. It lowers the temperature of the stream and thus stops (quenches) any further, undesired, chemical reaction.

quench time: That required to quench the discharge of a Geiger tube. Dead time for internal quenching, paralysis time for electronic quenching, although dead time is often used synonymously for the other two terms.

quench zones: Those parts within the combustion chamber of an engine where the temperature of the air-fuel mixture is lower than necessary for optimum combustion, due to contact with the relatively cold metal surface; incomplete combustion in the quench zones is one of the two major factors contributing to HC and CO concentrations in the exhaust gas

query language: A method of retrieving information interactively from a database without having to write a complex program. Simple commands such as FIND postcode = "SO9 2QU" are used.

queue: A list for which insertions are made at one end and deletions at the other. The arrangement is called FIFO.

queuing: Programs waiting, in order determined by their priority, for access to the central processor in a time-sharing system.

queuing: The situation that arises in a digital network or other system when data arrives at a device faster than the device can process it, in which data is allowed to accumulate in a buffer until a reduction in data rate allows it to be dealt with.

quick-break switch: A switch having a spring or other device to produce a quick break, independently of the operator.

quicking: Electrodeposition of mercury on a surface before regular plating.

quicklime: See caustic lime lime

quick make-and-break switch: See snap switch

quick release: See quick-release.

quick-release: A cam-lever mechanism used to rapidly tighten or loosen a wheel on a bike frame, a seatpost in a seat tube, or a brake cable within cable housing.

quick release skewer:

See quick-release skewer.

quick-release skewer: A thin rod that runs through the center of a wheel axle; a cam-lever is attached to one end and the other end is threaded to receive a nut. See skewer.

quick return mechanism: A reciprocating motion, for operating the tool of a shaping machine etc, in which the return is made more rapidly than the cutting stroke, so as to reduce the "idling" time.

quicksand: Loose sand mixed with such a high proportion of water that its bearing-pressure is very low. Also called "running sand."

quick-setting inks: A general term for inks formulated to set quickly, allowing handling of the stock after printing

quick-setting level: See fixed-needle surveying

quicksilver: The metal mercury. Often used in thermometers.

quick sweep: A term applied to circular work in which the radius is small.

quick take-up valve: A residual pressure valve with a relief hole in a brake master cylinder

quick test: A functional diagnostic test of Ford's EEC system that displays test results as a series of service codes

quiescent:

A general term for a system waiting to be operated, as a valve ready to amplify or a gas-discharge tube to fire.

quiescent carrier transmission: One for which the carrier is suppressed in the absence of modulation.

quiescent current: A current in an active device in the absence of a driving or modulating signal.

quiescent operating point: The steady-stats operating conditions of a valve or transistor in its working circuit but in the absence of any input signal.

quiescent period: That period between pulses in a pulse transmission.

quiescent push-pull amplifier: (QPP) Thermionic valve or transistor amplifier, in which one side alone passes current for one phase, the other side passing current for the other phase.

quiescent tank: A form of sedimentation tank in which sewage is allowed to rest for a certain time without flow taking place.

quiet automatic volume control: The application of this is known as "quieting." Also delayed automatic gain control.

quieting sensitivity: The minimum input signal required by a frequency-modulation radio receiver to give a specified signal/noise ratio at the output.

quill: [1] Similar to the rattrap type of bicycle pedal except that the two sides of the pedal frame are joined by a piece of metal that loops around the dust cap. [2] A form of drive used for electric locomotives in which the armature of the driving motor is mounted on a quill surrounding the driving axle, but connected to it only by a flexible connection. This enables a small amount of relative motion to take place between the motor and the driving axle.

[3] A hollow non-rotating shaft in which another shaft rotates under power, for providing axial movement as in a drilling machine spindle.

quill bearing: See needle bearing.

quill drive: See quill

quill pedal: Similar to the rattrap type of bicycle pedal except that the two sides of the pedal frame are joined by a piece of metal that loops around the dust cap.

quill shaft: A hollow shaft

quill-type bearing: See needle bearing.

quinaldine: 2-methylquinaline. C10H9N. Bp 246°C. A colorless refractive liquid, which occurs to the extent of 25% in quinoline obtained from coaltar.

Quincke's method: A method for determining the magnetic susceptibility of a substance in solution by measuring the force acting on it in terms of the change of height of the free surface of the solution when placed in a suitable magnetic field.

quinhydrone: C6H4O2 + C6H4(OH)2. An additive compound of one molecule of l.4 quinone and one molecule of l.4-dihydroxybenzene. It crystallizes in green prisms with a metallic lustre.

quinhydrone electrode: A system consisting of a clean, polished, gold or platinum electrode dipping into a solution containing a little quinhydrone, for determining pH-values, making use of the pH dependence of the redox properties of the system

quinine: C20H24O2N2N23H2O. Mp 177°C. An alkaloid of the quinoline group, present in Cinchona bark. It is a diacid base of very bitter taste and alkaline reaction. It crystallizes in prisms or silky needles; the hydrochloride and sulphate are used as a febrifuge but have been largely superseded as a remedy for malaria, although they are still used in the treanment of leg cramps.

quinizarine: A synonym for 1.4-dihydroxy-anthra-quinone

quinol: See hydroquinone

quinoline: A heterocyclic compound consisting of a benzene ring condensed with a pyridine ring. It is a colorless, oily liquid, mp -19.5°C, bp 240°C, rel.d. 1.08, of characteristic odor, insoluble in water, soluble in most organic solvents. It is found in coaltar, in bone oil, and in the products of the destructive distillation of many alkaloids. It can be synthesized by heating a mixture of aniline, glycerine, and nitrobenzene with concentrated sulphuric acid.

quinones: Compounds derived from benzene and its homologues by the replacement of two atoms of hydrogen with two atoms of oxygen, and characterized by their yellow color and by being readily reduced to dihydric phenols. According to their configuration they are divided into 1.2-quinones and 1.4-quinones.

quinonoid formula: A formula based upon the diketone configuration of 1.4-quinone (benzoquinone), involving the rearrangement of the double bonds in a benzene nucleus; adopted to explain the formation of dyestuffs, e.g., coloured salts of compounds of the triphenylmethane series.

quinoxalines: A group of heterocyclic compounds consisting of a benzene ring condensed with a diazine ring. They can be obtained by the condensation of 1.2-diamines with 1.2diketones.

quintal: (q) Unit of mass in the metric system, equal to 100 kg.

quintic equation: An algebraic equation of the fifth degree. Unlike like equations of lower degree, its general solution (and that of equations of higher degree) cannot be expressed in terms of a finite number of root extractions.

quintozene: (PCNB) Pentachloronitrobenzene. Used as a fungicide

quintuple point: A point on a concentration-pressure-temperature diagram at which a threecomponent system can exist in five phases.

quire: A paper quantity: 25 sheets or 1/20 of a ream

quire spacing: On a rotary printing press, as the product is delivered, it is separated into quires or batches by the kicker which delivers a kick copy at the required interval.

quirewise: Sections which after printing are folded and insetted one in the other. This method allows the booklet to be stitched instead of stabbed.

quirk: The narrow groove alongside a bead sunk flush with a surface.

quirk-bead: See bead-and-quirk

quirk float: A plasterer's trowel specially shaped for finishing mouldings.

quirk moulding:

A molding having a small groove in it

quirk-router: A form of plane for shaping quirks

quitclaim: A deed of relinquishment of a claim or portion of mining ground.

quoin: [1] An exterior angle of a building, esp. one formed of large squared cornerstones projecting beyond the general faces of the meeting wall surfaces. [2] A wooden wedge or a metal device used to lock up formes.

quoin header: A brick laid at the external angle of a building to be a header in the wall proper and a stretcher in the return wall.

quoin post: See heel post

quotations: Metal spaces of varying widths, 1, 2, 3, or 4 em used for filling blanks in pages or formes.

quotient group: The group G/N whose elements are the cosets of N in G, where N is a normal subgroup of G. The product of two cosets is defined to be equal to the coset which contains the product of an element of the first coset and an element of the second.

Q-value: [1] Quantity of energy released in a given nuclear reaction. Normally expressed in MeV, but occasionally in atomic mass units. [2] Ratio of thermonuclear power output to power needed to maintain the plasma.

QWERTY keyboard: A keyboard laid out in the standard typewriter pattern where the top row of letters begins with the letters "QWERTY"

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Ra] [Re] [Ri] [Ro] [Ru]

R: [1] Letter designation for tires to indicate that they are radial as in P185R13 tire. See speed rating. [2] Reverse. [3] A letter on a fuel gauge indicating low fuel; when first illuminated it indicates that there is approximately five litres left in reserve

RAC: Acronym for the Royal Automobile Club

race: [1] The inner or outer ring that provides a contact surface for the balls or rollers in a bearing. [2] A competition (usually based on speed) between two vehicles. See drag race race camshaft [3] To run an engine at high speed when not in gear. See bearing race drag race inner race

race cam: A type of camshaft for race car engines which increases lift of valve, speed of valve opening and closing, length of time valve is held open, etc. Also called full cam, three-quarter cam, or semi-race cam, depending upon design

race camshaft:

A camshaft, other than stock, designed to improve engine performance by altering cam profile. Provides increased lift, faster opening and closing, earlier opening and later closing, etc. Race camshafts are available as semi-race or street grind, threequarter race camshaft or full race. Grinds in between these general categories are also available.

racer: See boy racer cafe racer

racing: See banger racing

Racing Green: See british Racing Green

racing harness: See 4-point racing harness

racing start: A start on a normal street, e.g., at traffic lights, using excessive throttle resulting in wheelspin and screeching tires

rack: A long, toothed bar. See ache rack head ache rack luggage rack roof rack steering rack trunk rack

rack and pinion:

See rack and pinion gearbox.

rack and pinion gearbox: A type of steering system with a pinion gear on the end of the steering shaft. The pinion engages a long rack (a bar with a row of teeth cut along one edge). When the steering wheel is turned, the pinion turns and moves the rack to the left or right. This movement is carried through tie rods to the steering arms at the wheels.

rack and pinion steering: See rack and pinion gearbox.

rack-and-pinion steering: See rack and pinion gearbox.

rack galvanizing: A galvanizing method for objects which can be placed on a rack

rad: Abbreviation for radiator

radar detector: A device which will sense the presence of a radar device which law enforcement officers might be using to spot speeders.

radial: See radial engine radial tire

radial bearing: A bearing designed to absorb the radial forces acting on a pump. Compare thrust bearing

radial clearance:

See radial play

radial compressor: A compressor with pistons radiating out from the centerline of the compressor. The Harrison (Frigidaire) is a typical example

radial cracking: Cracking of sidewall rubber running perpendicular to the tire beads. May result from underinflation or exposure to ozone.

radial discharge nozzle: Booster venturi with four spokes or arms which carry fuel to the outer circumference of the booster before discharging it from tiny holes in the ends of the spokes. Used only on the Corvair Model H carburetor.

radial engine: An engine with a number of cylinder arranged in a circle around the crankshaft center line. A design often used for aircraft engines.

radial-flow pump: An end-suction centrifugal pump with the liquid flowing perpendicular to the pump shaft

radial play: A bearing clearance in the radial direction

radial ply: The ply or plies used in tire in which the cords run at right angles to the bead and parallel to the tire radius. See radial tire.

radial runout: [1] A tire assembly that does not form a true circle; the radii of the circle are not equal. Most usual causes are bent wheel (out of round) or tire not mounted properly (beads not seated). This is one of the main causes of vehicle vibration. [2] A variation in the diameter of a brake disc, wheel, or tire from a specified amount

radial shaft seal:

A typical seal design used to prevent leaks between stationary parts and rotating shafts and to exclude foreign matter. A lip seal, typically of neoprene, is held in a metal retainer and applies a sealing pressure to a rotating shaft, the pressure being provided by an annular garter spring winch surrounds the sealing lip; radial shaft seals are used wherever a shaft penetrates a casing, such as on crankshafts, camshafts, water pump shafts, etc.

radial tire: A type of tire construction which has the main carcass plies or cords which run at right angles to the bead and parallel to the radius. By itself, this construction is very weak because when the bias angle is smaller, the structure is stiff. However, the radial tire has a very large bias angle. In order to strengthen the tire, a belt surrounds the circumference. This belt is made of low-angle plies (usually about 15 degrees). In this way, the tread area is stiff and the sidewall are flexible. In this way they can act independently of each other. In a P185/80R13 tire, R indicates a radial tire. Also see steel belted radial tire

radiant drier: See infrared radiant drier

radiation: The transfer of heat from one object to another when the hotter object sends out invisible rays or waves that upon striking the colder object, cause it to vibrate and thus heat. Also see thermal radiation

radiator: A device that cools the liquid in the cooling system by allowing it to circulate through a series of water channels, which are exposed to air ducts. See crossflow radiator downflow radiator heat exchanger pressure radiator cap rodding the radiator

radiator cap: A pressure cap at the top of the radiator. Also see pressure radiator cap

radiator drain cock:

A radiator tap; unlike the radiator drain plug, tools are not required to drain the coolant from a radiator with a drain cock

radiator drain plug: A threaded closure plug located at the underside of a radiator used to drain the coolant; usually equipped with a hex or Allen head

radiator fan: Two types are used on automobiles: a crankshaft-driven fan connected by a temperature-sensitive viscous coupling, or a fan driven by an electric motor

radiator fan motor: An electrically operated motor responsible for driving the radiator fan. An electric motor allows much more freedom in radiator location and engine bay design and permits aftercooling of the engine with the engine switched off: most engines mounted crosswise at the front (as on most front-wheel-drive subcompacts) use electric radiator fans which also lead to reduced power losses, since the vehicle's engine is not also required to drive the radiator fan also. The problem with them, however, is that even with the engine off, the fan may start up unexpectedly for the person inspecting the engine bay.

radiator fill hole: An opening at the top of the radiator through which new water and coolant can be added. The pressure cap seals the fill hole.

radiator grille: The grating that admits cooling air to the radiator

radiator grille surround: The sheet metal panel for mounting the radiator grille; often combined with the front apron to form a single front panel

radiator guard: See side radiator guard

radiator hose: The rubber pipe connecting the radiator to the cylinder block

radiator hose shark tooth pliers: A special automotive tool for removing and installing radiator and heater hoses; round and toothed jaws securely grip the hose while the handles provide leverage to twist the hose free

radiator pressure cap: See pressure cap.

radiator support panel: A panel located behind the radiator grille surround which provides a mounting for the radiator and connects the mudguard skirts at their front edge

radiator tank: A reservoir containing the coolant in a radiator. Early units were made from sheet metal, typically brass or aluminum. Newer versions used advanced polymer technology and injection molding processes have made it possible to produce radiator tanks from thermoplastics. Since all modern cars use forced circulation systems, there is no need for a vertical flow through the radiator. Thus most radiators are horizontally arranged

radio: A device which receives radio signals (either AM, FM, or both) and plays the sound through the speakers. Automobile radios began to appear in vehicles in 1928. Even in the mid-1960s, many cars came without radios. See car radio cb radio citizens band radio din radio mobile two-way radio

radio/cassette deck: (r/c) A combined radio and tape deck

radio choke: An electric coil used to prevent static in the radio caused by opening and closing of the contact points in the instrument voltage regulator

Radio Data System: (RDS) A system which interrupts a radio broadcast with the latest information on e.g., traffic problems

radio frequency interference: (RFI) interference generated by the ignition system and other electrical apparatus; counteracted by suppressors

radiograph: A photograph obtained by passing X-rays or gamma rays through the object to be photographed and recording the variations in density on a photographic film.

radius: See buffered radius crown radius free radius loaded radius radius rods rolling radius scrub radius static loaded radius turning radius unloaded radius

radius arm: An additional suspension link in a beam axle layout providing fore-and-aft location of the axle

radius rod: An additional suspension link in a beam axle layout providing fore-and-aft location of the axle

radius rods: Rods or arms which are part of the suspension, usually a live rear axle. They are attached to the axle and pivoted on the frame. They are used to keep the axle at right angles to the frame (i.e., prevent lateral movement) and yet permit an up and down motion. On some cars like the Triumph Spitfire, they are used to help locate the swing axles.

radius seat: A spherical seat that provides positive centering of the wheel bolt head in the wheel

rag: See tack rag.

rage: See road rage

ragtop: Colloquial term for convertible.

RAI: Acronym for "Nederlandse vereniging de Rijwiel-en-Automobiel Indusrie" (Netherlands).

rail: A dragster built around a relatively long pipe frame. The only body panels used are around the driver's cockpit area. See drip rail fender rail fuel rail oil rail roof rail running on rails seat rail shift rail shift rails side rail

rail console: See seat rail console

rails:

See running on rails shift rails

rail, shift: See shift rails.

Railton: A vehicle brand of which the 1925-1948 models, with required application, are classic cars.

rain: See acid rain

raising: The action of beating a rounded shape out of a flat panel by starting in the center and working outward in a spiral to the edge; the metal is shrunk around the edge but remains about the same in the center

rake: [1] The angle at which a rod is attached. Also see fork rake. [2] The fore-and-aft inclination from the vertical

raked: Ground clearance, at either front or rear of the vehicle, reduced or increased, thus giving the vehicle a tilted appearance.

RAM: Acronym for "Random Access Memory" -- memory that serves as a temporary storage place for data from the sensors

ram air: In a ram air system, carburetors get fresh air to be mixed with the gasoline via forward facing ducts. The idea is that as the bike moves faster, more air is forced or rammed into the carburetors resulting in improved performance.

ram induction: Using the forward momentum of vehicle to scoop air and force it into carburetor via a suitable passageway.

ram intake manifold: An intake manifold that has very long passageways that at certain speeds aid the entrance of fuel mixture into the cylinders.

ramp: [1] Equipment used to support a vehicle's front or rear for underbody work. [2] A device used to raise a vehicle in the air

ramp-over angle: An indication of how high a hump the vehicle can negotiate without scraping the undercarriage or becoming high-centered; that is, stuck with the center of the vehicle on the hump and the wheels in the air.

ram pressure: The pressure generated by the deflection of the fluid flow due to the curvature of the stator blades, resulting in a momentum acting on the turbine

R&D: Acronym for "Research & Development."

randonnée: A long bicycle touring ride of 160 to 1200 kilometers made up of several controls (checkpoints).

randonneur: A male long-distance cyclist. Also see the female randonneuse

Randonneur 5000: One of the most prestigious awards a randonneur can earn. To be one of the recipients, a randonneur must do a full series of 200, 300, 400, 600, and 1000km brevets, a Paris-Brest-Paris randonneur event, a Fl`che team ride, and the remaining distances ridden on sanctioned brevets for a total of 5000 kilometers. The qualifying events must all be completed within a four-year period.

Randonneurs Mondiaux: An "umbrella" organization of national randonneuring groups. Its primary functions are to organize foreign (i.e., France, Spain, United Kingdom, Holland, Belgium, Australia, Denmark, Sweden, Norway, Finland, Austria, Germany, Russia, South Africa, Canada, and the United States) participation in Paris-Brest-Paris and other 1200-kilometer brevets, encourage the exchange of information of interest to randonneurs, and reward clubs' and individuals' participation in long-distance randonnées with various medals and trophies.

randonneuse: [1] A female long-distance cyclist. [2] A bicycle specifically designed for randonneuring.

range: See gear range heat range heat range reserve high/low range gearbox high/low range transmission load range mid-range product range rev range

range-change: See auxiliary gearbox

range gearbox: See high/low range gearbox

range gearing: See wide range gearing

range reserve: See heat range reserve

Range Rover: A model of SUV manufactured in England

Click for books on Range Rover

range transmission: See high/low range transmission

rank: See taxi rank

rash: See road rash

rasp: [1] A tool like a file with coarse teeth used to prepare a tire for section repair and for buffing prior to retreading. [2] The action of using a rasp tool.

ratchet: [1] A feature of a special wrench which allows you to turn the handle in one direction to tighten a nut or bolt, but turning it in the opposite direction does nothing but position the handle back where you started and leaves the wrench on the nut or bolt. Likewise you could set the wrench to loosen a nut or bolt. [2] A drive handle with ratchet mechanism, usually called a socket wrench. [3] A toothed rack or wheel which is engaged by a lever to permit motion in only one direction. Also see tap ratchet

ratchet adapter: A device which converts a torque wrench or drive handle without a ratchet mechanism into a reversible ratchet tool

ratchet handle: A ratchet tool

ratchet screwdriver: A screwdriver with a ratchet mechanism

rate:

See base interest rate burn rate charging rate conversion rate damping rate deflection rate discharge rate flat rate flat rate manual flow rate net interest rate progressive rate spring rising rate suspension spark rate spring rate turn-in rate

rated capacity: The quantity of electricity which can be drawn from a fully charged battery for 20 hours by a constant discharging current until cutoff voltage of 1.75 volts per cell is reached. Compare ampere-hour capacity

rated horsepower: See SAE horsepower.

rated power: The power output of an engine as horsepower or kilowatt

rated pressure: A nominal pressure rating applied to vehicle parts

rated voltage: The voltage given for electrical equipment or devices which refers to specified operating conditions

rate manual:

See flat rate manual

rate spring: See progressive rate spring single rate spring variable rate springs

rates: See door rates

rate suspension: See rising rate suspension

rating: See amp/hr. rating amperage rating axle weight rating capacity rating cetane rating gross axle weight rating gross Combined Weight Rating gross Vehicle Weight Rating load rating manufacturer's performance ratings octane rating ply rating rated capacity speed rating tow rating

ratio: A fixed relationship between things in number, quantity or degree. For example, if the fuel mixture contains one part of gas for fifteen parts of air, the ratio would be 15 to 1. See

a/f ratio a/f ratio air-fuel ratio air fuel ratio air ratio aspect ratio axle ratio back axle ratio bore-stroke ratio braking ratio compression ratio economy ratio final drive ratio fuel-air ratio fuel air ratio gear ratio overall gear ratio power-to-weight ratio power to weight ratio primary compression ratio rear axle ratio speed ratio stall torque ratio steering overall ratio steering ratio stoichiometric ratio

rationalization: An industrial reorganization primarily aimed at a more cost-effective and timesaving production process

ratio steering: See variable ratio steering

rat-tail file: A round file

rattle: See body rattle

death rattle diesel rattle

rattle spring: See spreader spring

rattrap: The type of bicycle pedals that have thin metal plates with jagged edges running parallel on each side of the pedal spindle.

RAVE valve: A device used on two-stroke engines which automatically alters or varies the exhaust port size. It stands for Rotax adjustable variable exhaust.

Ravigneaux planetary gear set: A system which is composed of two sun gears of different diameters, one internal gear, and several planet pinions

raw exhaust gas: The exhaust gas upstream of any emission control device, e.g., before it passes through a catalytic converter

raw rubber: Natural rubber that has not been vulcanized

Raymond-Mays: A vehicle brand of which the 1925-1948 models with required application are classic cars.

rayon: A synthetic fiber.

rays: See infrared rays

ultraviolet rays

r/c: See radio/cassette deck

RDS: Acronym for radio data system

rdstr: Abbreviation for "roadster."

reach: The distance from the sealing washer of a spark plug to the end of the thread

reaction: See air injection reaction reinforced reaction injection molding

reaction distance: The time needed to respond to a situation, translated into the distance required for this, depending on the speed of travel; braking distance plus reaction distance equals the stopping distance

reaction injection molding: (RIM) A processing technique for the production of large foamed automotive components, based on the simultaneous injection of the liquid components and the chemical reaction in the mold. Compare polymerization. In some cases, the components are mixed immediately before being injected into the mold. The term "RIM" is also applied to refer to the plastic material produced by this technique, e.g., "RIM-PUR." Also see reinforced reaction injection molding

reaction member:

See stator

reactive suspension: See electronic ride control

reactor: See stator thermal reactor

reactor one-way clutch: See stator roller clutch

reader: See fault reader

real-time four-wheel drive: An automatic four-wheel drive engagement by means of an electro-hydraulic clutch or a viscous coupling incorporated in the drivetrain

ream: [1] To enlarge (e.g., worn valve guides) with a reamer. [2] To finish a hole accurately with a rotating fluted tool

reamer: A conically or cylindrically shaped tool with longitudinally cut teeth for manual or machine operation, used for precision finishing of bores. See terminal reamer tubing reamer valve guide reamer

rear: The back of a vehicle or component.

See five-link rear suspension folding rear seats four-link rear suspension heated rear window independent rear suspension multi-link independent rear suspension multi-link rear suspension

rear apron: See rear valance

rear-axle: See front-axle and rear-axle split twist-beam rear axle

rear axle crossmember: A tubular frame member at the rear of the body shell that incorporates the mounting points for the rear axle, e.g., on the VW Beetle and the Porsche 911

rear axle differential: A differential situated in the final drive of the transmission assembly in a conventional rear-wheel drive vehicle

rear axle housing: See banjo type split type

rear axle housing, banjo type: A rear axle housing from which the differential unit may be removed while the housing remains in place on the vehicle. The housing is solid from side to side.

rear axle housing, split type: A rear axle housing made up of several pieces and bolted together. The housing must be split apart to remove the differential.

rear axle ratio: The number of times the rear wheels turn compared to a particular transmissionspeed. The higher the rear axle ratio, the slower the engine can run and still allow the vehicle to achieve a given speed. Also called "Final axle ratio."

rear-axle split: See front-axle and rear-axle split

rear bulkhead: The vertical panel across the width of the car that extends behind the rear seat backrest and separates the interior from the trunk

rear bumper skirt: A rear bumper with integral skirt; a large plastic molding

rear cabin pillar: See C-pillar

rear corner panel: The bottom corner of the rear fenders. For manufacturing reasons, often a separate panel

rear corner valance: The bottom corner of the rear fenders. For manufacturing reasons, often a separate panel

rear deck: The surface of the rear of a sedan which includes the lid of the trunk

rear deck panel: The sheet metal panel extending from the bottom of the rear window to the rear panel and enclosing the cutout for the trunk lid, extending sideways to the top of both rear fenders. In some cases, this panel covers only the area between the bottom of the rear window and the front edge of the trunk lid

rear differential: A differential situated in the final drive of the transmission assembly in a conventional rear-wheel drive vehicle

rear end: The rear part of the body shell, extending approximately from the rear seat pan to the rear apron of the car, incorporating the trunk floor

rear end lift: The tendency of the back of a speeding vehicle to rise, reducing traction. It can be counteracted by a spoiler

rear engine: An engine located at the rear of a vehicle but outside the wheelbase (i.e., behind the rear wheels). Compare front engine and mid-engine car

rear fender: The body panel which partially encloses a rear wheel

rear fog lamp: A red light with the same intensity as a brake light

rear fog light: A red light with the same intensity as a brake light

rear head restraints: (rhr) head rests located on the back passenger seats

rear-hinged door: A older type of door construction that had the hinges at the rear of the door so that the opening was toward the front (i.e., opposite to modern car doors)

rear lamp cluster: A group of lights at the rear corners of a vehicle, commonly comprising: tail lamp, brake lamp, back-up lamp, rear fog lamp, reflector, and signal light

rear light surround: A separate panel spot-welded at the juncture between the trailing edge of the rear fender and the rear valance to provide a mounting base for the rear lights

rear license plate lamp: A white light illuminating the rear license plate

rear license plate light: A white light illuminating the rear license plate

rear panel: A British term for back panel

rear quarter valance: See rear corner valance

rear seat belt: An inertia reel belt attached at each end of the rear seats; a passenger riding in the middle of the rear seats must be satisfied with just a lap belt, which many safety experts regard as inadequate. Some manufacturers (notably those from Scandinavia) are tackling the somewhat costly problem and providing secure lap and shoulder belts for all passengers riding in the rear seats

rear seats: See folding rear seats split folding rear seats split rear seats

rear sets: Racing-style footrests mounted toward the rear of the machine to allow the rider to adopt a racing crouch

rear shelf:

The interior shelf extending over the trunk at the level of the top of the rear seats

rear side window: One of several types of side body glass: the side window between the B-posts and C-posts of two-door sedans and coupes, the rearmost side window of station wagons between the C-post and D-post, i.e., behind the rear seat backrest, and the third side window found on some four-door sedans behind the rear side doors

rear spoiler: An aerofoil mounted on the rear deck or trunk, typically made of shock-resistant polyurethane with paintable matt black finish. It is effective only at high speeds, but frequently used for the sake of appearance. Most sports cars are equipped with front and rear spoilers (air dams and rear spoilers) to improve the aerodynamic performance by reduced lifting force

rear suspension: The axles, springs, and linkages which control the movement of the rear wheels. See five-link rear suspension four-link rear suspension independent rear suspension multi-link independent rear suspension multi-link rear suspension

rear tack strip: A fixed or hinged bar on a convertible top which holds the rear end of the hood against the rear deck

rear triangle: A bicycleframe triangle formed by the chainstays, seatstays, and the seat tube.

rear valance: A separate panel set below the rear panel which extends approximately from behind the rear bumper downward to protect the rear end from splashes of mud. In designs with a single-piece rear panel that incorporates the rear valance, the whole area is sometimes referred to as the rear valance or rear panel

rearview mirror:

An interior mirror which allows the driver to see behind him.

rear wash/wipe system: An electrical system for cleaning the rear window, comprising a water pump, reservoir, and wiper

rear-wheel drive: (RWD) A configuration in which the rear wheels of the vehicle are driven

rear-wheel drive transaxle: A rear-wheel drive construction incorporating a transmission-differential unit placed between the rear wheels of a front-engined car. The engine may be a front engine (as in most cars and all trucks), a mid-engine (as in some sports and racing cars), or a rear engine (as in some city cars, VW Beetle, the Porsche 911 series, and most buses); RWD ensures good acceleration without wheelspin even on cars with powerful engines; on most small cars, RWD has been superseded by front-wheel drive

rear wheel skirt: See fender skirt

rear wheel spat: British term for fender skirt

rear window: The central window at the rear of a vehicle. Although the American term is backlight, most Americans still call it the rear window or back window. Also see heated rear window

rear window heater system: A heating element that removes the fog, mist, or even ice from the inside and outside of the rear window (i.e., backlight)

rear window heating: See rear window heater system

rear window louvres:

A plastic molding attached to the rear window which deflects sun rays to keep the interior cool; usually hinged to lift up for easy window cleaning

rear wiper: A window wiper that cleans the rear window

reboard system: A child restraint system typically installed backwards on the front passenger seat and having the benefit that the child's relatively heavy head is pressed into the back of the child seat instead of being displaced forward in a frontal crash. A system initially available only for babies, but originating from Sweden, they are increasingly offered for children up to six years old; some reboards cannot be used in conjunction with a passenger-side air bag system

rebore: To grind out a worn or damaged cylinder usually .25 mm or (.01") at a time to fit an oversize piston.

rebound: The action of a shock absorber to spring back to its fully extended state. The opposite of rebound is jounce. See bump and rebound jounce and rebound

rebound clip: A metal clip that holds the leaves of a multi-leaf spring together

rebound stroke: The downstroke of a piston in a damper or shock absorber. Compare compression stroke

rebuild: To disassemble a particular device, clean it thoroughly, replace worn parts, and reassemble it. Also called "overhauling" or "recondition."

rebuilt engine:

An engine reassembled using either new parts or reconditioned components

recap: [1] Adding a top strip of synthetic or reclaimed rubber to buffed and roughened surface of a worn tire. [2] The top strip itself See retread.

recharge: The action of bringing a product back to its full or original level. Recharging a battery brings the voltage back to its recommended level. Recharging the air conditioner means filling the system with refrigerant.

receiver: [1] (e.g., of radio remote control system) device that receives incoming electrical or radio signals. The opposite is transmitter. [2] A steel tubing and channel structure that accepts the ball-mount platform of a removable trailer coupler. See air receiver air tank

receiver-dehydrator: Storage tank and filter for liquid refrigerant and containing a drying agent to remove moisture from circulating refrigerant. Also called receiver-drier

receiver-drier: A device on the high side of an air-conditioning system, somewhere between the condenser and the expansion valve, which stores excess refrigerant and removes moisture from the refrigerant; consists of a tank, a filter, a drying agent, a pick-up tube, and, on some units, a sight glass. Also called receiver-dehydrator Compare accumulator-drier

recess: See combustion chamber recess

recessed spark position: A position where the spark gap is actually in the shell of the spark plug. It is used for racing and special engines

rechargeable battery: See storage battery

reciprocating action: A back-and-forth or up-and-down movement such as the action of the pistons.

reciprocating compressor: A positive displacement compressor with pistons that move back and forth in cylinders; rarely used for supercharging, more frequently used for air conditioning

reciprocating engine: An engine with a piston that moves to and fro, coming to a standstill at each reversal

reciprocating pump: See piston charging pump

reciprocation: A back-and-forth or up-and-down movement such as the action of the pistons.

recirculating ball: See recirculating-ball-and-nut steering.

recirculating ball and nut steering: See recirculating-ball-and-nut steering.

recirculating-ball-and-nut steering: A very popular type of steering gear. It uses a series of ball bearings that feed through and around and back through the grooves in the worm gear and nut on the steering shaft. The turning forces are transmitted through these ball bearing to a sector gear on the pitman-arm shaft. When the steering wheel is turned, the worm gear on the end of the steering shaft rotates and the movement of the recirculating balls causes the ball nut to move up and down along the worm. Movement of the ball nut is carried by teeth to the sector gear which in turn moves with the ball nut to rotate the pitman-arm shaft and activate the steering linkage. The balls recirculate from one end of the ball nut to the other through a pair of ball return guides. This system is also called ball-and-nut steering or worm-and-recirculating-ball steering.

recirculating ball steering: A special version of the worm-and-nut steering in which ball bearings circulate between the nut and worm to reduce friction

recirculating ball worm and nut: See recirculating-ball-and-nut steering.

recirculation: See exhaust-gas recirculation fuel vapor recirculation system

recirculation system: See fuel vapor recirculation system

recognition: See voice recognition

recon: A colloquial term for reconditioned engine

reconditioned engine: A worn engine that has been given a new lease of life by reboring the cylinders, regrinding the crankshaft journals and generally replacing any worn or damaged parts

recorder: See crash recorder trip recorder

recovery:

See breakdown recovery vapor recovery

recovery/recycling equipment: Equipment that must now be used when servicing air conditioner systems. This equipment captures refrigerant removed from an air conditioning system and stores or recycles it

recovery system: See coolant recovery system vapor Recovery System

recreational vehicle: (RV) [1] Any vehicle (motorized or trailered) in which temporary camping is done. They are divided into seven categories: • • • • • • •

Folding camping trailer Truck camper travel Trailer Fifth-wheel travel trailer Type A motorhome Type B motorhome Type C motorhome

. [2] A British term for any vehicle used for pleasure rather than business or transport (e.g., dune buggy, quad) (i.e., an ATV)

rectangular headlight: A modern shape of headlight as opposed to the traditional circular headlight

rectangular-section ring: A compression ring with a rectangular cross-section

rectification: The process of changing AC to DC

rectifier: A device used to change AC (alternating current) into DC (direct current). Some small motorcycles use a single diode for this purpose (half-wave rectifiers), the overwhelming majority use four diodes connected in a bridge which yields fullwave rectification. See diode full-wave rectifier half-wave rectifier

rectifier diode: A semiconductor diode in an alternator that converts alternating current to direct current

rectifier pack: A diode heat sink with diodes in an alternator

recumbent: A bicycle in which the rider sits low between the two wheels. The seat is "Lshaped." The rider's back is against the upright portion of the seat. His feet are almost straight forward. The pedals are just behind the front wheel. The handlebar is located below the rider.

recycling: See charge-air recycling vapor recycling

recycling car: A car built with recycled materials and designed so as to facilitate recycling

red flag:

A solid red flag is used to stop the race immediately. Generally races are stopped for bad accidents or weather. Occasionally, a multiple car pileup will halt a race. Wreckers and fire marshals clear the track of cars, debris and fluids. Alternatively, rain makes the surface of the race track dangerous. Once NASCAR officials authorize the race to start again, a green flag resumes the race.

red lead: (pronounced "LED") A poisonous, bright-red powder, soluble in excess glacial acetic acid and dilute hydrochloric acid; used for corrosion protection

red line: [1] Top recommended engine rpm. If a tachometer is used, it will have a mark (red line) indicating maximum rpm. Some tachometers mark the red line with a colored sector. Others have two lines: the lower one marking the maximum allowable sustained engine rpm, the higher line indicating the absolute maximum rpm. [2] (RL) Tires with a red concentric line which were marketed in the late '60s and early '70s.

reduced shank: A shank whose diameter approximately equals the effective pitch diameter

reducer: The solvent that is used to thin enamel. See thinner general purpose lacquer thinner

reducer valve: See vacuum reducer valve

reducing adapter: An adapter whose male end for the socket is smaller than the female end for the drive handle. Opposite to increasing adapter

reducing agent: A material which adds electrons to an element or compound in chemical reactions, i.e., which increases the positiveness of its valence

reducing catalyst: A catalyst such as rhodium which converts nitrogen oxides into harmless nitrogen and oxygen in a reducing catalytic converter. Compare oxidizing catalyst

reducing flame: An oxygen-fuel gas flame with a slight excess of fuel gas.

reducing furnace: A section in continuous galvanizing lines in which the oxygen content of steel surfaces is reduced at 900-980°C by means of hydrogen

reduction: A chemical reaction in which an element gains electrons, i.e., has an increase in positive valence. Compare oxidation. See cap cost reduction capitalized cost reduction double reduction gearing noise reduction

reduction effort: See supplier cost reduction effort

reduction gearbox: A gearbox located at the wheels, which reduces the drive speed and may also increase ground clearance; often found on 4WD off-road vehicles

reduction gearing: See double reduction gearing

reduction of area: Difference in cross sectional area of a specimen after fracture, as compared to original cross sectional area.

reed:

A part of a reed valve made of flexible steel, or of glass fiber reinforced resin, attached to the valve case and normally closed. The reeds are designed to open readily under pressure from the incoming mixture, but will close rapidly once the pressure inside the crankcase reaches that of the surrounding atmosphere; in this way, the maximum amount of mixture is admitted and any back-leakage is prevented

reed stop: A component of a reed valve used to limit upward travel of the reed

reed valve: A one-way valve used in a two-cycle engine. It is made of a flat strip of metal that lies on the floor of the crankcase over a hole connected to the carburetor. As the piston moves up, the vacuum developed in the crankcase lifts the reed valve off the hole. The vacuum causes the fuel-air mixture to flow from the carburetor into the crankcase. Then, as the piston starts to move down, pressure increases in the crankcase pushing the reed valve down, closing the hole and sealing the crankcase.

reed valve induction timing: Using a reed valve located in the intake system to control induction timing

reefer: [1] A refrigeration unit which is mounted on a large truck to cool the contents in the trailer. [2] A ship designed for carrying goods requiring refrigeration

reefer container: An insulated container fitted with a refrigeration unit for carrying cargo requiring temperature control

reel: A revolving, often cylindrical device for winding up or letting out cord, wire, or strap. See inertia reel seat belt inertia reel locking reel

reel seat belt: See inertia reel seat belt

reface: A general term for reconditioning of the interface between valves and their seats in the cylinder head; depending on valve seat condition, refacing may involve lapping, grinding, or cutting

reference ignition pattern: An oscilloscope pattern of an intact ignition system for comparison purposes

reference input: In a closed-loop control, the reference input is fed to a controller that changes a controlled variable in a controlled system to achieve a certain output condition or actual value

reference mark sensor: A magnetic pick-up attached to the flywheel for sensing the crankshaft position and transferring the signal to the electronic control unit, which calculates the ignition point; the reference mark sensor scans a pin or a hole in the flywheel and produces one output signal per crankshaft revolution

reference pressure: The fuel bowl is vented to the outside air to maintain a constant (atmospheric) pressure on the fuel, thus maintaining a constant fuel level as a point of reference for the other system in the carburetor

reference temperature: The temperature at which measuring tools and pieces being worked on must have the specified measurements; the reference temperature 20°C applies to all statements of technical measurements unless the contrary is expressly stated

reference voltage: A voltage provided by a voltage regulator to operate potentiometers and other sensors at a constant level

refinishing:

See paint refinishing

refinishing paint: A paint sold specifically for resprays; many paint formulas used in the factory are not suited for respray equipment, so special paints for the repair trade are required

refinish system: The complete product lines and product support offered by many paint manufacturers for respray operations in body shops; these include all materials from primers and thinners to the topcoat plus additional respray products; all products are matched for optimum results

refit: closure of a plant for the purpose of plant conversion or retooling.

reflectance: The ratio of reflected luminous flux to that reflected from an ideal, perfectly reflecting surface when similarly illuminated

reflector: [1] A part of a headlight which receives light from the bulb and reflects it back through the lens. [2] A part of a rear lamp cluster which reflects the light from headlights behind. See parabolic reflector triangular safety reflector

reformulated gasoline: Fuel with less volatility and reduced levels especially of toxic hydrocarbons.

reformulated gasolines: Fuels with less volatility and reduced levels of especially toxic hydrocarbons.

refrigerant: The liquid used in refrigeration systems to remove heat from the evaporator coils and carry it to the condenser. It absorbs and gives up heat as it changes from a liquid to a gas to a liquid. Freon-12 was a common automotive refrigerant, but it has been

replaced by C134A.

refrigerant-12: The name applied to refrigerant generally used in automotive air conditioning systems and refrigerators. Also called freon-12.

refrigeration cycle: The complete circulation of refrigerant through an air conditioning system as it changes temperature and pressure, i.e., Changes its state from vapor to liquid, then back to vapor. Air-conditioning refrigerant in vapor form is pressurized in the compressor, air-cooled in the condenser, and becomes a liquid which passes through the receiver-drier into the expansion valve where it expands into low-pressure liquid. It then flows through the evaporator where it expands again and starts to boil, absorbing heat from the core and cooling the air going into the passenger compartment. The compressor draws off the low-pressure vaporized refrigerant and recycles it

refrigeration oil: A highly refined lubricating oil which is free of contaminants such as sulphur, moisture, and tar

refundable deposit: This is a refundable deposit required at lease inception. In some cases it may be used to satisfy the final monthly payment. It is sometime called a security deposit.

Regal: A model of automobile manufactured by Buick

Click for books on Buick Regal

regenerative braking: A system in which an electric motor can be switched to a generator mode when braking, so that the kinetic energy involved may be stored in the battery

register: To align with. The two-stroke piston is provided with cut-outs that line up with the intake ports as the piston moves up and down in the bore, i.e., they register with the ports. The fresh charge can thus enter the crankcase

registered keeper:

A British term for a person who keeps the car, i.e., who is registered and pays tax and insurance for the car, but is not necessarily the owner or the driver.

registered owner: The person who owns the car, i.e., the car is registered in his name and he pays the licence, tax, and insurance for the car.

registered tons: See gross registered tons

registration: [1] Motor vehicle ownership that is filed with the province/state. [2] The act of entering the details of a new vehicle in a supervised record

registration document: Papers giving details of a vehicle, including its manufacturer, date of registration, engine and chassis numbers, and owner's name. Also see vehicle registration document

registration number: A unique sequence of letters and numbers assigned to a vehicle when it is registered, usually indicating the year and place of registration, displayed on the vehicle license plate

registration plate: See license plate

registry: See certificate of registry open registry

regrind: [1] To smooth and polish again (e.g., valve seats). [2] A resin batch material produced by regrinding thermoplastic scrap and waste; such recycled material can be used to produce plastic parts which are not critical in terms of engineering properties or color, such as wheel arch liners or battery cases.

The opposite is virgin resin

regrooveable tire: See special mileage tire.

regrooving: The act of cutting new tread grooves into the crown of the tire after the original tread is worn down. A practice which is legally forbidden in many places.

regular gasoline: Gasoline which has the normal amount of octane and is less than premium or hightest gasoline.

regulated proportioning valve: See load-sensitive proportioning valve

regulating: See main regulating system pressure regulating valve

regulating system: See main regulating system

regulating valve: See pressure regulating valve

regulation traction control system: See anti-spin regulation traction control system

regulator: Any device which controls fluid (gas or liquid) flow, pressure, temperature, voltage, etc. See acetylene regulator

current regulator height regulator oxygen regulator pressure regulator valve pressure regulator system pressure regulator
regulator valve: See pressure regulator valve

regulator, voltage: See voltage regulator.

reinforce: To increase the strength of plastics by filling them with whiskers of glass, metal, fibres, etc. See glass reinforced filler paste glass reinforced plastic hinge pillar reinforcement

reinforced filler paste: See glass reinforced filler paste

reinforced plastic: See glass reinforced plastic

reinforced reaction injection molding: (RRIM) [1] A reaction injection molding of reinforced plastics. [2] The term also refers to the material produced by this technique. Compare reaction injection molding

reinforcement:

Any material, usually rubber and fabric, vulcanized to the tire to return strength to the cord body upon an injury. Also see hinge pillar reinforcement

reinforcement of weld: Excess metal on the face of a weld.

relative humidity: (RH) A dimensionless ratio of the actual vapor pressure of the air to the saturation vapor pressure

relay: [1] An electro-magnetically operated switch used to make and break the flow of current in a circuit. As low amperage current is passed through one circuit of the relay, it switches a greater current through another line. For example, when installing auxiliary lights with a heavy draw, the stock light switch may not be able to take the current. Thus a relay is installed so that when the light switch is turned on, low current is sent to the relay. The relay closes the circuit of heavy wiring directly from the battery to the lights. Also called "cutout" and "circuit breaker." [2] An automatic device which controls the setting of a valve, switch, etc. by means of an electric motor, solenoid, or pneumatic mechanism. See cutout relay hot-start pulse relay time delay relay

relay lever: See idler arm

relay rod: An intermediate rod between the pitman arm and idler arm

relay valve: See ABS Relay Valve.

release: See bonnet release

hood release quick-release quick release skewer

release agent: A substance to prevent a molding, i.e., a GRP part, from sticking to the mold and to facilitate its removal from the mold; as opposed to release wax, this is marketed only in liquid form

release bearing: See clutch release bearing

release button: A button at the end of the park brake lever which, when depressed, allows the pawl to be released from the ratchet

release finger: See clutch release finger clutch semi-centrifugal release finger semi-centrifugal release finger

release fingers: See clutch semi-centrifugal release fingers.

release lever: See clutch release lever

release skewer: See quick release skewer

release tool: See trim panel release tool

release wax: See release agent

releasing fluid: Penetrating oil for loosening seized parts

relief: [1] Amount one surface is set below or above another surface. [2] See high pressure relief valve pressure relief valve

relief passage: See bypass

relief valve: [1] See pressure relief valve. [2] A valve in the air pump of an air injection system which dumps part of the air at high pump speeds to prevent pump damage. It may be combined with the air gulp valve. See high pressure relief valve pressure relief valve

relieve: To remove, by grinding, the small lip of metal between the valve seat area and the cylinder and removing any other metal deemed necessary to improve the flow of fuel mixture into the cylinders. Porting is generally done at the same time.

relieved shank: See reduced shank

relieving: [1] Removal of some metal from around racing engine valves and between cylinder and valves to facilitate flow of gases.

[2] See stress relieving

reline: To replace the brake shoes in drum brakes

reluctor: See trigger wheel

remains: See sheet metal remains

remanufacturing: The process of taking a used part and returning it to original equipment (OE) specifications through disassembly and cleaning of the core, testing, and remachining or replacement of worn components.

re-metalling the bearings: A bearing repair method used on pre-war engines with poured bearings instead of Babbitt metal inserts. The Babbitt metal is poured into the bearing surfaces and is then scraped until a correct bearing surface is established

reminder: See lights-on reminder

remold: See retread

remote: See infrared remote control ir remote control

remote bulb: A sensing device connected to the expansion valve by a capillary tube. The bulb senses the temperature of the evaporator outlet pipe and controls the expansion valve accordingly

remote choke: Vacuum diaphragm is mounted on the carburetor, but the bimetal spring is mounted either on a pad on the intake manifold or in a heat well in the exhaust man. Choke lever is operated by a mechanical linkage rod from the bimetal spring. Also called divorced choke

remote control: [1] The control of something from a distance. [2] The device used for this. See See infrared remote control ir remote control

remote-control locking: A central locking device operated by a remote control from outside the car

remote keyless entry: A system where the door locks can be opened or locked by a small hand-held switching device located several meters/feet away. Some also contain a panic button that causes the lights to flash and the horn to honk if an intruder is seen near the vehicle. Most remote keyless entry devices turn on the vehicle's interior lights while unlocking the driver's door.

remote mirror: An outside mirror that is adjusted by a toggle device inside the passenger compartment. Older styles relied on a cable that transferred physical movement from the toggle to the mirror. On newer vehicles, the mirror is controlled by electrical controls.

remote starter switch: A special automotive tool that allows the ignition switch to be bypassed for cranking the engine

removable rim: See detachable rim

remover: A chemical or compound used to clear away unwanted material. See bug and tar remover rust remover spot-weld remover stud remover tar remover valve guide remover

Renault: A vehicle brand of which the 45 HP models of 1925-1948 with Click for books on required application are classic cars. Renault Reo: A vehicle brand of which the 1931-33 Royale 8-31, Royale 8-35, Royale 8-52, and Royale Custom 8 and 1934 N1, N2, and 8-52 are classic cars.

repair: To restore something to working condition, e.g., by reconditioning, rebuilding, or replacing. See body repair independent repair shop plug repair section repair

Repair and Service Council: See Canadian Automotive Repair and Service Council

repair gum: See cushion gum.

repair kit: A package of the parts needed to repair a particular component (e.g., carburetor, generator, pump, universal joint, etc.)

repair manual: A book which details the procedure for repairing one or more components of a vehicle. Compare service manual

repair section: A special panel supplied for body repairs that does not include the full panel used for assembling the car but only the most vulnerable areas; i.e., for fenders, separate repair sections are supplied for the headlight area and the bottom fender edges, where damage usually occurs. Compare replacement panel

repair shop: See independent repair shop specialty repair shop

repeater lamp: A British term for a signal light on the side of a vehicle

replacement market: all products and services used in the repair and maintenance of vehicles.

replacement panel: A body panel supplied for repair purposes; sometimes also used to denote a repair section

replacement vehicle: A car loaned by a dealer to a customer while the customer's car is under repair

replenishing port: An opening in the master cylinder body which connects the fluid reservoir to the annulus of the primary piston. Compare compensating port. In a tandem master cylinder, there is one replenishing port for each piston. It is the first port as seen from the pushrod end of the master cylinder and it is always open. Also called a breather port

replica panel: See pattern panel

repmobile: A colloquial term for a car used by a sales representative

repro: Abbreviation for "reproduction."

reproduction: Parts or complete vehicles that have been manufactured to closely follow or exceed original specifications, materials, and performance. Also called "repro" or "repros." These parts often are so perfect that not even a concours judge can tell that they are not NOS or OEM.

reproduction panel: See pattern panel

required ignition voltage: The maximum high voltage required to produce a spark under particular conditions

RES: [1] An abbreviation for "resume" on a cruise control switch which sets the cruise speed back to what it was after being shut off. [2] A ballast resistor

research & development: R&D expenditures (product and process development).

Research and Experimental Development Program: See scientific Research and Experimental Development Program

research octane number: (RON) A fuel octane rating determined by the research octane test, one of many test procedures. Compare octane number

reseat:

To recut a valve seat after repeated grinding-in has worn it out of shape

reservation: See central reservation central reserve

reserve: The amount left in the fuel tank. On many motorcycles there is no gas gauge. Instead, the fuel tap has two settings. The regular setting allows most of the fuel to be used. When this amount is finished, the fuel tap can be adjusted so that the remaining portion can be used. During this time, it is wise to fill up the tank. See central reserve heat range reserve high-voltage reserve voltage reserve

reserve capacity: The time, in minutes, that a battery can maintain a discharge rate of 25 amps

reservoir: [1] Any container filled with fluid. [2] The space between the outer and inner tubes of a double-tube shock absorber which takes up the oil squeezed out of the working chamber corresponding to the volume of the piston rod immersed in the working chamber. Also see brake fluid reservoir

reset button: A switch which puts the configuration of a component back to its standard setting.

reshaping: [1] A panel beating process for removing dents: the panel is brought roughly into its original shape before detailed work is performed in the finishing stage. [2] The process of forming a panel from sheet steel

residual: See expected residual value

residual check valve: See residual pressure valve

residual discount: If the end-of-lease purchase price (stated residual value) is greater than the expected end-of-lease value (expected residual value), the dollar difference represents the value of the vehicle that you will not pay for during the lease.

residual exhaust gases: The exhaust gas remaining in the cylinder of a two-stroke engine after the exhaust ports have been closed, i.e., these gases have not been scavenged

residual penalty: If the end-of-lease purchase price (stated residual value) is less than the expected end-of-lease value (expected residual value), the dollar difference represents the additional value of the vehicle you'll pay for during the lease.

residual pressure: Fuel pressure maintained within the system after engine shutdown. Also, pressure remaining in a hydraulic circuit after the brakes have been released

residual pressure check valve: A small valve, usually located in the outlet port(s) of the master cylinder, which maintains a certain amount of pressure in the hydraulic circuit(s) when the brakes are released

residual pressure valve: A valve mounted in the cylinder outlet between piston and brake lines of drum brake circuits. It maintains a certain minimum pressure in the system. Disc brakes do not require a residual pressure valve

residual value: See stated residual value expected residual value

residue: See combustion residue

resin: [1] A secretion from trees used in varnishes, printing ink, and plastic as a binder. [2] A synthetic product with some of the same physical properties as the plant secretion. [3] A liquid plastic used in body work. See acrylic resin epoxy resin gel-coat resin lay-up resin virgin resin

resist: A substance applied onto aluminum pieces before etching; no surface particles are removed where the surface is covered with the protective coating

resistance: [1] An opposing force. [2] A measure of a conductor's ability to retard the flow of electricity. See air resistance corrosion resistance fatigue resistance impact resistance test internal resistance knock resistance polarization resistance rolling resistance roll resistance surface resistance wear resistance

resistance shrinking:

Ripples in the bodywork are removed by shrinking the panel with the aid of heat from an electric current provided by the electrode of a special tool which is brought into contact with the rippled area

resistance test: See impact resistance test

resistance thermometer: An electrical temperature sensor which, in contrast to a thermocouple, needs an external voltage supply; the actual sensing element is a resistor whose resistance is an accurate indication of the temperature

resistance welding: Fusing metals using the resistance of the metals to the flow of electricity, as the source of heat.

resistant: See impact-resistant weather resistant

resistivity: The ability of a material not to conduct electricity. The opposite is conductivity

resistor: A device placed in a circuit to lower the voltage. It will also decrease the flow of current. See ballast resistor coil resistor ignition coil resistor load resistor

resistor spark plug: A spark plug containing a resistor designed to shorten both the capacitive and inductive phases of the spark. This will suppress radio interference and lengthen

electrode life. Using a non-resistor spark plug may also damage a CDI box.

resleeve: See re-sleeve.

re-sleeve: This is a term used of the piston cylinders. The old cylinder inserts are completely removed and new inserts or sleeves are pressed in. This action is done when the cylinder cannot be rebored. Also see cylinder sleeve.

resonator: [1] A small muffler-like device that is placed into the exhaust system near the end of the tail pipe. It is used to provide additional silencing of the exhaust. [2] Any device that attenuates pressure spikes

Resource Conservation and Recovery Act: Federal act that covers businesses that generate, transport, or manage hazardous wastes

response: See steering response

respray: To add one or more coats of paint to the existing finish. Also see partial respray

rest: See armrest backrest start from rest

restoration: The act of working on a vehicle with such care as to bring it back to its original condition (including original parts, paint, chroming processes, etc.) rather than merely rebuilding or repairing one.

restorationitis: A term coined by Mark A. Rock of Columbia Station, OH. A quasi-disease which affects a person with a restorable vehicle so that he feels compelled to work on his vehicle rather than eat, sleep, or anything else. While working on his vehicle to repair or replace a particular part, the "disease" compels him to disassemble, clean, polish, repair, etc. everything associated with the initial part and he justifies his actions by saying, "While I am at it, I might as well do it right." Also see detailitis

restorer: See finish restorer

restraint: A device used to halt the movement of something. See head restraint child restraint system passive restraint system rear head restraints supplementary inflatable restraint voluntary Export Restraint

Restraint Agreement: See Voluntary Restraint Agreement

restraint inflatable air-bag system: See supplemental restraint inflatable air-bag system

restraint system: A general term for occupant safety systems such as seat belts, belt tensioners, air bags, child seats, etc. See airbag restraint system child restraint system passive restraint system supplemental restraint system

restrictor:

See nozzle restrictor

restrictor plate: A plate attached to the carburetor that limits the amount of airflow entering the combustion chamber. It decreases horsepower.

rest stop: A place at the side of a road where drivers can stop (to rest). The British term is "lay-by"

resume: A switch on the cruise control system. If you are driving on cruise control, for example at 100 kph, and approach some slow traffic, you would normally apply the brakes. This action will disengage the cruise control and allow you to slow down. Once you are past the slow traffic, you can go back to the speed you had previously set by simply hitting the "resume" button. The vehicle will accelerate to that speed.

resurfacing: If the cylinder head is warped due to thermal differences, its mating surface will have to be machined to ensure first that a level surface is created and second that the engine's compression ratio is not increased above a tolerable value

retail: The price of something that the customer pays (in contrast with wholesale). See manufacturer's suggested retail price

retail price: See manufacturer's suggested retail price

retainer: A device which holds something in place. See pad retainer pin pad retainer valve keeper valve retainer valve spring retainer

retainer pin: See pad retainer pin

retainer plate: A plate which prevents a valve from sliding out of its bore

retainer spring tool: A special automotive tool used on drum brakes for restraining the shoe retaining springs for removal and installation. It comes in a variety of shapes, e.g., as a screwdriver-type tool with a special socket end to grip retaining washers

retaining ring: See truarc retaining ring

retard: [1] To set the ignition timing so that a spark occurs later or less degrees before TDC. It involves adjusting the camshaft, distributor spark, or valve operation. In this way, the spark plugs fire or the valves open later in the cycle. See ignition retard spark retard vacuum retard The opposite of advance. [2] The device for doing this action.

retarded: occurring late

retarder: [1] An additive to decrease the evaporation rate of a thinner or reducer in paint; used to improve viscosity in hot weather. [2] An auxiliary brake used on commercial vehicles and coaches (it is a requirement in some European countries). Also see energy retarder

retard unit:

See vacuum retard unit

retract: To draw back, pull back, or rewind

retractable aerial: A telescopic aerial or power antenna

retractable antenna: See power antenna

retractable headlights: See concealed headlights or hideaway headlights

retractor: A seat belt device which locks the reel of a seat belt when the forward acceleration of the occupants exceeds a certain value. See belt retractor headlight retractor indicator lamp

retractor indicator lamp: See headlight retractor indicator lamp

retread: [1] A means of extending the life of a tire that has worn its original tread, yet still has a sound carcass. The casing is prepared by buffing off tread rubber and vulcanizing new tread rubber stock in its place. [2] A casing to which tread rubber has been affixed to extend the useable life of the tire after the original tread has been worn out. [3] The term in some parts of the USA and Australia is "recap." Also see production retread shop

retreading: See retread.

retread shop: See production retread shop

retrofit: To equip a vehicle with new parts after it has been manufactured

return: See earth return fuel return line ground return

return line: See fuel return line

return spring: A spring which is attached to a lever so that when the lever is moved in one direction, the spring forces it back. See brake shoe return spring throttle return spring

return sweep: A body panel section presenting a concave appearance; its most common function is to strengthen loose panel areas such as the finish along the wheel aperture of the fender

rev: Abbreviation for revolution

rev counter: A colloquial term for tachometer

ReVere:

A vehicle brand of which the 1925-1948 models are classic cars.

reverse: [1] To drive backward or to back up. [2] Reverse gear (R). Also see auto reverse

reverse bias: Nonconductive condition that exists when current flow is blocked by a diode

reverse brake shoe: See trailing brake shoe

reverse clutch: A clutch which couples the components of planetary gear sets or trains in such a way that the vehicle can be driven backwards

reversed Elliot axle: An axle design in which the axle beam terminates in an eye, the steering knuckle axis dividing as a yoke or fork-shaped end which straddles the axle beam end

reversed polarity: (Electrode positive-anode) referring to DC and causing electrons to flow from the base metal to the electrode.

reverse Elliot steering knuckle: Type of axle construction in which steering spindle straddles ends of axle beam

reverse-Elliot type axle: A solid bar front axle on which the steering knuckles span or straddle the axle ends.

reverse-flow scavenging: A scavenging system for two-stroke engines in which a cylinder has two pairs of transfer ports, at the front and rear respectively, with two exhaust ports located on either side of the two pairs of transfer ports; the incoming streams of mixture spread out like a fan, are deflected downward and expel the spent gases

reverse flush:

Cleaning the cooling system by pumping a powerful cleaning agent through the system in a direction opposite to that of normal flow.

reverse gear: A very low gear for driving backwards, denoted by the letter "R" on a gear knob or gear selector

reverse idler gear: A gear used in the transmission to produce a reverse rotation of the transmission output shaft.

reverse inhibitor valve: A valve which prevents the engagement of the reverse clutch in an automatic transmissions if the vehicle road speed exceeds 10 kph (6 mph)

reverse lock: A steering condition where the front wheels are pointed in the opposite (reverse) direction of the turn. This technique is used in a rear wheel skid

reverse process: An immersion or combined spray/immersion process employed to apply two protective coatings which, in the case of body shells, replace the dip primer coat and the filler coat. The designation derives from the fact that the sequence in which the dip primer coat and the filler coat are applied is reversed. Compare electrostatic powder coating

reverse scavenging: See loop scavenging

reversible gear puller: A puller with two or more reversible jaws, allowing it to be used for inside and outside pulling

reversing light: A British term for back-up light

reversing warning signal:

British term for backup alarm

reversion: Excessive heating of a cured rubber compound leading to deterioration of its physical properties.

rev limiter: See engine speed limiter

revolution counter: [1] A tachometer, which measures the engine speed in rpm. [2] A counter which counts the total revolutions of a shaft as opposed to rpm

revolutions per kilometer: (RPK) A measurement of the number of times a tire turns in one kilometer of travel.

revolutions per mile: (RPM) A measurement of the number of times a tire turns in one mile of travel.

revolutions per minute: (RPM) The speed the engine crankshaft is turning. Also see RPM.

rev range: Automotive jargon for the range of speeds (expressed as revolutions per minute) in which an engine is designed to operate. The lowest point in the rev range is the idle speed; the highest point is the redline.

revs: [1] To increase the speed of an engine. [2] The number of revolutions per minute. See high revs peak revs

revving:

See free-revving

RFI: Acronym for radio frequency interference

RFI suppressed spark plugs: Fully shielded and resistor spark plugs

RH: [1] Acronym for "right hand," as in RH drive. For all vehicles, left and right are from the perspective of sitting in the driver's seat. [2] Acronym for relative humidity

RHD: Acronym for "right-hand drive."

rheostat: A resistor with variable resistance, e.g., the switch that dims the dash lights

rhodium: A silver-white noble metal in the platinum family; atomic number 45, atomic weight 102.905; used in thermocouples and, together with other platinum metals, as a catalyst in catalytic converters

rhr: Acronym for rear head restraints

rib: [1] The continuous raised portions of rubber that run circumferentially (straight or in a zigzag pattern) making up the tread on the tire. Also the term applies to various raised surfaces circling the sidewall, i.e., guide rib. [2] A structural member for reinforcing bodywork. See scuff rib tread rib

ribbing: [1] A series of raised portions in castings or moldings to increase rigidity. [2] A narrow recess stamped into relatively flat body panels, e.g., floorpans, that helps to reinforce the panel and to suppress vibrations in it

ricardo principle: An arrangement in which a portion of the combustion chamber came in very close contact with the piston head. The other portion, off to one side, contained more space. As the piston neared TDC on the compression stroke, the fuel mixture was squeezed tightly between the piston and head thus causing the mixture to squirt outward into the larger area in a very turbulent manner. This produced a superior mixture and allowed compression ratios to be raised without detonation.

rich: An air/fuel mixture that has more petrol than normal. The opposite is lean

rich air-fuel mixture: A mixture of air and fuel in which there is less air and more fuel. See air-fuel ratio.

rich mixture: A mixture of air and fuel in which there is less air and more fuel. See air-fuel ratio. The opposite is lean mixture. Also compare stoichiometric ratio. A slightly rich mixture generates the maximum achievable engine power, an overly rich mixture causes spark plug fouling, loss of engine power, and excessive fuel consumption. Any rich mixture increases exhaust emissions

ride: The degree of comfort, especially with regard to the suspension, experienced by the passengers. Also see electronic ride control

ride control: See electronic ride control

ride height: A measurement between the ground and some fixed reference point on a car's body. The exact location of the fixed point varies among manufacturers. This dimension can be used to measure the amount of suspension deflection or the height of the body from the ground. See ground clearance

ride-height adjuster: See ground clearance control

ride levelling: See automatic level control

rider: [1] A person who operates a motorcycle. [2] A passenger (but generally not the driver) of a car or truck. [3] A vehicle. See low rider

ride steer: A generally undesirable condition in which a wheel steers slightly as its suspension compresses or extends. Also called "bump steer."

ridge: [1] An edge, ledge, or lip which protrudes beyond the normal face of an object. See rim ridge. [2] The cutting edge of a screw thread above the flanks. [3] See pressure ridge. [4] A hump. See piston ring ridge burr

riding the clutch: A situation where the driver rests his foot on the clutch pedal while the vehicle is being driven. This action can cause undue wear on the clutch plates because they may be rubbing against each other ever so slightly.

rig: A large truck. See big rig jury rig

rigged: See jerry rigged jury rigged

rigger: See out-rigger

right: When referring to the side of a unit, the right side is always from the perspective of operation. In other words, when sitting in the driver's seat or when riding a bicycle or when pushing a mower, the right side is the operator's right hand side. In other words the left or right side is determined by facing the rear of the unit.

right-hand drive: (RHD) A steering system in which the steering wheel is located on the right-hand side of the vehicle; used for driving on the left, as in the UK, Japan, Australia, etc. The opposite is left-hand drive

right hand thread: See right-hand thread.

right-hand thread: The common direction (clockwise) which is used to secure a nut to a bolt. Also see left-hand thread.

right hand turn signal: A device which is attached to the turn signal lever on the left side of the steering wheel to allow disabled people to operate the turn signals from the right side. rights: See intellectual property rights

rigid:

Inflexible, without any flexural or elastic characteristic

rigid axle: A simple non-independent suspension, consisting of a rigid transverse member with wheel hubs solidly bolted to it. The axle can be attached to the body by leaf springs, or by a combination of suspension arms and links. A rear axle which may be either live (in rearwheel drive cars) or dead (in front-wheel drive cars)

rigid axle connection: fixed drive

rigidity: See torsional rigidity

Riley: A vehicle brand of which the 1925-1948 models with required application are classic cars. The 1945-55 2.5 (RMA, RME) models are milestone cars.

rim: [1] The outer edge of a dented area in a body panel that is heat shrunk towards the center of the dent. [2] On a bicycle, the metal or wooden hoop of a wheel that holds the tire and tube and the outer ends of the spokes. [3] On a truck, the metal assembly consisting of a base and either a side ring or a side and lock ring combination, which are removable from one side for tire mounting. The opposite side has a fixed flange to retain the tire. Note: Passenger and tubeless rims do not have removable side and lock rings. See ah rim asymmetric rim base rim center rim curing rim dc rim demountable rim detachable rim drop-center rim drop-centre rim drop center rim taper drop center rim drop centre rim

flat base rim taper flat base rim high center rim horn rim steering wheel hump rim intermediate rim taper multi-piece rim nominal rim diameter nominal rim width one-piece rim one-piece rim designation overall rim diameter removable rim safety rim semi-drop center rim single-piece rim split rim standard rim symmetric rim td rim tr-denioc rim tr rim well-base rim wheel rim wheel trim rim

RIM: Acronym for reaction injection molding

rim bead seat: The portion of the wheel rim below the rim flange providing radial support to the bead of the tire

rim bead seat taper: The narrowing of the rim width towards the rim well. The taper must be designed to lock the tire to the rim and provide a good seal; well-base rims for passenger cars have a 5° taper, those for commercial vehicles have a 15° taper; flat base rims for commercial vehicles have no taper

rim brake:

Any type of brake that slows or stops a wheel by pressing its pads against the sides of the wheel rim.

rim designation: The nominal rim diameter, nominal rim width and any abbreviations and codes for the contour of the rim. Compare multi-piece rim, and one-piece rim designation

rim diameter: The distance between the intersection of the bead seats and the vertical walls of the rim flanges. See nominal rim diameter overall rim diameter

rim drivers: Riveted or welded metal blocks or extrusions on both sides of the valve slot to prevent valve damage due to rim slippage on cast spokes.

rim flange: The part of a rim that supports the tire bead in a lateral direction; the linear distance between the two rim flanges is termed rim width

rim offset: A measurement in inches from the center of the rim (between the flanges) to the tip of the 28° gutter bevel.

rim pull: Actual amount of effort in pounds available at the point of contact of tire and road surface.

rim ridge: See hump

rim size: The dimension of a wheel covering the rim width and rim diameter and is measured in inches

rim steering wheel: See horn rim steering wheel

rim strip: See rim tape

rim tape: A rubber strap which covers the spoke nipples on the inside of the rim to protect the spoke from poking into the tube.

rim taper: The slope of the rim. See advanced rim taper base rim taper center rim taper drop center rim taper flat base rim taper intermediate rim taper semi-drop center rim taper

rim type: Depending on the type of tire, rim types differ according to the rim profile and the number of rim parts. Compare multi-piece rim, one-piece rim, and safety rim

rim well: The portion of the rim with a substantially smaller diameter than the bead seats and located with sufficient depth and width to enable the tire beads to be forced over the mounting side of the rim flange and bead seat taper for installation or removal

rim well base: The portion of the rim with a substantially smaller diameter than the bead seats and located with sufficient depth and width to enable the tire beads to be forced over the mounting side of the rim flange and bead seat taper for installation or removal

rim width:

The nominal distance between the rim flanges. The width of a rim is an important factor in the handling characteristics of a car: a rim that is too narrow in relation to the tire width will cause the tire to distort sideways under fast cornering. Unduly wide rims on an ordinary car tend to give a rather harsh ride because the sidewalls of the tire have insufficient curvature to make them flex properly over irregularities in the road. Also see nominal rim width

ring: A circular piece or band of metal. See balk ring blocking ring chainring chrome ring compression ring control ring D-ring D ring dykes ring fire ring flywheel ring gear fulcrum ring grooved compression ring heavy-duty ring wrench horn ring L-section ring lockring lock ring pliers molybdenum piston ring moly ring O-ring oil control ring oil ring pinned piston ring pinned ring piston ring clamp piston ring end gap piston ring expander piston ring flutter piston ring gap piston ring groove cleaner piston ring groove piston ring job piston ring pliers piston ring ridge

piston ring side clearance piston ring stop piston ring pivot ring rectangular-section ring ring and pinion ringbolt ring gear rotating seal ring rubber ring scraper ring side ring slip ring snap ring spacer ring stepped compression ring tapered compression ring truarc retaining ring valve seat ring wear ring

ring and pinion: A term used to describe the differential drive pinion and ring gear. See final drive ratio ring and pinion ring belt: The lands and rings of a piston

ringbolt: An iron bolt having a ring through an eye at one end, through which a rope can be passed and tied.

ring, chrome: See piston ring, chrome.

ring clamp:

See piston ring clamp

ring, compression: See piston ring, compression.

ring end gap: See piston ring end gap.

ring expander: See piston ring expander piston ring pliers

ring flutter: See piston ring flutter

ring gap: The gap between the piston ring ends with the piston installed in the bore. See piston ring end gap.

ring gear: [1] The large bevel, circular gear which is attached to the flange or carrier of the differential case. It meshes with the drive pinion on the end of the propeller shaft. [2] The outer gear in a planetary gearset. Also see flywheel ring gear. [3] annulus gear. [4] See crown wheel. [5] A toothed rim of a flywheel which engages the pinion of the starter motor. See flywheel ring gear starter ring gear ring groove: See piston ring groove.

ring groove cleaner:

See piston ring groove cleaner

ring groove insert: See top ring groove insert

ring job: See piston ring job.

ring, pinned: See piston ring, pinned.

ring pliers: See lock ring pliers piston ring pliers

ring ridge: See piston ring ridge.

rings: See piston ring.

ring side clearance: See piston ring side clearance.

ring spanner: A British term for a box wrench

ring stop: See piston ring stop

ring wrench: See heavy-duty ring wrench

rings: See whitewall rings

rinse: See no rinse treatment

rinse treatment: See no rinse treatment

ripping hammer: A hammer which looks like a claw hammer, but the claw is straight

rise: See dead rise

riser: See handlebar riser heat riser

rising rate: A suspension system that becomes harder to compress the farther it is compressed. This is usually achieved by a mechanical linkage with variable leverage ratio

rising rate suspension: See rising-rate suspension.

rising-rate suspension: A suspension system where the spring rate increases when the wheels move further into jounce. This action can be accomplished by configuring the geometric shape of the suspension, by using springs which change tension as they are compressed, or by using two or more springs with rubber stops. The purpose of a rising-rate suspension is to maintain consistent ride and handling characteristics under a variety of situations: loaded or unloaded, straight roads or curves, and smooth roads or bumpy.

rivet: A metal pin used to hold two objects together. One end of the pin has a head and the other end must be set or peened over to create another head See blind rivet pop rivet

riveted brake lining: A brake shoe that is attached to the backing plate with rivets rather than glued on.

riveter: A tool with pliers-like handles and nose piece to insert rivets. It is used, for example, in body repair work to rivet sheet metal material together

rivet gun: A tool with pliers-like handles and nose piece to insert rivets. It is used, for example, in body repair work to rivet sheet metal material together

riveting hammer: A hammer with a special head for securing rivets.

Riviera: A model of automobile manufactured by Buick

Click for books on Buick Riviera

RL: Refers to red line tires which were marketed in the late '60s and early 70s.

RMA: Acronym for "Rubber Manufactures Association"

road: Any large path upon which vehicles travel. See gravel road pit road rolling road

toll road

road closure: An action by the authorities to stop vehicles from using a road. It is usually done when there has been a serious accident blocking the road or when the road conditions are bad (such as snow storms, earthquakes, avalanches, etc.)

road course: A closed course with turns to both the right and the left mimicking a normal road.

road-draft tube: British term for oil breather pipe or oil breather tube

road feel: The feeling imparted to the steering wheel by the wheels of a vehicle in motion. This feeling can be very important in sensing and predetermining vehicle steering response.

road fund licence: A British licence showing that road tax has been paid

road hazard: Injury to a tire sustained in normal operation, excluding collision or vandalism and that is not reparable by accepted standards.

road hog: A selfish, often aggressive driver

roadholding: The ability of a vehicle to grip the pavement. Technically described as "lateral acceleration," because cornering is actually a continuous deviation from a straight path. Measured in g's.

road holding:

See roadholding

road load horsepower: The amount of power at the driving wheels needed to move a vehicle down the road at a steady speed. This power varies according to the vehicle's speed, aerodynamic drag, mechanical friction, and the tires' rolling resistance. Road-load horsepower is distinct from engine power because the output of the engine is sapped by various mechanical losses between the engine's output at its flywheel and the driving wheels.

road rage: The violent behavior by a driver which may be precipitated by being cut off, forgetting to signal, getting an insulting gesture, etc.

road rash: Any type of bruise or wound that is inflicted when you hit the ground, generally in a low-speed crash. A skinned knee is a type of road rash; multiply that by 100 and you get road rash that happens to unprotected motorcycle riders during an accident. High-speed crashes do much more damage.

road speed: A vehicle's speed along a road, measured in mph or kph

roadster: (Rdstr) This term derives from equestrian vocabulary where it was applied to a horse used for riding on the roads. Old dictionaries define the roadster as an opentype car designed for use on ordinary roads, with a single seat for two persons and, often, a rumble seat. It is an open-type body with one bench seat and a luggage compartment in the rear deck. The weatherproof fabric top may be folded, and side curtains may be removed. The windshield usually may be folded down. The original concept is maintained by the Morgan Plus 8 but modern roadsters include power features such as power steering, electric windows, etc. as in the Mercedes-Benz SL. Also see sport roadster.

road surfaces: See split-friction road surfaces

road tax:

An annual tax paid in order to use a vehicle on the roads

road test: [1] A test to check that a car is roadworthy after repair. [2] A test of a car (e.g., a new model) in actual use; for example, by a magazine for comparison with other models. See also test drive

road-test: To give a vehicle a road test

road train: Several linked trailers pulled by a large truck; common in Australia for transporting stock

roadworthiness: A vehicle which is fit to be driven on the roads

roadworthy: A mechanically sound vehicle which is fit to be driven on the roads

Roamer: A vehicle brand of which the 1925 8-88, 6-54e, 4-75; 1926 4-75e and 8-88; 1927; 1928; 1929 8-88; 1929 8-125; and 1930 8:125 models are classic cars.

Robertson screw: A screw with a recessed square hole. It is more commonly found in Canada than the US, especially in woodworking situations. It is easier to install and remove than a Phillips screw and does not strip the head as easily. There are four basic sizes (measured across the flats): 1.6 mm, 2.0 mm, 2.6 mm, and 3.0 mm.

robot: See painting robot

robot spraying: The application of paint by robots

Rochet-Schneider:

A vehicle brand of which the 1925-1948 models with required application are classic cars.

rocker: See closing rocker forked rocker arm forked rocker high lift rocker arms

rocker arm: A curved lever that pivots in the middle. One end is attached to the top of the valve stem. In overhead-valve engines the other end is attached to the push rod. In some overhead-cam engines the other end is attached directly to the camshaft lobe. As the camshaft rotates, the rocker arms pivot causing the valves to open and close. See ball joint rocker arm forked rocker arm high lift rocker arm

rocker arm cover: A metal lid located on top of the cylinder head on vehicles that have valves that are activated by an overhead cam or by rocker arms. See valve cover.

rocker arm shaft: The shaft upon which the rocker arms are mounted so that the rocker arms can pivot

rocker box: A British term for valve cover (i.e., a cylinder head cover above the valve train)

rocker cover: A British term for valve cover (i.e., a cylinder head cover above the valve train)

rocker cover gasket: A British term for valve cover gasket, (i.e., a gasket between the cylinder head and the valve cover; usually either a flat paper or cork gasket or an O-ring

rocker panel: That section of the vehicle body between the front and rear fenders and beneath the doors. A sill

rocker shaft: A British term for cross shaft (i.e., the outgoing shaft of the steering gearbox, to which the pitman arm is connected)

rocket: See crotch rocket

rocking: See piston rocking

Rockwell hardness: A measurement of the degree of hardness of a given substance.

rod: [1] A modified car. Also see street rod. [2] To drive a vehicle hard. [3] A connecting rod. See connecting rod boxed rod throwing a rod [4] To clean out a radiator by passing a rod through the lines. See rodding the radiator. [5] A thin bar. See boxed rod brake rod connecting rod con rod filler rod forked con rod hood rod hot rod intermediate rod

master con rod metering rod panhard rod mounting box panhard rod piston rod push rod push rod engine radius rod relay rod selector rod side rod slave con rod steering rod street rod strut rod threaded rod throwing a rod tie rod torque rods track rod transverse rod TV rod welding rod

rod arm: See tie rod arm

rod bearing: See big-end bearing connecting rod bearing con rod bearing

rodding the radiator: The top and sometimes, the bottom tank of the radiator is removed. The core is then cleaned by passing a cleaning rod down through the tubes. This is done when radiators are quite clogged with rust, scale, and various mineral deposits.

rod end:

See tie rod end

rod engine: See push rod engine

rod mounting box: See panhard rod mounting box

rod puller: See tie rod puller

rod separator: See tie rod separator

rod shank: See connecting rod shank

Rohr: A vehicle brand of which the 1925-1948 models are classic cars.

roll: The motion of a vehicle in which the springs on one side of the vehicle compress while the springs on the other side extend. If the roll is extensive, the vehicle will fall on its side. Also less accurately called "sway" or "lean," it occurs in corners because the car's center of gravity is almost always higher than the axis about which it rotates. See anti-roll bar body roll integrated roll cage period of roll rollbar roll cage roll center roll steer roll stiffness slip roll

roll angle: The angular displacement of a vehicle about its longitudinal axis, i.e., tendency of a vehicle to tip over when cornering or in high cross winds

roll axis: The axis through the front and rear roll centers

rollbar: A heavy steel bar or tubular steel that goes from one side of the frame, up and around in back of the driver in a hoop, and back down to the other side of the frame. It is used to protect the driver in the event his vehicle rolls over. Also see anti-roll bar

roll cage: A protective structure which surrounds the driver in the event of a rollover or crash. It includes a rollbar and other bars welded to the rollbar. The roll cage also adds chassis strength and stiffness which makes for better handling characteristics. Also see integrated roll cage

roll center: A term which is used to describe the point around which the body of the vehicle rolls when it corners. If the movement of the vehicle is controlled only by linkages, the roll center can be discovered by the geometry of the suspension.

roll coating: An application method for organic or chemical conversion coatings using rolls

rolled bead: See beaded edge

rolled thread: Rolled threads are cold formed by squeezing the blank between reciprocating or revolving serrated dies, similar to rolling a pencil between your two hands. This acts to increase the major diameter of the thread over and above the diameter of the unthreaded shank, if any. Rolled threads are both stronger and smoother than cut threads and more economical in so far as the process is faster with no waste of material. Virtually all cold headed fasteners within the Aerospace Industry today

have rolled threads.

roller: [1] A device for replacing sliding friction with rolling friction. [2] While ball bearings use a series of balls in a cage, roller bearings use a series of small cylinders. See cam roller double roller chain sheet metal roller tread roller worm and roller [3] A colloquial term for a Rolls-Royce.

roller bearing: A bearing using a series of straight, cupped, or tapered rollers engaging an inner and outer ring or race. See tapered roller bearing timken roller bearing

roller cage: A metal or plastic enclosure which keeps the rollers in place in a roller bearing

rollercam brake: See rollercam brakes.

rollercam brakes: Mountain bike brakes that are attached to the frame posts and use a cam and pulley system to modify pressure on the rims.

roller cell pump: See roller-vane pump

roller chain: A power-transmitting chain in which each link consists of two free-moving rollers located by pins connected to sideplates. Compare double roller chain, duplex chain,

simplex chain, single roller chain, and triplex chain

roller clutch: A clutch, using a series of rollers placed in ramps, that will provide drive power in one direction but will slip or freewheel in the other direction. Also see stator roller clutch

roller dynamometer: A dynamometer attached to a number of rollers so that the vehicle's driving wheels are placed on them to simulate road conditions. In this way a vehicle's actual power to the wheels can be determined. Also see rolling road

roller foot lever: See roller tappet

roller levelling: A process in which steel strips pass rollers which remove excess zinc after the actual immersion process of galvanizing has begun.

roller lifter: See roller tappets.

roller lifters: See roller tappets.

rollers: A stationary training device that consists of a boxlike frame and three rotating cylinders (one for a bike's front wheel and two for its rear wheel) on which the bicycle is balanced and ridden.

roller tappet: See roller tappets.

roller tappets: valve lifters that have a roller placed on the end contacting the camshaft. This is done to reduce friction between the lobe and lifter. They are generally used when special camshafts and high tension valve springs have been installed. Also called "roller lifters."

roller-vane pump: A rotary vane pump with rollers as pumping elements which slide against the pump body when the rotor rotates. Also see vane pump

rolling: See free rolling wheel temper rolling

rolling bearing: See antifriction bearing

rolling circumference: The circumference of a fully inflated tire under load

rolling friction: A rolling bearing's frictional resistance to rotation

rolling radius: The distance from the center of the tire's ground contact patch to the center of the wheel rim.

rolling resistance: As the wheels begin to turn, there are forces which resist its motion such as low tire pressure, rough road surface, increased tire temperature, tire composition, increased vehicle weight, and even air resistance.

rolling road: Rollers set in the floor of a service center and designed to simulate road conditions; the rollers can be driven by the driving wheels of a car and connected to a dynamometer for testing the power output of an engine or may be independently powered, e.g., to test the brakes

rolling start:

A form of race start that begins with the cars already in formation, while also in motion.

rolling wheel: See free rolling wheel

roll-off: See tire roll-off.

roll oversteer: Oversteer caused by roll when cornering. The opposite is roll understeer

roll pin: A split, tube-like pin made of spring steel for retaining disc pads, gears to shafts in gearboxes, etc.. See spiral wrapped pin.

roll resistance: See roll stiffness.

rolls: [1] Aconym for rolls Royce. Also see mixing rolls

Rolls-Royce: A vehicle brand of which the 1925-1948 models are classic cars. All the 1947-67 models are milestone cars.

Click for books on Rolls-Royce

Rolls Royce mascot: See Emily

roll steer: A characteristic of handling which gives a slight improvement to steering as the suspension moves in body roll. Sometimes a bad roll steer occurs when the suspension is poorly designed. A steering effect induced by load transference from side to side. The axles may move out of their normal parallel relationship due to spring deflection.

roll steer effect:

See roll steer

roll stiffness: The turning moment or torque that the suspension makes when the body rolls and the suspension tries to pull the body back to its normal upright position. It is usually measured in lb-ft/degree of roll. When the springs are stiffer or when the perpendicular distance from the springs to the roll center is greater then the roll stiffness increases. As a result, the vehicle corners flatter. Also called roll resistance.

roll test: An examination of the drive train functions; may include separate tests for front and rear axle, left-hand and right-hand sides, noise test

roll understeer: Understeer caused by roll when cornering. The opposite is roll oversteer

ROM: Acronym for read Only Memory -- memory that contains the computer's operating instructions (programs). It also stores general information that tells the computer how various components should perform under specific operating condition

Romeo: See Alfa Romeo.

RON: Acronym for "Research Octane Number" see octane number.

roo bar: An Australian term for nerf bar

roof: See pagoda-style roof pagoda roof pent-roof T bar roof

roof box: An enclosed, multi-purpose roof carrier

roof brace: A transverse rail that supports the roof panel; there are usually several roof braces

roof panel: The horizontal outer layer of the sheet metal roof panels that is spot-welded along its edges to the top of the root door and screen pillars

roof pillars: The steel pillars that surround the front and rear windshields and front and rear doors in a sedan. Pillars between the windshield and the front door are referred to as A-pillars. Pillars between the front and rear doors are referred to as B-pillars. Pillars between the rear doors and the rear windshield are called C-pillars. They provide greater rigidity to the car and making a hardtop possible.

roof rack: A luggage rack on the roof of a vehicle

roof rail: A longitudinal side member above the doors to which the roof panel is attached. Also called "cantrail"

roof spoiler: A spoiler attached to the roof of a truck cab, or vehicle towing a trailer or motor home, to reduce drag and increase stability

room temperature vulcanizing sealer: (RTV) semi-liquid, silicone rubber sealant which is proof against oil and water but not gasoline

root: The lowest point of a screw thread. The opposite is crest. See

thread root veeder root

Roots compressor: A typical lobe-type positive displacement compressor; uses two two-lobed or threelobed internal rotors phased to prevent clashing of the lobes by gears; normally driven from the crankshaft by toothed or V-belts, can achieve speeds up to 10,000 rpm; provides low-end torque and boost without lag but is less fuel-efficient than a turbocharger

Roots supercharger: A typical lobe-type positive displacement compressor; uses two two-lobed or threelobed internal rotors phased to prevent clashing of the lobes by gears; normally driven from the crankshaft by toothed or V-belts, can achieve speeds up to 10,000 rpm; provides low-end torque and boost without lag but is less fuel-efficient than a turbocharger

rope: See hoisting rope

RO/RO ship: A cargo or ferry ship on which trucks and other vehicles can be driven on and off on ramps through large openings at the bow, stern or side

rosette weld: See plug weld

rotary compressor: A compressor which has rotating rotors, or vanes, that compress and pump refrigerant

rotary disc valve: A valve employed as an intake control in modern two-stroke engines, consisting of a thin steel disc attached to one end of the crankshaft. The intake port passes trough to the disc valve assembly, and thus is normally closed off by the disc. To permit induction at the correct part of the engine cycle, part of the disc is cut away, opening the intake port for the required duration, independent of the piston position

rotary engine: An internal combustion engine which is not of a reciprocating (piston) engine design. There is no true crankshaft, although the power-take-off shaft is sometimes called the crankshaft. It is stationary or fixed in that it simply spins in place. The central rotor turns in one direction only and yet produces the required intake, compression, firing and exhaust strokes. Because it uses rotary motion instead of reciprocating motion, the rotary engine has better balance and less vibration than piston engines. Two common rotary engines are the gas turbine and the Wankel.

rotary flow: The movement of the oil as it is carried around by the pump and turbine in a torque converter. The rotary motion is not caused by the oil passing through the pump, to turbine, to stator, etc., as is the case with vortex flow. Rotary flow is at right angles to the center line of the converter whereas vortex flow is parallel (more or less depending on the ratio between the speeds of the pump and turbine).

rotary hammer: A power hammer

rotary pump: A pump with rotating members. See rotary-type pump

rotary valve: An engine or pump component forming part of a rotating assembly; may be designed as a cylindrical or a disc valve

rotary vane pump: See vane pump

rotate tires: See tire rotation.

rotating seal ring: A rotating element of a mechanical seal

rotation: The motion of a body about an axis within the body.

See direction of rotation tire rotation wheel rotation

rotational atomization unit: A painting unit equipped with rapidly rotating spray bells

rotator: See valve rotator.

Rotax: A trademark name of an Austrian manufacturer of two-stroke engines used in SkiDoo snowmobiles and Sea-Doo watercraft.

rotbox: A colloquial term for a vehicle in very poor shape. See rust bucket

roto cap: A device fitted to some engines which turns a valve slightly every time it opens or closes, to prevent the valve sticking or burning. Also called valve rotator

Rotoflex coupling: One design of a flexible coupling in the shape of a hexagonal rubber ring. See doughnut coupling

rotor: [1] Any component which rotates. [2] A small rotating cap-like unit at the end of the distributor shaft. It is located on the breaker cam inside the cap. It connects between the center electrode and the various outer spark plug terminals as it turns, thus distributing the high voltage from the ignition coil secondary winding to the proper spark plug. [3] A rotating armature inside a stator. As the rotor turns within the stator, electricity is produced to power the electrical components. [4] A trichoidal device in a rotary engine. [5] A rotating displacement element of a rotary pump, such as a gear, screw, piston, etc. [6] A moving part of a pulse generator. The opposite is stator.

[7] A rotating element of a Roots supercharger. See brake rotor disc brake rotor distributor rotor eccentric rotor pump pump rotor timing rotor

rotor arm: See rotor(def. 2)

rotor pump: An engine oil pump in which an internal rotor, e.g., with four external lobes, is used to drive an eccentric external gear, e.g., with five internal lobe-spaces; operates in a similar way to gear pumps, but has higher pump capacity, and is quieter and more expensive. Compare eccentric rotor pump, gear pump, and internal gear pump

rotor-type pump: An engine oil pump in which an internal rotor, e.g., with four external lobes, is used to drive an eccentric external gear, e.g., with five internal lobe-spaces; operates in a similar way to gear pumps, but has higher pump capacity, and is quieter and more expensive. Compare gear pump and internal gear pump

rotovalve: See Thompson rotovalve.

rotowelding: See friction welding

rotten-egg smell: In cars equipped with catalytic converters, this smell is the result of an excessively rich air/fuel mixture

rough: The sound or condition of an engine which is running unevenly

roughening: A mechanical or chemical treatment of a surface to produce minute irregularities

roughing stone: A coarse stone used for quick removal of material during honing.

round: See outboard round hump out of round

roundabout: A British term for a traffic circle

roundel: See BMW roundel

round file: A file in the shape of a round bar, rather than a blade

round head bolt: A general term including carriage bolts, cup head bolts, and mushroom head bolts

round hump: A safety contour on both rim bead seats preventing the tire from sliding into the rim well. Also see outboard round hump

route: [1] The direction or path that wiring or a cable takes. [2] To feed wiring or cable into a certain direction or path. [3] The roadway that a vehicle takes from one point to another.

routine: See check routine

Rover: A model of automobile manufactured in the UK Also see Land Click for books on Rover and Range Rover Rover Royal Automobile Club: (RAC) A motoring organization in the UK

Royce: See rolls-royce rolls Royce mascot

Royce mascot: See rolls Royce mascot

RPK: Acronym for "revolutions per kilometer" in measuring the number of times a tire turns in one kilometer of travel.

RPM: [1] Acronym for "revolutions per minute." A tachometer measures engine revolutions in terms of rpm. See engine speed red line [2] Acronym for "revolutions per mile" in measuring the number of times a tire turns in one mile of travel.

rpm sensor: See engine speed sensor

RRIM: Acronym for reinforced reaction injection molding

RS:

[1] Acronym for "Rally Sport"; a term used to identify some Chevrolet Camaro models. [2] Acronym for "rumble seat."

r/seat: Abbreviation for "rear seat"

RTV: Acronym for "Room Temperature Vulcanizing" sealant.

rubber: [1] All the rubber seals, mats, and pads that cushion and protect vehicle windows, trim, handles, bumper sections, carpets, etc. [2] The tires. See also peel rubber. [3] An elastic substance used in tires. See blade rubber bonnet bump rubber bump rubber butyl hard rubber hood bump rubber natural rubber peel rubber precured tread rubber raw rubber synthetic rubber

rubber bush: A British term for rubber bushing

rubber bushing: A tubular rubber sleeve for mounting a shaft or rod

rubber coupling: A flexible coupling using pressurized rubber blocks

rubber doughnut coupling:

A typical flexible coupling, made of vulcanized rubber, shaped like a doughnut

rubber-isolated crossmember: A laterally aligned structural member that is attached to the body or the frame via vibration-absorbing rubber isolators. By bolting suspension or driveline components to such crossmembers, automotive engineers can reduce the transmission of noise and/or ride harshness to the body.

rubberize: To coat or impregnate with rubber

rubber mallet: A hammer with a rubber head

rubber plug: A molded rubber stopper used to close cutouts or holes in body panels that have to be opened only infrequently, e.g., access holes for rustproofing of box sections

rubber ring: See doughnut coupling

rubber spring: An element of a rubber suspension system such as hydrolastic suspension

rubber squeegee: A special spreader used for filling hollow, concave or rounded body areas; the rubber material adapts better to these surfaces than plastic spreaders and helps to prevent flat spots

rubber valve: See sponge rubber valve

rubbing block: A little block located on the movable point that contacts the distributor cam wheel and causes the points to open. A spring causes the points to close.

rubbing compound:

A polish that contains abrasives harsh enough to remove layers of "dead" paint. Useful in radical restoration procedures, rubbing compounds should not be used on new cars or those with delicate finishes.

rubbing strip: A strip of plastic at the widest point of the body, along doors and fenders down each side of the car to protect the bodywork from minor nicks, (as from the open door of a neighbouring car)

rudder stock: A vertical rudder shaft that connects to the steering gear

rudder stop: A stout bracket to limit the swing of the rudder to the maximum 37 degree starboard or port

Rudge nut: A quick-release nut for central-locking wheels

rule: See two second rule

rumble: [1] A noise found in high-compression engines and associated with bending vibration of the crankshaft. It is caused by abnormally high rates of pressure rise near top dead center. [2] A vibration caused by loose components. Also see rumble seat.

rumble seat: (RS) An open-air seat at the back of some older automobiles. Called a "dickey" in Britain.

rumble strip: A series of small ridges placed across the driving lanes to warn the driver that a stop sign is ahead.

run: [1] The trail of a paint drip; a dribble of paint

[2] To form a paint run which is usually caused by moving the spray gun too slowly or spraying too close to the panel surface thus causing an excessive build-up of paint. [3] To start an engine and keep it going. See chain run runabout run channel

runabout: [1] An open sporting-type vehicle, lightweight, with two seats and with simple bodywork, i.e., a roadster. [2] A small car used strictly for driving in town run channel: A U-section rubber used to hold glass parts and other body features in place or to protect panel edges. Also see runabout run channel

run flat: Damage sustained by a tire due to driving with insufficient air pressure or while flat. Some types of tires will allow you to run the tire with no air pressure for a short period of time.

run-flat properties: The capability of a deflated tire to operate effectively, i.e., to permit further driving. To achieve this, the following must be fulfilled: the tire beads must be retained against the rim flanges and on the rim bead seats when the tire deflates; the tire must be able to support all possible stresses imposed by deflation: the tire must remain undamaged by internal friction and heat generated when running flat; the tire should be able to self-seal any punctures, so that the remaining air will be trapped and heat will be generated to reinflate the tire within limits

run-flat tire: A tire which can run for a certain length of time without air in it. In the inflated state, conventional tubeless tires perform the task of containing air and rolling. Once deflation occurs, the tire bead becomes dislodged from the rim bead seat and slides into the rim well. As a result of friction, the tire will become distorted and the rim may plough into the road, leading to loss of control and potentially resulting in an accident. Run-flat tires are designed to operate effectively with or without air, providing acceptable handling qualities when deflated, and good handling qualities when inflated

run in: A British term for break-in.

run-in: See break-in.

runner: See seat runner

running: See daytime running lights slow-running

running board: A long flat footboard on either side of a vehicle which acts as a step for passengers. They were particular common on vehicles before 1940.

running fit: See running-fit.

running-fit: A fit in which sufficient clearance has been provided to enable the parts to turn freely and to receive lubrication. Where sufficient clearance has been allowed between shaft and journal to allow free running without overheating

running gear: [1] The system of the engine, transmission, drive shaft, differential, and wheels. [2] The parts of the vehicle which cause the wheels to roll, i.e., suspension, steering components, springs, shock absorbers

running-in: Driving a vehicle or running an engine or other mechanical unit at reduced speed and load when new, to prevent pick-up and seizure of the bearing surfaces, and to ensure even initial wear

running lights: See daytime running lights

running-on: A condition of a spark ignition engine in which fuel continues to burn after the ignition switch has been turned off, causing the engine to keep on running. Also called dieseling

running-on control valve: See idle stop valve

running on rails: Used to describe a car that is handling perfectly, as though it were actually attached to railroad tracks.

run on: Condition when the engine continues to run, even when the key is turned off. See dieseling.

run-on tire: A tire with a limited ability to run without air in it; sufficient to pull over safely. Compare run-flat tire

runout: The amount a gear or wheel moves in and out away from its true center as it is rotated. If runout is excessive the gear or wheel can be seen to wobble as it rotates. See vacuum runout point lateral runout radial runout

runout point: See vacuum runout point

rupture:

To break, burst, or split

rush-hour traffic: A road or area that is full of vehicles during peak time such as in the morning when commuters are going to work, at noon when people are going for lunch or coming back to work, and after work when people are going home.

rust: [1] Oxidized iron or steel, the product of corrosion. [2] To form rust. See anti-rust treatment scale rust white rust

rust bucket: A colloquial term for a badly corroded car

rust converter: A chemical substance containing phosphoric acid etc. which transforms rust into a stable, firmly adhering iron compound by means of a chemical reaction

rust eater: See rust killer

rusting: A chemical or electrochemical destruction of iron and ferrous metals

rust inhibitor: A substance which reduces or prevents the formation of rust on iron and ferrous metals

rust inspection: A vehicle inspection conducted to detect rust and corrosion damage, usually by means of an endoscope

rust killer: A substance which convert rust into a dry mass which can be removed with water

rust neutralizer: See rust converter

rust pinhole: The early stage of rust penetration of a panel; rust pinholes will often reveal larger rust damage once the surface rust bubbles have been ground away

rustproof: [1] Resistant to rust. [2] To make resistant to rust

rustproofing: A process in which metal (such as iron and steel) is sealed from moisture and oxygen so that it will not corrode. Also see aftermarket rustproofing

rustproofing agent: An anti-corrosion, wax-based sealant

rust protection: Reducing the possibility of rust forming on iron and steel by coating with protective materials or by rendering them passive

rust remover: Any chemical substance which removes rust

rust sealer: A rust converter that provides a coat on metal surfaces to protect them against air exposure and thus to prevent continued corrosion

rust treatment: See anti-rust treatment

Ruxton:

A vehicle brand of which the 1925-1948 models are classic cars.

RV: Acronym for recreational vehicle

RVSV: Rollover/vapor separator valve

RWD: Acronym for rear-wheel drive

RWL: Acronym for "raised white letter," as in rwl tires.

Rzeppa-type joint: A constant velocity joint incorporating balls as a means of torque transmission. Named after Alfred Rzeppa, a Ford engineer

Rzeppa-type universal joint: A constant velocity joint incorporating balls as a means of torque transmission. Named after Alfred Rzeppa, a Ford engineer

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Sa] [Sc] [Se] [Sh] [Si] [Sk] [Sl] [Sm] [Sn] [So] [Sp] [Sq] [Ss] [St] [Su] [Sw] [Sy]

S: [1] A letter rating for tires to indicate that they are theoretically rated for speeds up to 180 kph (110 mph), as in P220SR15. The next higher rating is T. [2] Abbreviation for "Special" or "Sport," indicating better performance than a standard car model.

SA: API classification for straight mineral oil used in early gasoline engines.

Saab: A model of automobile manufactured in Sweden

Click for books on Saab

Sacco panels: See side bumper panels

sacrificial anode: An electropositive metal coating, such as aluminum or zinc, that protects the steel of a car body by corroding first when attacked by electrolytic action

sacrificial protection: See cathodic protection

saddle: [1] Seat on a bicycle. [2] Metal piece on a centerpull brake. See yoke. [3] Upper main bearing seat

saddlebag: A large bag or one of a pair which hangs down from the saddle or straddles the rear wheel of a bicycle or motorcycle.

saddle tank: [1] A fuel tank mounted above the rear axle. [2] A fuel tank that fits over the top tube of the frame of a motorcycle

SAE: Acronym for "Society of Automotive Engineers". It publishes automotive research papers and defines various automotive standards of measurement.

SAE gross bhp: An older unit of engine power. In the SAE gross bhp test, a "bare" engine is used, i.e., an engine equipped with only those accessories that are necessary for its operation, such as the oil pump and fuel pump; water pump, alternator, exhaust system, etc. are not used; this results in a higher power rating than achievable by the same engine under real operating conditions

SAE horsepower: A simple formula of long standing is used to determine horsepower. The formula is: (bore diameter) squared times (number of cylinders) divided by 2.5. This formula is used primarily for licensing purposes and is not very accurate for determining actual brake horsepower. Also called rated horsepower. Compare SAE gross horsepower and SAE net horsepower. Also see horsepower.

SAE gross horsepower: A production engine's actual power available at the flywheel or output shaft (usually crankshaft) as tested with an absorption dynamometer. It differs from SAE net horsepower in that many of the accessories (such as alternator, water pump, etc.) are not attached. Engines before 1973 were primarily measured with these "gross" numbers. Since 1973, "net" figures were published. This confusion caused many people to suppose that their engine had been seriously de-tuned when they saw that the same engine in 1972 had 400 hp but in 1973 had only 235 hp. (This example is from the Cadillac 500 cubic inch engine). Compare SAE net horsepower. See brake horsepower horsepower SAE net bhp: A newer unit of engine power. A fully-equipped engine (as when installed in a vehicle) is used to determine SAE net bhp figures; as a rough guideline, SAE net is about 70-85 percent of SAE gross

SAE net horsepower: The brake power (power available at the flywheel or output shaft -- usually the crankshaft) of a fully equipped engine fitted with all the accessories necessary to perform its intended functions unaided. In 1973, automobile manufacturers began publishing their engine specifications in "net" horsepower and "net" torque instead of "gross" figures. In many cases the published numbers were significantly lower in 1973 than in 1972. Some of the decrease was attributed to the addition of pollution equipment, the lowering of compression, and the use of regular unleaded gasoline instead of premium leaded fuel. However most of the decrease in number was a switch to "net" figures. Compare SAE gross horsepower. See brake horsepower horsepower SAE steels: A numerical index used to identify composition of SAE steel

safe stop wheel: A run-on tire

safety: See active safety child safety driveshaft safety strap experimental Safety Vehicle infant safety seat integrated child safety seat integrated safety belts motor Vehicle Safety Act park safety switch passive safety features passive safety propeller shaft safety strap safety factor safety hub safety pressure cap safety rim safety valve Safety Act:

See motor Vehicle Safety Act

safety, active: See active safety.

safety bead seat: A general term for a safety contour on the rim bead seat preventing the tire bead from sliding into the rim well especially during cornering maneuvres

safety belt: See seat belt integrated safety belts safety catch: A secondary latch usually located under the front edge of the hood, near the center, which prevents accidental release of the hood if the main cable-operated hood lock is activated by mistake

safety chains: Two, crossed chains linking the trailer and vehicle frame as a safeguard if the towing hitch fails

Safety Compliance Certification Label: (SCC) An American label which must be attached to the lower half of the left-hand front door lock facing; specifies the VIN and other relevant information

safety factor: [1] Providing strength beyond that needed, as an extra margin of insurance against part failure. [2] Degree of strength above normal requirements which serves as insurance against failure

safety features: See passive safety features

safety glass:

See laminated glass

safety goggles: A close-fining glasses or mask to protect the eyes (e.g., during welding)

safety harness: See harness

safety hub: A device that is installed on the rear axle to prevent the wheels leaving the vehicle in the event of a broken axle.

safety hubs: See safety hub.

safety ledge: A raised area (hump) around the circumference of the bead seat area of passenger wheels. Its function is to prevent the tire beads from becoming unseated during hard cornering or while running with low air pressure. A must with tubeless passenger tires. Also called special ledge

safety pressure cap: See pressure cap.

safety reflector: See triangular safety reflector

safety relief valve: A spring-loaded valve designed to open and relieve excessive pressure in a device when it exceeds a predetermined safe point

safety rim: A rim having two safety ridges, one on each lip, to prevent the tire beads from entering the drop center area in the event of a blowout. This feature keeps the tire on the rim.

safety seat:

See child safety seat infant safety seat integrated child safety seat safety steering column: See collapsible steering column

safety strap: See driveshaft safety strap propeller shaft safety strap safety switch: See neutral safety switch park safety switch safety valve: A valve designed to open and relieve the pressure within a container when container pressure exceeds a predetermined level.

Safety Vehicle: See experimental Safety Vehicle

safety wheel: A general term referring to either a wheel with a safety bead seat or a wheel with run flat properties

SA-FV: Acronym for separator assembly-fuel Vacuum

sag: [1] To bend or droop under weight or pressure. As a result of a front or rear end collision, the frame may develop a sag in the middle, much like a hammock. [2] To fail to meet projected sales. [3] A paint problem. See sags

sagging: [1] An aggravated condition of paint where a band of paint runs down the side of a vertical area of the body. It may be caused by excessive build-up of paint, thinners which are too slow-acting, or excessively slow movement of the spray gun. [2] The straining of a ship that tends to make the middle portion lower than the bow and stern

sagging door: A door that sits too low in the door opening which is often indicated by an uneven door gap that widens towards the rear bottom and front top of the door but narrows down at the rear top and front bottom. This condition may be caused by faulty setting of the door hinges and lock/striker assembly. On convertibles, it often pinpoints structural damage, because the chassis may be bending in the middle

sags: An aggravated condition of paint where a band of paint runs down the side of a vertical area of the body. It may be caused by excessive build-up of paint, thinners which are too slow-acting, or excessively slow movement of the spray gun

sag wagon: A support vehicle for touring bicycles or motorcycles to provide food, repairs, or a ride home.

SAI: Acronym for steering axis inclination

sailing: See plane sailing

Sainte Claire: See wills Sainte Claire

SALA suspension: Acronym for short arm/long arm suspension

sales: total automotive product sales (vehicles, automotive parts, including OE and aftermarket).

See fleet sales net sales value sales value: See net sales value

saloon: A British term for sedan

salt fog testing: See salt spray testing

salt spray chamber: A test chamber for salt spray testing

salt spray testing: Spray tests with sodium chloride solutions

salt water splash: An open-air corrosion test facility

salvaged: A vehicle totalled in an accident and then repaired. There is no guarantee of street worthiness for a salvaged vehicle. It may look good, but be hazardous to drive.

sampling: See constant-volume sampling.

sand: [1] to smooth or clean a surface by rubbing with sandpaper. Sanding usually refers to hand tools such as sandpaper, while grinding always refers to power tools such as angle grinders. [2] A term popularly applied to loose, unconsolidated accumulations of detrital sediment, consisting essentially of rounded grains of quartz. In the mechanical analysis of soil, sand, according to international classification, has a size between .06 and 2.0 mm. Also see silica sand

sand blast: Cleaning by the use of sand propelled at high speeds in an air blast.

sandblasting: The cleaning of a surface with a jet of sand (or grit) under air or steam pressure

sand casting: The formation of shapes by pouring molten metal into a cavity shaped in sand in a molding flask

sander: A power-driven tool with a rotating abrasive disc for smoothing and cleaning surfaces. See belt sander disc sander orbital sander sanding: See block sanding wet sanding sanding block: A block of rubber or plastic to which the sandpaper is fastened, offering the operator a good grip. The block should be used for most sanding jobs because it distributes the pressure evenly and gives a more uniform surface.

sandpaper: An abrasive paper coated with sand for smoothing and cleaning. Compare glasspaper

sand scratch: See sand scratches.

sand scratches:

The marks left in metal or in the old finish by abrasives. They may also show in the finish coat due to lack of filling or sealing.

sand scratching: A paint fault characterized by the paint film appearing low in gloss and showing primer and metal imperfections in the top coat; may be caused by excessively coarse sanding and too thin a paint coat

sand scratch swelling: Solvents present in surface scratches that cause the old finish to swell.

sandwich construction: A composite construction of alloys, plastics, and other materials consisting of a foam or honeycomb layer and glued between two hard outer sheets. Also called sandwich laminate

sandwich laminate: See sandwich construction

SAP: See AIA-SAP

SAS: Acronym for "Scandinavian Automotive Suppliers"

SASE: Acronym for "self-addressed stamped envelope." Often used in advertisements where the seller will provide information if potential buyers will send a SASE enclosed in their query letter. Also see SSAE.

satellite: A block of controls near the steering wheel rim. Also see global Positioning Satellite

saturation period: The length of time the breaker points are closed and current is flowing through the primary windings of the coil.

Saturn: A model of automobile manufactured by General Motors Click for books on Saturn saver spare: See space saver spare

saver wheel: See space saver wheel

saving tire: See space saving tire

saybolt viscometer: An instrument used to determine the fluidity or viscosity (resistance to flow) of an oil.

SB: Oil with some additive protection, for early gasoline engines only.

SBS: Acronym for seat-integrated belt system

SC: Oil for 1964 and previous model years.

scab corrosion: A scab-like corrosion occurring along a scratch in a coating

scale: [1] The accumulation of rust and minerals within the cooling system. [2] A weigh scale

scale rust:

Loose, flaking rust

scan: A feature of modern radios which plays a few moments of each station before proceeding to the next one. Also see frequency scan button

scan button: A radio button which, when pressed, causes the tuner to scan the frequencies of stations with sufficient signal strength and plays that station for about 5 seconds before going to the next one. When the driver or passenger wants to listen to the currently played selection, he can press the same button (or a different one) to select that station. Often called a "scan button." Also see frequency scan button

scanimet: A nickel-silicon-carbide coating for particularly wear-resistant cylinder walls. Compare Nicasil

scanner: See system scanner

scan tool: A device that interfaces with and communicates information on a data link

scatter shield: A steel or nylon guard placed around the bell or clutch housing to protect driver and spectator from flying parts in the event of part failure at high rpm. Such a shield is often placed around transmissions and differential units. See clutch explosion.

scavenge: A feature in a two-stroke engine to clear away, particularly to expel exhaust gas from a cylinder and to fill the cylinder with a fresh charge. These processes take place simultaneously in a two-stroke engine

scavenging: The removal of the exhaust gases from the cylinder by using the momentum of the exhaust gases in a long exhaust pipe or by taking advantage of the pressure waves set up in the exhaust pipe by the discharge of the gases. See

backflow scavenging crankcase scavenging cross scavenging loop scavenging perfect scavenging reverse-flow scavenging reverse scavenging schnürle scavenging tangential-flow scavenging transverse flow scavenging unidirectional flow scavenging uniflow scavenging scavenging jet: The jet of fresh charge supplied into the cylinder, the shape and direction of which determine the effectiveness of the scavenging process

scavenging losses: If the exhaust gases remain in the cylinder, they prevent a full charge of fresh mixture from entering; the power output is thus reduced

scavenging passage: The passage inside a two-stroke engine that serves to scavenge the exhaust gas from the engine; in most cases it refers to the transfer passage, as the gas column supplied across the transfer port initiates the scavenging process

scavenging picture: In experimental two-stroke engine development, a map of the scavenging air velocity distribution and the scavenging jet orientation inside a cylinder

scavenging port: See third scavenging port

scavenging pump: An oil pump in a dry sump system which returns oil from the crankcase to the main oil reservoir

scavenging system:

A method used to accomplish the charge-changing process in a two-stroke engine

scavenging valve: In evaporative emission control systems, a valve in the purge line between the activated charcoal canister and inlet manifold which controls the purge air flow that regenerates the charcoal filter

SCC: [1] Acronym for spark control computer. [2] Acronym for safety compliance certification

schematic: A drawing system for portraying the components and wires in a vehicle electrical system using standardized symbols

scheme: See color scheme

Schneider: See rochet-schneider

Schnürle scavenging: See loop scavenging

Schrader valve: A bicycle tire valve similar to the type found on automobile tires. Also see Presta valve.

Scientific Research and Experimental Development Program: (SR&ED) This program provides generous incentives for industrial research and development in Canada. The program allows individuals and companies to deduct 100 percent of qualified current SR and ED expenditures and capital SR and ED expenditures.

scissors jack: A device for lifting a corner of the vehicle. As it is applied, the arms are in the shape of the letter "X" or a diamond.

scoop: See airscoop side scoop scooter: [1] A two-wheel motorcycle usually with a small engine and a step-through frame. Also see motor scooter. [2] A small three or four wheeled vehicle designed for a handicapped person and is usually powered by two 12-volt batteries (producing 24 volts).

scope: A colloquial term for oscilloscope

score: [1] A scratch or groove on a finished surface. It is usually caused by dirt or some other object which mars the finish. Cylinder walls, for instance, can be scored by broken rings or a piston pin clip which has come loose. [2] (SCORE) An acronym for "Supplier Cost Reduction Effort."

scored: A brake disc that is scratched, grooved, or lined with small cuts

SCR: Acronym for "Silicon Controlled Rectifier."

scrap: waste metal

scrap dealer: A person or company which collects and recycles metal, especially from unusable vehicles.

scraper: See gasket scraper

ice scraper scraper ring: An oil scraper ring

scrap metal: Metal from unusable vehicles

scrap pile: Discarded tire casings having service life exhausted through wear or damage.

scrappage: a vehicle registered in the previous year but not re-registered in the current year.

scrap yard: The premises of a dealer in scrap metal

scratch: See sand scratch

scratches: See sand scratches

scratching: See sand scratching

scratch swelling: See sand scratch swelling

screamer: Slang for a high-performance car, possibly due to the reaction of passengers with an over-enthusiastic driver.

screen: To shield from electrical interference. See

filter screen oil screen pick-up screen split screen screen bulkhead: Light nonwatertight transverse bulkhead fitted in some Great Lakes ore carriers

screw: [1] A spiral path along a cylinder. [2] A fastening device. A screw is like an inclined plane wrapped up. It can take a rotating force and change it into a much larger straight-line force. See adjusting screw aiming screw air bleed screw air screw allen screw bendix screw bleeder screw bleed screw bypass air screw capstan screw countersunk screw cross-head screw edison screw fast idle screw fillister screw grub screw headlight adjusting screw horsepower screw idle air bleed screw idle mixture adjustment screw idle mixture screw idle speed screw machine screw metallic drive screw mixture control screw mixture screw phillips head screw phillips screw piston extension screw robertson screw self-tapping screw

speed screw tappet adjusting screw thread-cutting screw valve adjusting screw volume control screw screwdriver: A device used to remove or install screws. See angle screwdriver ball end hexagon screwdriver chubby screwdriver cross-head screwdriver cross-point screwdriver cross-head screwdriver electrical screwdriver electric screwdriver flat-bladed screwdriver flat-tip screwdriver impact screwdriver magnetic screwdriver offset screwdriver phillips screwdriver pozidriv screwdriver ratchet screwdriver screw-holding screwdriver stubby screwdriver torque screwdriver screwdriver bit: A hex shank with a screwdriver tip at one or both ends to loosen and tighten recessed screws; designed for use with magnetic or power-driven screwdrivers

screw extractor: A device used to remove broken bolts, screws, etc., from holes.

screw-holding screwdriver: A tool used to hold screws for easy placement in extremely tight places; also appropriate for loosening and tightening

screw pitch gauge:

A measuring tool used to identify thread sizes, featuring a selection of blades with different thread profiles to determine screw pitch

screw starter: A tool used to hold screws for easy placement in extremely tight places; also appropriate for loosening and tightening

scribe: To cut or scratch with a pointed instrument, e.g., (in) a painted surface, for testing purposes or to mark the position of a part

scriber: A pointed steel hand tool for marking metal

scrubber: See chain scrubber exhaust scrubber scrubbing: A heavy wear on a tire caused by sliding sideways across the road surface, as when skidding

scrub radius: The distance from the point where the steering axis intersects the ground to the longitudinal line that runs through the center of the tire's contact patch. Also called "steering offset." See negative offset steering.

scuff: See tire scuff

scuff plate: [1] Any protective plate. [2] The finishing trim on a door sill

scuff rib:

The raised rib on the sidewall of a tire to protect it from impact with the curb

sculpture line: See swage line

scuppers: Drains from decks to carry off accumulations of rainwater, condensation, or seawater

scuttle: [1] A small circular or oval opening fitted in decks to provide access. [2] A British term for cowl

scuttle panel: A British term for cowl

scuttle section: A subassembly of the body shell that includes the bulkhead, scuttle, and windscreen pillars; it is preassembled in the factory and spot-welded with the other subassemblies to form the body shell

scuttle shake: A typical shake exhibited by open cars on rough roads due to lack of torsional stiffness

scuttle side panel: A vertical panel at either end of the scuttle

SD: Improved oil for 1968 and previous model years.

SDC: Acronym for semi-drop center rim.

SDV:

Acronym for spark delay valve

SE: [1] Further improved oil for 1972 and previous model years. [2] Acronym for "special edition."

seabee: A self-propelled sea barge larger than the lash but using rollers to move aboard the ship

sea chest: An opening for supplying seawater to condensers, pumps, etc. located in the hull below the waterline and having means for the attachment of the associated piping

seal: [1] A flexible ring, disc or washer that prevents the passage of liquid, air, gas or dirt. See apex seal cup seal door seal dynamic seal flange seal glass seal grease seal lip seal with garter spring mechanical face seal mechanical seal oil seal piston seal primary seal radial shaft seal rotating seal ring secondary seal shaft seal sillment seal static seal stem seal valve guide seal valve oil seal valve stem seal [2] To prevent the passage of liquid, air, gas, etc. by means of a seal or sealant (e.g., on seams, joints, flanges).

[3] to coat a surface (e.g., when undersealing a car) by closing the pores of the anodic oxide layer in order to increase the resistance to staining and its effectiveness against corrosion

sealant: An organic compounds (such as wax, oil, grease) used to protect seams or surfaces. Also called cavity sealant, mastic seam sealant, sealer, silicone-rubber sealant, or sealing compound

sealed beam: See sealed beam headlight.

sealed beam headlight: A headlight lamp in which the lens, reflector, and filament are fused together to form a single unit. They are relatively inexpensive, but when one component breaks, the whole unit is replaced. Newer vehicles use the more expensive composite type with separate bulb and lens which can be replaced individually in the event of failure. Only a few types of bulbs are used in the composite headlight, but the lens differs because it is shaped to the contour of the vehicle.

sealed beam unit: See sealed beam headlight.

sealed bearing: A bearing that has been lubricated at the factory and then sealed, it cannot be lubricated during service. It is sealed to keep out contaminants.

sealer: [1] A substance you can add to the liquid in the cooling system to seal leaks. Also called "stop leak." [2] Other kinds of sealing compounds are used to coat surfaces before installing hoses or gaskets. These are effective in preventing leakage but usually make the hose or gasket hard to remove. [3] An intercoat between the top coat and the primer or old finish, giving better adhesion. See body sealer room temperature vulcanizing sealer rust sealer

sealing: See pvc seam sealing

sealing apparatus: See vacuum sealing apparatus seam sealing sealing bath: A hot water bath for the sealing treatment after anodizing

sealing cell: See seam sealing cell

sealing compound: See sealer underbody sealing compound sealing smut: smut which forms after the anodized aluminum pieces are immersed in hot water

sealing strip: gas seal to the epitrochoidal surface in a rotary piston engine, with the same function as the piston ring on a conventional piston engine

seal installer: See valve stem seal installer

seal pliers: See valve stem seal pliers

seal ring: See rotating seal ring

seal with garter spring:

See lip seal with garter spring

seam: See inflation control seam mastic seam sealant pvc seam sealing tear seam seamed tubing: Tubing made from steel strip stock that is curved until its edges meet, then welded together. Contrast seamless tubing.

seamless tubing: Tubing made from solid blocks of steel that are pierced and drawn into tube shape. Contrast seamed tubing.

seam sealant: See mastic seam sealant

seam sealing: The sealing of seams, usually using organic compounds, to prevent the penetration of corrosive agents. Also see pvc seam sealing

seam sealing cell: A flexible manufacturing cell in which seam sealers are applied

seat: [1] A surface upon which another part rests or seats. Example: valve seat is matched surface upon which valve face rests. [2] Minor wearing of the piston ring surface during initial use. Rings then fit or seat properly against the cylinder wall. [3] The cushions on which the driver and passengers rest. See automatic seat belt baby seat bead seat bench seat bucket seat child safety seat

child seat conical seat flat seat front seat inertia reel seat belt infant safety seat innerspring seat integral molded seat integrated child seat integrated child safety seat power seat radius seat rear seat belt rim bead seat rim bead seat taper rumble seat saddle safety bead seat solo seat split bench seat spring seat taper seat valve seat valve spring seat [4] A metering control that is regulated by a needle. See needle and seat seat adjuster: A device which operates manually or electronically to move the position of the seat cushion forward or backward. It may tilt the front or back of the seat cushion up or down and may also move the seat back forward or back -- even to a reclining position. In some cases the adjuster will allow complete removal of the seat assembly.

seat belt: A passive restraint system which encircles the hips to prevent the occupant from being ejected from the vehicle. Often the seat belt is part of the shoulder harness. The use of seat belts is mandatory in every province and state in North America and in most every country. See automatic seat belt inertial reel seat belt

inertia reel seat belt rear seat belt three-point seat belt seat belt anchorage: The point where the end of a seat belt is attached to the body of a vehicle

seat belt system: See seat-integrated seat belt system

seat belt tensioner: A device that pulls the seatbelt tight in the event of a collision, taking up extra slack and reducing the force with which the occupant's body hits the belt. It is sometimes referred to as a "pretensioner," though this implies that it deploys when a crash is imminent, which is misleading. Tensioners are generally tied into the same sensors that trigger the airbags and deploy at the moment of collision.

seat belt warning light: A light on the dash which illuminates or flashes if the seat belts are not fastened.

seat cluster: On a bicycle, the conjunction of top tube, seat tube, and seatstays near the top of the seat.

seat cushion: The part of the seat upon which one sits or leans against.

seat cutter: See valve seat cutter

seat diameter: See bead seat diameter

seat face: See valve seat face

seat grinding:

See valve seat grinding

seating capacity: The number of people for which a car is designed

seat insert: See valve seat insert

seat-integrated belt system: A seat belt with all belt elements and deflection points integrated in the seat; this improves occupant restraint in every seating position, but particularly sturdy seats and floorpans are required

seat-integrated seat belt system: See seat-integrated belt system

seat mat: See bead seat mat

seat pan: See seat well

seat panel: See under seat panel

seatpost: On a bicycle, the part to which the saddle clamps and which runs down inside the seat tube.

seat rail: Tracks on which the front seat frame is mounted to provide fore and alt seat adjustment

seat rail console: A mounting panel for the seat rails, spot-welded to the floorpan; the front consoles are usually somewhat higher than the rear ones to produce the desired angle of the seating surface

seat ring: See valve seat ring

sea trials: A series of trials done at sea to determine whether the ship has met the specifications of design, modification, or repair

seat runner: Tracks on which the front seat frame is mounted to provide fore and alt seat adjustment

seats: See contre pente on both bead seats, folding rear seats, front seats, split folding rear seats, and split rear seats

seat skin: The covering (usually leather or vinyl) of the saddle on a motorcycle or bicycle.

seatstay: On a bicycle, one of the two parallel tubes that run from the top of the seat tube back to the rear axle.

seatstays: On a bicycle, the two parallel tubes that run from the top of the seat tube back to the rear axle.

seat taper: See bead seat taper rim bead seat taper seat tube: On a bicycle, the tube that runs from just below the saddle down to the bottom bracket.

seat well:

A sheet metal panel to cover up the area below the car seats, especially below the rear seat bench

sea worthiness: The condition of a vessel with regards to materials, construction, equipment, crew and outfit which is considered safe for the trade in which it is employed

seaworthiness certificate: A certificate issued by a classification society surveyor allowing a vessel with a mishap affecting its seaworthiness to proceed to another port where permanent repairs can be carried out.

second: See second gear

secondary air: In some exhaust emission control systems, e.g., thermal reactor or two-bed converter, secondary (outside) air is added to the exhaust to ensure sufficient supply of oxygen to promote oxidation of HC and CO, thus converting these pollutants into harmless water vapor and carbon dioxide

secondary battery: See storage battery

secondary brake shoe: See primary brake shoe trailing brake shoe secondary braking system: (HGV) A spring brake system which exerts force when air pressure is released

secondary cell: See storage cell

secondary circuit: [1] The high voltage part of the ignition system.

[2] The circuit which comprises the secondary winding of the ignition coil, the distributor, and the spark plugs

secondary compression: A term that is used in two-stroke engines. Primary compression takes place in the crankcase and is then pushed up into the combustion chamber where secondary compression takes place as the piston squeezes the mixture. If the crankcase seals are poor, primary compression will be reduced resulting in reduced secondary compression so that it may be difficult to start the engine.

secondary damage: See indirect damage

secondary failure: The failure which occurs as a result of a primary failure (e.g., the primary failure is a nail hole; but as the tire is run flat, the secondary failure may be a tire roll-off.

secondary key: A key which operates only the locks needed for valet parking, i.e., door locks, ignition switch and steering column lock; does not allow access to trunk, glove box, etc.

secondary pattern: An oscilloscope pattern of the secondary circuit

secondary piston: In a tandem master cylinder, a floating piston which isolates the two braking circuits from each other and actuates the secondary circuit

secondary pump: An oil pump driven via the gearbox output shaft. Compare primary pump

secondary, reverse shoe: The brake shoe that is installed facing the rear of the vehicle. See trailing brake shoe.

secondary seal:

A secondary piston seal in a tandem master cylinder

secondary shoe: See trailing shoe

secondary visor: In a dual visor system, the main visor is moved to the side and the secondary visor is flipped down, thus shielding the driver from the sun from both the front and side

secondary winding: An inner winding of the ignition coil; typically 20,000 to 30,000 turns of very fine wire. The opposite is primary winding

secondary wire: See secondary wires.

secondary wires: The high voltage wire from the coil to the distributor tower and from the tower to the spark plugs.

second gear: A middle gear which has a faster ratio than low gear, but slower than high gear. It is used for climbing or descending steep hills

second rule: See two second rule

section: See box section castle section channel section chassis section cowl section cross section dogleg section front nose section midship section

phosphate section repair section scuttle section U section section damage: See center section damage

section height: The vertical measurement from the bead seat of a tire to the top of the crown when it is mounted, inflated and not under load. (Overall diameter less nominal rim diameter, divided by two.)

section repair: [1] Reinforcement made to the casing when an injury has extended through the tread or sidewall of a tire. The damaged cord is removed and a new cord is replaced in the form of a repair unit or patch. [2] A major repair in the sidewall or tread of a tire. This repair unit must have cord material for reinforcement, made specifically for the type tire-bias-ply or radial. [3] An effective and economical repair method where extensive damage is confined to a specific section of the body shell and an undamaged section is taken from a vehicle which has been written off

section width: The measurement across the tire width at the widest point when mounted and inflated (not under load), excluding any decorative moldings.

sector: See worm and sector.

sector shaft: See rocker shaft

security system: See anti-theft system

sedan: The term sedan originally described a conveyance seen only in movies today: a wheelless vehicle for one person, borne on poles by two men, one ahead and one

behind. Automakers borrowed the word and applied it to cars with an enclosed fourdoor body type, permanent back panels, and top with full-width cross seats front and rear, and passenger capacity from five to seven depending on wheelbase. Longer-wheelbase models accept extra passengers in fold-down auxiliary seats. Sedans usually have quarter windows in the rear quarter in addition to windows in all four doors. Trunk racks often were standard offerings. Called saloon in U.K. According to Car and Driver, the term "sedan" refers to a fixed-roof car with at least four doors or any fixed-roof two-door car with at least 33 cubic feet (934 liters) of rear interior volume, according to measurements based on SAE standard J1100. See close-coupled sedan convertible sedan four-door sedan imperial sedan Landaulet sedan six-light sedan two-door sedan sediment: An accumulation of matter which settles to the bottom of a liquid.

seed: A paint fault where a uniform distribution of small particles of regular size and pattern exist in a paint film. It is caused by contamination of the paint and poor filtration of the air lines. It is not to be confused with dirt contamination which is caused by dust settling on the painted surface before it has dried

seek: A feature of a car stereo where the radio will find a requested station.

SEFI: Acronym for sequential electronic fuel injection

seize: [1] The condition when two items bond together so that they cannot be removed easily. [2] The condition when a piston bonds itself to the sides of the cylinder wall because of the lack of lubricant or overheating. See freezing.

seizure:

See piston seizure

selective corrosion: The corrosion of alloys where the components react in proportions differing from their proportions in the alloys

selective transmission: The conventional manual transmission of today in which any gear may be selected at will as opposed to the very early progressive transmission in which the gears had to be selected in order.

select-low principle: The method by which the rear brake application of an ABS brake system is monitored and controlled, based on the rear wheel with the least amount of traction

selector: See gear selector indicator gear selector selector fork: A part of the selector mechanism of a manual gearbox, shaped like a two-pronged fork, which fits into the groove round a coupling sleeve and moves a sliding pinion forward or back along a selector rod

selector indicator: See gear selector indicator

selector lever: an automatic transmission lever which permits the driver to adapt the gearchanging processes to particular road or driving conditions (slippery road surface, hilly terrain, towing) by choosing one of the drive ranges. Reverse, neutral, and parking lock are also selected by means of the selector lever

selector lever lock: A lock the selector lever in "Neutral" or "Park" unless the driver depresses the brake pedal

selector rod: A rod running the length of the transmission, along which the selector fork travels

select valve: See air select valve

self-adjusting: A mechanism that adjusts itself to compensate for wear or to maintain a certain distance or heat level

self-aligning torque: A torque which is created by the tire when the vehicle corners. The force created at the tire patch acts toward the rear of the actual center of the wheel. This action is called "pneumatic trail." It has the same effect as positive caster and can be increased by increasing the positive caster. Thus the trail distance (distance from the point at which the cornering force acts to the center of the wheel or steering axis) is a moment arm that results in a torque that tends to decrease the existing slip angle and force the wheel back to the straight-ahead position. This self-aligning torque is transmitted through the steering mechanism to the steering wheel and can be felt as steering effort or road feel.

self-cancelling indicator: All modern signal light switches (direction indicators) switch off automatically when the steering wheel is returned to the straight-ahead position

self-centering: The forces in a steering system that set the front wheels straight when the driver's grip on the steering wheel is released after cornering

self-centering effect: The forces in a steering system that set the front wheels straight when the driver's grip on the steering wheel is released after cornering

self-cleaning: The ability of a spark plug to burn off the deposits of carbon and oil which build up due to tracking across the tip

self-cleaning limit:

The lower limit of the self-cleaning temperature, generally about 500°C

self-cleaning tread: A tread pattern with tapered grooves and ribs, bars, etc., arranged in a manner that resists packing loose materials, (mud, etc.) in the grooves.

self-diagnosis: A test function in electronic engine management systems with a test program monitoring input and output signals, detecting errors and storing them permanently in a fault memory

self-diagnostic code: The ECM can detect malfunctions in the CCC systems. If a malfunction occurs, the ECM turns on the "check engine" light. A diagnostic code can be obtained from the ECM through the "check engine" light. This code will indicate the area of the malfunction

self-energizing: See self-energizing brake shoe servo brake self-energizing brake: See single-anchor self-energizing brake

self-energizing brake shoe: A brake shoe (sometimes both shoes) that when applied develops a wedging action that actually assists or boosts the braking force applied by the wheel cylinder. Also see primary brake shoe.

self-grip: See long-nose self-grip pliers

self-grip pliers: See long-nose self-grip pliers

self-ignition:

The ignition of the air/fuel mixture in a diesel engine caused by high pressure and temperature. Different from a spark ignition

self-induction: This occurs when the current in an inductive circuit changes and the magnetic field cuts the conductors; this induced electromotive force opposes the change in current, restricting it if the current is increasing and enhancing it if the current is decreasing

self-induction back-voltage: Back-voltage produced by self-induction. This induced electromotive force opposes the change in current, restricting it if the current is increasing and enhancing it if the current is decreasing.

self-levelling shock absorber: See air shock absorber

self-levelling strut: A suspension strut incorporating a shock absorber with a rubber boot filled with compressed air, serving as an auxiliary pneumatic spring

self-levelling suspension: See automatic levelling.

self-locking nut: A nut with a nylon insert that binds on the thread and resists vibration

self-operating clutch: See centrifugal clutch

self-parking: The ability of a car to park automatically, without any input from the driver; introduced by the VW Futura in 1991

self-parking wiper: A windshield wiper that automatically returns to the (horizontal) park position when switched off

self-priming pump: A pump which is able to evacuate and prime the suction pipe

self-regulating sheathed-type glow plug: Originally a sheathed-type glow plugs with a self-regulating heating coil, now with a heating and regulating coil

self-starter: See starter motor

self-sustaining ship: A containership fitted with her own crane for loading and discharging containers

self-tapping screw: A screw which cuts its own threads as it is inserted into the hole

self test: A part of functional diagnostic test procedure that verifies operation of sensors and actuators, detects hard faults, and stores information for later retrieval

self-trimming ship: A ship whose cargo holds are shaped so that the cargo levels by itself.

self-unloader: A bulk carrier which is equipped with cargo unloading gear

self-vulcanization: Vulcanization at room temperature or above, activated by chemical agents without the application of heat from an outside source.

selling: See fixed price selling one price selling sem:

A preassembled fastener, consisting of any type of screw or bolt, furnished with a toothed washer

SEMA: Acronym for "Specialty Equipment Market Association," the aftermarket and reproduction vehicle parts organization.

semaphore indicator: A signal light indicator used before flashers were introduced (such as the Austin and Flying Standard), consisting of a lighted arrow that popped out from the side of the car (usually the B-post) when the turn signal switch was actuated. Also called trafficator

semi: See tractor semitrailer semi-active suspension: A suspension whose characteristics can be tuned to driving conditions, such as by hydraulic adjustment of spring supports plus electronic correction of the damping rate

semi-automatic transmission: A transmission in which the clutch is disengaged and re-engaged automatically when the driver actuates the gear lever

semi-centrifugal release finger: See clutch semi-centrifugal release fingers.

semi-centrifugal release fingers: See clutch semi-centrifugal release fingers.

semiconductor: A solid material such as silicon that has a resistivity midway between that of a conductor and a resistor, with properties of both a conductor and an insulator; used as substrates for semiconductor devices such as diodes, transistors, and integrated circuits

semiconductor ignition system: An ignition system that uses semiconductors for the switching operations

semi-diesel: A semi-diesel engine operates on comparatively high compression and utilizes solid injection of fuel, however, it does use an electrical ignition system rather than depend solely upon heat generated by compression to furnish ignition

semi-drop center rim: (SDC) A rim having a demountable flange, for use on light commercial application. A slight depression in the center of the rim facilitates tire mounting and removal.

semi-drop center rim taper: A rim where both bead seats are tapered 5°.

semi-elliptic leaf spring: See semi-elliptic springs.

semi-elliptic spring: See semi-elliptic springs.

semi-elliptic springs: A type of leaf spring that takes its name from the shape which is part of an ellipse.

semi-floating axle: Type of axle commonly used in modern car. The outer end of the axle shaft does two things: (1) it supports the weight of the vehicle and (2) it is the means of propulsion. The inner end of the axle shaft which is splined, "floats" in the differential gear. In this design a single bearing is placed between the axle shaft and the axle bearing; to remove the axle the wheel must first be removed.

semi-independent suspension: A rear axle design with a torsionally flexible crossmember, the wheels being located on trailing links

semi-race cam:

A type of camshaft for race car engines which increases lift of valve, speed of valve opening and closing, length of time valve is held open, etc. Also called full cam, three-quarter cam, or race cam, depending upon design

semi-tractor: See tractor.

semi-trailer: A type of trailer that has wheels only at the rear, the front is supported by the towing vehicle. See trailer.

semi-trailing arm: A type of independent rear suspension where the pivot axes are usually at about 25 degrees to a line running straight across the car. This arrangement gives rear-wheel camber somewhere between that of a pure trailing arm (which has no camber change relative to the body) and a swing axle (which has large camber change).

semi-trailing arm suspension: See semi-trailing arm.

semi-trailing link: An arm of a coil spring, independent rear suspension system which pivots at an angle to the centerline of the vehicle, thus imparting negative camber with increase in load. Also called semi-trailing arm

send: See guided send test

sender: A sensor unit conveying information about an engine to a gauge, warning light, or other component. Also see fuel tank sender

sending unit: A device used for transmitting a signal to a gauge.

send test:

See guided send test

Sendzimir process: A continuous strip galvanizing process, named after its inventor. The strip is wound from a coil while the oil or grease adhering to it is removed by oxidation. It is then annealed, and the oxides are reduced by ammonia, after which it is cooled to 500°C and immersed in a zinc bath, which is kept molten at about 45O°C by the heat from the steel strip. On leaving the bath, the strip is cut and coiled

Senna, Ayrton: Ayrton Senna (full name Ayrton Senna Da Silva) of Brazil was, without question, the greatest race car driver in history. He was the embodiment of the professional race car driver. From his first appearance in a Grand Prix event in 1984, the racing world was on notice. The man was on a single-minded mission to win a World Championship title. No driver ever pursued this goal with such determination. Senna won his first title in 1988 and then again, two more times, in 1990 and 1992. He sat on the pole for more than 55% of all races he entered. Ayrton Senna was killed during the opening laps of the 1994 Grand Prix of San Marino at the Circuit Dino Ferrari near the town of Imola in Italy. His death was mourned the world over. Both Brazil and Japan took national holidays to mourn his passing. At the time of his death, Ayrton Senna was so significant to Brazil as a hero and source of income, he was responsible for nearly 20% of that country's gross national product. His body lay in state in the National Assembly before being buried with full state rights. At the time of this writing, rather pointless charges of manslaughter have been brought against the team Senna drove for at the time of his death. Frank Williams (the team owner), Adrian Newey (team Chief Designer) and Patrick Head (team Technical Manager) all face charges.

sensing: See electronic sensing device

sensing device: See electronic sensing device

sensitive limited slip differential: See torque sensitive limited slip differential

sensor: An electronic detection device that receives and reacts to a signal, such as a change in voltage, temperature or pressure.

See absolute pressure sensor airflow sensor air sensor barometric pressure sensor boost sensor clearance sensor coolant temperature sensor crankcase position sensor crash sensor detonation sensor engine speed sensor engine temperature sensor ground clearance sensor hall-effect sensor hall sensor hego sensor impact sensor knock sensor lambda sensor low oil sensor magnet sensor manifold absolute pressure sensor oil level sensor oil pressure sensor oxygen sensor oxygen sensor system thermo-switch reference mark sensor rpm sensor throttle position sensor transistorized coil ignition with Hall sensor vacuum sensor wheel speed sensor sensor flap: A part of an airflow sensor which serves as a measure for the induced air volume; a potentiometer converts sensor flap movement into changes in electrical voltage, a form in which these signals can be evaluated by the fuel injection control unit

sensor plate: A plate in the mixture control unit of a CIS, attached to a lever that operates the control plunger in the fuel distributor; the sensor plate position is governed by the amount of air admitted to the engine via the throttle valve and auxiliary air regulator

sensor system: See oxygen sensor system thermo-switch

sensor system thermo-switch: See oxygen sensor system thermo-switch

sensing device: See electronic sensing device.

sentinel: See twilight sentinel

Sentra: A model of automobile manufactured by Nissan in Japan Click for books on Sentra separate-application adhesive: An adhesive consisting of two parts; one part being applied to one face and the other part to the other face and the two faces brought together to form a joint

separate chassis: The traditional body and frame design before the introduction of unitary construction; the body was lowered onto the chassis and bolted to it

separate lubrication: An engine lubrication principle where the oil is no longer mixed with the fuel, but is fed by a metering pump from a separate oil tank to the engine components to be lubricated

separation: [1] The parting of retread rubber from the buffed casing or the parting or debonding of any adjacent parts of the tire (ply to ply, ply to rubber, etc.), usually due to excessive heat. [2] After long storage, liquid ingredients of paints and fillers may separate in the can on top of the material; in most cases, this can be overcome by stirring the contents of the can thoroughly before use. See bead separation ply separation

tread separation separation solid tire: Rubber pulling away from steel bands.

separator: See ball joint separator bearing separator envelope separator oil separator separators tie rod separator vapor separator water separator separator assembly-fuel vacuum: (SA-FV) fuel vacuum separator FVS

separator plate: See valve body separator plate

separators: [1] Generally, anything that physically separates one part from another. [2] The wood, rubber, or plastic sheets or plates inserted between the positive and negative plates in a battery to prevent contact. [3] A filter or trap. See bearing separator oil separator vapor separator water separator sequence: The order in which events take place. See cylinder sequence engine sequence test welding sequence sequence test:

See engine sequence test

sequential electronic fuel injection: (SEFI) a computer controlled fuel system that distributes fuel through an injector located in each intake port of the engine. Each injector is fired separately and has individual circuits. Also called sequential fuel injection (SFI)

sequential fuel injection: (SFI) A computer controlled fuel injection system in which bursts of gasoline are sprayed into the intake ports by injectors at timed intervals. Each injector is fired separately and has individual circuits. Also called timed fuel injection or sequential electronic fuel injection (SEFI)

sequential spark: See follow-up spark

serial number: The individual, consecutive numbering of a product during production. It may be a combination of letters and numbers. Also see batch number.

series: [1] A particular type of an automobile make and model. For instance, in 1952 Cadillac fielded three series: a 62 (with a 126 inch wheelbase); a 60 (with a 130 inch wheelbase); and a 75 (with a 147 inch wheelbase). [2] The alignment of electrical components. See series circuit. [3] A numerical representation of a tire's aspect ratio. A 50-series tire has an aspect ratio of 0.50. Also see spec series

series circuit: A circuit with two or more resistance units so wired that the current must pass through one unit before reaching the other. In contrast with parallel circuit.

series parallel circuit: See series-parallel circuit.

series-parallel circuit: A circuit of three or more resistance units in which a series and a parallel circuit are combined.

serpentine belt: A poly-v-belt which wraps around several pulleys and idlers

serrated shaft: A shaft with V-shaped grooves

serration: A series of teeth on an edge (as on a saw)

service: [1] periodic maintenance usually carried out by a garage; includes changing the oil and oil filter, checking the brakes, tires, ignition (usually changing the spark plugs), electrical, fuel and cooling systems, and taking the vehicle on a test run to check the steering, suspension, and transmission systems as well as the performance of the engine and brakes. [2] To carry out a service on a vehicle. See breakdown service full service history service brake: A foot-operated brake used for retarding, stopping, and controlling the vehicle during normal driving conditions

service codes: A series of two digit numbers that represent results of a self test

service history: See full service history

service hose: Specially manufactured hose designed to withstand the operating pressures of air conditioner system and equipped with threaded fittings that can be attached to service valves, manifold gauge sets, vacuum pumps, refrigerant containers, etc.

service interval:

The time or mileage between services (e.g., 12 months or 10,000 miles, whichever should come first)

service life: The length of time a component or system will remain reliable and safe

service manual: A handbook published by a vehicle manufacturer or a specialized publishing company that contains instructions and specifications for the maintenance and repair of specific cars. They also include wiring diagrams and troubleshooting guides. Most service manuals deal with only one make, model, or year, and nearly all are intended for professionals or the very experienced amateur.

service port: A fitting, on stem-type service valves and some control devices, to which manifold gauge set service hoses can be connected

services: See special services

service station: outlets which sell gasoline and are operated by the major oil companies.

service valve: See high-side service valve low-side service valve service writer: At many dealerships, the person responsible for writing repair orders (work orders) is the service writer. He communicates to the mechanic and service manager the problems in your vehicle that you have outlined. He also estimates the nature and cost of repairs and gives you an idea when the work will be finished.

servicing: To carry out a service

servo:

[1] An oil operated device used to push or pull another part, such as tightening the transmission brake bands. [2] Any system used to assist a mechanism to operate with greater force than that initially applied to it. [3] Abbreviation for servomechanism See brake servo unit brake servo master vac servo unit vacuum servo servo action brake: See servo action brakes.

servo action brakes: Brakes so constructed as to have one end of the primary shoe bearing against the end of the secondary shoe. When the brakes are applied, the primary shoe attempts to move in the direction of the rotating drum and in so doing applies force to the secondary shoe. This action, called "servo action," makes less brake pedal pressure necessary and is widely used in brake construction.

servo-assisted: See power-assisted

servo brake: A drum brake in which the shoes are arranged so that one shoe helps to apply the other, to create a self-energizing effect in both shoes servomechanism : A device that provides power assistance to operate a control (e.g., a brake or clutch)

servo motor: A small electric motor that supplies power to a servomechanism

servos: Servos apply certain mechanical functions. For instance, if first gear is actuated by the application of a band, the servo is what applies that band. The servo is nothing more than a piston that is connected to a mechanical linkage, moved by hydraulic pressure. When the need for a certain application arises, oil pressure moves the servo and the servo makes the application.

servo unit: See brake servo unit master vac servo unit set: [1] To adjust (e.g., a screw) to a standard. [2] To allow to harden (e.g., body filler, glue, etc.). See aligning set bracket set contact set planetary gear set straightening set setscrew: A fully threaded bolt with a parallel shaft. It is used to secure metal parts together (such as a hub or wheel to a shaft); can have a variety of heads, the most common being hexagonal, round or countersunk

setter hammer: See tile setter hammer

setting: [1] adjustment. [2] hardening. See basic ignition setting beam setting headlight beam setting settle: To sink to the bottom (of a liquid). The weight of the pigments in a paint varies greatly depending on their color. Heavy pigments give color, opacity, and specific properties to the paint. Some pigments weigh seven or eight times as much as the liquid part of the paint and because of this, they tend to settle to the bottom of the container

settling:

The pigment in the paint collecting at the bottom of the spray gun container.

set-up: [1] Premature vulcanization of a rubber compound during processing or storage. [2] The action of a gel-like substance which goes from a liquid to a rubbery solid or when a paste turns solid.

seven: See group of seven

Seville: A model of automobile manufactured by General Motors Cadillac division

Click for books on Cadillac Seville

sew up tire: See sew-up tire.

sew-up tire: A bicycle tire with an inner tube stitched inside the casing; also known as a tubular.

SF: Further improved oil for 1980-1988 model years and previous years.

SFC: Acronym for specific fuel consumption

SFI: Acronym for sequential fuel injection

SG: Improved oil for 1989 model years and previous years.

shackle: A swinging support which is used to attach the ends of a leaf spring to the frame of the vehicle. The shackle is needed to take care of the changes in length of the spring as it moves up and down.

See spring shackle swinging shackle shade: See off shade

shadeband: A sunvisor. Also see windshield shadeband

shaft: A long smooth-surfaced bar of metal with a circular (round) cross section. See armature shaft arm shaft auxilliar drive shaft axle shaft balance shaft bevel drive shaft cardan shaft clutch shaft composite propeller shaft cross-shaft cross shaft distributor shaft divided propeller shaft drive shaft eccentric shaft gearbox input shaft gearbox output shaft halfshaft input shaft intermediate shaft main shaft output shaft pilot shaft pinion shaft pitman shaft primary shaft propeller shaft safety strap propeller shaft prop shaft pump shaft

quill shaft radial shaft seal rocker arm shaft rocker shaft sector shaft serrated shaft side shaft silencer shaft splined shaft steering gear shaft steering shaft third motion shaft throttle shaft timing shaft transmission input shaft transmission output shaft universally jointed shaft shaft distributor: A distributor whose drive shaft projects into the engine; the shaft is driven via a gearing system or a coupling

shaft drive: A description of a motorcycle which uses a drive shaft between the transmission and the rear wheel instead of a chain.

shaft safety: See propeller shaft safety strap

shaft safety strap: See propeller shaft safety strap

shaft seal: A seal used to do two things: to prevent fluid from leaking out between a stationary part and a rotating shaft and to prevent foreign matter from getting in. Also see radial shaft seal

shaft sleeve: A sleeve which protects a shaft from erosion, corrosion, and wear at shaft seals

shaft-to-cage coupling: A viscous coupling design in which the outer disc carrier is connected to the differential cage, while the inner disc carrier is connected to an axle shaft

shaft-to-shaft coupling: A viscous coupling design in which the outer disc carrier is connected to the lefthand axle shaft and the inner disc carrier to the right-hand axle shaft

shake: See cowl shake scuttle shake side shake shallow angle: An angle that positions the bicycle frame tubes relatively farther from vertical and closer to horizontal than do steep angles.

shallow angles: Angles that position bicycle frame tubes relatively farther from vertical and closer to horizontal than do steep angles.

shallow pits: Corrosion in the form of pits whose diameter is substantially larger than their depth

shammy leather: See chamois.

shank: [1] The part of a bolt between the head and the thread. [2] The part of a bit which is held in the drill. See connecting rod shank increased shank reduced shank relieved shank shank length:

The distance from the last full form thread of a bolt to the bearing face

shape: See free shape

shaper: See pulse shaper

shape template: A guide or a pattern used in manufacturing items

shaping: The preliminary sanding or forming of the filled surface with coarse grit paper or a body file to establish the approximate body contours; this step is followed by final sanding

share: See market share

shared component: A part or component which is identical in various models of a car family, such as those used on a sedan and its convertible derivative; typical shared components are body panels, suspension components, brakes, wheels

sharing: See component sharing

shark: See radiator hose shark tooth pliers

shark tooth: See radiator hose shark tooth pliers

shark tooth pliers: See radiator hose shark tooth pliers

shave: [1] Removal of some chrome or decorative part. [2] Removal of metal from the contact surface of the cylinder head or the block.

shaving: A modification of the body of a car to remove all chrome parts at the front or rear end to achieve smooth contours highlighted only by the paint and the body modifications; in most cases, only a side chrome strip is retained. Also called "nosing" or "decking"

shear: [1] To distort or fracture as a result of excess torsion or transverse load. [2] To cut between two blades. See modulus in shear shears shear bolt: A bolt whose head may intentionally be sheared off to make extraction difficult

shear pin: A cylinder shaped item that is made of a substance which will break when subject to great pressure. In this way the main component which is more expensive will not be damaged. The pin can usually be easily replace. Also see spiral wrapped pin.

shears: A scissors-like tool for heavy-duty cutting. Also called snips. See metal shears tinmen's shears sheathed glow plug: See SR sheathed glow plug

sheathed-type glow plug: A single-pole glow plug having a tubular heating element with a heating coil or a heating and regulator coil enclosed in a thermally conductive insulator ceramic. Also see self-regulating sheathed-type glow plug

sheath flame: the outer area of an oxyacetylene flame surrounding the inner cone and the flame feather

shedder drip molding: A metal strip spot-welded below the roof drip rail to deflect rain water away from the door seal

sheer: The longitudinal curve of a vessel's decks in a vertical plane. Due to sheer, a vessel's deck height above the baseline is higher at the stem and stern than at amidships

sheer strake: The course of shell plating at strength deck level

sheet: See dust sheet, heavy sheet metal, and light sheet metal

sheet metal: Steel metal in the form of a thin layer or sheet which can be pressed to form panels of the car body. See heavy sheet metal light sheet metal sheet metal blank: A flat sheet metal panel before it has been cut and bent to be applied to a panel of a car to repair a damaged section

sheet metal clamp: A lock-grip pliers with wide, flat jaws used to secure sheet metal parts for welding or to bend small sheet metal parts along the edges of the jaws. When used for bending sheet metal, they may also be referred to as bending pliers

sheet metal cutter: Any tool used to cut sheet metal. See nibbler

shears snips sheet metal folder: A machine used to bend sheet metal along a predetermined line using mechanical force

sheet metal remains: A strip of metal left on the edges alter the bulk of a panel has been cut out; this strip is then removed carefully to ensure that the flanges required on adjacent panels for welding in the new part are not damaged and to avoid cutting out excessive material

sheet metal roller: A large machine to curve or roll metal in a single plane. The machine is handoperated and consists of a frame, three rollers and a hand crank. The rollers are arranged with one top and two bottom rollers, and the degree of curvature is controlled by how closely the bottom rollers are set in relation to the top roller. The pressure of the bottom rollers against the top roller causes the metal to curve

sheet molding compound: (SMC) Formerly called prepreg, SMC is supplied as a lightweight, pliable sheet which consists of a mixture of chopped strand mat pre-impregnated with resin, fillers, catalyst, and pigment. A sheet is placed between the halves of a heated mold and under the application of pressure it conforms to the contours of the mold

sheet wheel: A vehicle wheel (before the tire is installed) made from aluminium sheet material. Compare alloy wheel. The manufacturing process of the sheet wheel is comparable to that of the steel wheel but the advantage of the sheet wheel is its reduction in weight (up to 40% compared to a steel wheel)

Shelby: A vehicle brand of which the 1965-67 350GT and 500GT are milestone cars. See also AC Shelby Cobra Shelby Cobra: See AC Shelby Cobra

shelf:

Click for books on Shelby

See rear shelf squab shelf shelf life: A time limitation for the storage of uncured retread materials (usually 6 months), beyond which certain properties are lost. Storage of materials in a cool, dark, dry environment insures quality.

shelf panel: A deep-drawn steel panel fitted horizontally behind the rear seat backrest of a notchback sedan to support the plastic or foam molding that makes up the rear shelf, visible from the outside

shell: The structural case or housing, usually for mounting instruments. See bare shell bearing shell body shell converter shell spark plug shell shell bearing: A type of bearing used for main bearings and big-end bearings, consisting of a circular housing which can be divided into two halves, and which encloses a pair of bearing shells

shell expansion: A plan showing the seams and butts, thickness, and associated welding or riveting of all plates comprising the shell plating, framing, etc.

shell plating: The plates forming the outer side and bottom skin of the hull

shelter deck: A superstructure deck fitted continuous from stem to stern and fitted with at least one tonnage opening

sherardizing: The coating of iron objects with zinc powder by tumbling them in powdered zinc at about 250-375°C

shield: [1] An eye and face protector held in the hand when welding. It enables a person to look directly at the electric arc through a special lens without being harmed. [2] A relatively broad protective device which keeps away unwanted liquid or vapor. See air shield dust shield grass heat shield hand shield heat shield laminated windshield scatter shield splash shield static shield stone shield sunroof deflector shield windshield wing shield shielded arc: A form of electric welding in which a heavy flux-coated electrode is used.

shielding: Any form of screening. See shield

shift: To change gears. See floor shift rail, shift side shift stick shift shift cables: A term for the cables used to operates gears in some transmissions. In most vehicles rods and joints are used because cables tend to stretch

shift down: The action of selecting a lower gear. The British expression is "change down."

shifter: A device for changing the gearing on a transmission. See column shifter dash shifter floor shifter friction shifter hurst six-speed shifter index shifter index shifters J gate transmission shifter, an T-handle shifter shifter fork: See selector fork

shifter knob: The knob at the end of a lever. The British term is "gear knob"

shifter linkage: A system of rods and joints used to operate the transmission

shifter mechanism: A system of rods and joints used to operate the transmission

shifters: See friction shifters index shifters shift fork: See shift forks selector fork

shift forks: The devices that straddle slots cut in sliding gears. The fork is used to move the gear back and forth on the shaft.

shift gate: The mechanism in a transmission linkage that controls the motion of the gearshift lever. The shift gate is usually an internal mechanism; however, in some transmissions -- including Ferrari five-speeds and Mercedes-Benz automatics -- the shift gate is an exposed guide around the shift lever.

shift gear: The action of selecting a different gear. The expression in Britain is "change gear."

shift indicator light: (SIL) a system that provides a visual indication to the driver when to shift to the next higher gear to obtain optimum fuel economy

shifting: [1] Moving the ship to suit the location of shore cargo loading gear. [2] Changing gears in a transmission. Also see cargo shifting

shifting board: Portable bulkhead members, generally constructed of wood planking and fitted fore and aft in cargo holds when carrying grain or other cargo to prevent shifting when the ship is rolling

shift interlock: A device which prevents different shift forks in the transmission from being moved at the same time, by locking into the inoperative shift fork as the other is being moved; a gearchange cannot be made unless the inoperative shift fork is in its neutral position

shift into: The act of shifting into another gear, such as "shift into second" (shift into second gear) or "shift into high" (shift into high gear). In Britain, the expression is "change into."

shift lever:

[1] A device which is attached to the side of a steering column or to the center console which will allow the operator to change the gears of the transmission. Also called "gear lever." Also see left hand gear lever. [2] A lever inside an automatic transmission which connects the selector lever cable to the manual valve of the control valve body. [3] A component used in pre-engaged starter motors to force the pinion against the flywheel ring gear

shift linkage: The rods, levers, etc. used to transmit motion of the shift lever into movement of the gears in a gearbox.

shift lock: See selector lever lock

shift on the fly: The ability of a four-wheel-drive vehicle to be shifted between two-wheel drive and four-wheel drive while the vehicle is in motion.

shift point: This refers to the point, either in engine rpm or road speed, at which the transmission should be shifted to the next gear.

shift rail: See shift rails.

shift rails: Sliding rods upon which the shift forks are attached. Used for shifting the manual transmission.

shift up: A term meaning to shift to a higher gear

shift valve: A valve in an automatic transmission which raises the oil pressure as the vehicle speed increases. In Britain it is called the change valve.

shim:

A thin spacer installed between two parts to increase the distance between them. See adjusting shim anti-squeal shim valve shim shimmy: The front wheels shaking or vibration from side to side because the front end is out of alignment or the tires are out of balance or the suspension has worn components. See caster wobble wheel shimmy shim pliers: See valve shim pliers

shim-type head gaskets: A hard thin, high-performance steel head gasket that raises the compression ratio

shim under bucket: A valve adjusting system where the valve clearance is adjusted by placing an appropriate thickness of shim under the tappet instead of using an adjusting screw.

shingler's hammer: A hammer with a blunt side on one end of the head and an axe-like blade on the other side of the head.

ship: See aboard ship container ship dry cargo ship dual purpose ship flush deck ship great Lakes ship lighter aboard ship multipurpose ship OBO ship passenger ship RO/RO ship

self-sustaining ship self-trimming ship shipment: See value of shipment

shipments, value of: summation of value of shipments produced by establishment, receipts of custom and repair revenue.

ships: See sister ships

shock: See adjustable shock direct-acting shock absorber double-tube shock absorber flexural shock friction shock absorber gas shock gas shock absorber lever-type shock absorber monotube shock absorber shocks shock absorber: Properly called a damper, this is an oil filled device used to control spring oscillation in the suspension system. At least one shock absorber is found at each wheel. See adjustable shocks air shock absorber direct-acting shock absorber double-tube shock absorber friction shock absorber gas shock absorber lever-type shock absorber monotube shock absorber self-levelling shock absorber single-tube shock absorber

telescopic shock absorber shock absorbers: See shock absorber

shock absorber tower: A sheet metal panel of hollowed or box-section design that is spot-welded to the body and serves as an anchoring point for the top shock absorber mount

shocks: An abbreviation for "shock absorbers." See adjustable shocks.

shoe: See brake shoe double leading brake shoe forward brake shoe leading brake shoe leading shoe pole shoe pole shoes primary brake shoe primary forward brake shoe primary shoe reverse brake shoe secondary brake shoe secondary shoe self-energizing brake shoe single leading brake shoe trailing brake shoe trailing shoe yellow shoe shoe grinder: See brake shoe grinder

shoe heel: See brake shoe heel

shoe return spring:

See brake shoe return spring

shoes: see shoe

shoe toe: See brake shoe toe

shooter: The accelerator pump discharge nozzle; squirts extra fuel into the throttle bore when the accelerator pump circuit is pressurized by the pump piston

shooters: Small pump-discharge restrictions in the cluster assembly. These small cavities prevent accelerator pump pullover feeding from the pump system at high airflows

shooting brake: An old term for station wagon. It refers mainly to larger British station wagons with wooden rear and side panels that were popular during the early post-war such as coachbuilt models by Daimler, Armstrong-Siddeley, Allard, etc.

shop: See body shop chop shop independent repair shop paint shop production retread shop specialty repair shop shopping: See Canadian cross border shopping

shopping car: A vehicle similar to a city car, but may be even smaller

shop primer:

A coating which temporarily protects a work from corrosion, e.g., during shipment

shore: A brace or prop used for support while building a ship

shore hardness: A test method for the determination of indentation hardness of nonrigid plastics

short: See short circuit long and short arm suspension short arc: A gas metal- arc process which uses a low arc voltage, where the arc is continuously interrupted as the molten electrode metal bridges the arc gap.

short arm: See long and short arm suspension

short arm/long arm suspension: (SLA) See unequal-length wishbone suspension

short arm suspension: See long and short arm suspension

short block: The lower portion of an engine below the cylinder head. It includes the crankshaft and piston assemblies but not the external parts such as head, sump, oil pump, or fuel pump. The opposite is the long block

short block engine: An engine with a relatively short crankshaft. Compare long block engine. Normally a short block engine refers to a 4-cylinder in-line engine or a V-8 engine where either engine has a shorter block than a 6 cylinder in-line engine

short circuit:

An electrical problem in which the "hot" or positive wire touches ground. It takes a "short" path to ground instead of going through the prescribed component. Usually a short circuit (also called a short) will burn out a fuse or a component.

short circuit between the plates: An undesirable electrically conductive connection between the positive and negative plates within a battery cell, making the battery inoperative

short circuiting: A condition which occurs during the scavenging process of a two-stroke engine when some of the fresh mixture entering the cylinder may flow across the cylinder and escape via the exhaust ports without producing any scavenging effect

short cycling: A term referring to the condition in which the compressor in a cycling clutch system cycles too frequently

short engine: A fully reconditioned engine but without external parts such as head, oil pan, oil pump, or fuel pump, etc.

short stroke engine: An engine where the length of the stroke is shorter than the diameter of the cylinder bore. Theoretically a relatively short stroke improves high end revving ability but is poorer at low-end torque.

short ton: 2,000 pounds.

short track: Any oval-shaped or circle-shaped course less than one mile long.

shorty: A general term for a short manifold or exhaust pipe

short-type distributor: A distributor without a drive shaft; the drive coupling is located directly at the base of the ignition distributor housing. The opposite is shaft distributor

shot bag: A leather bag filled with very fine lead shot or sand over which metal is shaped

shot blasting: A blasting process in which rounded particles are impacted onto a surface

shoulder: [1] The outer edges of the tread of a tire. [2] The outer edges of a road. [3] The raised portion of a specialized bolt just under the head. It looks like a collar, but it is not removable

shoulder belt: A restraint belt pulled diagonally across the chest or the shoulder belt portion of a combined lap-shoulder belt. See 3-point seat belt lap belt show through: Sand scratches in the undercoat visible through the paint

shredded wire: Short pieces of fine steel wire mixed into a tread or undertread compound.

shrink: To reduce in size. See heat shrink tube

shrinkage: The size or coverage reduction of automotive paint as it dries. All automotive paints shrink, and if scratches or surface imperfections have not been properly filled, they will show up as the paint shrinks into them. Also see mold shrinkage

shrink fit: A fit between two parts which is very tight. The outer or encircling piece is expanded by heating so it will fit over inner piece. Sometimes the inner piece is contracted by chilling. As the two pieces reach operating temperature or room

temperature, the outer piece shrinks and the inner piece (if it was chilled) expands. As a result, the two pieces fit tightly.

shrinking: A body repair technique used to repair locally stretched areas by using heat or special body hammers. See heat shrinking resistance shrinking shrinking dolly: A special dolly with a large crowned grid surface, used to facilitate panel shrinking

shrinking hammer: A special hammer with faces shaped to allow for correction of locally stretched sheet metal. When shrinking metal, the panel is beaten into the recesses of the grid, which help stretching

shrink tube: A thin plastic tube which shrinks in diameter when heated. It is used primarily in covering exposed wire splices. Also see heat shrink tube

shrink wrap: A clear plastic film, often a foot or more wide used to protect something from dust and moisture.

shroud: A metal enclosure around the fan, engine, etc., to guide and facilitate the flow of air. Also see heat shroud

shudder: See clutch shudder wheel shudder shunt: [1] To bypass or turn aside. [2] An alternate or bypass portion of an electrical circuit. [3] A colloquial term for to crash.

[3] A crash, especially one caused by running into the back of the vehicle in front of you

shunt firing: A short circuit at the firing end of a spark plug, caused by electrically conductive deposits. Also called "shunting."

shunting: A short circuit at the firing end of a spark plug, caused by electrically conductive deposits. Also called "shunt firing"

shunt winding: A wire coil forming an alternate or bypass circuit through which the current may flow.

shut: See cut-and-shut door shut shut line: The line between a closed door and the bodywork

shutlines: Lines in the body where two body parts abut each other, such as where a door meets a fender. Can also be a seam where two immovable parts meet i.e., plastic bumper cover meets quarter panel.

shut-off: See fuel pump shut-off switch overrun cut-off/shut-off shut-off switch: See fuel pump shut-off switch

shutter:

A curved metal vane or blade of a Hall generator

shuttle valve: A valve in which the actuating member shuttles back and forth diverting pressure from one channel to another

SI: Acronym for spark ignition

siamesed: Arrangement of ports when intake or exhaust valves are in pairs which allows twointo-one passages to be cast into the cylinder head. For example, with the usual valve arrangement in a four-cylinder engine the head can be designed so only two ports connect to the intake manifold and only three to the exhaust manifold. Also, when the engine cylinders are connected solidly together (as in the Vega block) instead of being totally surrounded by water jackets, the cylinders are said to be siamesed.

SIC: Acronym for "Standard Industrial Classification" on "http://strategis.ic.gc.ca/SSGF/am00655f.html". Industry class that represents a level of organization of production by type of specialization. Currently the 1980 Standard Industrial Classification is in effect identifying each industry at the 4 digit level.

SID: Acronym for side impact dummy

Siddeley: See Armstrong-Siddeley.

side: See differential side gear discharge side exhaust side federal side impact standard heavy side pattern high side

low side outlet side piston ring side clearance rear side window ring side clearance suction side side aperture panel: See aperture panel

side bumper panels: Large plastic body side moldings attached to the lower body sides which protect the body against road debris, road salt corrosion, and mechanical impact. Sometimes called Sacco panels because they were introduced by Bruno Sacco, the chief designer at Mercedes-Benz

sidecar: An addition to a motorcycle which is added to its side. It has an outboard wheel and is designed to carry a passenger or luggage.

side clearance: See piston ring side clearance ring side clearance side curtain: The early name for side windows which were made of celluloid in a rigid frame supported by the sides of the body and the doors; some had a hinged flap through which the driver could extend his hand for signalling purposes. On classic roadsters, the entire assembly of sliding windows and flaps; wedge-type side curtains permit the side curtain brackets to be wedged into the door plates without bolts; regular spring-type side curtains are mounted to the doors by means of wing nuts or bolts. The curtains can be stored behind the rear seat squab or in a pocket at the back of the front seats

side cutters: A tool like a pair of pliers except the end opposite the handles have sharp edges used to cut wire, etc. The British term is end cutters or end cutting pliers

sidedraft carburetor:

A carburetor in which the air passes through the carburetor into the intake manifold in a horizontal plane. Contrasts with a downdraft carburetor.

sidedraught carburetor: British spelling for sidedraft carburetor

side electrode: The ground electrode at the side of the threaded part of a spark plug shell

side flasher: A small amber or red signal light located in the side of the front or rear fenders

side gear: See differential side gear

side-hung float: Float design has a pivot axis that is perpendicular to the vehicle axles. It has slightly better float control and fuel handling during acceleration and braking than its centerpivoted counterpart

side impact: See federal side impact standard

side impact air bag: Fabric bags installed in the doors of some cars that inflate rapidly during a side impact collision. Inflation occurs at speeds of 12 miles per hour or higher, preventing passengers from hitting their heads against the windows or pillars of the car.

side impact bar: A longitudinal reinforcing beam in a car door, designed to withstand side impact. Also called side impact intrusion beam

side impact dummy: (SID) A dummy developed to investigate the effects of side impact crashes

side impact intrusion beam:

A metal beam in the door or along the side of the passenger compartment that adds additional protection in the case of an accident. It reinforces the side of the car.

side impact standard: See federal side impact standard

sidelamp: See sidelight

side-lift jack: See tower jack

sidelight: A low-intensity white lamp usually located on the side of front fender ahead of the front wheel. It is usually illumined in a steady glow when the signal lights are activated.

sidelight pod: A design feature of older cars that had their side or parking lights incorporated into a separate sheet metal molding on top or at the side of the front fenders

side marker lamp: A low-intensity lamp mounted on the side of a vehicle to indicate its presence when seen from the side

side marker light: A low-intensity lamp mounted on the side of a vehicle to indicate its presence when seen from the side

side member: A box-section member inboard of the outer sill that often runs from the front to the rear of the car and provides reinforcement of both sides of the floorpan

side molding: See body side molding

side panel:

[1] A quarter panel between the B-pillar and the rear. [2] An aperture panel. [3] A vertical panel on the inside of a body shell, e.g., the panel joining the lock pillar to the rear wheel housing. See cowl side panel scuttle side panel side pattern: See heavy side pattern

side pipe: An exhaust pipe running along the side of the car. Compare lakers or lakes pipes

side radiator guard: A molded cover panel fitted to the sides of the radiator to protect it from water splashes

side rail: See side member

side ring: A demountable metal flange to hold the tire on the rim base. It can be self contained, locking into the gutter, or may be held in place by a lock ring, depending on the type.

side rod: See tie rod

side scoop: An air intake for the engine and/or for cooling on mid-engine or rear-engine cars; typically found on sports cars such as the Ferrari range

side shaft: See axle shaft

side shake:

See end play

side shift: damage to the frame when the vehicle has been hit from the side

side skirt: An extra body panel fitted over the sills (for cosmetic reasons only)

side step: A step plate below the doors to facilitate entry into the relatively high cabin of a commercial vehicle

side styling: See straight-through side styling

sideswipe: [1] Body damage caused by a car hitting an obstacle at an acute angle, causing the panels to be dented over a relatively large area. [2] To scrape along the side of a car.

side valve: Valves positioned at the side of cylinder

side-valve engine: (SV) An engine with the valves to the side of the cylinders

sidewall: That portion of a tire between the tread and bead. See tire sidewall. [2] The vertical part of the box section of a side member

side window: See rear side window sliding side window SI engine:

A spark ignition engine or gasoline engine: internal combustion engine of the reciprocating type in which an air/fuel mixture is compressed and then ignited by an electric spark. It is unlike a diesel engine

sight glass: A viewing glass or window set in the refrigerant pipe of a car's air-conditioning system, usually in the top of the receiver-drier, which allows a visual check of the refrigerant passing from the receiver to the evaporator. The fluid should be clear and free from foam

sighting point gauge: A device incorporating a sighting pin, used to measure car bodies for misalignment

sigma welding: See gas metal- arc welding

signal: [1] To indicate a change in direction (turning, stopping, etc.). [2] An indicator. See reversing warning signal right hand turn signal signal amplifier: Any device, such as the booster venturi, that amplifies a vacuum signal

signal indicator: See turn signal indicator

signal light: The small lights which blink on either side of the front of the vehicle and either side of the rear of the vehicle. Some early cars (like the Austin and Flying Standard) had small illuminated arms that flipped out from the B-post instead. The purpose of signal lights is to warn other drivers of a change in direction when turning a corner or changing lanes. Also called "direction indicator." In Japan they are called "winkers."

signal light warning light:

A light on the instrument panel which flashes when the signal lights are operating. Usually this light is in the shape of a green arrow. On some cars, like Cadillac, a secondary light is mounted in a pod on the upper edge of each front fender and in a pod inside the cab above the backlight (i.e., back window). Also called "direction indicator warning light."

SIL: Acronym for shift indicator light

silencer: [1] A muffler. [2] A device in an air-conditioning system designed to minimize pumping sounds from the compressor. See air silencer front silencer straight-through silencer silencer shaft: See balance shaft

silencer-tailpipe tool: [1] A chisel-type tool with several cutting edges to cut muffler sleeves without damaging tailpipes. [2] An L-shaped tool whose short end is driven between the silencer and tailpipe to break the bond

silent chain: A quiet timing chain with V-shaped teeth

silica: A common mineral (silicon dioxide) found as sand, quartz, etc., used in the manufacture of glass, ceramics and abrasives

silica gel: A form of silica capable of absorbing large quantities of water, used to keep electronic apparatus, etc., dry

silica sand:

A form of silica used for sherardizing or mechanical plating

silicon: A non-metallic chemical element occurring in several forms (principally sand and rock), used in the manufacture of glass and steel (as well as transistors etc.)

silicon carbide: A material of excellent abrasion and corrosion resistance used in bearings and mechanical seals

silicone: A silicon compound with a high resistance to heat, water, and chemicals, and with good insulating and lubricating properties; used in oils, polishes, sealants, etc.

silicone brake fluid: A brake fluid which does not absorb water

silicone-rubber sealant: A semi-liquid sealant which keeps out oil and water but not gasoline. Also called RTV sealant

silicon glove: See barrier cream

silicon steel: An alloy of silicon and chromium with steel, often used for exhaust valves

sill: [1] A longitudinal box-section member of the body shell at floor level, located below the doors. [2] A box-section crossmember just below the lower edge of the trunklid (when closed). See door sill inner sill outer sill sill cover:

A non-structural part covering the sill on its entire length; used on certain designs with separate chassis but also on unitary designs

sill end piece: A small panel at the front and rear end of the sill that closes off the hollow sill section towards the front and rear wheel arches. Compare closing panel

sill membrane: A horizontal stiffening panel between the outer sill and the side member box section; it is ribbed or drilled for extra rigidity

Sillment seal: A gas-tight seal between center electrode of a spark plug and insulator and between insulator and shell

sill panel: See under sill panel

sill stiffener: See sill membrane

sill structure: The overall design of the sills including outer sills, side member, or inner sill and sill membrane

silver-plating: The electrolytic deposition of silver

silver solder: Similar to brazing except that a special silver solder metal is used. It is used primarily on bicycle tubing.

SIMA: Acronym for "Special Import Measures Act."

simple circuit:

The simplest circuit includes an electrical power source, a load, and some wire to connect them

simple tappet: See flat tappet

simplex chain: A chain with only one row of rollers. See duplex chain triplex chain Simpson gear set: It consists of two simple planetary gear sets with a common sun gear and internal gears of different diameter; the planet carrier of one set is fixed to the internal gear of the other set

Simpson planetary gear set: It consists of two simple planetary gear sets with a common sun gear and internal gears of different diameter; the planet carrier of one set is fixed to the internal gear of the other set

single: [1] A small, lightweight motorcycles. What the bike lacks in overall power, it gains in its lightweight, small size that makes it easy to ride even if it has a large engine displacement. [2] Any single cylinder engine vehicle (especially, a motorcycle)

single-acting: Having a piston or pistons of a reciprocating engine or pump that are pressurized on only one side

single-anchor self-energizing brake: A type of servo brake where both shoes pivot about one fixed point

single barrel: See single-barrel carburetor.

single-barrel: See single-barrel carburetor.

single barrel carburetor: See single-barrel carburetor.

single-barrel carburetor: A carburetor with one throttle opening or barrel from the carburetor to the intake manifold. See carburetor double-barrel carburetor and four-barrel carburetor single bead: A tire built with only one wire bundle in the bead.

single-bed 3-way catalytic converter: A converter for the control of HC, CO, and NOx emissions, consisting of one threeway catalyst; in combination with an oxygen sensor, this type of converter yields the lowest emission values

single-bed oxidizing converter: A converter with one catalyst bed for HC and CO control

single-circuit braking system: An old form of hydraulic braking system in which a single circuit serves all four brakes. Not to be confused with single-line braking system

single coat: A coat of paint, with each stroke overlapping the previous stroke by 50%. Also see double coat

single-coil twin ignition: In the early days of straight eight engines, a distributor with two sets of contact points, firing alternately

single-connector system:

An electrical circuit, where only one wire comes from the voltage source to the load. To complete the circuit, the electricity uses the metal body of the vehicle

single-cut file: A file with teeth in only one direction and used for filing soft material

single-cylinder engine: An engine with just one cylinder such as used on some motorcycles and utility engines (e.g., lawn mower engine, water pump, portable generator, etc.)

single-decker bus: A bus with one storey or deck. See double-decker bus

single-grade oil: oil suitable for use within a narrow temperature range; outside this range, its flow characteristics will not allow adequate lubrication. Also called "straight-weight oil." Compare multigrade oil

single leading brake shoe: The use of a single hydraulic plunger and a common pivot point which expands two shoes against the drum with equal pressure whether braking from forward or reverse direction. The leading brake shoe is usually called the "Primary Shoe" and trailing shoe is called the "Secondary Shoe." Also see double leading brake shoe.

single-leaf spring: A suspension spring which has just one flexible beam

single-line braking system: A braking system in which a single line is used to connect towing vehicle and trailer. It is not to be confused with single-circuit braking system

single overhead cam: (SOHC) The camshaft is located between the valves and is driven by a chain or belt from the crankshaft; the valves are normally opened by short rocker arms. See overhead cam.

single-overhead cam:

(SOHC) An engine with a single overhead camshaft to operate both intake and exhaust valves. See overhead cam.

single overhead camshaft: (SOHC) The camshaft is located between the valves and is driven by a chain or belt from the crankshaft; the valves are normally opened by short rocker arms. See overhead cam.

single-overhead camshaft: (SOHC) An engine with a single overhead camshaft to operate both intake and exhaust valves. See overhead cam.

single-piece rim: A one-piece rim

single-piece wheel: A one-piece wheel

single-pivot steering: A steering system in which a beam axle is pivoted at its mid-point; rare except on horse-drawn vehicles and trailers. Also see double-pivot steering

single-plate clutch: A normal type of clutch, with one driven plate; usually dry (i.e., without oil). Also see multi-plate clutch

single point injection: (SPI) A gasoline fuel-injection system which sprays fuel under pressure into the intake air at one place, usually the throttle body on the inlet manifold. It is less complicated than a multi-point injection system but achieves better carburation than a carburetor. Also see multi-point injection

single rate spring: A spring with a constant spring rate. For example, if a 100-pound force deflects the spring by one inch, an additional 100 pounds will deflect it one more inch, and so on until the spring either bottoms or fails. The opposite of progressive rate spring.

single roller chain:

See simplex chain

single-spark ignition coil: In a distributorless ignition system with an odd number of cylinders, each cylinder requires its own ignition coil; distributor logic on the low-voltage side performs the voltage distribution to each coil. Also see multi-spark ignition coil

single-tube shock absorber: A common type of shock absorber with the working cylinder and reservoir contained in one tube. See double-tube shock absorber gas shock absorber single-wheel suspension: See independent suspension

single wire circuit: An electrical system in which the hot line is in a wire, but the ground line uses the frame.

single wire system: Lighting circuit which uses car frame for return ground line

sink: See heat sink

sink in: A tendency of a hardened filler to settle excessively, making the feather edges of the filled area stand out on the painted surface

sinter: [1] To manufacture parts from powdered metals by heating or pressure or both. [2] The fine powdered metal itself

sintered bronze: Tiny particles of bronze pressed tightly together so that they form a solid piece. The piece is highly porous and is often used for filtering purposes.

sintered metal brake pad: A type of brake pad made of sinter and is designed to reduce noise and increase performance and life.

sipe: Fine lines or grooves cut into the tread of tires. They allow the tire to flex and give better traction on wet surfaces. They may also reduce tire noise.

SIR: supplementary inflatable restraint

sissy bar: A chrome rail which projects up from the back of a motorcycle saddle.

sister ships: Ships built on the same design.

site: See nucleation site

sitting position: See upright sitting position

six: See flat six straight six V-six six banger: Six cylinder engine.

six-cylinder engine: An engine with six cylinders; may be in-line (a straight six) or in a V-layout (a V-6)

six-light sedan: An old designation of a four-door body style that features another small quarter window behind the rear side doors, resulting in three side windows per side or six windows overall

six-pack: Refers to a special triple two-barrel induction system used on some Chrysler V8 engine in the late 1960s and early 1970s. However, other special heavy-duty parts were used in engine that came from the factory equipped with this induction system, so "six-pack" is frequently used as an adjective to describe other engine components used on these engines. E.g., six-pack connecting rods

six-speed: See hurst six-speed shifter

six-speed shifter: See hurst six-speed shifter

six-speed transmission: A manual transmission with six forward gears. See Hurst six-speed shifter.

sixteen: See V-sixteen

sixteen valve engine: (16V) A four-cylinder engine with four valves to each cylinder. This system permits more air-fuel into the cylinder and exhaust out of the cylinder.

size: See die size engine size metric size rim size size designation: See tire size designation

size marking: The first part of a tire marking molded on the sidewall, giving the tire's width in millimeters

size markings: See tire size markings

skeg: A deep, vertical, fin-like projection on the bottom of a vessel near the stern

skeleton construction: A modern construction layout of the unitary type, using a skeleton-like assembly as the main structural member, thus relieving stress from the body sheet metal. See coachbuilt construction unitary construction skewer: A pin with a loop at one end for insertion and removal. See quick-release skewer.

skid: [1] A sideways slip or slide of a wheel through failure to grip the ground. Also see anti-skid. [2] To slide sideways (often out of control). [3] To slide in a straight line (as after sudden braking with, maybe, locked brakes). Also see turn into the skid

skid braking system: See anti-lock brakes

skid depth: See tread depth.

skid lid: A helmet.

skid mark:

The mark left on the road surface by the tires, as a result of emergency braking

skid pad: See skidpad

skidpad: A large area of smooth, flat pavement used for various handling tests. Roadholding is measured by defining a large-diameter circle (Car and Driver magazine uses 300 feet) on the skidpad and measuring the fastest speed at which the car can negotiate the circle without sliding off.

skidpan: [1] British term for skidpad. skid plate: A steel, aluminum, or plastic shield attached to the underside of the chassis to protect vulnerable components (oil pan, transmission, differentials, and transfer cases) from off-road obstacles. Also called sump guard

ski flap: A flap in the rear bulkhead (behind the rear seat), for long, thin loads (like skis)

skin: The outer surface or body panel. See door skin natural oxide skin seat skin skins skinning: The formation of a film on a thick paint layer before the solvents in the layer under it have evaporated

skins: [1] Colloquial term for tires. [2] A covering (usually plastic) for skis on a snowmobile.

skirt: [1] A cover for the rear fender cutout.

See fender skirt side skirt [2] The portion of the piston below the rings and bosses. It absorbs the thrust caused by the crankshaft as it makes contact with the cylinder wall. See bumper skirt fender skirt piston skirt expanding piston skirt rear bumper skirt rear wheel skirt side skirt split skirt skirt expander: See piston skirt expander.

skirt expanding: See piston skirt expanding

skirt piston: See split skirt piston

skive: The action of cutting into something or cutting away rubber from an injury in preparation for a section repair.

Skylark: A model of automobile manufactured by Buick Click for books on Buick Skylark skylight: A glass covered framework fitted over a dock opening for admitting light and air into the compartment below. A pop-up window in the roof of a trailer

SL: Acronym for special ledge

slack: The amount of free play in a chain or belt: too much slack could cause the chain/belt to slip and jump the sprockets; too little slack (the chain seems tight) causes excessive wear on the final drive system. Also see belt slack

slag inclusions: Non-fused, non-metallic substances in the weld metal.

slant engine: This is an in-line engine in which the cylinder block has been tilted from a vertical plane. Also called inclined engine

slap: See piston slap.

slapper: A colloquial term for a bumping blade

SLA suspension: Acronym for short arm/long arm suspension

slatted grille: An aerodynamic radiator grille developed by Ford in 1976. The horizontal aerofoil grille elements are shaped like aircraft wings to allow the cooling air to flow towards the radiator at low speeds, whereas excess airflow is directed upwards across the front of the car at higher speeds to produce an effect similar to that of a spoiler

slave con rod: A connecting rod of two-stroke dual piston engines which is articulated on the master con rod, not directly on the crankpin. Also see master con rod

slave cylinder: A small cylinder containing a piston which, under hydraulic pressure from a master cylinder, operates the brake shoes or pads in hydraulic brakes or the working part in any other hydraulically operated system (such as a clutch slave cylinder). Also see master cylinder

sled: A snowmobile. Also see lead sled

sledge hammer: A large, heavy hammer usually with a long handle. The head is double sided so that either end can be used to strike an object

sleeve: [1] A tube fitted externally over two cylindrical parts in order to join them. [2] A cylindrical insert. See adjusting sleeve coupling sleeve cylinder sleeve dry sleeve liner re-sleeve shaft sleeve wet sleeve sleeve bearing: Any bearing of tubular or sleeve-like construction

sleeve nut: See inner cap nut.

sleeve valve: Consists of metal sleeves located between the piston and cylinder wall. When moved up and down, holes in the sleeves coincide with inlet and exhaust parts to provide passage for the gases at the right time.

slewed axles: Axles that are not parallel.

slick: A very wide tire, without a tread pattern, designed to provide a maximum amount of traction. It is used for racing on dry surfaces.

slide:

See pocket slide caliper

slide caliper: See pocket slide caliper

slide carburetor: A type of carburetor often used in motorcycle engines, in which a slide valve modifies the venturi of the carburetor

slide hammer: A tool with a long round shaft on which a hammer weight slides; the force produced by quickly moving the weight towards the end of the shaft is used for loosening or pulling off tight parts; often used in combination with pullers. Also see panel puller

slider: (CVT) A device which senses the position of the half of a primary pulley that slides. Also see pin slider caliper disc brake

slider caliper: See pin slider caliper disc brake

slider caliper disc: See pin slider caliper disc brake

slider caliper disc brake: See pin slider caliper disc brake

slide valve: A valve that slides across an aperture to expose the port or opening

sliding-caliper disc brake: A disc brake design with a sliding caliper. In one type, the caliper floats on the caliper frame grooves. The major components are: caliper (a casting with one cylinder and piston), caliper frame (casting) which is bolted to the suspension. In another type, the caliper floats on caliper locating pins. See pin slider caliper disc brake. A third type, is the floating-frame disc brake. Sometimes subtle design differences are used to differentiate between "sliding caliper disc brakes" and "floating caliper disc brakes," but usually these terms are treated synonymously.

sliding contacts: An ignition assembly developed by Lucas, that causes the moving contact to slide vertically across the face of the fixed contact when the spark is advanced

sliding fit: Parts that are assembled so that there is clearance between them so that one part can slide in or on the other. Also called "clearance fit"

sliding-fit: See running-fit.

sliding friction: A frictional resistance to relative movement of surfaces on loaded contact. Also see rolling friction

sliding gear: A transmission gear that is splined to the shaft. It may be moved back and forth for shifting purposes.

sliding joint: See slip joint

sliding-mesh gearbox: An obsolete type of transmission or gearbox in which the gears on the layshaft are fixed to the shaft rigidly, whereas the gears on the main shaft can slide on it by means of splines but are otherwise in permanent rotational mesh with the shaft. Also see constant-mesh gearbox

sliding-pillar suspension: A once popular front suspension layout (e.g., in Lancia and Morgan cars), in which a carrier-mounted stub axle slides up and down a vertical pillar with enclosed coil springs providing the suspension; less sophisticated versions were used in several pre-war cycle cars

sliding side window: A window style of classic roadsters, consisting of aluminum frames with tracks for two sliding window panels made of clear Plexiglas, and with draught seals; on some

cars, also furnished with flaps. Also see side curtain

sliding T-bar: A drive handle with square drive sliding on round bar for T-handle turning operation

sliding-vane pump: A positive displacement pump in which an eccentric rotor revolves in an eccentric or circular case. Also see external-vane pump. The pumping element consists of multiple blades which slide in slots in the rotor and divide the crescent-shaped fluid space into variable volumes. Some sources state that in the sliding-vane type, vanes do come into contact with the casing, whereas in "vane-type pumps" a clearance of about 0.004 inches is maintained between vanes and casing.

sliding weight: A functional part of a sliding hammer that provides the inertia required for the pulling force

slinger: A ring on a shaft that throws oil from the shaft before it gets to the oil seal. See oil slinger.

slingshot: [1] A form of dragster using a rather long thin frame with a very light front axle and wheel assembly. [2] A maneuver in which the driver of the trailing vehicle in a draft line breaks the draft by turning (usually to the left if on an oval track), propelling the car around the leader.

slip: The relative motion between driving and driven parts. See belt slip clutch slip half-moon slip joint pliers limited slip differential wheelslip slip angle:

The difference in the actual path taken by a vehicle making a turn and the path it would have taken if it had followed exactly as the wheels were pointed. The slip angle is the result of the tire carcass's flexibility and is the angular difference between the direction the wheel is travelling and the direction of the tread. If the slip angles of the rear tires are greater than the slip angles of the front tires, the vehicle is said to be oversteering. See oversteer tire deviation angle tire slip angle slip-control differential: See automatic slip-control differential

slip differential: See limited slip differential torque sensitive limited slip differential slip friction: See sliding friction

slip-in bearing: A liner, made to extremely accurate measurements which can be used for replacement purposes without additional fitting

slip joint: [1] A joint that will transfer driving torque from one shaft to another while allowing longitudinal movement between the two shafts. A variable length connection that permits the driveshaft or axle shaft to change its length as the shaft moves up and down. The British term is "sliding joint." [2] A connection in an exhaust pipe where one pipe slips into another. Also see slip joint: half-moon slip joint pliers

slip joint pliers: See half-moon slip joint pliers

slip-on: Any device which slides on to the main component, e.g., a slip on muffler slides onto the existing exhaust pipe

slipper piston: a piston with the lower edge cut away so that the piston skirt is short on the two sides not used as thrust surfaces. Such a design lightens the piston making it easier to accelerate and decelerate, wastes less power, and is easier on the bearings. Cutting away the skirt also allows the connecting rod to be made shorter but leaves enough room between the counterweights and the pistons so the overall height of the engine can be reduced.

slip ring: One of several conductive metal rings attached to the rotor shaft in an alternator that periodically changes the direction of current flow.

slip-ring end bracket: A cover housing the bearing at the slip-ring end of an alternator. At the other end is the drive end bracket

slip roll: See sheet metal roller

slip stream: [1] A stream of air behind a moving vehicle. [2] A racing technique in which one vehicle tucks in closely behind another (catches a tow). The total aerodynamic drag acting on the two vehicles is actually less than the drag that acts on each vehicle when they are separated by greater lengths; this allows both vehicles to gain straightaway speed. The lead vehicle cuts into the air acting as a wind break for the following vehicle, and the closeness of the second vehicle reduces the turbulence normally generated at the rear of the first vehicle. Also called drafting.

slip the clutch: To operate the clutch so that it partially disengages, as when keeping up the revs when driving off; causes wear on the clutch. Also see clutch slip

slop tank: A container in a tanker into which the residue of tank washing are pumped.

sloper:

A colloquial term for an inclined engine

sloping headlight: An old headlight type used on the VW Beetle prior to 1967

slot: A narrow channel or aperture, especially the groove in the head of a screw which receives the tip of the blade of a screwdriver. See T-slot valve slot ventilation slot vent slot slotted piston: See split skirt piston

slow charging: The charging of a battery by using a charging current which corresponds to 10% of the battery capacity. Also see fast charger

slow down indicator: An indicator light on the instrument panel that warns the driver to slow down in the event of excessive catalytic converter temperature. A protective warning circuit causes the indicator to flash if the catalytic converter becomes overheated. If the temperature increases beyond a certain second level, the lamp will glow continuously

slow leak: A tire which loses its air pressure over a period of time. It is usually caused by a small puncture, a leaking tire valve, or a tire that is not properly seated on the rim.

slow-running: See idling

sludge: A thick, black, mushy, greasy deposit found throughout the interior of the engine. Caused from a mixture of dust, oil, gasoline, water, and blowby being whipped together by the moving parts. Some engines oils have detergent to break down

sludge. A composition of oxidized petroleum products along with an emulsion of oil and water, forming a pasty substance that clogs oil lines and passages and interferes with engine lubrication. Sludge is formed in engines with neglected oil changes. Also see oil sludge

sluggish: Unresponsive; functioning at below normal rate or level

sluggish acceleration: To increase speed slowly. See acceleration.

slush: Soft melting snow. Also see powder slush molding

slush box: A derogatory colloquial term for an automatic transmission used by those who prefer a manual transmission.

slushbox: A derogatory colloquial term for an automatic transmission used by those who prefer a manual transmission.

slush molding: A thermoplastic casting in which a liquid resin is poured into a hot, hollow mold where a viscous skin forms; excess slush is drained off, the mold is cooled, and the molded product is stripped out. Also see powder slush molding

small-block engine: During the '60s and '70s, GM, Ford, and Chrysler made two types of V8 engines of the same displacement: e.g., 350 cu. in. small-block and 350 cu. in. big-block. The small-block engine was an enlarged smaller displacement engine (e.g., GM enlarged the 283 to 327 then to 350 by boring the cylinders). The big-block engine was a completely different basic engine size even though it displaced the same as the enlarged small-block engine. Thus, as vehicles grew smaller and more equipment was stuffed into the engine bay, the small-block engine was favored over its larger brother.

small end:

The top of a connecting rod, attached to the piston pin

small end bearing: The smaller bearing of the two on a connecting rod and through which the piston is attached; usually fitted with a plain bearing or a needle-roller assembly

SMC: Acronym for sheet molding compound

smell: See rotten-egg smell stink-bomb smell SMMT: Acronym for "Society of Motor Manufacturers and Traders"

smog: Fog made darker and heavier by chemical fumes and smoke. A fog-like layer, often brown in color, that hangs over many areas under certain atmospheric conditions. Smog, a contraction of the words smoke and fog, is compounded from smoke, moisture and numerous chemicals produced by combustion (from power plants, automotive engines, etc.) and from natural and industrial processes. Formation of smog is aided by the presence of sunlight which reacts with many chemicals and combustion products such as hydrocarbons and oxides of nitrogen to form other more noxious compounds.

smoke: the visible product of combustion; a common problem with diesel cars when starting or pulling hard, caused by too much fuel (black smoke) or oil (blue smoke).

smoke meter: An instrument which measures the density of exhaust smoke, especially in diesel engines

SMPI: Acronym for "sequential multi-point electronic fuel injection."

smut: See sealing smut

Sn: The symbol for tin

snail-cam chain adjuster: Axle-mounted helical cams that allow accurate chain adjustment

snake: A condition when pulling a trailer where it swings from side to side when being towed too fast

snap fastener: A securing device with a projecting knob on one part that is pressed in securely into a corresponding hole on another part, used on some roadsters to attach the convertible top or tonneau cover to the rear deck and/or windshield header.

snap ring: A split ring or clip that is snapped into a groove in a shaft or in a groove in a hole. It is used to hold bearings, thrust washers, gears, etc., in place. An internal snap ring is used in a groove in a housing; an external snap ring fits in a groove cut on the outside of a cylindrical piece such as a shaft. Also called a circlip snap-splice connector: Solderless connector used to tap an additional wire into an existing wire without cutting the original. Often used in installing trailer wiring to a tow vehicle

snatch: To take up the drive suddenly when the clutch pedal is released

snicking: A positive click and feel, as when the gears click into place.

snipe: A long extension applied to the handle of a wrench in order to increase the leverage in removing a stubborn bolt or nut.

snipe-nose pliers: See long-nose pliers needle-nose pliers snips: A tool used to cut straight, circular, and irregular patterns in sheet metal material; available in various designs for straight, left-or right-hand cut. See hole cutting snips straight pattern snips tinners snips tin snips snow: See mud and snow tire

snowbird: Recreational vehicle owners who travel to Florida or Arizona during the winter and fly back when the weather warms up at home.

snow chains: chains which are wrapped around tires to provide extra traction in snow or ice

snow chain switch: signals the ASR system that snow chains are fitted to the drive wheels

snow tire: See winter tire mud and snow tire snubber: See bump stop

soak:

See heat soak

soaking time: The time required before a dry-charged battery is ready for use after being filled with acid

soapstone: Lubricant used to prevent sticking between tire and tube.

society: See car society classification society Milestone Car Society society of Automotive Engineers: (SAE) See SAE.

Society of Motor Manufacturers and Traders: (SMMT) An official organization of the British motor industry

sock: The fuel pick up strainer in the fuel tank. The sock is made of saran, so water won't enter until the sock is entirely engulfed in water

socket: [1] A hollow part or piece adapted or contrived to receive and hold something. [2] As a tool, it is usually barrel-shaped with one open end to fit over a nut or bolt and the other open end with a female square drive to accept a drive tool (i.e., usually a ratchet). See ball and socket ball joint ball socket bayonet socket bihexagon socket cigar lighter diagnostic socket double hexagon socket

impact socket insert socket lamp socket socket wrench spark plug socket T-handle socket universal joint socket universal spark plug socket socket bit: A bit for use with socket drive tools

socket driver: A screwdriver-type handle for use with sockets

socket joint: See ball and socket joint

socket spanner: British term for socket wrench

socket wrench: A tool with socket end or a drive tool combined with a socket

sock filter: A foam device which shaped like a cylinder with one end closed and the other open. The open end is secured to a carburetor so that the sock acts like a filter. It is used especially on snowmobiles to keep out the snow.

socket wrench: A socket wrench is made up of a ratchet and a variety of sockets. The ratchet end fits into the sockets. The end is usually one of three common sizes: 0.25" (6.35 mm), 0.375" (9.5 mm), and 0.5" (13 mm). The socket (a cylinder) completely covers all the corners of the head of a bolt or nut. Some sockets have six faces while others have twelve.

sodium-cooled exhaust valve: The exhaust valves of some high-performance engines are filled with sodium to improve the heat dissipation from the valve stem to the valve guide, since the

exhaust valve is subject to higher thermal loads than the intake valve

sodium cooled valve: See sodium-cooled valve.

sodium-cooled valve: An exhaust valve with a hollow stem that is partially filled with metallic sodium. When the valve gets hot enough (138°C), the sodium melts and moves up and down in the valve stem. The sodium absorbs heat from the hot valve head and carries it away to the outer part of the stem and then into the valve guide in the cylinder head and next to the cylinder head itself. This circulation cools the valve head and thus the valve is allowed to run at a lower temperature.

sodium-sulphur battery: A new type of battery, with higher energy density than conventional batteries such as the lead-acid battery; developed for use in electric powered vehicles

softening agent: See plasticizer

softening temperature: See vicat softening temperature

soft face hammer: A hammer with a head that is made of a material which will not damage the object being hit. It usually has replaceable screw-on faces made of plastic, nylon, or rubber

soft paint: A paint fault apparent when the paint surface can be marked easily even after full drying has been allowed; caused by excessive film thickness or, in the case of twopack paints, an insufficient quantity of catalyst

soft-sided trailer: A trailer with canvas or other fabric walls, which folds compactly to the size and shape of a small trailer whose light weight and low profile result in low wind resistance and fuel consumption Also see hard-sided trailer

soft top:

A convertible with a roof made of fabric rather than metal

soft-top trailer: A camping trailer that has a solid box mounted on a chassis. The top portion is made of canvas and unfolds to create one or two wings

soft trim: A vehicle's interior decoration, including the upholstery, roof, and door linings. Also called just "trim."

SOHC: Acronym for "single overhead camshaft" where one cam operates both intake and exhaust valves. See overhead camshaft engine type solar car: A lightweight electric vehicle powered by solar generators

solar collector: A heat exchanger that transforms solar radiant energy into heat; typical solar collectors are flat-plate collectors and concentrating collectors

solar generator: A panel-shaped array of photovoltaic cells designed to transform solar radiant energy directly into electric energy; installed on car roofs, they can be used to recharge the batteries of electric-powered cars

solder: [1] A compound of two or more metals which have a relatively low melting point. Soft solder is an alloy of lead and tin while hard solder is an alloy of copper and zinc. With the application of heat, it is used to join wires or two pieces of metal together. See braze flux silver solder sweating

tinning [2] To join together using solder

soldering: Joining two pieces of metal together with a lead-tin mixture. Both pieces of metal must be heated to insure proper adhesion of the melted solder. Also see silver solder.

soldering iron: A tool with a handle attached to a copper or iron tip which is heated, electrically or in a flame, and used to melt solder to make joints

solder joint: See cold solder joint

solder paddle: A tool made of maple or beech, designed for spreading body solder over the surface of a panel

solder paint: A paste used to prepare the area to be leaded so the body lead will stick to the metal surface; consists of a flux in which powdered lead is held in suspension

solenoid: An electrically operated magnetic device used to operate some unit. A movable iron core is placed inside a coil of wire which moves because of magnetic attraction when electric current is fed to the coil. When current flows through the coil, the core will attempt to center itself in the coil. In so doing, the core will exert considerable force on anything it is connected to. See clutch solenoid fast idle solenoid idle stop solenoid starter solenoid stop solenoid throttle solenoid vacuum solenoid solenoid starter switch:

A solenoid-operated starter motor switch

solenoid valve: A valve actuated electrically by means of an electromagnet, or solenoid

solenoid vent valve: (SVV) energized by ignition switch to control fuel vapor flow to the canister. When the ignition is off, the valve is open

sole proprietorship: Business owned entirely by one person

solid: [1] Anything which does not have a tendency to flow (such as vapor or fluid). See solids. [2] Unventilated brake discs. Also see industrial solid

solid brake disc: A brake disc that is solid metal between its friction surfaces

solid disc wheel: See plain disc wheel

solid height: The height of a coil spring when it is totally compressed to the pont at which each coil touches the adjacent coil.

solidity: to become solid, compact, or hard

solid injection: System used in full diesel and semi-diesel where fuel in fluid state is injected into cylinder rather than a mixture of air and fuel drawn from a carburetor

solid injection:

See direct injection

solid paint: Paint of one uniform color, not metallic.

solid phase pressure forming: A special type of thermoforming of polypropylene sheeting

solid propellant: A propellant in pellet form, used to inflate air bags

solids: [1] The ingredients ( pigments and binders) of the paint that remain on the surface after the solvents evaporate. [2] Industrial tires made without an air chamber.

solid state: Electronic device or assembly that does not have moving parts

solid state controller: An electronic controller which uses transistors, diodes, and other semiconductor devices.

solid-state ignition: See distributorless ignition system

solid state ignition system: (SSI) a system used by Ford

solid tire: A solid rubber tire that is not inflated by air. The opposite is pneumatic tire. Solid tires are used on slow-moving wheels (i.e., wheelchairs, buggies, children's wagons, etc.). Also see separation solid tire

solo seat:

A motorcycle saddle designed for just the operator.

soluble anode: positive electrode of a galvanic cell at which metal ions pass into solution

solution: A single, homogeneous liquid, solid, or gas phase that is a mixture in which the components (liquid, gas, solid, or combination thereof) are distributed uniformly. See aqueous solution phosphating solution solution pressure: A measure of the tendency of hydrogen, metals, and certain non-metals to pass into solution as ions

solvent: A fluid that dilutes, liquefies, or dilutes another liquid or solid. Solvents include thinners, reducers and cleaners. Examples: Alcohol thins shellac; gasoline dissolves grease.

solvent pop: Small bumps in a paint film which, under close inspection, can be seen to have small holes in the top; caused by excessive film depth being applied in one coat, preventing the thinners from escaping properly

solvent popping: Blister that form on the paint film, caused by trapped solvents

sone: A measurement of the noise level of a fan. The lower the sone rating, the lower the noise level.

sonic idling: A system developed by Ford, for a fixed jet carburetor which uses air at the speed of sound to atomize fuel supplied by the idling circuit; makes idling smoother and reduces exhaust pollution. Also called "sonic throttling"

sonic throttling: A system developed by Ford, for a fixed jet carburetor which uses air at the speed of sound to atomize fuel supplied by the idling circuit; makes idling smoother and reduces exhaust pollution. Also called "sonic idling"

sonoscope: A diagnostic tool used to listen for noises in engines and identify trouble spots such as faulty valves, worn gears and water pump, bearing knock, damaged gaskets, or piston slap. Also called a mechanic's stethoscope

sooted plug: A carbon-fouled spark plug

sooty plug: A carbon-fouled spark plug

sounding pipe: A pipe leading to the bottom of an oil or water tank, for guiding a sounding tape or jointed rod when measuring the depth of liquid in the tank

sound absorption: The weight and space restrictions of modern cars call for sound absorption using thin-walled materials, whose thickness is small in relation to the wave length of the sound to be absorbed

sound metal: An intact metal panel not substantially weakened by rust that provides a basis, for example, for welding on repair panels

soundproofing material: Any material used to deaden the sound from surfaces which transmit or generate noise; (e.g., felt lining on the underside of a hood). Also see anti-drum compound

souped up: A vehicle is souped up when it is tuned to produce the maximum amount of power.

souping:

Hopping up or increasing engine performance through various modifications.

source: See linear source lamp

source lamp: See linear source lamp

south pole: The magnetic pole in a magnet toward which the lines of force emanate; travel is from North to South pole.

space: See combustion space dead space parking space unmanned machinery spaces space frame: A type of frame construction which has high rigidity for its low weight. It is used with some racing and low production cars. It is made up of several lengths of tubing welded into a strong, light web-like structure to which the engine, suspension, and other components are attached.

spacer: [1] A component which moves two items further apart. Sometimes it is just a washer and at others it is a metal or plastic cylinder or a block of rubber or plastic. [2] A band on demountable rims which fits between two rims in dual mounting to provide clearance between the duals. [3] A circular metal plate having a bolt hole circle and center bore and fitting between the faces of disc wheels to provide additional dual clearance. See between wheel spacer expander spacer expander spacer wheel spacer spacer entry EGR system:

Exhaust gases are routed directly from the exhaust manifold through a stainless steel tube to the carburetor base

spacer plate: See body separator plate

spacer ring: See expander spacer

spacer washer: A sheet of metal or other material placed between two surfaces to reduce clearance or to provide a better surface for a fastener

space saver spare: A spare wheel and tire which is much smaller than the regular tires and can be used to replace a flat tire. However, the spare is limited in speed as well as performance. The British call it a "tempa spare wheel." Also called collapsible spare tire. Also see full-size spare

space-saving spare wheel: See space saver spare

space saver wheel: See space saver spare

space saving tire: A spare tire which is smaller than normal and has limited use only when a flat tire occurs.

space wagon: A vehicle category introduced in the USA in 1983 with the Chrysler Voyager, and in Europe at the end of the 1980s with the Renault Espace; a multi-purpose vehicle for everyday and recreational use that combines the handling and luxury of a sedan with the space and headroom of a van; usually with three rows of seats for at least six people and with a sliding door on the side

spacing:

See dual spacing

spade terminal: A terminal used to connect a wire to a screw or stud terminal. The spade the has two forked ends, either straight or with upturned tips. They are more convenient to install than ring term, but slight less secure for rugged applications. Comes in soldered and unsoldered versions

spalling: A flaking of the surface of a bearing

spangles: Crystal structure on hot-dip galvanized metals

spanner: Although a British term for a wrench, it is also used for many bicycle tools in the U.S.A. and Canada. See adjustable spanner box spanner brake adjusting spanner C-spanner chainring nut spanner combination spanner double-ended spanner drain plug spanner electrical spanner flare nut spanner girder spanner line spanner pin spanner ring spanner socket spanner spark plug spanner tap spanner spare: See full-size spare instant spare mini spare wheel

space saver spare spare part spare wheel tempa spare spare part: A replacement part, either available from a dealer or carried with the vehicle (like bulbs, fuses, plugs, etc.)

spares car: See donor car

spare tire: An extra wheel and tire assembly which is stored in the vehicle in the event of a flat tire. See space saving tire collapsible spare tire spare tire carrier: The horizontal rack near the rear axles, below the loading area of light commercial vehicles where the spare wheel is usually mounted

spare wheel: See conventional spare wheel mini spare wheel space-saving spare wheel spare tire tempa spare wheel temporary spare wheel spare wheel well: An indentation in a flat trunk floor that houses the spare wheel in a horizontal position

spark: The bridging or jumping of a gap between two electrodes by a current of electricity. One of the essential factors in a combustion engine (Fuel, Air, Proper proportion of mixture, compression, timing, Spark).

See electronic spark advance electronic spark control electronic spark timing follow-up spark high energy ignition system with electronic spark timing hot spark plug jump spark microprocessor spark timing system negative spark platinum spark plug projected spark position recessed spark position resistor spark plug RFI suppressed spark plugs sequential spark transmission controlled spark spark advance: Causing the spark plug to fire earlier by altering the position of the distributor breaker points in relation to the distributor shaft. See advance electronic spark advance ignition advance spark air gap: The gap between the electrodes of a spark plug. Also see surface gap

spark angle: See ignition angle

spark-angle map: See ignition map

spark arrester: A device which hinders flames from exiting the exhaust pipe.

spark breakaway:

The end of spark duration

spark control: See electronic spark control

spark control computer: (SCC) electronic control unit with electronic spark timing

spark current: Current that flows across the electrodes of a spark gap at a particular point in time

spark delay valve: (SDV) a valve in the vacuum advance hose that delays the vacuum to the vacuum advance unit during rapid acceleration from idle or from speeds below 15 mph, and cuts off spark advance immediately on deceleration. Has an internal sintered orifice to slow air in one direction, a check valve for free air flow in the opposite direction and a filter

spark discharge voltage: See ignition voltage

spark duration: The burning time of the arc following the initial flashover between the spark plug electrodes until the residual energy decays

spark gap: The space between the center and side electrode tips on a spark plug. Also see gap.

spark gap coil tester: A tester providing a spark gap or neon tube to provide a comparison for the coil being tested. The coil to be tested is connected to the spark gap of the tester, and the length of the spark it produces is measured; a good coil is used as a standard of performance

spark head: displayed as a firing spike on an oscilloscope pattern

spark ignition: An ignition initiated by an electric spark in a spark ignition engine. See self-ignition twin spark ignition spark ignition angle: See ignition angle

spark ignition engine: (SI engine) In contrast with a diesel engine (which does not use a spark plug), a spark ignition engine uses a spark plug to ignite the fuel/air mixture.

spark knock: See preignition engine knock spark map: See ignition map

spark method: See waste spark method

spark plug: A device containing two electrodes across which electricity jumps to produce a spark to fire the fuel charge. The center electrode is insulated from the spark plug shell by means of a molded insulator resembling porcelain. The side electrode protrudes from the bottom edge of the spark plug shell and is so positioned that there is a gap between it and the center electrode. See cold spark plug hot spark plug platinum spark plug resistor spark plug RFI suppressed spark plugs split electrode spark plug surface gap spark plug TC spark plug temperature-measuring spark plug

thermocouple spark plug sparkplug: See spark plug.

spark plug body: See spark plug shell

spark plug boot: A molded rubber or plastic insulator which fits over a spark plug terminal

spark plug boot puller: A special automotive tool for the safe removal and installation of spark plug boots

spark plug brush: A hard, compact brush for removing carbon from spark plug electrodes

spark plug cable: British term for spark plug wire

spark plug cable cover strip: The connecting system that integrates the spark plug connectors, spark plug leads, distributor cap, distributor connector, high-voltage cable, and ignition coil connector

spark plug cable loom: Typically, a T-shaped and sometimes chrome-plated steel holder with cable guide holes and plastic inserts; keeps cables neatly in place and eliminates ignition leakage

spark plug cable separator: Typically, a T-shaped and sometimes chrome-plated steel holder with cable guide holes and plastic inserts; keeps cables neatly in place and eliminates ignition leakage

spark plug cable marker:

A numbered snap-on C-clip which identifies the firing order

spark plug cap: The device on the end of the high tension wire coming from the coil and mounted on the spark plug. Also called plug cap

spark plug condition: A visual appearance of the spark plug electrodes and insulator

spark plug electrode: The two electrodes in a spark plug are the center electrode and the side (or ground) electrode

spark plug gap: The space between the center and side electrodes of a spark plug across which the spark must jump to ignite the air-fuel mixture in the combustion chamber.

spark plug gauge: A tool used for checking spark plug gaps; usually with metal feeler blades or calibrated wire feelers (the wire-type is preferred over the blade type). It often includes an electrode adjusting tool for altering the gap between the electrodes

spark plug insert tap: A tool used to enlarge and tap new threads in damaged spark plug holes in order to accept spark plug inserts

spark plug insulator: A highly stressed part of the spark plug, usually made of alumina ceramic, which serves to insulate the center electrode and the terminal stud from the shell; its material must have high dielectric, mechanical and thermal strength as well as good thermal conductivity

spark plug lead: See spark plug wire

spark plug pliers: A pliers-like tool with specially shaped jaws to securely grip spark plug boots for removal and installation, and insulated handles for a shock-proof grip

spark plug shell: The metal body of the spark plug which encloses the lower part of the insulator

spark plug socket: A tool used to remove or install spark plugs. Also see universal spark plug socket

spark plug spanner: See spark plug wrench

spark plug tester: [1] A screwdriver with a bulb inside the handle, which lights up if a spark is present when the blade is touched against the outside insulation of the spark plug wire. [2] A large instrument into which a spark plug is screwed and a high tension wire is secured to the top of the plug to duplicate an ignition system. By looking into the sight glass, you can see how well the spark plug is firing.

spark plug whiskering: See gap bridging

spark plug wire: A high-voltage wire (either copper core or carbon core) with thick insulation. It comes from the distributor to the spark plug. Also called ignition cable

spark plug wire cover strip: The connecting system that integrates the spark plug connectors, spark plug leads, distributor cap, distributor connector, high-voltage wire, and ignition coil connector

spark plug wire loom: Typically, a T-shaped and sometimes chrome-plated steel holder with wire guide holes and plastic inserts; keeps wires neatly in place and eliminates ignition leakage

spark plug wire separator: Typically, a T-shaped and sometimes chrome-plated steel holder with wire guide holes and plastic inserts; keeps wires neatly in place and eliminates ignition leakage

spark plug wire marker:

A numbered snap-on C-clip which identifies the firing order

spark plug wrench: A tool for removing and installing spark plugs. It comes in a variety of shapes, e.g., with swivel or T-handle, and many have rubber inserts to prevent damage to the fragile insulating porcelain

spark position: The position of the spark gap in the combustion chamber. Also see projected spark position and recessed spark position

spark rate: The spark rate per minute in a spark ignition engine is the number of cylinders multiplied by half the engine speed

spark retard: The action of changing the ignition timing so that the spark occurs after what is specified by the manufacturer. See retard ignition retard spark timing: See electronic spark timing high energy ignition system with electronic spark timing ignition timing microprocessor spark timing system spark timing system: See microprocessor spark timing system

spark voltage: [1] The voltage required to maintain the spark after reduction of the firing voltage. [2] The voltage measured at the electrodes of a spark gap at a particular point in time. [3] See ignition voltage

sparring:

See cargo battens

spat: See rear wheel spat

spatter: Sparks produced during the welding process; more pronounced if the welding parameters are not correctly set or if impurities are present on the welded area

spd: Abbreviation for "speed," as in 4-spd. transmission.

speaker: A sound device which contains a magnet and a relatively large vibrating diaphragm which translates electrical impulses into sound vibrations. See door speaker flush mounted speaker surface-mounted speaker speaker grill: A covering over the speaker which protects the sensitive diaphragm and yet permits the maximum output of sound.

speaker enclosure: The housing for the speaker (i.e., its box) which may enhance the output of sound.

spec: Abbreviation for "special," as in spec. paint colors or for specification

special body: A body not supplied by the car manufacturer or by an approved body supplier in the case of manufacturers that do not build their own bodies, but rather by an independent coachbuilder who produces a body different from the standard body. A "one-off body" refers specifically to a body of which only one example is made, whereas in general, "special" or "coachbuilt bodies" may be produced in small-scale series

Speciale: See Alfa Romeo.

special Import Measures Act: (SIMA) Helps to protect Canadian producers from harm or injury caused by the dumping of goods into Canada by foreign exporters or the subsidizing of goods by foreign governments.

special ledge: (SL) A safety bead seat contour mainly used on American passenger cars

special mileage tire: A tire manufactured with an extra layer of rubber between the cord body and the original tread design. This extra layer is designed for the purpose of recutting and regrooving, and is specifically labelled as a special mileage commercial tire. Also called "regrooveable tire."

special services: a category that describes plants which add value to automotive parts manufactured by others by using process such as painting, plating, heat treatment, etc.

specialty repair shop: retail outlet which offers specialized vehicle products and service.

specific activity: The conversion rate of a given catalytic converter per unit volume; it is desirable to have a high specific activity, i.e., a small but efficient converter

specification: See specifications.

specifications: A list of the measurements of each component of a vehicle and the requirements for proper installation. The size, description, or part numbers for various items needed to maintain or repair a vehicle.

specific fuel consumption:

(SFC) The amount of fuel consumed by an engine for each unit of energy produced; measured in kilograms-per-megajoule or kilograms-per-kilowatt-hour or poundsper-bhp-hour

specific gravity: The relative weight of liquid (battery electrolyte) as compared to the weight of an equal volume of water.

specific heat capacity: (SHC) The quantity of heat which unit of mass of a substance requires to raise its temperature by one degree.

specific speed: An index which provides information on the general profile or shape of the impeller of a pump. The specific speed is the speed in revolutions per minute at which an impeller would run if reduced in size to deliver one gallon per minute against a total head of one foot; impellers for high heads usually have low specific speeds and impellers for low heads usually have high specific speeds

specs: Abbreviation for "specifications."

spec series: A general describing several of the racing series where the rules for the series specify a certain chassis, or engine that the racers are required to use. Thus, the reference to "spec." Examples of a spec series is the Formula Atlantic series, where all the cars must use the Toyota engine.

spectacle frame: A large casting extending outboard from the main hull for supporting for the ends of the propeller shafts in a multi-screw ship

specular finish: A mirror-like finish of high reflectivity

specular gloss: A mirror-like finish of high reflectivity

speech synthesizer: An electronic device which simulates speech to warn the driver of something wrong (such as an unclosed door). Also see voice alert system

speed: [1] The average rate at which an object is travelling. Measured as a relationship of distance per time -- e.g., meters per second (m/s), kilometers per hour (kph or km/h), feet per second (ft/sec.), miles per hour (mph), or revolutions per minute (rpm). [2] The number of gears in a transmission. See average speed cornering speed cranking speed critical speed cruising speed cut-in speed engine speed limiter engine speed sensor engine speed five-speed transmission five speed transmission four-speed four-speed transmission four speed high speed direct injection idle speed idle speed adjustment idle speed screw idle speed stabilizer idling speed low speed circuit low speed traction control nominal engine speed output speed piston speed road speed specific speed stall speed straight-line speed three-speed three-speed transmission three speed top end speed top speed

two-speed speed adjustment: See idle speed adjustment

speed brace: A drive handle in the shape of a crank; appropriate for fast operation but not having sufficient leverage for large nuts and bolts

speed category: See speed rating

speed circuit: See low speed circuit

speed control: Another name for cruise control. Also see automatic speed control

speed control vacuum advance: A system which cuts off vacuum ignition advance when a car is cruising at low speeds, typically under 35 mph; for this purpose, a solenoid-operated valve is hooked into the distributor advance vacuum line, which is governed by a speeddependent signal from a switch mounted on the transmission

speed direct: See high speed direct injection

speed direct injection: See high speed direct injection

speeder: A drive handle in the shape of a crank; appropriate for fast operation but not having sufficient leverage for large nuts and bolts

speed limit: The maximum speed that the law allows on a particular road. A speed limit is set for various factors: school and playground zones; safety in negotiating curves and off

ramps; national limits; fuel conservation; divided highways vs two-way traffic; construction zones; and city ordinances.

speed limiter: See engine speed limiter

speed nut: A self-locking device used especially to secure sheet metal screws; consists of a small steel plate with a hole and two arched prongs that engage with the screw thread; used extensively to attach plastic parts to a steel car body

speedo: Abbreviation for "speedometer."

speedo cable: See speedometer cable.

speedometer: Instrument usually found on the dashboard which is used to determine forward speed of a vehicle in kilometers per hour or miles per hour. See analog speedometer digital speedometer HUD speedometer cable: A long specially constructed wire inside a housing. The one end of the speedometer cable is inserted into the back of the speedometer head and the other end is usually attached to the transmission. When the speedometer needle moves erratically or the cable makes noise, the cable needs to be lubricated with specially formulated compound. Oil will cause it to stick.

speedometer drive cable: See speedometer cable

speedometer head: The instrument cluster which displays the road speed.

speed rating: The maximum driving speed for which a tire is designed, indicated by a letter in the tire designation on the sidewall. The speed rating evolved gradually and is thus not directly proportional to the alphabetical order. P = up to 150 kph (95 mph) Q = up to 160 kph (100 mph) R = up to 170 kph (105 mph) S = up to 180 kph (113 mph) T = up to 190 kph (118 mph) U = up to 200 kph (125 mph) H = up to 210 kph (130 mph) also called "high speed" thus the "H" V = over 210 kph (over 130 mph) also called "very high speed" thus the "V" speed ratio: The ratio of the speed of the driving member of a mechanical drive to the speed of the driven member

speed screw: See idle speed screw.

speed-sensitive steering: A type of power-assisted steering which is light at low speeds and increasingly heavier at higher speeds, giving the driver more feel

speed-sensitive wiper system: A system which increases blade pressure on the windshield as the car increases speed

speed sensor: See engine speed sensor wheel speed sensor speed stabilizer: See idle speed stabilizer

speedster:

A fast, sporty car model

speed symbol: See speed rating

speed traction: See low speed traction control

speed traction control: See low speed traction control

speed transmission: See five speed transmission

speedway: Specialized sport run on short, oval dirt tracks with four riders from two teams in each race.

spent gas: The gases burnt during the previous firing cycle that remain in the combustion chamber of a two-stroke engine after the charge changing process has been completed and the ports have been closed by the piston. An excessive proportion of spent gas in the cylinder weakens the mixture available for combustion

sphere: See glass sphere suspension sphere spherical combustion chamber: The combustion chamber of an internal combustion engine equipped with reciprocating pistons is ideally very compact in design, i.e., without gaps, grooves, edges, etc.; the most favourable design would thus be a sphere but the valves of a four-stroke engine make this impossible. The combustion chamber in diesel engines, however, is located in the piston crown, where it is in fact spherical

SPI:

See single point injection

spicer: A gearbox splitter which provides a second range of gears

spider: [1] On a bicycle, the multi-armed piece to which the chainwheels are bolted, usually welded to or part of the right crankarm. [2] A four arm piece on a constant velocity joint. [3] A central crosspiece linking the two yokes of a universal joint. [4] A cross-shaped wheel wrench with a different-sized box socket head on each of the four legs. [5] A wheel spider [6] A type of sport vehicle. In the early 1900s it meant a light two-seater car. In the 1950s the word was revived by some Italian manufacturers for an open two seater sports car. Also spelled "spyder." See Alfa Romeo planet spider wheel spider spider gear: A small gear (usually in a set of two to four gears) mounted on a shaft pinned to the differential case. They mesh with the bevel gear on the ends of the axles and drive them. Also see pinion gear.

spigot: A short, cylindrical projection on one part designed to fit into a hole in another part, for location or retaining purposes (as for road wheels)

spigot bearing: A British term for pilot bearing. A small bearing in the center of the flywheel end of the crankshaft, which carries the forward end of the clutch shaft

spigot mounting: Unlike stud-mounted wheels, spigot-mounted wheels incorporate a center hole in the wheel disc which is machined to provide a close-tolerance fit on the hub spigot for location

spillover point: The location of the main circuit discharge in the venturi, which is always higher than the fuel level in the bowl so fuel won't run into the venturi when it shouldn't. When the spillover begins is determined by the size of the venturi and by the displacement of the engine pulling air through the carburetor. Also called pullover point

spin: See wheel spin

spindle: [1] The machined shaft upon which the inside races of the front wheel bearings rest. The spindle is an integral part of the steering knuckle. Also see steering spindle. [2] Another term for an axle, such as a pedal axle or a bottom bracket axle. Also see throttle spindle

spindle cap: A small metal cap on the front wheel bearing

spine-back: See backbone chassis

spine frame: A frame with a single main structural member from which the engine is suspended

spin galvanizing: A hot dip galvanizing process for small objects. The objects are immersed into the molten zinc in a perforated basket which, once the coating forms, is centrifuged at high speed so that the spinning action throws off the surplus zinc and ensures a clean profile

spin imbalance: See radial run-out

spinner: A knock-off/on nut for central-locking wheels. Originally developed by the British company Rudge-Whitworth to enable racing car wheels to be changed quickly by knocking the nut on and off with a soft-headed hammer; the wheel is positioned by matching tapered faces within the wheel center and on its hub, the splines enabling

driving or braking forces to be transmitted from hub to wheel; the spinner is a selftightening nut with a left-hand thread for LH-side wheels and a right-hand thread for RH-side wheels; modern cars use large hexagon nuts See amputee spinner nut spinner palm spinner spinner handle: A screwdriver-type handle for use with sockets, used to quickly tighten and loosen fasteners

spinner knob: A device which is attached to a steering wheel to allow disabled people to steer a vehicle by the use of the knob. spinout: A race car that spins around due to being tapped, racing too close to another car, or clipping another while attempting a pass.

spin reculation: See anti-spin regulation

spiral bevel gear: A ring and pinion setup widely used in automobile differentials. The teeth of both the ring and the pinion are tapered and are cut on a spiral so that they are at an angle to the center line of the pinion shaft. See bevel gear.

spiral casing: See volute casing

spiral-type glow plug: A glow plug having an exposed coil with a high number of turns

spiral wrapped pin: A tube-like pin that is made by rolling a sheet of metal tightly together. Used as a shear pin.

spirit level: A tool for testing if a surface is level (or vertical) using a glass tube containing an air bubble

spirits: See methylated spirits

spkrs: Abbreviation for "speakers," as in dual rear spkrs.

splash: See oil-combination splash and pressure system oil-splash system salt water splash splash shield. splash and pressure: See oil-combination splash and pressure system

splash and pressure system: See oil-combination splash and pressure system

splash apron: See fender splash apron

splashed graphics: A custom paintwork resembling paint drops and splashes on the body which look as if a can of paint had been spilled over the car; also available as stickers

splash guard: See splash shield mud flap splash lubrication: Oil from the crankshaft journals, under pressure from the oil pump, is splashed onto the cylinder bores and piston pins to provide lubrication

splash panel: A vertical closing panel mounted inside the wheel arch ahead of the rear edge of the front fender and/or hinge area to protect these areas from splash water and road dirt

splash shield: A removable device found on disc brakes to keep water and dirt from fouling the brakes.

splash system: See oil splash system

splash zone: The sections of a car body subject to extreme corrosion loads due to water splash

splayed crankpins: The slight spreading apart of a crankpin in a V-type engine so that each rod has its own crankpin; this reduces vibration in some V-6 engines that have a 90° angle between the banks

splayed spring: A design in which the leaf springs are placed at other than an 90° to the axle

spline: In order to secure one object on a shaft, longitudinal grooves or splines are cut all around the shaft with matching grooves in the object. In this way the object slides on the shaft for installation so that both the object and the shaft rotate together.

splined hub: The hub of a driven plate in a clutch which is splined so that it can move along the gearbox input shaft

splined joint: A joint between two parts in which each part has a series of splines cut along the contact area. The splines on each part slide into the grooves between the splines on the other part.

splined shaft: A shaft having multiple grooves, or keyseats, cut around its circumference.

spline joint: Two mating parts that have a series of splines around their circumferences, one inner and one outer, to provide a longitudinally movable joint without any circumferential motion

split: See asymmetic power distribution axle housing split constant power split diagonally split system diagonal split braking system equal power split fifty-fifty power split front-axle/rear-axle split front-axle and rear-axle split rear axle housing, split type torque split split bearing: See shell bearing

split bearing attachment: See bearing separator

split bench seat: A front seat arrangement in which the left side is independent from the right side. While a bucket seat is shaped for an individual, split bench seats can still hold three people. Most are split 60/40 where the smaller portion is for the driver. It avoids the disadvantage of the bench seat in that the driver can position his seat differently from the passenger.

split braking: See diagonal split braking system

split braking system:

See diagonal split braking system

split collar: See collet

split electrode spark plug: A spark plug with a V-shaped side electrode

split folding rear seats: Rear seats which may be folded down in two sections, thus combining some extra luggage space with the possibility of a passenger sitting in the back of the car

split-friction road surfaces: differing road surfaces (such as ice and tarmac) offering differing tire adhesion

split hydraulic brake system: Service brake system with two separate hydraulic circuits to provide braking action in one circuit if other one fails

split-lit-type rear main seal bearing: A two-piece neoprene seal; easier to install and has less friction than a rope-type main seal

split loom: Flexible, corrugated conduit used to bundle wires into a harness

split manifold: An exhaust manifold that has a longitudinal baffle placed near its center. An exhaust pipe leads out of each half.

split pin: A metal pin for securing a nut or rod, whose ends are bent backwards after insertion. See cotter pin

split propshaft:

see divided propshaft

split rear seats: Rear seats which may be folded down in two sections, thus combining some extra luggage space with the possibility of a passenger sitting in the back of the car

split rim: A rim which is made of two or three pieces and uses a demountable flange.

split screen: A divided windshield on the original Morris Minor

split single: A two-stroke engine with two pistons that share a single combustion chamber

split skirt: The piston skirt is manufactured to be either partially or completely split. When the piston warms and begins to expand, the split closes instead of binding in the cylinder. split skirt piston: A precursor of the modern solid piston skirt, with a narrow slot in one side of the piston to allow for expansion

split spray: An incorrect setup of a spray gun, giving a spray pattern that is heavy at the top and bottom but narrow in the middle

split system: See diagonally split system triangle split system split-system master cylinder: See tandem master cylinder

splitter:

See nut splitter

splitting: See joint splitting tool

splitting chisel: An extremely flat chisel used for body work and panel beating

splitting lanes: The action of straddling the center line between two lanes of traffic so that following vehicles cannot pass on either side. This is a discourteous procedure unless it is the action of a police officer to slow down traffic because of an accident some distance ahead.

splitting tool: See joint splitting tool

split type: See axle housing split type rear axle housing, split type split washer: See spring lock washer

split-window Beetle: The original VW Beetle with a two-part rear window split vertically; produced up to 1953

spoiler: An aerodynamic wing-shaped device attached to a vehicle (usually under the front bumper or on the decklid) to either reduce drag or induce downforce on the vehicle. So called because it spoils the normal flow of air over or under the vehicle. See boot spoiler ear front spoiler rear spoiler

roof spoiler trunk spoiler whale tail spoke: One of several wires used to hold the hub in the center of a wheel rim and to transfer the load from the perimeter of the wheel to the hub and on to the frame. Also see wire spoke

spoke assembly: See cast spoke assembly

spokes: See spoke.

spoke steel type: See motor wheel type.

spoke type: See cast spoke type

spoke wheel: A styled, cast or forged alloy wheel with a wheel spider which incorporates a spoke design. Spoke wheels can be distinguished according to the respective number of spokes; many alloy spoke-type wheels, however, have a wheel spider with 28, 30, 32, or 34 spokes which are arranged in different angles and in a criss-cross pattern: these are referred to as cross-spoke wheels. See cross-spoke wheel wire spoke wheel spoke wrench: A tool for securing or removing spokes by turning the nipple.

sponge: See car sponge

sponge rubber valve:

A sponge-rubber-lined valve plate attached to a bimetallic strip, which controls the air intake temperature to the carburetor in some BL cars. The bimetallic strip moves the plate up or down according to temperature, in its extreme positions, the sponge rubber seals either the cold air intake or the hot air intake

spongy brake pedal: Air in hydraulic lines, distortion or stretching of connecting parts, or swelling of hydraulic hose may allow pedal to be spongy or springy instead of solid. See spongy pedal

spongy lead: Pure lead which serves as the active material in the charged negative plates of a battery. Also see lead peroxide

spongy pedal: When there is air in the brake lines, or shoes that are not properly centered in the brake drums, the brake pedal will have a springy or spongy feeling when the brakes are applied. The pedal should normally feel hard when applied.

spool: See valve spool

spool balance valve: A hydraulic valve in automatic transmissions that balances incoming oil pressure against spring control pressure to produce a steady pressure to some control unit.

spool valve: A hydraulic control value shaped somewhat like a spool upon which thread is wound.

spoon: [1] A tire-iron tool used to remove a tire (especially a bicycle or motorcycle tire) from its rim. Usually two or three spoons are necessary to do the job. Using a flat blade screwdriver instead of a spoon may puncture the tube. [2] See body spoon bumping spoon high crown spoon

inside pry spoon metalworking spoon spring beating spoon surface spoon S-port: A special carburetor port for ported vacuum

sport and Imperial phaeton: Similar to the phaeton, but with extra equipment or refinements, such as wire wheels, trunk rack, and ultra-modish paint treatments and finish. The Imperial type indicates a tonneau or second windshield in front of the rear seat passengers.

sportbike: A motorcycle type which originally began as a cafe racer. The rider is bent forward for better flow of the air (as opposed to the upright position of a touring bike). Also called a "crotch rocket" because of the strain it places on the rider's crotch and because of its very fast speed.

sport coupe: In other respects similar to the coupe, it has a rumble seat in the rear deck and a small compartment for storage of golf clubs.

sport roadster: In addition to being a roadster, it has provision for a rumble seat in the rear deck, along with a golf locker for storage.

sports car: Term commonly used to describe a relative small, low slung car with a high performance engine and excellent handling. Originally, sports cars were faster than sedans; today, many sedans can easily outperform sports cars in terms of top speed as well as acceleration

sports racer: A two-seat race car with enclosed wheels.

sportster:

See sports car

sports tourer: A bicycle whose structure, geometry, and components are designed to make it a compromise between one suitable for racing and one suitable for loaded touring -good for general pleasure riding.

sport utility vehicle: A vehicle built on a truck chassis but is configured much like a station wagon. Some examples are: Blazer, Jimmy, Bronco, Explorer, Ram, and Cherokee

sporty driving style: A manner of handling a vehicle in which the driver turns corners fast, brakes and accelerates hard, uses high revs in every gear, and shifts down before corners.

spot: See blind spot flat spot high spot hot spot low spot spot faced: On a connecting rod, a bolt head seating surface that is machined so it describes a radius on the inboard-side of the bolt head as viewed from the top of the bolt head

spot glazing: Filling minor imperfections (sand scratches).

spot lamp: See spot light

spotlight: An auxiliary light used to shine a narrow beam of light.

spotting:

See water spotting.

spotting in: The paint respraying of very small areas

spot weld: Fastening parts together by fusing, at various spots. Heavy surge of electricity is passed through the parts held in firm contact by electrodes.

spot welding: A type of resistance welding in which two pieces of metal are joined at a series of points (spots) by means of heat (usually electrically generated) and pressure; the most important welding method in auto body construction

spot-weld drill: See spot-weld remover

spot-welded flange: A sheet metal strip forming a flange at the edge of panels joined by spot welding

spot-weld remover: [1] A special drill bit used to drill out weld spots on sheet metal material without damaging the panels. [2] A tool for use with a hand drill; features reversible cutting blade to cut out weld spots without damaging the sheet metal material; the cut depth can be varied, e.g., to release the upper panel only

spout: See tailpipe

sprag brake: A sprag is a stick (of wood or metal) which is inserted into gears or even into the dirt to stop the motion of something.

sprag clutch: A clutch that will allow rotation in one direction but that will lock up and prevent any movement in the other direction.

spray: See dry spray gravity-feed spray gun plasma spray process pressure-feed spray gun split spray spray arc: Gas metal arc process which has an arc voltage high enough to continuously transfer the electrode metal across the arc in small globules.

spray bell: A dome-shaped, rotating paint spray element

spray booth: A closed section in a painting line in which paint is sprayed on workpieces or body shells

spray chamber: See salt spray chamber

spray coating: An application method for chemical conversion coatings

spray flap: See mud flap

spray gun: An apparatus shaped like a pistol which delivers an atomized mist of liquid. See airless spray gun compressed-air spray gun gravity-feed spray gun pressure-feed spray gun suction-feed spray gun

spray gun nozzle cleaning unit: A special cleaning unit for paint shops which holds several spray guns in such a position that the nozzle is soaked in thinners

spraying: See airless spraying cold spraying electrostatic spraying hot spraying metal spraying robot spraying zinc spraying spraying booth: A closed section in a painting line in which paint is sprayed on workpieces or body shells

spraying viscosity: The viscosity required to make paint suitable for spraying, i.e., neither too thick nor too thin

spray mist: A fogging caused in the course of spray painting; part of this settles as overspray on adjacent panels and nearby objects. See overspray mask spray pattern: The shape of the jet of spray leaving a spray gun

spray process: See plasma spray process

spray testing: See salt spray testing

spread:

See bearing spread overall gear ratio spread axle: Trailer axle, usually 6 to 9 feet ahead of another axle and located near the center of the trailer.

spreader: [1] A hand-held tool used to apply body filler to a damaged area prepared for filling. [2] A hydraulic jack with ends designed to reach behind dented double panels and to press them back into shape by the hydraulic action of the wedge-shaped ends. See tire spreader anti-rattle spring spreader spring: A cross-shaped part made of spring steel sheet which applies radial pressure to the brake pads to prevent rattling. See anti-rattle spring

spring: A device on the suspension system to cushion and absorb shocks and bumps and to keep the vehicle level on turns. After the stress or pressure exerted by the flexing of the spring has been removed, the spring returns to its original state. The spring does this by first absorbing and then releasing a certain amount of energy. The form of spring may be leaf springs, coil springs, torsion bars, or a combination of these. See air bellows air spring anti-rattle spring ball and spring brake shoe return spring brush spring cantilever spring carbon brush spring cart spring clutch diaphragm spring clutch spring coil spring compression spring contact spring

damper springs detent ball and spring diaphragm spring clutch diaphragm spring door hold-open spring extension spring flat spring garter spring gas spring hairpin valve spring helical spring lock washer helper spring inside spring caliper leaf spring lip seal with garter spring locating spring longitudinal leaf spring meshing spring multileaf spring outside spring caliper overload spring parabolic spring piston spring progressive rate spring progressive spring progressive valve spring progressively wound valve spring quarter-elliptic leaf spring retainer spring tool rubber spring semi-elliptic leaf spring semi-elliptic spring single-leaf spring single rate spring spreader spring tapered leaf spring taper leaf spring tensioning spring throttle return spring torsion spring transverse leaf spring valve spring variable rate springs variable spring spring and damper settings: Suspension settings for springs and or struts. Stiffer settings provide better handling with a bumpier ride. Softer settings give a smoother ride but compromise

performance.

spring balance: An instrument for measuring weight or force which does so by the elasticity of a spiral spring.

spring bar: In a 5-bar convertible roof mechanism, it is an additional bar between the main bar and the rear window; spring loaded, it assists the main bar in shaping the roof; a similar effect can be achieved by spring-steel leaves embedded in the canvas

spring beating: A metalworking process for removing pressure ridges in body panels in which a spring beating spoon is laid on the ridge area and is gradually moved across the ridge while the spoon surface is hammered with a body hammer

spring beating spoon: A light pressed-steel blade designed specially for beating on ridges; the spoon is placed directly on the ridge and sharp blows with a hammer are delivered to the back of the spoon, spreading the force over a large area

spring-biased: See spring-loaded

spring booster: A device used to "beef up" sagging springs or to increase the load capacity of standard springs.

spring bow: In a 5-bar convertible roof mechanism, it is an additional bar between the main bar and the rear window; spring loaded, it assists the main bar in shaping the roof; a similar effect can be achieved by spring-steel leaves embedded in the canvas

spring bracket: See spring hanger

spring brake:

Emergency or auxiliary brake system utilizing a spring load as a force for braking. May be automatically actuated by low air pressure or mechanically controlled for use as a parking brake.

spring caliper: See inside spring caliper outside spring caliper spring cap: See valve spring cap

spring choke: See thermostatic spring choke

spring clip: [1] A fastening device made of an incomplete circle of spring steel, e.g., for covers. [2] A rebound clip which holds the spring leaves of a leaf spring together and to keep them in alignment. [3] A fastener used to provide a screw hole for a sheet metal screw; certain variants of this fastener may be moved slightly at their mounting to provide a certain degree of adjustment. Also see speed nut

spring clutch: See coil spring clutch diaphragm spring clutch spring collar: See valve spring collar

spring compressor: A tool used to restrain coil springs for safe removal and installation. They are available in a variety of shapes, as manual or hydraulic designs; the most common type consists of two steel jaws running on a threaded screw which securely hook into the coil spring; turning a nut reduces the distance between the jaws and compresses the spring. This type of spring compressor is always used in pairs, e.g., to remove MacPherson strut springs. See

coil spring compressor valve spring compressor spring depressor: See valve spring depressor

spring divider: A divider with a spring for accurate setting

spring eye: A cylindrical hole formed by bending the end of a leaf spring around, for attachment to the vehicle

spring hanger: A rubber-bushing bracket on a vehicle chassis on which a leaf spring eye is mounted. Also see shackle

springing: A term for suspension. See air springing air suspension spring lifter: See valve spring lifter

spring loaded: A device held in place, or under pressure from a spring or springs.

spring lock: See helical spring lock washer

spring lock washer: A toothed, spring steel washer used as a locking device. Also see helical spring lock washer

spring mounting:

See spring hanger

spring rate: Rate of deflection versus amount of load applied. In other words, how much force is needed to bend a spring a given distance. Also see rising rate suspension

spring retainer: See valve spring retainer

springs: See spring.

spring seat: Support on which the spring is anchored. Also see valve spring seat

spring shackle: See shackle

spring steel: A heat treated steel having the ability to stand a great amount of deflection and yet return to its original shape or position.

spring tool: See retainer spring tool

spring washer: A warped-looking washer, typically used to prevent rattling by spring-loading certain movable threaded connections

spring windup: The curved shape assumed by the rear leaf springs during hard acceleration or braking.

sprint: See Alfa Romeo.

sprocket: A disc with teeth on its circumference for driving a chain, a general term that applies both to chainrings and to freewheel cogs. See camshaft drive sprocket camshaft sprocket crankshaft sprocket driven sprocket drive sprocket sprocket wheel: See sprocket

sprung mass: See sprung weight

sprung weight: This refers to the weight of all the parts of the vehicle that are supported by the suspension system. Unsprung weight includes wheels and tires, brake assemblies, the rear axle assembly and other structural members not supported by the springs. Unsprung weight can be reduced with independent rear suspension because the differential, and in some cases the brakes, can be attached to the body. Also called "sprung mass." Also see unsprung weight

spur differential: A differential in front-wheel drive vehicle which uses spur gears rather than bevel gears, since input and output shafts are not at right angles. Also see bevel differential

spur gear: A gear on which the teeth are cut parallel to the shaft. They are not used very often in modern gearboxes because they are noisier than helical gears. Also called straight-cut gear.

spurt hole: A small hole in the connecting rod big end that indexes (aligns) with the oil hole in the crank journal. When the holes index, oil spurts out to lubricate the cylinder walls. Also called "squirt hole"

Spyder:

In the early 1900s, a light two-seater car. In the 1950s the word was revived by some Italian manufacturers for an open two seater sports car. Also spelled "spider."

SQ: Acronym for "Sound Quality."

sq. ft.: Abbreviation for "square foot."

sq. in.: Abbreviation for "square inch."

squab: A seat's backrest

squab panel: A panel supporting the rear seat squabs, separating the passenger compartment from the luggage space

squab shelf: The rear parcel shelf

square: See over square engine

square engine: An engine in which the bore diameter and the length of the stroke are the same. See over square engine under square engine square-four engine: A four cylinder engine in which each cylinder axis forms one corner of a square. This represents a way of doubling parallel twin cylinders to make a four cylinder unit, with two separate parallel crankshafts connected by gears or chain. This arrangement allows the engine width to be kept to that of a twin cylinder unit with only a small increase in length, thus providing the advantages of an in-line four without the problem of width. Applied in four-stroke and two-stroke motorcycles;

in two-strokes mainly to permit rotary valve induction

square jetting: Same size jetting in all four holes or same size in primary barrels with a difference same size in the secondaries

square key: A small bar of any length but its height and width are the same.

squat: The action of the rear end of the vehicle to point downward during hard acceleration. Squat is caused by a load transfer from the front to the rear suspension. Also see anti-squat system.

squeak: An expression used particularly with two-stroke engines where the pistons have run without sufficient lubrication. It is caused by a poor injection system or a pre-mix that is too lean (not enough oil in the gasoline).

squeal: See tire squeal

squeal shim: See anti-squeal shim

squeegee: See rubber squeegee

squib: A device for detonating the airbag

Squire: A vehicle brand of which the 1925-1948 models are classic cars.

squirm:

See tread squirm

squirt box: A colloquial term for carburetor

squirt hole: See spurt hole.

squish: An area in the combustion chamber of some engines where the piston squishes or squeezes part of the fuel-air mixture at the end of the compression stroke. As the piston approaches top dead center, the mixture is pushed out of the squish area and this promotes turbulence, further mixing of the fuel-air mixture and more efficient combustion.

squish band: A narrow section of a combustion chamber in which the fuel charge is more compressed by the piston than in the rest of the chamber; designed to help direct the flow of the fresh charge and to improve scavenging

squish zone: A narrow section of a combustion chamber in which the fuel charge is more compressed by the piston than in the rest of the chamber; designed to help direct the flow of the fresh charge and to improve scavenging

sr: sunroof

SR&ED: Acronym for " Scientific Research and Experimental Development Program."

SRS: Acronym for "Supplemental Restraint System," or "Supplemental Restraint inflatable air-bag System." The letters appear on the steering wheel and/or instrument panel. In fact, dual airbags are standard in all of the 1998 cars, except for some sub-compacts and very small models.

SR sheathed glow plug:

A self-regulating sheathed-type glow plug

SRS warning light: An air bag warning light

SS: [1] A vehicle brand of which the SS and SS Jaguar models for 1932-1940 except the 4-cyl. are classic cars. [2] Abbreviation for stainless steel. [3] Abbreviation for steamship

SSAE: Acronym for "Stamped, self-addressed envelope."

SSC: Acronym for stress corrosion cracking

SSI: Acronym for solid state ignition system

ST: Acronym for short ton which is 2,000 lbs.

stab braking: See cadence braking

stability: [1] The quality or state of a vehicle to remain controllable. See directional stability. [2] The ability of a ship to return to her normal upright position when listed by the action of waves, wind, etc. See directional stability lateral stability straight-line stability stabilize:

To make or keep stable

stabilizer: A variety of devices used to keep the passenger compartment of a vehicle from swaying and lurching on sharp curves and turns. See idle speed stabilizer stabilizer bar UV stabilizer stabilizer bar: A transverse mounted spring steel bar that controls and minimizes body lean or tipping on corners. Also see anti-roll bar.

stabilizer belt: A radial tire belt consisting of cords (usually fine steel wire) embedded in rubber directly beneath the tread and above the radial cord body plies

stabilizer link: A suspension link which connects the anti-roll bar to the lower wishbone

stabilizing plies: Two or more plies, of steel, fiberglass, etc., forming a belt around the circumference of a tire, between carcass and tread rubber. It reduces tread distortion of radial and bias belted tires.

stack: See velocity stack

stage: See green stage

staged carburetors: Carburetors equipped with a secondary system. Staged carburetors are activated either mechanically or by a vacuum diaphragm. Think of staged four-barrels as two two-barrels in parallel

stagger:

[1] To place items (like carburetors, pistons) so that every second item is offset from the previous one. [2] The difference in the circumference of the tires on the right and left sides of the car. Since oval track racing is always done turning left, teams put larger tires on the right to help the car naturally turn left. Also see cross-jetting

stainless steel: (SS) A type of steel containing nickel and chromium, which is resistant to corrosion

stainless-steel exhaust system: A more hard-wearing and therefore more expensive system than one made of mild steel

stainless-steel mesh: See wire mesh

stake: [1] A panel-beating tool formed like a dolly, but with a shaft attached allowing it to be clamped in a vice. [2] The wooden bars which fit into the sides of the bed of a truck.

staked nut: A nut secured to a bolt with a metal tab (e.g., a wheel bearing adjusting nut)

stalk: See control stalk multi-function control stalk stall: An engine which stops unintentionally. The usual causes of stalling are: sudden increase in load without an accompanying increase in fuel flow (often occurring when a driver engages the clutch to drive away without increasing the engine speed) and braking to a very low speed without disengaging the clutch

stall speed: The test characteristic of a fluid converter; result of the stall test

stall test: A short-time (5 seconds) full throttle operation with the vehicle brakes fully applied and the selector lever of an automatic transmission in "D" position; the test results in an engine speed (stall speed) that indicates the performance of the fluid converter

stall torque ratio: The torque conversion in fluid converters on taking up drive, i.e., when the turbine is still stationary; stage of maximum torque multiplication

stamping: A sheet metal part formed or shaped by pressing rolled sheet metal between metal dies (hardened metal blocks).

stance: See aerodynamic stance

stand: See axle stand hardtop stand jack stand taxi stand standard: See federal side impact standard

standard equipment: Those parts and systems of a vehicle supplied by the manufacturer at no extra cost, i.e., they are included in the basic price for a given model

standard Industrial Classification: (SIC) industry class that represents a level of organization of production by type of specialization. Currently the 1980 Standard Industrial Classification is in effect identifying each industry at the 4 digit level.

standard rim: A rim that has been calibrated and found to meet the precise measurements specified by Tire and Rim Association, Inc. or, where applicable, by European Tire & Rim Association.

standards: See emission standards international Standards Organization low Emission Vehicle Standards Standards Organization: See international Standards Organization

standard transmission: A transmission that must be shifted manually to effect a change in gearing. Also called "conventional transmission" or "manual transmission."

standard wheel: The original wheel on a vehicle supplied by the car manufacturer

Standard Whitworth: See British Standard Whitworth

standard work week: average number of hours worked normally scheduled in a work week.

standing start: A race which begins with none of the vehicles in motion.

Stanyl: A proprietary polyamide with unusual temperature stability, mechanical strength, and resistance to oil and grease

Stanza: A model of automobile manufactured by Nissan in Japan star:

Click for books on Nissan Stanza

See diamond star

starboard: The right-hand side of a ship when facing forward

Starlet: A model of automobile manufactured by Toyota Click for books on Toyota Starlet start: To use the starter motor to crank the engine until it fires and runs on its own. See bump start cold start hot start hot start enrichment jump start kick start push start racing start rolling start standing start starting system start boosting: Bypassing the ballast resistor of an ignition system when starting the engine

start bypass: bypass of the ballast resistor

start enrichment: See after-start enrichment cold start enrichment hot start enrichment starter: [1] A small electrical motor that causes the engine crankshaft to begin to turn, which starts the engine running and so starts the vehicle. Invented in 1911 by Cadillac engineers, the manual crank-starter was replaced by an electric motor and

thus made it easier and safer for people to start and drive cars. Also called the "cranking motor." [2] A person who indicates that a race is to begin. See bendix starter Bendix type starter drive clutch starter glow plug starter switch inboard starter nut starter overrunning clutch starter drive overrunning clutch starter pre-engaged Bendix starter pre-engaged starter remote starter switch screw starter self-starter starter drive: See bendix type starter drive clutch starter drive overrunning clutch starter drive starter inhibitor switch: A switch which prevents starting of the engine unless certain system conditions are fulfilled; e.g., on cars with automatic transmission, the selector lever must be in Neutral or Park

starter interlock: A switch which prevents starting of the engine unless certain system conditions are fulfilled; e.g., on cars with automatic transmission, the selector lever must be in Neutral or Park. Also see clutch starter interlock

starter lockout: A switch which prevents starting of the engine unless certain system conditions are fulfilled; e.g., on cars with automatic transmission, the selector lever must be in Neutral or Park

starter motor:

See starter.

starter punch: A tool used to start the removal of pins, shafts, or rivets by breaking them loose; longer and thinner than a drift punch

starter ring gear: A gear fitted around the flywheel that is engaged by teeth on the starter drive to crank the engine

starter solenoid: A device that uses electrical current to start and engage the starter. Also see solenoid. Also called a "starter relay"

starter switch: See glow plug starter switch remote starter switch solenoid starter switch starter switch control cable: A mechanical cable to the starter switch on vehicles without a starter solenoid (e.g., Fiat 500)

start from rest: to drive off from a standing start

starting: See cold starting hot starting starting carburetor: A simple slide carburetor which works in parallel with the main carburetor and acts as a starting aid

starting handle:

A cranked handle for turning an engine over manually

starting interlock: See starter inhibitor switch

starting switch: On certain classic cars, separate switches are used to turn the ignition on and to operate the starter; on such cars, the starting switch was a push button, often located in the center of the dashboard; on modern cars, the starting switch is integrated in the ignition and starter switch

starting system: The portion of the electrical system that starts the vehicle. Consists of the ignition switch which closes the circuit and allows current to flow from the battery to the starter by way of the starter solenoid. Also called the "cranking circuit."

start injector: See cold start injector

starvation: See fuel starvation

star wheel: An adjusting nut on a drum brake or clutch. The portion of a brake action that turns the adjustment screw

state: See 49 state car forty-nine state car state car: See 49 state car forty-nine state car state controller:

See solid state controller

state indicator: See battery charge indicator battery state indicator state of charge: See battery charge

stated residual value: The stated residual value is usually the same as the end-of-lease purchase price. The higher the stated residual value of the car, the lower your monthly payments. Stated residual values are often higher or lower than the expected residual value for a car, the lessor can raise or lower the monthly payments and the net interest rate for the lease. Stated residual value also determines whether you should buy the vehicle at the end of the lease. If at the end of a lease, the vehicle's market value is less than the stated residual value, the lessee would be prudent not to purchase the car. On the other hand, if the actual market value were greater than the predetermined residual, then the lessee could buy the car, sell it, and pocket the difference.

static balance: When a tire, flywheel, crankshaft, etc., has an absolutely even distribution of the weight mass around the axis of rotation, it will be in static balance. For example, if a front wheel is jacked up and the tire, regardless of where it is placed, always slowly turns and stops with the same spot down, it would not be in static balance. If, however, the wheel remains in any position in which it is placed, it would be in static balance, (bearings must be free, no brake drag, etc.). Also called "kinetic balance." Also see dynamic balance.

static belt: A seat belt with no automatic belt retractor and whose length is manually adjusted. Also see inertia reel seat belt

static electricity: Electricity generated by friction between two objects. It will remain in one object until discharged.

static friction:

See stiction

static high-voltage distribution: high-voltage distribution achieved without a rotary distributor, using multi-spark ignition coils or one coil per spark plug

static ignition timing: An obsolete timing procedure carried out by rotating the engine until the timing marks are aligned and then connecting a test lamp or a voltmeter between the negative coil terminal and ground; when the points open, the test lamp lights up or the voltmeter registers battery voltage. The opposite is dynamic or stroboscopic ignition timing

static loaded radius: See loaded radius.

static pressure: A certain amount of pressure that always exists in the brake lines even with the brake pedal released. Static pressure is maintained by a check valve.

static seal: An oil seal between two stationary parts. Opposite to dynamic seal

static shield: A device found on some distributors that reduces radio interference caused by the working of the vehicle's ignition system.

static timing: An obsolete timing procedure carried out by rotating the engine until the timing marks are aligned and then connecting a test lamp or a voltmeter between the negative coil terminal and ground; when the points open, the test lamp lights up or the voltmeter registers battery voltage. The opposite is dynamic or stroboscopic ignition timing

station: See battery charging station filling station

gas station last station memory liftback station wagon petrol station preset station button service station station button: See preset station button

station memory: See last station memory

station wagon: (SW) Originally this was a car with an enclosed wooden body of paneled design with several rows of folding or removable seats behind the driver. It became a different and popular vehicle after 1945. There is usually a tailgate but no separate luggage compartment. Early station wagons and compact station wagons had only two doors while the larger ones had four doors. The British term is "estate car." See four-door station wagon liftback station wagon two-door station wagon stator: [1] A small hub, upon which a series of vanes are affixed in a radial position, that is so placed that oil leaving the torque converterturbine strikes the stator vanes and is redirected into the pump at an angle conducive to high efficiency. The stator makes torque multiplication possible. Torque multiplication is highest at stall when the engine speed is at its highest and the turbine is standing still. [2] The stationary windings in an alternator in which electric current is generated; located between drive end and slip-ring end fittings, consisting of a stator frame with windings in three circuits to generate three-phase current which is then rectified by diodes. Also see rotor. [3] A self-contained unit of the magnetic pick-up, consisting of a permanent magnet, an inductive winding, and the pick-up core; the stator can be a disc-shaped pole piece with stator tooth or a simple pole piece [4] The wheel with curved blades (sometimes adjustable) mounted on a one-way clutch in a fluid converter or automatic transmission. It serves as a reaction member, i.e., it multiplies the torque output of the turbine by increasing the momentum of the fluid flow acting on the latter. [5] The fixed electrical windings on a magneto, alternator, or generator. It turns within the rotor.

See impeller thermal reactor turbine wheel variable pitch stator stator roller clutch: A device which holds the stator stationary in a fluid converter as long as its blades are struck by the fluid flow against the rotational direction of pump and turbine; if the fluid flows in the direction of rotation, the stator starts running

stay: An arm or brace use to support another component. See bonnet stay chainstay door stay hood support stay seatstay std: Abbreviation for "standard," as in std. transmission. See standard transmission.

steady: See corner steady

stealer: A single wide plate that is butt-connected to two narrow plates, usually near the ends of a ship.

Stealth Bra: A nose covering composed of composite materials that absorb microwaves emitted by radar devices and significantly diminish the return signal, making a car less detectable to police radar; ineffective against speed cameras or light-operated speed guns. Also see nose protector)

steam clean: To clean the engine with a high-pressure jet of steam

steam engine: An external combustion engine where water is converted to steam in a boiler outside the cylinder. The steam is then admitted to the cylinder where it expands against a piston. As the steam expands it cools and begins to condense. This mixture of water droplets and steam is forced out of the cylinder on the return stroke and into the condenser where the remaining steam is condensed into water. This water is forced into the boiler by a pump and the cycle is repeated. Steam engines have some notable drawbacks: slow warm up, freezing of the water system in cold weather, and contamination of the water by scale, oil, and sludge which can wreak havoc with the boiler, pumps, and condenser. But they also offer certain advantages: the potential for high fuel economy with low emissions, the ability to start from rest against a load so a clutch is not needed, and the torque developed is greatest at low rpm so in some applications a multiple-ratio gearbox is not necessary.

steam injection system: Based on the same principle as water injection systems, the steam injection system uses engine exhaust heat and a boiler to pre-heat and boil the water before it is injected into the inlet manifold as steam

Stearns-Knight: A vehicle brand of which the 1925-1948 models are classic cars.

steel: An alloy of iron containing a small (up to 2%) percentage of carbon. See alloy steel carbon steel chrome steel chromium steel high carbon steel low-carbon steel low carbon steel mild steel spring steel stainless steel steel backing: The supporting part of a plain bearing insert

steel belted radial tire:

A radial tire with belts of steel to provide both protection and longevity.

steel body: See all-steel body

steel casting: Cast iron to which varying amounts of scrap steel have been added

steel pack muffler: A straight through (no baffles) muffler using metal shavings surrounding a perforated pipe. Quiets exhaust sound.

steel strip: A sheet of steel less than 600 mm wide

steel strut: Steel braces or rings which are cast into aluminum pistons. Because steel expands slower than aluminum, the steel struts tend to control or minimize the expansion of the piston. steel thrust belt: A large number of steel plates with slots in each side to receive the two composite steel bands which hold them together; transmits torque between two pulleys

steel type: See spoke steel type

steel wheel: A wheel consists of a steel disc and steel rim which are welded together to provide better impact-resistance, lower price, and higher weight than alloy wheels. See alloy wheels sheet wheel steep angle: See steep angles.

steep angles: Angles that position frame tubes relatively closer to vertical than do shallow angles.

steer: See bump steer neutral steer ride steer roll steer roll steer effect toe steer torque steer steer effect: See roll steer effect

steerer tube: The tube that forms the top of the fork and rotates inside the head tube of a bicycle.

steering: A mechanism for controlling the direction of a vehicle. See absorbing steering ackermann steering adjustable steering all-wheel steering assisted steering axle and steering ball-and-nut steering ball steering cam-and-lever steering cam-and-peg steering cam-and-roller steering cam-and-lever steering center point steering center steering linkage double-pivot steering energy absorbing steering column four-wheel steering four wheel steering gemmer steering heavy steering

height adjustable steering column horn rim steering wheel hydrostatic steering in-line power steering integral-type power assisted steering integral-type power steering jeantaud axle and steering light steering linkage power steering manual steering marles steering negative offset steering offset steering parallelogram steering linkage parallelogram steering system parallelogram steering power-assisted steering power steering pump power steering rack-and-pinion steering rack and pinion steering recirculating ball and nut steering recirculating-ball-and-nut steering recirculating ball steering single-pivot steering speed-sensitive steering variable assist power steering variable assist steering variable ratio steering worm-and-lever steering worm-and-nut steering worm-and-peg steering worm-and-roller steering worm-and-sector steering zero-offset steering steering, Ackermann: See Ackermann steering.

steering angle: A horizontal angle between the plane of a steered wheel when cornering, and the plane when adjusted straight ahead steering angle sensor

steering arm:

Arms, either bolted to, or forged as an integral part of the steering knuckles. They transmit the steering force from tie rod to the knuckles, thus causing the wheels to pivot. Also called tie rod arm.

steering axis: The line through the center of the ball joints in a front suspension system. The line that intersects the upper and lower steering pivots on a steered wheel. Also see kingpin axis

steering axis inclination: (SAI) See kingpin inclination.

steering axle: An axle that directs control of the vehicle. It can be powered or non-powered and more than one steering axle can be present.

steering box: The part of the steering system that is located at the lower end of the steering shaft; changes the rotary movement of the steering wheel into the linear motion of the front wheels for steering

steering column: A shaft connecting the steering wheel to the steering gear assembly. Also called the steering shaft. See absorbing steering column adjustable steering column collapsible steering column energy absorbing steering column height adjustable steering column safety steering column telescopic steering column steering column controls: consist mainly of control stalks for some or all of the following: lights, windshield wipers and washers, direction indicators, and horn

steering column gearchange:

See column shifter

steering damper: A shock absorber-like bump stop which absorbs vibrations in the steering system

steering feel: Steering feel is the general relationship between forces at the steering wheel and handling. Ideally, the steering effort should increase smoothly as the wheel is rotated away from center. In addition, the steering effort should build as the cornering forces at the steered wheels increase. Finally, the friction built into the steering mechanism should be small in comparison with the handling-related steering forces.

steering gain: The relationship between yaw and the steering wheel's position and effort. All three should be proportional and should build up smoothly.

steering gear: The gears, mounted on the lower end of the steering column, that are used to multiply driver turning force. It converts the rotary motion of the steering wheel into straight-line motion. This straight-line motion then moves the linkage connected to the steering arms and attached to the steering knuckles and this causes the front wheels to move to the right or the left in response to the steering wheel direction.

steering gear arm: See pitman arm

steering gearbox: See steering box

steering gear shaft: The rotating, torque-transmitting part of the steering column

steering geometry: A term sometimes used to describe the various angles assumed by the components making up the front wheel turning arrangement, camber, caster, toe-in, etc. Also used to describe the related angles assumed by the front wheels when the vehicle is negotiating a curve.

steering head: That portion of a motorcycle frame where the front fork and wheel assembly attach to the frame.

steering input: See step steering input

steering kickback: The sharp and rapid movements of the steering wheel as the front wheels encounter obstruction in the road; the shocks of these encounters "kick back" to the steering wheel

steering knuckle: The inner portion of the spindle that is affixed to and pivots on either a kingpin or on upper and lower ball joints. See ball joint steering knuckle grease fittings steering knuckle angle: The angle formed between the steering axis and the center line of the spindle. This angle is sometimes referred to as the included angle.

steering knuckle arm: See steering arm

steering linkage: The system that connects the steering wheel to the front wheels and allows the wheels to change direction in response to commands from the driver. Contains grease fitting to cushion against wear and friction. See alignment center steering linkage idler arm parallelogram steering linkage steering lock:

[1] The number of degrees that the front wheels can be turned from straight ahead before they are physically restrained from turning any further. Generally, the more lock designed into the front geometry, the smaller the turning circle but the more the tires scrub as the wheels approach the extreme lock positions. Turns lock-to-lock refers to the number of rotations of the steering wheel required to go from one extreme lock position to the other. [2] The locking mechanism usually contained in the steering column that locks the steering wheel when the ignition switch is turned off or the key is removed from the switch. [3] A lock on a motorcycle which prevents the front wheel from being turned left or right.

steering overall ratio: The ratio of the degrees you must turn the steering wheel to turn the road wheels one degree from their straight ahead position.

steering pump: See power steering pump

steering rack: The device by which the movement of the steering wheel is transferred to the front wheels of an automobile.

steering ratio: The ratio of the gearing within a steering system such as the rack to the pinion or the worm gear to the recirculating nut.

steering response: A subjective term that combines steering feel and steering gain.

steering rod: One of two metal rods on each end of the steering rack that connect it to the front wheels via ball joints (tie rod ends).

steering shaft: See steering column.

steering spindle:

A shaft-like projection from the steering knuckle to which the wheel is mounted. See spindle.

steering support: The mounting locations and reinforcements for attaching the steering box to the bulkhead or side member

steering support structure: The mounting locations and reinforcements for ataching the steering box to the bulkhead or side member

steering swivel: See steering knuckle

steering-swivel axis: See swivel axis

steering-swivel inclination: See kingpin inclination

steering system: The mechanism that allows the driver to guide the vehicle down the road and turn the wheels as he desires. The system includes the steering wheel, steering column, steering gear, linkages, and the front wheel supports. Also see parallelogram steering system

steering wheel: The device that the operator uses to control the direction of the front wheels. Most are circular with spokes that attach to the steering column. See drag wheel horn rim steering wheel telescoping steering wheel tilt steering wheel steering wheel and brake lock: An anti-theft device in the form of an extendable steel rod that engages in a spoke of the steering wheel and the brake or clutch pedal; when locked, neither wheel nor pedal can be operated

steering wheel balance: measures the steering wheel angle in an automatic steering wheel centring system

steering wheel centering: adjusts the steering wheel and steering system so that the wheel is in its center position when the front wheels are pointing straight ahead

steering wheel damper: See steering damper

steering wheel puller: A special puller for removing steering wheels

Stellite: A proprietary range of very hard, wear-resistant alloys containing cobalt, chromium, carbon, tungsten, and molybdenum. It has a high melting point, good corrosion resistance, and unusual hardness when hot. It is used for tools, castings, valve seat inserts, coating exhaust valves, etc.

stem: [1] The upright bow frame forming the apex of the intersection of the forward sides of a ship. [2] See valve stem.

stem seal: A valve stem seal between the valve and cylinder head. Also see valve stem seal

stem seal installer: See valve stem seal installer

stem seal pliers: See valve stem seal pliers

step: A ledge formed by an edge setter in a sheet metal panel to provide a level mounting and welding surface with the adjacent panel.

See door step half step gearing side step step feeler gauge: A feeler gauge with metal feeler blades; the thickness of the blade increases from one end of the blade to the other

step gearing: See half step gearing wide step gearing stepless transmission: A continuously variable transmission

step on it: To increase the speed of a vehicle.

step on the accelerator: The action of pressing down on the gas pedal (accelerator) to cause more fuel to enter the engine thus making the vehicle go faster. Opposite to "ease up on the accelerator."

step on the gas pedal: The action of pressing down on the gas pedal (accelerator) to cause more fuel to enter the engine thus making the vehicle go faster. Opposite to "ease up on the gas pedal."

step on the throttle pedal: The action of pressing down on the throttle pedal (accelerator) to cause more fuel to enter the engine thus making the vehicle go faster. Opposite to "ease up on the throttle pedal."

stepped compression ring: See L-section ring

stepped piston: An obsolete design of two-stroke pistons; the diameter of the lower part of the piston was larger than the top diameter; it ran in a similarly stepped bore and was said to give better compression of the incoming mixture

stepped planet gear: A planet gear with different diameters

stepper motor: On some carburetor cars, stepper motors are used to adjust the air/fuel mixture; they are controlled by the ECM

step plate: [1] A small step for climbing into a vehicle (e.g., on an ATV or [2] See scuff plate

step steering input: A rapid change in steering angle, for example when a steered wheel hits an obstacle

step-through: A motorcycle/scooter frame layout with a low structure between the seat and the steering head. On early machines it was commonly called an open frame

steradian: (sr) A unit of solid angular measure. It is defined as the solid angle subtended at the center of a sphere by an area on its surface numerically equal to the square of the radius.

stereo: An abbreviation for "stereophonic." It indicates sounds which appear to have their source distributed in space even when they are emitted by the vehicle's speakers. Also see car stereo

Sterling: A model of automobile manufactured in the UK stern:

Click for books on Sterling

See clearwater stern cruiser stern transom stern stern, clearwater: See clearwater stern. A stern with a "shoeless" stern frame

stern cruiser: See cruiser stern

stern frame: A large casting attached to the after end of the keel, incorporating the rudder gudgeons and propeller post in single-screw ships

sternpost: The vertical part of the stern frame to which the rudder is attached

stern transom: See transom stern

stern tube: The watertight tube enclosing and supporting the propeller shaft on bearings

sternway: The reverse movement of a vessel. See astern

stethoscope: A device (such as used by doctors) to detect and locate abnormal engine noises. A very handy tool for the trouble-shooter. Also see mechanic's stethoscope

Stevens Duryea: A vehicle brand of which the 1925-1948 models are classic cars.

Steyr: A vehicle brand of which the 1925-1948 models with required application are classic cars.

stick: See hood stick

sticker: See decal monroney sticker toll sticker sticker price: A manufacturer's suggested retail price (as displayed on an affixed sticker), usually subject to a negotiable discount

sticking: A fusing of the electrode to the surface of the piece being worked on, mainly at the beginning of the welding cycle

stick shift: This refers to a transmission that is shifted manually through the use of various forms of linkage. Often refers to the upright gearshift stick that protrudes through the floor. Also see four on the floor.

sticky clutch: See clutch drag

stiction: A shortened form of static friction; the frictional force which must be overcome to set one object in motion when it is in contact with another

stiff: [1] Not easily bent or turned. As opposed to a rigid object, a stiff object does not break when subjected to bending stress, and implies a certain degree of flexibility; a bridge, for example, is stiff, not rigid, and steel panels are inherently stiff; however, a particularly high degree of stiffness, e.g., when steel panels are shaped to a loadcarrying structure, is sometimes referred to as rigid. [2] A stiff ship is one which have a short period of roll and therefore will roll uncomfortably

stiffener: An angle, T-bar channel, built-up section etc, used to stiffen plating of a bulkhead, etc. Also see sill stiffener

stiffness: A stiff ship is one which have a short period of roll and therefore will roll uncomfortably. See lateral stiffness roll stiffness torsional stiffness stiffness under flexure: A measure of the resistance offered by a test specimen to its tendency to bend under the action of forces (own weight)

stiff nut: See self-locking nut

still-air pocket: An area of relatively turbulence-free air immediately behind the windshield of convertibles with the top down

Stillson wrench: A very large heavy-duty adjustable wrench

stink-bomb smell: See rotten-egg smell

Stirling engine: An external combustion engine that uses air or an inert gas as the working fluid operating on a highly efficient thermodynamic cycle. The heat released from the burning fuel is transferred to the confined gas (such as hydrogen) which activates the pistons; named after the Scottish engineer, Robert Stirling (1790-1878)

stirring paddle:

A component of the agitator of a paint power mixer

stirrup bolt: A U-bolt

stirrup cable: On bicycle centerpull brakes, a short cable, each end of which attaches to a brake arm and which is pulled up at the center to activate the brakes.

stirling engine: An external combustion engine in which heat is applied through the wall of a chamber within which a gas is successively heated and cooled, alternately expanding and contracting to power a piston inside the chamber. Its advantages include: exceptional silence, lack of vibration, long life, high efficiency, extremely low emissions and adaptability to many different kinds of fuel. Its main drawbacks are the need for extremely effective seals, inflexible control systems, and cost.

stitching: A hard rolling method used to both remove trapped air and improve rubber contact for better adhesion, during repair, and retreading.

stock: See die stock gum stock rudder stock stripping stock super stock wing stock stock car: A car as built by the factory (i.e., production car). Usually one that is raced without any modifications beyond factory installed equipment. Also see super stock.

stocker: The stock, or original equipment.

stoichiometric:

Having the exact proportions for a particular chemical reaction

stoichiometric ratio: In a spark-ignition engine, the ideal air/fuel mixture ratio of 14.7:1, which must be maintained on engines with dual-bed and three-way catalytic converters. Also see air ratio

stone: See finishing stone honing stone roughing stone stone chip damage: A paintwork defect caused by gravel or stones

stone deflector: A separate panel fitted below the front bumper or on the leading edge of the rear fender to provide protection from rocks, dirt, etc.

stone guard: A separate panel fitted below the front bumper or on the leading edge of the rear fender to provide protection from rocks, dirt, etc.

stone shield: A separate panel fitted below the front bumper or on the leading edge of the rear fender to provide protection from rocks, dirt, etc.

stop: [1] A component which limits the motion, travel, or stroke of a moving part. A colloquial term for an abutment. See air stop bump stop check stop clutch brake clutch stop hard stop idle stop solenoid

idle stop valve piston ring stop pit stop reed stop rest stop rudder stop sealer stop-and-go penalty: Punishment for a rule infraction during a race (usually speeding down pit road). The driver must come down pit road, stop in his pit stall, usually for 15 seconds, then proceeds back to the track.

stop leak: See sealer.

stop-leak: See sealer.

stop light: [1] A red light on a traffic signal indicating that vehicles should stop. [2] A brake light

stopper: A filler or putty used for filling holes, dents, etc. See chain stopper knifing stopper stopper plate: See reed stop

stopping distance: The total amount of time (translated into distance) a vehicle and driver need in which to come to a halt; the shortest stopping distance is the reaction (or thinking) distance (of the driver) added to the braking distance (of the vehicle)

stop solenoid:

See idle stop solenoid.

stop valve: See idle stop valve

stop wheel: See safe stop wheel

storage: See broken storage

storage battery: A rechargeable single cell or connected group of two or more storage cells such as the type used in vehicles. The opposite of primary battery. See battery.

storage cell: An electrolytic cell for generating electric energy; rechargeable by sending a current through it in the opposite direction to the discharging current

store: A general term for provisions, materials and supplies used aboard ship. See auto parts store tire store stormer: A hot car that really moves out (i.e., accelerates rapidly).

stove: [1] To dry a coat of paint in heat. [2] See choke stove.

stovebolt: Generally refers to Chevrolet (GMC) 6-cylinder, in-line, valve-in-head (push rod operated) engine.

stoving:

A process of drying or curing a paint coating by the application of heat; immediately after stoving, the paint film is still soft, taking some time to harden

stowage: The placing of goods in a ship in such a way as to ensure the safety and stability of the ship

stp: Acronym for "standard temperature and pressure"

straddle cable: See stirrup cable.

straight cut gears: See straight-cut gear.

straight-cut gear: A gear that has teeth cut in the edge of the circumference of the gear. Unlike helical gears, the teeth are cut in line with the shaft on which it fits. See spur gear helical gear. straightedge: A rule-type tool without graduation for checking, e.g., warp of cylinder block and head

straight eight: An eight-cylinder in-line engine

straightened panel: A panel brought into its original shape with hammer and dolly or straightening equipment

straight engine: See in-line engine.

straightening bench: A workbench or fixture equipped to hold single panels such as doors or hoods for straightening and metalworking jobs

straightening kit: Powerjacks used to straighten localized body damage, essentially comprising special ram cylinders, pumps, attachments, and extensions

straightening set: Powerjacks used to straighten localized body damage, essentially comprising special ram cylinders, pumps, attachments, and extensions

straight-line speed: The highest speed obtainable by a vehicle driving in a straight line.

straight-line stability: See directional stability

straight-line tracking: The ability of a car to resist road irregularities and run in a straight line without steering corrections.

straight pattern snips: snips with cutting blades designed for straight cuts on sheet metal material

straight polarity: (Electrode negative-cathode) connecting DC to cause electrons to flow from the electrode to the base metal.

straight six: A six-cylinder in-line engine

straight-through side styling: An all-enveloping body

straight-through silencer:

A type of absorption silencer with a single perforated tube surrounded by soundabsorbing fiber which creates less back pressure and consequent loss of power than other types

straight time: The actual time that a mechanic takes to complete a repair job. In contrast with flat rate.

straight weight: Term designating motor oil as suitable for use within a narrow range of temperatures. Outside the narrow temperature range its flow characteristics will not adequately lubricate.

straight weight engine oil: See single-grade engine oil

straight-weight oil: oil suitable for use within a narrow temperature range; outside this range, its flow characteristics will not allow adequate lubrication. Also called "single-grade oil." Also see multigrade oil.

strain: Reaction of an object to a stress.

strainer: A wire mesh filter, as used in an oil pump strainer in the sump. Also see oil pump strainer

strain in the drive train: Strains resulting from the different track arcs travelled by the four wheels of a vehicle when cornering with center or axle differentials locked up

strake: See bilge strake garboard strake sheer strake

strand: One of a number of wires twisted together to form an electrical conductor or cable

stranding: The running of a ship on shore on a beach.

strangler: An old colloquial term for choke

strap: [1] A long flexible strip (usually of leather or rubber) used to connect two items. [2] A lead section to which battery plates of a group are joined. See battery strap butt strap check strap door check strap driveshaft safety strap earth strap ground strap plate strap propeller shaft safety strap safety strap strap drive: A drive transmitted from the clutch cover to the clutch pressure plate in diaphragm spring and coil spring clutches, using flexible spring-steel straps attached to the clutch cover

strap wrench: A tool for loosening and tightening round or irregularly shaped objects such as oil filters, featuring a strap which is wrapped around the object, and a lever or key by means of which the object is turned

stratified charge: In a SI engine, an air/fuel charge which consists mainly of a lean mixture and a small layer or pocket of rich mixture; the rich mixture is ignited first, then ignition spreads to the leaner mixture filling the rest of the combustion chamber

stratified charge engine:

An internal combustion engine in which a small portion of extremely rich fuel and air is ignited and in turn ignites a much leaner fuel-air mixture. The lean mixture might not fire by itself unless it is ignited by the flame of the burning rich mixture. Its advantage is lower peak c‘bustion temperatures, greater fuel economy, and a decrease in pollutant emissions. The Honda CVCC engine which initiates combustion in a small auxiliary prechamber is one type of stratified charge engine (to be precise, the CVCC should actually be called a dual-combustion engine). Another type is Texaco's which uses turbulence in the incoming mixture to induce stratification.

straw: A convenient DIY tool for blowing debris from the spark plug recess before plug removal

streak: A long thin trace of dirt a damaged wiper blade will leave streaks and smears on the windshield

stream: See slip stream.

streamline: To design the shape of a car body or truck cab so that it reduces air resistance to a minimum

street bike: A motorcycle which is permitted to be ridden on public roads and must be licensed. In contrast with an off-road bike.

street car: An electrically driven public transportation vehicle which runs on rails (tracks) inset into the surface of the road and powered by overhead cables. The British term is "tram" or "tram car"

street rod: A slightly modified rod (car) that will give good day-to-day performance on the streets.

street version:

A detuned version of a vehicle, usually of a racing car

strength: The stress at which material ruptures or fails. See bending strength fatigue strength film strength impact strength tensile strength yield strength strength deck: The deck that is designed as the uppermost part of the main hull longitudinal strength girder

strengthening buttress: See fender strengthening buttress

stress: [1] Load imposed on an object. [2] A force causing deformation or strain. See impact stress mechanical stress stress concentration: A condition in which a stress distribution has high localized stresses; usually induced by an abrupt change in the shape of a member (often in the vicinity of notches etc.)

stress corrosion cracking: (SSC) Cracking due to stress corrosion, a process involving joint corrosion and straining of a metal due to residual or applied stresses

stress cracking: Damage of parts, especially body panels, subject to constant overload caused by improper mounting; this introduces strain into the panels, causing them eventually to crack

stressed body: A vehicle body designed so that the outer body panels share a proportion of the total load or stresses in the whole structure instead of the frame taking all the loads. The Jaguar E-Type is one example.

stressed member: A component that is an integral part of the whole structure

stress fracturing: Damage of parts, especially body panels, subject to constant overload caused by improper mounting; this introduces strain into the panels, causing them eventually to crack

stress line: See stress lines.

stress lines: Low areas in a damaged panel, usually starting at the point of impact and travelling outward.

stress relieving: Even heating of a structure to a temperature below the critical temperature followed by a slow, even cooling.

stretch limo: A colloquial term for a limousine that has been lengthened to provide extra seating and more legroom

striker: The mating part of door lock or hood latch mechanism which is secured to the body; the striker itself has no mechanism and provides only the anchor for the door or hood latch; typical strikers are stud or U-shaped. Also see lock striker

striker plate: An anchor plate to which the striker is attached

striking blow: A dent removal technique in which the hammer does not hit the panel straight on but is drawn to one side on hitting the surface, thus spreading the impact over a larger area

string: A thin length of twisted fiber.

stringer: A fore-and-aft girder running along the side of a ship at the shell and also to the outboard strake of plating on any deck. Also see deck stringer

stringer bar: The angle connecting the deck plating to the shell plating or to the inside of the frames. The strength deck stringer bar is usually called the gunwale bar

strip: [1] Area used for drag racing. [2] Removing tires and wheels, battery, hubcaps and other items of value as done by thieves. See gut. [3] To remove the insulation from a wire. [4] To tear off or break the thread from a screw, bolt, etc., or the teeth from a gear. See chafer strip feeler strip filler strip flipper strip glazing strip kick strip rear tack strip rim strip rubbing strip rumble strip sealing strip steel strip stripe: See body stripe

striper:

See pinstriping tool

striping tool: A tool used to apply paint in long narrow lines.

stripped down: See base model

stripper: See automatic wire stripper base model paint stripper wire strippers stripper/crimper tool: See wire stripper/crimper tool

strippers: See wire strippers

stripping stock: Rubber stock used to extend the wing of tread rubber when retreading a tire.

strobe lamp: A colloquial term for a stroboscope

strobe light: A colloquial term for a stroboscope

stroboscope: See timing light.

stroboscopic ignition timing: See dynamic ignition timing

stroke: The distance the piston moves when travelling from bottom dead center (BDC) to top dead center (TDC) or vice versa. [2] To modify the stroke of an engine by using a different crankshaft to increase or (rarely) reduce the displacement. See ascending stroke charging stroke compression stroke effective stroke exhaust stroke expansion stroke firing stroke four stroke cycle engine four stroke power cycle induction stroke intake stroke intake tract intake stroke long stroke engine power stroke rebound stroke two stroke up-stroke stroke cycle: See four stroke cycle engine two stroke cycle stroke cycle engine: See two stroke cycle engine four stroke cycle engine stroke engine: See long stroke engine short stroke engine stroked: The action of lengthening the stroke on an engine. Sometimes an engine manufacturer will produce an identical engine as he did in the previous year, but this time the stroke is longer. Thus it has been stroked. If the bore is also increased,

it is bored and stroked.

stroked crankshaft: A crankshaft, either a special new one or a stock crank reworked, that has the connecting rod throws offset so that the length of the stroke is increased.

stroke intake: See intake stroke intake tract

stroke intake tract: See intake stroke intake tract

stroke power: See four stroke power cycle

stroke power cycle: See four stroke power cycle

stroker: An engine using a crankshaft that has been stroked.

stroking: A method for increasing the displacement of an engine by lengthening the crankshaft throws so that the piston stroke is increased. The crankshaft throws were remachined "off center" to alter the stroke. Also see four-stroking

Stromberg carburetor: A type of variable venturi carburetor

structural part: Any part of a vehicle that plays a role in ensuring the rigidity and integrity of the vehicle as a whole and that, if it collapses, could make the vehicle unsafe

structure: See frame structure

primary structure component sill structure steering support structure underbody structure structure component: See primary structure component

strut: [1] A single, self contained pivoting suspension unit that integrates a coil spring with a shock absorber. Struts are used on front wheel drive automobiles. [2] A structural member, especially as part of a framework, used to stiffen, give strength or carry weight. [3] A bar that connects the lower control arm to the car frame; used when the lower control arm is attached to the frame at only one point. [4] A air strut, Chapman strut, damper strut, gas prop. See macpherson strut tower MacPherson strut modular air strut parking brake lever strut self-levelling strut steel strut suspension strut strut bar: Another name for "sway bar" or anti-roll bar.

strut rod: See push bar

strut tower: See MacPherson strut tower

stub axle: A short axle that carries one of the front wheels and has limited angular movement about a kingpin

stubby screwdriver:

A screwdriver with a short handle and blade for reaching into confined spaces. In Britain it is called a "chubby screwdriver."

stud: [1] A metal rod or shaft with threads on both ends. Similar to grub screw which has uniform thread throughout, while the stud has an unthreaded part in the "middle." [2] Metal spikes installed in snow tires to increase traction on ice and hard-packed snow. Studded tires have been banned in many areas because of the damage they inflict upon road surfaces. [3] A bolt projecting from a plate, like a wheel stud. Also see wheel stud

Studebaker: A vehicle brand of which the 1929-33 President models are classic cars. The 1963-64 Avanti models are milestone cars. The 1962-64 Gran Turismo Hawk models are milestone cars. The 1947-49 Starlight Coupe models are milestone cars. The 1953-54 Starliner Hardtop (Six and V-8) models are milestone cars. The 1955 President Speedster is a milestone car. stud end: The opposite end of a stud to the nut end

stud extractor: A tool like a socket wrench for the removal (and installation) of studs

stud hole: A hole in a wheel through which the wheel studs pass

stud puller: A tool used to install or remove studs.

stud remover: A tool like a socket wrench for the removal (and installation) of studs

stuffing box: See packed gland

stuffing-box packing:

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A sealing element of a stuffing box consisting of rings of tissue (e.g., cotton) or metal rings

stumble: A driveability-related problem similar to but more severe than hesitation. See bog.

Stutz: A vehicle brand of which the 1925-1948 models are classic Click for books on cars. Stutz STV: See suction throttling valve

style: See driving style gap style sporty driving style styling: See straight-through side styling

styling kit: See body styling kit

Subaru: A model of automobile manufactured in Japan

Click for books on Subaru

subassembly: An assembled unit designed to be fitted to a larger unit of which it is a component; e.g., the steering gear and front suspension or the final drive and rear suspension

sub-compact: A designation no longer used because even "full-size cars" are now about the size of what was the compact car. In 1970, for instance, a Chevrolet Impala was a full-size car, a Chevelle was an intermediate, a Nova was a compact. When cars smaller than the Nova came out (i.e., Chevette), they were called sub-compacts.

sub frame: A partial frame that is sometimes bolted to the chassis of unit-body cars. It can be used to support the engine, transmission and suspension instead of having these components directly connected to the main body structure. This more expensive design generally results in better road isolation and less harshness. See engine subframe suspension subframe subframe: Any auxiliary framework attached to the main body of a vehicle. On a motorcycle this often refers to the rear section of the frame, which supports the seat See sub frame engine subframe suspension subframe submarining: A sliding under the lap belt in a frontal collision

subplate: See distributor baseplate

subsidiary: a subsidiary is an organization operating in a particular country that is owned or controlled by a foreign company which may or may not manufacture in that country.

subsidiary petal: A secondary petal of a dual-stage reed valve. Opposite of main petal

subsidized lease: A subvented lease is a lease offered by manufacturers with special incentives to make it more attractive. Special incentives often take the form of a lower base interest rate, higher residual values, and manufacturer discounts. In many cases, a subvented lease will have a lower net interest rate than other leases. Subvented leases are usually only available for a limited time and the terms are not negotiable. Any negotiated change in the terms will result in a different net interest rate.

substrate: The surface that is to be finished (painted). It can be anything from an old finish or primer to an unpainted surface. Also see catalyst substrate

substation: [1] A switching, transforming, or converting station which is found between the generating station and the low-tension distribkution network. [2] The apex of a subsidiary triangle in a survey skeleton

substructure: An underbody structure

subvented lease: A subvented lease is a lease offered by manufacturers with special incentives to make it more attractive. Special incentives often take the form of a lower base interest rate, higher residual values, and manufacturer discounts. In many cases, a subvented lease will have a lower net interest rate than other leases. Subvented leases are usually only available for a limited time and the terms are not negotiable. Any negotiated change in the terms will result in a different net interest rate.

SU carburetor: A widely used type of variable venturi carburetor in Britain. It was named after Skinners' Union, a long-established manufacturer of variable venturi carburetors: the first SU carburetor was patented in 1905 by George Herbert Skinner who went on to found a company with his two brothers to manufacture SU carburetors

suction: See negative suction head POA suction throttling valve vacuum suction chamber: The space above the piston in the piston chamber of a variable venturi carburetor

suction cup:

See vacuum suction cup

suction cup dent puller: See vacuum suction cup

suction-feed spray gun: A type of spray gun with a paint pot mounted underneath

suction head: See negative suction head

suction lift: The vertical distance, in feet, from the liquid supply level to the pump centerline, the pump being above the liquid level. The suction lift should not exceed the recommended maximum limit and when viscous fluids are being pumped, they should be avoided altogether

suction line: A pipe on the suction side of a pumping system leading from the suction tank to the pump.

suction pipe: A pipe on the suction side of a pumping system leading from the suction tank to the pump.

suction side: The side of a pumping system or pump at which the liquid to be pumped enters the suction line or pump casing

suction throttling: See poa suction throttling valve

suction throttling valve: (STV) A backpressure-regualted valve on some Ford and GM systems placed between the air conditioning evaporator and compressor which controls evaporator pressure to provide maximum cooling without icing evaporator core. See

POA suction throttling valve pilot operated absolute valve suction valve grinder: See valve grinding tool

suggested: See manufacturer's suggested retail price

suggested retail: See manufacturer's suggested retail price

suggested retail price: See manufacturer's suggested retail price

suicide door: See suicide doors.

suicide doors: Doors that have the hinge toward the back of the vehicle. It's name came from the greater possibility of falling out of the vehicle with a door positioned this way.

Suiza: See hispano Suiza

sulphate: See lead sulphate

sump: That part of the oil pan that contains the oil. See dry sump dry sump lubrication oil sump sump drain plug:

See oil pan drain plug

sump gasket: See oil pan gasket

sump guard: See oil pan guard

sump lubrication: See dry sump lubrication wet sump lubrication sump plug: See oil pan drain plug

sun: See main sun visor mean distance to the sun sun and planet gears: See planetary gearset.

sun-and-planet gears: See planetary gearset.

Sunbeam: A vehicle brand of which only the 8-cyl. and 3-litre twin-cam models for 1925-1948 are classic cars. The 1965-67 Tiger Convertible models are milestone cars. Sunbird: A model of automobile manufactured by Pontiac division of General Motors sun car:

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Click for books on Pontiac Sunbird

A colloquial term for a solar car

sun gear: The center gear around which the planet gears revolve. Also called "sun wheel." Also see planetary gear.

sunroof: (sr) A panel (often translucent) in the roof of a car which may be tilted or slid open, either manually or electrically to provide extra light and/or ventilation. Also see tilt/slide sunroof

sunroof aperture panel: A panel which accommodates the sunroof guide rails and draining channels and fits below the roof panel

sunroof deflector shield: A shield or visor that can be attached to the front of the sunroof to deflect the wind

sunroof top: A folding canvas sunroof

sunshield: A tinted strip of transparent vinyl attached to the top of the windshield to cut glare from the sun. Also called a "windshield shadeband" or "tinted windshield."

sun visor: [1] A hinged flap above the windshield that can be pulled down to shield the driver's or front seat passenger's eyes from sunlight; often contains a vanity mirror on the inside. [2] A body accessory mounted on the outside of the windshield on pick-up trucks, RVs, and in the 1950s a short-lived fad on cars - not at all aerodynamic. Also see main sun visor

sun wheel: See sun gear

super:

Premium gasoline with a high octane rating, typically 98

superbike: A large engined-sport bike

super car: A car with a high horsepower engine that will provide fast acceleration and high speed.

supercharge: [1] To increase the intake pressure of an internal combustion engine with a supercharger. [2] to tune the exhaust pressure in such a manner that the pressure wave propagating back to the exhaust port of a two-stroke engine arrives there as soon as the transfer ports close, thus pushing the final amount of fresh charge that has already escaped into the exhaust back into the cylinder

supercharged Engine: An engine that is similar to a turbocharged engine which uses a series of belts or chains from the crankshaft to turn the turbines that forces the air/fuel mixture into the cylinder heads under pressure creating a bigger explosion which generates more power. A turbocharger use the exhaust gases to turn the turbines to create the same effect.

supercharger: An air compressor designed to force air, under pressure, into the cylinder. Can be mounted between the carburetor and cylinders or between the carburetor and the atmosphere. It boosts the power of the engine. See blower comprex supercharger lobe-type supercharger lysholm supercharger pressure wave supercharger roots supercharger turbo-supercharger turbocharger supercharging: A method of increasing engine power by forcing larger amounts of air into the cylinders. Also see dynamic supercharging

superheat: A gas or vapor that is not in contact the generating liquid (steam not in contact with water e.g.,) that has been heated to such a degree that its temperature may be lowered or it pressure increased without the conversion of any of the gas into liquid. Also called superheated vapor

superheat switch: A device that is connected in series with a thermal limiter (fuse) mounted on the rear of the compressor of GM system equipped with low refrigerant protection

superheated vapor: A gas or vapor that is not in contact the generating liquid (e.g., steam not in contact with water) that has been heated to such a degree that its temperature may be lowered or it pressure increased without the conversion of any of the gas into liquid. Also called superheat

super randonneur: A special medal awarded to those randonneurs who successfully complete a challenging series of brevets (200, 300, 400, and 600-kilometers) in a year. Only super randonneurs are allowed to ride a 1200-kilometer event.

superspeedway: Any oval-shaped or circle-shaped track more than one mile long.

super stock: Factory car (stock) with engine, suspension, running gear, etc., modified to increase horsepower and overall performance.

supplemental restraint inflatable air-bag system: See SRS.

supplemental restraint system: See SRS.

supplementary inflatable restraint:

See sir

Supplier: See tier 1 Supplier tier 2 Supplier tier 3 Supplier supplier cost reduction effort: (SCORE) A United States program that urges suppliers to develop processes to cut costs. Suppliers are allowed to keep half the savings and pass on the other half to the automakers.

supply: See days' supply fuel supply supply pump: A pump that transfers fuel from the tank and delivers it to the injection pump

supply voltage: The voltage obtained from the power supply to operate a circuit

support: See bearing support bonnet support catalyst substrate catalyst support lumbar support main bearing support metal support plate support radiator support panel steering support support bracket:

See fender support bracket

support panel: See radiator support panel windshield support panel support stay: See hood support stay

support structure: See steering support structure

supports: See main bearing supports

suppressed: See rfi suppressed spark plugs

suppressed spark: See RFI suppressed spark plugs

suppressed spark plugs: See RFI suppressed spark plugs

suppressor: An electrical device used in car circuits to damp out and filter out radio or TV interference caused mainly by the ignition system and battery circuit

surface: See bearing surface machined surface mating surface mechanical surface treatment surface discharge plug:

See surface gap spark plug

surface dry: A condition in which the outer layer (surface) of the finish dries while the underneath remain soft and not thoroughly dried.

surface gap: The spark gap of a surface gap spark plug in which the sparks glide over the insulator-filled gap

surface gap spark plug: A type of spark plug in which the spark is fired across the insulator surface between the center electrode and the shell; there is no side electrode

surface ignition: Ignition initiated by hot spots in the engine cylinder rather than by a timed spark

surface-mounted speaker: A speaker mounted on top of the bearing surface. Opposite to a flush-mounted speaker

surfacer: See primer surfacer

surface resistance: The electrical resistance of the surface of an insulator

surfaces: See split-friction road surfaces

surface spoon: A special body spoon with a relatively long, smooth working surface set at a steep angle to the handle

surface tack: A condition occurring after filler is applied to a panel surface, characterized by the fact that the filler will not cure in certain places. This may be caused by improper

mixing of the filler paste with the hardener, insufficient curing time or insufficient hardener being used

surface treatment: See mechanical surface treatment

surface-type filter: A filter design in which particles accumulate on the surface, e.g., of a folded paper element; typical design of air and cartridge-type oil filters

surge: [1] A drive problem where the vehicle on its own seems to gain power for a brief moment and then back down to the previous speed. The reason the engine will not run at a steady speed and surges is probably due to very lean air-fuel mixture (improper carburetor setting, clogged air filter, plugged main jet, etc.) or retarded timing. [2] An ignition fault due to misfiring

surge line: Line on compressor map which represents the minimum stable flow at each pressure ratio, below which the compressor output is unsteady

surround: See door surround radiator grille surround rear light surround tail light surround windshield surround suspension: [1] The assembly of springs, shock absorbers, torsion bars, joints, arms, etc., that cushions the shock of bumps on the road and serves to keep the wheels in constant contact with the road, thereby improving control and traction. [2] A mixture of fine, non-settling particles of any solid within a liquid or gas. The particles are the dispersed phase, while the suspending medium is the continuous phase; used engine oil, for example, is a suspension with suspended combustion residues which produce a blackish appearance. See active suspension

air suspension arm suspension double wishbone suspension dubonnet suspension five-link rear suspension flex arm suspension four-link rear suspension front suspension hotchkiss suspension hydragas suspension hydroactive suspension hydrolastic suspension hydropneumatic suspension I-beam suspension independent front suspension independent rear suspension independent suspension long and short arm suspension macpherson suspension moulton Hydragas suspension moulton Hydrolastic suspension multi-link independent rear suspension multi-link rear suspension multilink suspension oleopneumatic suspension parallelogram suspension parallel trailing link suspension pneumatic suspension progressive suspension reactive suspension rear suspension rising-rate suspension sala suspension self-levelling suspension semi-active suspension semi-independent suspension semi-trailing arm suspension short arm/long arm suspension single-wheel suspension sla suspension sliding-pillar suspension swing arm suspension three-link suspension torsion bar suspension twin A-arm suspension twin I-beam suspension

unequal-length wishbone suspension suspension aids: Items designed to reinforce the rear suspension when carrying heavy loads or towing trailers; they include: extra, single-leaf springs, coil springs, and heavy duty spring dampers

suspension link: Any arm which links the chassis to the axle. See leading arm semi-trailing link trailing arm transverse link wishbone suspension mounting: Sheet metal parts, bores, etc. on the underbody designed to locate the axles and springs on the body

suspension raft: A patented part of a Lotus suspension system to provide precise suspension location and a comfortable ride, through the use of directional bushings.

suspension sphere: A pressurized, nitrogen-filled ball used in hydropneumatic suspension systems

suspension strut: A unitary construction of spring and damper elements; depending on whether the hub carrier is mounted to the spring or the damper element, the suspension strut is referred to either as a damper strut or as a MacPherson strut

suspension subframe: A suspension layout absorbing noise and vibration, in which all suspension elements are mounted on an insulated, detachable suspension subframe

suspension system: A system that cushions the passenger compartment of the vehicle from the bumps and shocks caused by the wheels moving over irregular road surfaces. Includes

springs, shock absorbers, steering linkage, upper and lower control arms, torsion bars, stabilizers, etc. Sometimes called "springing." See air suspension hydropneumatic suspension independent front suspension independent rear suspension independent suspension long and short arm suspension rising-rate suspension torsion bar suspension suspension turret web: A reinforcement supporting the MacPherson strut at the lower side of the strut tower panel; this allows the strut to rest against the top strut mounting from below

SUV: An acronym for "sport utility vehicle" which includes the Ford Bronco, GMC Jimmy, Chevrolet Blazer, Jeep Cherokee, Toyota Forerunner, and Nissan Pathfinder.

Suzuki: A model of automobile manufactured in Japan

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S.V.: Acronym for "side valve"

SV engine: See side-valve engine

SVV: Acronym for solenoid vent valve

SW: [1] Acronym for "station wagon." [2] An abbreviation for "switch" which is found on the coil terminal connected to the ignition switch

swage line:

A narrow profiled line in outer body panels, e.g., above the upper edge of the wheel cutouts, that helps to enhance the flowing lines of the bodywork

Swansea: The location for the British Driver and Vehicle Licensing Agency. Sometimes "Swansea" is a substitute for this agency.

swarf: Loose chips of metal produced when grinding

swash bulkhead: Longitudinal or transverse nonwatertight bulkheads fitted in a tank to decrease the swashing action of the liquid contents as a ship rolls and pitches at sea

swash plate: [1] A plate serving the purpose of a swash bulkhead, but not extending to the bottom of the tank. [2] A rotating disc or face plate on a shaft that is inclined at an oblique angle to the axis of rotation and either imparts reciprocating motion to push rods or plungers parallel to the shaft axis, as in a swash plate pump or, conversely, converts reciprocating motion to rotation (replacing the crankshaft), as in a swash plate motor

sway bar: A round bar which connects the left wheel suspension assembly with the right side. It may be found at the front and/or rear. Its main function is to keep both wheels rolling at the same rate when meeting bumps; but it also affects handling. A front anti-roll bar increases understeer and a rear bar increases oversteer. See anti-roll bar.

sweat: To join metal pieces by clamping them together with solder in between, the applying heat

sweating: Joining two pieces of metal together by placing solder between them and then clamping them tightly together while heat, sufficient to melt the solder, is applied.

sweep:

See return sweep

sweeper: A type of seal used along moving surfaces, e.g., door windows, that is often provided with a lip to ensure sealing. Also see window weatherstrip

swelling: [1] A paint fault condition that occurs when an excessively rapid thinner is used in a paint and the soft paint sinks into cuts. [2] An increase of volume conditioned by the absorption of liquids, vapors or gases in the coating film of plastics. See sand scratch swelling.

swept volume: that part of the cylinder capacity that is swept by the pistons on their up and down strokes (i.e., the volume through which a piston moves in one stroke) formed by the bore diameter and the piston stroke. Also called "displacement volume." See displacement.

swing: See low pivot swing axle

swingarm: A motorcycle suspension member pivoted at one end and supporting the wheel at the other. In most cases the swingarm is more accurately described as a pivoted fork, as the wheel is supported on both sides. It works in conjunction with the shock absorbers to absorb the impact of bumps in the road. Attaches the rear wheel to the frame of the bike with a single pivot point. It connects to the frame near the rear of the engine.

swing arm suspension: An independent suspension system in which each axle pivots near the center of the vehicle and the movement of the axle changes the angle of camber. Also called swing axle

swing axle: An independent rear suspension system in which each driving wheel can move up or down independently of the other. The differential unit is bolted to the frame and various forms of linkage are used upon which to mount the wheels. Drive axles, using one or more universal joints, connect the differential to the drive wheels. When cornering hard, cars with swing axles are prone to wheel jacking which can

lead to large positive camber at the outside rear wheel and can induce sudden oversteer. Also see low pivot swing axle.

swinging caliper: A type of floating caliper with wedge-shaped disc pads (only one of which is activated by hydraulic pressure from the piston, the other being fixed), which can pivot on its hinge pin to equalize the pressure on both pads

swinging shackle: See shackle

swirl: A rotary or swirling motion given to the charge mixture as it enters a cylinder by offsetting the inlet tract

swirl chamber: A small chamber or cavity in the cylinder head to promote swirl in the indirect injection combustion system of a diesel engine

swirl combustion chamber: See twin swirl combustion chamber

swirl marks: A circular pattern produced by an orbital sander on a paint surface; it must be handsanded with a sandpaper of finer grit, otherwise it will remain visible through the respray coat

switch: A device that opens and closes an electric circuit. See actuating switch ambient temperature switch authority Limit Switch battery master switch dimmer switch dipper switch door pillar switch fuel cut-off switch fuel pump shut-off switch

fuel pump switch glow plug starter switch hall-effect switch hall vane switch hamlin switch hatchback hazard flasher switch hazard flasher switch hazard warning switch headlight dimmer switch horn switch ignition switch inertia fuel cut-off switch interior light switch jamb switch kickdown switch kill switch lean Authority Limit Switch mercury switch neutral safety switch oil pressure switch park safety switch power cut-off switch power window lock-out switch pressure differential switch remote starter switch snow chain switch solenoid starter switch starter inhibitor switch starting switch tether kill switch thermal vacuum switch thermo-time switch throttle valve switch toggle switch vacuum control switch valet switch vane switch wash/wipe switch switch control cable: See starter switch control cable

switching: See

air switching electric air switching valve switching sensors: Sensors that turn on and off in response to specific conditions

switching valve: See air switching valve electric air switching valve swivel: [1] to turn or swing about a point [2] See steering knuckle impact swivel ball universal joint steering swivel swivel angle: See kingpin inclination

swivel axis: See kingpin axis

swivel axis inclination: See kingpin inclination

swivel ball: See impact swivel ball universal joint

swivel ball universal: See impact swivel ball universal joint

swivel ball universal joint: See impact swivel ball universal joint

swivel pin: See kingpin

symbol: See speed symbol type symbol symmetrical: Symmetrical tread is the most common tread design. Both halves of the tread face are the same design. It does not matter which side faces out. See asymmetrical Tread directional tire. symmetric rim: A rim type in which the rim well is located symmetrically on the wheel centerline. Opposite to asymmetric rim

synchromesh: A device in a manual transmission that allows two gears to mesh more smoothly. When a synchronizer gear matches the speed of the transmission main shaft to the speed of the gear being selected, they mesh smoothly and prevent grinding and clashing of gears. It was first introduced by Cadillac in 1928. See locking synchromesh porsche-type synchromesh proportional load synchromesh synchromesh transmission: A transmission using a device (synchromesh) that synchronizes the speeds of gears that are being shifted together. This prevents "gear grinding." Some transmissions use a synchromesh on all shifts while others synchronize second and high gearshifts.

synchronize: To bring about a timing that will cause two or more events to occur simultaneously; plug firing when the piston is in the correct position, the speed of two shafts being the same, a valve opening when the piston is in the correct position, etc. Also see synchronizer.

synchronizer: A cone or sleeve that slides to and fro on the transmission main shaft and makes the gears rotate at the same speed to prevent clash when the gears are about to mesh. Whenever a vehicle is rolling, the transmission main shaft is turning and the clutch gear is spinning. Even though the clutch is disengaged, the clutch gear continues to spin until friction slows it down or stops it. Thus when the driver shifts into another gear he is trying to mesh gears that may be moving at different speeds. By using synchronizers, the possibility of broken or damaged teeth is reduced and shifting effort is lowered. A transmission using synchronizers is called a synchromesh transmission.

synchronous motor: An alternating-current motor that runs at a speed that is equal to or is a multiple of the frequency of the supply (e.g., the drive motor of electric powered vehicles)

synergetic effect: A protective effect occurring as a result of the combination of a metallic and an additional organic coating

synergistic effect: A protective effect occurring as a result of the combination of a metallic and an additional organic coating

synthesizer: A device which generates quartz-controlled frequency steps in a PLL circuit. Also see speech synthesizer

synthetic engine oil: A non-petroleum based oil; more expensive than mineral oil but more resistant to breakdown at high temperatures and less viscous at low temperatures

synthetic oil: A non-petroleum based oil.

synthetic rubber: A man-made elastomer. The raw materials are generally derived from oil byproducts. Produced by the polymerization or copolymerization of petroleum-derived olefins or other unsaturated compounds. Also see natural rubber.

system: An orderly, interconnected, complex arrangement of parts. See accumulator system air filtration system air injection reaction system air system alarm system anti-dive system anti-lock brake system anti-noise system anti-squat system anti-theft system bleeding a system brake system braking system bumper system C-4 system charging system clear system closed loop system closing system controlled combustion system coolant recovery system cooling system diagonally split system electrical system electronic ignition system engine-control system exhaust system flushing the cooling system fuel system fuel vapor recirculation system ignition system induction system linear wiper system lubrication system microprocessor spark timing system oil-combination splash and pressure system oil-full pressure system oil-splash system open loop system PCV system performance handling system

positive crankcase ventilation system pulse air system starting system steering system supplemental restraint inflatable air-bag system suspension system triangle-split system vapor recovery system voice alert system system pressure regulator: A pressure relief valve located on the fuel distributor. In a continuous injection system, it holds system fuel pressure constant. See K-jetronic

system scanner: See message center

system thermo-switch: See oxygen sensor system thermo-switch

system with electronic: See high energy ignition system with electronic spark timing

system with electronic spark: See high energy ignition system with electronic spark timing

system with electronic spark timing: See high energy ignition system with electronic spark timing Sign My Guestbook 1

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Ta][Tb][Te][Tf][Th][Ti] [To] [Tr][Tu][Tv][Tw] [Ty]

T: A letter rating for tires to indicate that they are theoretically rated for speeds up to 190 kph (118 mph), as in P220TR15.The next higher rating is H and the one lower rating is S

tab: [1] A small projecting part as on a tab washer, or on a gasket where it engages with another seal. [2] Not a continuous flange as provided at the top mounting of a fender, but a short flange section to provide localized fitting of one panel to another

TAB: Acronym for thermactor Air bypass solenoid

table: See load and inflation table tray table tab washer: A washer with a projection that may be hammered against a flat side of a nut, or into a hole in the surface, or over an edge, in order to secure the nut to the surface on which it bears

TAC: Acronym for thermostatic air cleaner

tach: Abbreviation for tachometer.

tacho: Colloquial term for tachograph

tachograph: Instrument to record, on a graph, vehicle trip information such as mph, rpm, "stop" and "go" periods. It is used on transport trucks.

tachometer: (tach) A device used to indicate the speed of the engine in rpm. The tachometer is mounted on or near the dashboard (some even appear on the hood and others in a heads-up display on the windshield). It helps the driver to know the optimum rpm for changing gears on manual transmissions. A tachometer is also a diagnostic device which a mechanic uses to determine idle speed and other carburetor and running settings. Also called a "rev counter"

tack: A term used to describe the sticky quality of a rubber compound. See rear tack strip surface tack

tack cloth: A special cloth used to wipe sanded panels prior to spraying in order to remove even minute dust particles and other foreign substances from the panel surface

tack coat: The first coat of enamel that is allowed to dry until "tacky" usually about 10-30 minutes, depending on the amount of thinner used. The surface is "tacky" when it will not stick to the finger when light pressure is applied.

tack hammer: A special hammer with a magnetic head for inserting small nails or tacks

tacking: Attaching a panel provisionally by placing a few spots of weld along its outline; final spot or seam welding is carried out only afterwards

tack rag: A cloth impregnated with a non-drying varnish that is used to pick up dust and dirt particles.

tack strip: See rear tack strip

tack weld: Small weld used to temporarily hold together components of an assembly.

tack welding: Attaching a panel provisionally by placing a few spots of weld along its outline; final spot or seam welding is carried out only afterwards

TAC system: A contact breaker ignition system developed by Lucas, controlled by two transistors, one serving as a power output transistor

TAD: Acronym for thermactor air diverter solenoid

tail: The rear of a vehicle. See kamm tail whale tail tailboard: A board at the rear of a pick-up that can be removed or let down on a hinge. Compare tailgate

tail fin: A vertical fin on the back of the rear fenders. Copied from a lockheed P38 fighter plane, Cadillac introduced tail fins on a coupe in 1948; they were a fashion until the 1960s

tailgate:

[1] On a truck it is the fold down access door to the truck bed. On some station wagon and SUVs, it is the rear opening which usually requires the window to be lowered before the tailgate folds out. It differs from a liftgate in that the back opening is raised to allow entry. [2] As a verb, to follow closely behind another vehicle.

tailgating: Driving so close to the vehicle in front as to be affected by its slipstream; a very dangerous practice as available reaction time is reduced to a minimum. The correct distance is 2 or 3 seconds behind the vehicle in front.

tail heavy: The description of the towing vehicle if the vehicle being towed is too heavy

tail lamp: The red rear light that illuminates as soon as the lights are switched on, to show your vehicle to those behind you

tail lift: See brake dive

tail light: The red rear light that illuminates as soon as the lights are switched on, to show your vehicle to those behind you

tail light box: A deep-drawn panel spot-welded into the tail light aperture to accept the complete tail light cluster. The tail light box provides better corrosion protection for the electrical connections of the tail light than would be possible by installing the tail light with a rubber seal into the open light aperture

tail light panel: See rear panel

tail light surround: See rear light surround

tail pipe:

The exhaust pipe which runs from the muffler to the rear of the vehicle. and is open to the atmosphere, through which the exhaust gases are routed into the atmosphere.

tailpipe expander: A special automotive tool used for reshaping and expanding tailpipes evenly, to assure a tight fit and prevent exhaust leaks

tailshaft: A ship's propeller shaft. See gearbox output shaft

take: See power take off

take foot off the accelerator: The action of easing up on the accelerator completely so that there is only a minimal amount of fuel entering the engine thus the engine will slow down

take foot off the gas pedal: The action of easing up on the gas pedal completely so that there is only a minimal amount of fuel entering the engine thus the engine will slow down

take foot off the throttle pedal: The action of easing up on the throttle pedal completely so that there is only a minimal amount of fuel entering the engine thus the engine will slow down

take off: See power take off

take up: To begin to transmit the drive when the clutch is engaged

take-up: The act of taking up. See lifting platform take-up point quick take-up valve

take-up point: See lifting platform take-up point

take-up valve: See quick take-up valve

Talbot Lago: A vehicle brand of which all 150C models are classic cars.

Talbot: A vehicle brand of which all 105C and 110C models are classic cars. The 1946-54 Lago 4.5 models are milestone cars.

talc: Powder lubricant to prevent sticking between tube and tire. A soft mineral; a basic magnesium silicate usually occurring in foliated, granular, or fibrous masses, used in the manufacture of electrical insulators

talking warning system: Using the car radio speakers, this microprocessor-based system tells the driver the source of the problem in a clear, pleasant (female) voice. If the radio is on at the time of the alert, the computer automatically turns down the volume so the warning can be heard

tampering: See glass tampering detector

tampering detector: See glass tampering detector

tamperproof carburetor: A carburetor with factory-adjusted idle speed, sealed idle speed adjustment screw, and provisions to ensure that exhaust emission levels remain within specified limits over an extended period of time

tandem: [1] A bicycle that provides seats, bars, and pedals for two or more riders, one behind the other.

[2] A tractor-trailer truck.

tandem axle: See tandem axles.

tandem axles: A combination of two axles having a common suspension.

tandem drive: Two powered axles in combination.

tandem master cylinder: A master cylinder with two pistons; when the brake pedal is pressed, the pushrod activates the primary piston which in turn moves the secondary piston; necessary for dual-circuit braking systems

tang: A device mounted on a rotating shaft or component that engages in a recess of a component to be driven

tangential-flow scavenging: See loop scavenging

tank: A container into which any liquid or gas can be held. Also it may even be empty such as a vacuum tank. See acetylene tank air tank anodizing tank ballast tank bottom tank cylinder deep tank electropaint tank expansion tank fuel tank fuel tank sender gas tank

header tank radiator tank saddle tank slop tank, and vacuum tank tank bag: A bag that sits on the gas tank of the motorcycle, secured by a magnet or by straps. Tank bags are good for holding lightweight items such as gloves, maps, and wallets

tank-barge: A river barge for the carrying of liquid bulk cargo

tank bib: A leather or vinyl covering over the gas tank of a motorcycle to protect the finish from scratches

tank chap: A leather or vinyl covering over the sides of a gas tank of a motorcycle to protect the finish from scratches

tanker: [1] A truck designed to carry liquid in bulk. [2] A ship designed for transporting liquid cargo, usually petroleum products. See oil tanker petrol tanker tanker truck: A truck designed to carry liquid in bulk. British term is petrol tanker

tank sender: See fuel tank sender tanktop : A covering usually of wood, placed over the tank top for its protection

tap: [1] To cut threads in a hole or tube.

[2] The fluted tool used to cut the threads. Also see drain tap

tap and die set: A set of taps and dies for internal and external threading, usually covers a range of the most popular sizes.

tape: See adhesive tape bonnet tape hood tape insulating tape masking tape pvc tape rim tape taper: A gradual narrowing in size of a long round object toward one end. See advanced rim taper base rim taper bead seat taper center rim taper drop center rim taper flat base rim taper intermediate rim taper rim bead seat taper rim taper semi-drop center rim taper worm and taper pin taper-breaking tool: See ball joint separator

taper cutter: A tool used to ream, deburr, align, and enlarge holes, e.g., on car bodies. Also called tapered reamer

tapered compression ring: The upper compression ring which, due to its tapered cross-section, requires a reduced running-in period thus ensuring a tight seal quickly

tapered leaf spring: See parabolic spring

tapered punch: See drift punch

tapered roller bearing: An antifriction bearing using a series of tapered, cone-shaped hardened steel rollers operating between an outer and inner hardened steel race. It can accept axial thrust as well as providing shaft location

taper leaf spring: See parabolic spring

taper pin: See worm and taper pin

taper seat: [1] A conical seat that provides positive centering of a wheel bolt head in the wheel. The opposite of radius seat. [2] A seal without a gasket achieved by mating the conical surface of the spark plug shell and the cylinder head

tape weight: See adhesive weight.

tap holder: A tool used to hold and drive taps, reamers, and screw extractors with two long handles to provide high leverage for turning operation

tappet: [1] The screw used to adjust the clearance between the valve stem and the lifter or the rocker arm. [2] The valve lifter itself. See barrel tappet

bucket tappet cam follower flat tappet hydraulic tappet mushroom tappet roller tappet simple tappet valve tappet tappet adjusting screw: See valve adjusting screw

tappet gasket: See rocker cover gasket

tappet noise: Noise caused by the lash or clearance between the valve stem and rocker arm or between the valve stem and valve lifter.

tappet wrench: A wrench designed for adjusting valve clearances on OHV-engines with bucket tappet assembly that use an adjusting screw instead of valve shims for adjustment

tapping: See hinge tapping plate

tapping plate: See hinge tapping plate

tap ratchet: A tool with ratchet mechanism used to hold and operate bits such as taps, drills, reamers, or screw extractors

tap spanner: See tap holder

tap wrench:

See tap holder

tar: A black, sticky substance made from petroleum. It is useful for patching cracks in the road. However, when driving over it, the wheels kick up particles of it on a vehicle's painted surface. See bug and tar remover.

tare weight: The weight of a truck, exclusive of its contents, but including gas, oil, etc., ready to roil. Also called "curb weight."

targa: A removable-roof body style popularized by Porsche that is similar to a convertible except that it incorporates a fixed, roll-bar-like structure running from side to side behind the front seats.

targa bar: A type of roll bar made of a relatively wide band of sheet steel rather than of tubing; made popular by the Porsche 911 Targa

targa top: A rigid, removable roof section between the windshield and targa bar

tariff: A duty or tax imposed on imports. See Generalized Preferential Tariff agreement on Tariffs general Agreement on Tariffs and Trade

Tariffs and Trade: See agreement on Tariffs and Trade general Agreement on Tariffs and Trade

tarnish: To discolor due to the formation of a thin film of oxide, sulphide, or some other corrosion product

tar remover: See bug and tar remover.

Tatra: A vehicle brand of which the 1925-1948 models with required application are classic cars.

Taurus: A model of automobile manufactured by Ford

Click for books on Ford Taurus

tax: See car tax displacement taxes road tax vehicle tax tax disc: A road fund licence disc displayed on the windshield to show that a British road tax has been paid

taxi: A car in which passengers are carried for hire which is usually recorded by a meter

taxicab: A car in which passengers are carried for hire which is usually recorded by a meter

taxi rank: A British term for a taxi stand

taxi stand: A place where taxis wait to be hired

tb: Abbreviation for towbar

T-bar: A rod which is inserted into the holes of a box spanner. The British term is tommy bar. Also see sliding T-bar

T bar roof: A roof with a T-shaped bar connecting the windshield and the rear section of the roof

TBI: Acronym for throttle body injection

t Bone: [1] Model-T Ford car. [2] To hit another vehicle against its side.

t-Bone: Model-T Ford car.

t-boned: Hitting another vehicle on its side.

TC: Acronym for torque converter and twin carburetors

TCI: Acronym for transistorized coil ignition

TCI-H: Acronym for transistorized coil ignition with hall sensor

TCM: Acronym for transmission control module

t-connector: Any connector in the shape of the letter "T" -- often referring to a hollow unit. For example, the line coming from the windshield washer pump is connected to the bottom part of a "T" and the crossbar at the top sends the fluid to the two nozzles (one on each side of the windshield). It differs from a Y-connector in that the crossbar is straight across while the Y-connector has a V-shape crossbar.

TCS: Acronym for transmission controlled spark

TC spark plug: Acronym for thermocouple spark plug

T-cut: A proprietary rubbing compound used to give a finish to dull paintwork

TDC: Acronym for "top dead center."

TDI: Acronym for turbo diesel engine with direct injection

TD rim: A wheel rim which incorporates two grooves running around the circumference of the bead seats; the tires have special extended bead toes which fit into these grooves

TD wheel: A safety wheel incorporating a td rim with run-flat properties, which in case of a puncture allow further driving of up to 20 miles at a maximum speed of 40 mph. In the event of deflation, the reinforced bead toes are held firmly in place by the grooves, thereby preventing the tire from sliding into the rim well. The width and diameter of both tire and rim are given in millimeters, to prevent the fitting of a normal tire to a TD rim or conversely of a TD tire to a conventional wheel. Rim marking 150 TD 365 stands for a rim measuring 150 mm in width and 365 mm in diameter and having a TD contour

tear:

See wear and tear

tear it down: See pull it down.

tear seam: See inflation control seam

TEC: Acronym for thermactor exhaust control system

technique: See ionic-current measuring technique lost-core technique technology: See hybrid technology low zinc technology multiplex technology normal zinc technology teeth: See helical teeth

teflon: A plastic with excellent self-lubricating (slippery) bearing properties. Also see polytetrafluoroethylene

TEL: Acronym for tetraethyl lead

tele: Abbreviation for "telescoping steering wheel."

telephone:

See cellular telephone

telescopic forks: Front motorcycle suspension system with two fork legs, each with sliding and fixed tubular members that telescope together to allow suspension movement

telescopic shock absorber: A tubular spring damper operated by rod and piston; the most common type of shock absorber

telescopic steering column: A steering column that collapses in on itself on impact

telescoping steering wheel: (tele) A steering column which can be shortened or lengthened to provide the most comfortable driving position.

tempa spare: A spare wheel type with considerably reduced overall dimensions (rim width: 3.54.0 in), designed to operate at a higher inflation pressure than the standard tire and wheel unit

tempa spare wheel: A spare wheel type with considerably reduced overall dimensions (rim width: 3.54.0 in), designed to operate at a higher inflation pressure than the standard tire and wheel unit

temper: [1] To effect a change in the physical structure of a piece of steel through the use of heat and cold. [2] A thermal treatment of finished products (metals, alloys, plastics) to remove internal stresses

temperature: See air charge temperature ambient temperature baking temperature

charge temperature engine temperature sensor ignition temperature light-off temperature low temperature phosphating low temperature activity low temperature fouling oil temperature gauge outdoor temperature gauge particulate ignition temperature reference temperature room temperature vulcanizing sealer test current for low temperatures vicat softening temperature temperature activity: See low temperature activity

temperature compensator: In some SU carburetors, a wax-type‘bermostat contained in a housing at the base of the jet head; with increasing temperature, the wax expands and pushes the jet upwards, thereby reducing the effective area of the jet and restoring the correct fuel flow. As underhood temperature increases, fuel viscosity is reduced, resulting in increased fuel flow through the carburetor jet and an air/fuel mixture which is too rich; as this causes excessive emissions, particularly during idling, some SU carburetors feature a capstat temperature compensated jet

temperature control: See automatic temperature control.

temperature control element: A temperature-controlled valve spring bias regulator in an oil filter bypass valve which controls the bypass valve as a function of oil temperature

temperature gage: See temperature gauge.

temperature fouling: See low temperature fouling

temperature gauge: An instrument for measure the temperature of the coolant in engine block. See oil temperature gauge outdoor temperature gauge outside temperature gauge water temperature gauge temperature-measuring spark plug: See thermocouple spark plug

temperature of deflection under load: The ability of a test specimen to preserve its shape up to a given temperature under a given dead load; characterized by the temperature at which the specimen supported at both ends and heated continually and uniformly in a liquid heattransfer medium is deformed by a given amount when the load is applied midway between the supports

temperature phosphating: See low temperature phosphating

temperature sensor: See coolant temperature sensor engine temperature sensor temperature switch: See ambient temperature switch

temperature vacuum switch: (TVS) controls vacuum to the EGR valve and/or canister purge valve based on coolant or intake air temperature. Canister purge and EGR do not typically operate when the engine is cold

temperature valve: See thermovalve

temperature vulcanizing:

See room temperature vulcanizing sealer

temperature vulcanizing sealer: See room temperature vulcanizing sealer

tempered glass: See laminated windshield.

temper rolling: Rolling for the purpose of removing spangles on hot-dip galvanized steel sheet

template: A pre-cut pattern, usually metal, used to determine the contour of a buffed tire. See buffing template shape template Tempo: A model of automobile manufactured by Ford

Click for books on Ford Tempo

temporary spare wheel: See space-saving spare wheel

ten: See procon-ten v-ten tender: A tender ship is one which have a long period of roll but may list excessively in a strong wind and may be dangerous if a hold is flooded following a collision

tensile force: The stretching force that acts on the windshield header to keep the convertible top tight

tensile strength:

[1] Regarding a tire, it is a measurement of the greatest longitudinal stress a tire cord can bear without breaking. [2] Maximum pull stress in psi a specimen is capable of developing.

tension: [1] A pulling or stretching stress applied to an object. [2] Voltage. See high-tension high tension lead low tension lead low tension tensioner: A device designed to maintain the tension of a belt or chain. See belt tensioner chain tensioner seat belt tensioner timing belt tensioner tensioning spring: A spring designed to maintain tension in a drum brake

tension lead: See high tension lead low tension lead Tercel: A model of automobile manufactured by Toyota Click for books on Toyota Tercel term: See lease term

terminal: [1] A connecting point in an electric circuit. [2] When referring to the battery, it would indicate the two battery posts. See

battery terminal center terminal field terminal Ford-type terminal negative terminal outer terminal positive terminal primary terminal terminal block: A plastic or resin assembly containing two rows of terminals screws. Used to join the circuits in several wiring harnesses

terminal post: See battery post

terminal reamer: A tapered reamer-type tool used to remove corrosion from the inside of battery cable clamps

terminal tower: The terminals at the top of the distributor cap into which the spark plug wires fit. Also called "distributor tower"

terminal voltage: The sum of the individual battery cell voltages

termination: See early termination

term interest rate: See buy at end-of term interest rate

terrain: See all terrain

terrain bike:

See all terrain bike

terrain tire: See all terrain tire

terrain vehicle: See all terrain vehicle

test: See acceptance test bench test bend test board test brake test breathalyzer test breath test car test charpy test crash test ece test cycle endurance test engine sequence test fatigue test federal Test Procedure free bend test ftp test cycle guided send test helium leak test hydrostatic test impact resistance test izod test load test mot test needle-flame test oblique crash test pendulum impact test road test roll test stall test Testarosa:

A model of automobile manufactured by Ferrari

Click for books on Ferrari Testarosa

test bar: A test specimen with the shape of a bar as used in the impact resistance test

test-bed: An area equipped with instruments, used for testing machinery, engines, etc., under working conditions

test current for low temperatures: The specification for assessing battery starting behavior at low temperatures and under given conditions; indicated in amps on the battery case

test cycle: See ece test cycle ftp test cycle urban test cycle test drive: A trial drive of a car after it has been repaired, or of a new car to decide if one likes it enough to buy it

test-drive: to take a car for a test drive before purchasing it

test dummy: See crash test dummy

test equipment: See automatic test equipment

tester: See battery tester circuit tester compression tester cylinder head tester engine performance tester

leak down tester spark gap coil tester spark plug tester voltage tester test head: The head or height of a column of water which will give a prescribed pressure on the vertical or horizontal sides of a compartment or tank in order to test its tightness, or strength

testing: See diagnostic testing field testing non-destructive testing product testing salt fog testing test lamp: An automotive tool used to test powered circuits on 6-24 volt systems such as headlights, horns, signal, or tail lights. It consists of a handle with a bulb and sharp probe and a lead with a crocodile clip, The sharp probe is used to pierce the insulation on the wire leading to the defective part; if the bulb glows, the circuit is complete. Simpler designs do not feature a probe, but come in a standard screwdriver shape

test light: An automotive tool used to test powered circuits on 6-24 volt systems such as headlights, horns, signal, or tail lights. It consists of a handle with a bulb and sharp probe and a lead with a crocodile clip, The sharp probe is used to pierce the insulation on the wire leading to the defective part; if the bulb glows, the circuit is complete. Simpler designs do not feature a probe, but come in a standard screwdriver shape

test method: See vicat test method

test pilot: A person who responds to advertisements, takes the vehicle for a ride, but really has no intention of purchasing the vehicle. He is related to a "tire kicker." The difference is that a tire kicker wastes the seller's time examining the vehicle while a

test pilot wants to experience the ride.

test port: The Schrader valve fitting located on the fuel rail of a port injection system used for relieving fuel pressure and for hooking up a fuel pressure gauge

Test Procedure: See federal Test Procedure

tether kill switch: A safety device used on snowmobiles and personal watercraft. One end is attached to the operator's wrist and the other end is plugged into a special switch. When the operator falls off his vehicle, the tether pulls out of the switch causing the engine to die.

tetrachloride: See carbon tetrachloride.

tetraethyl lead: (TEL) a lead compound used as an additive to increase the octane rating and reduce the knock or detonation tendencies of gasoline. Also see lead free.

tetramethyl lead: (TML) An anti-knock fuel additive

T.E.U.: Twenty Foot Equivalent Unit for containers. See containers

TFI: Acronym for thick film integrated

t Ford: Model-T Ford car.

t-Ford:

Model-T Ford car.

TFT: Acronym for "Thin Film Technology."

t/glass: See tinted glass

T-handle shifter: A shift lever (usually found on automatic transmissions) mounted on the console and shaped like the letter "T"

t-handle socket: A tool in which a socket has been welded to a long rod (about 8 to 10 inches). At the other end of the rod, a crossbar has been welded. Thus it is formed in the shape of the letter "T". In some instances it speeds up the removal and installation of bolts.

THC: Acronym for total hydrocarbons

T head: See T-head engine engine type. T-head: [1] A type of cylinder head in a side valve engine where the valves are either adjacent and parallel or installed on opposite sides of the piston in a configuration resembling a "T". [2] A type of screw or bolt head shaped like a "T". See T-head engine engine type and crossflow head T head engine: See T-head engine.

T-head engine: An engine in which the arrangement of the valves on either side of the combustion chamber creates a "T" configuration. Usually the intake valves are on one side and the exhaust on the other. The modern crossflow cylinder heads are variations on this old concept. But the original design is not in current use.

theft: See car theft

theft protection: See anti-theft security system

theft system: See anti-theft system

Thermac: GM's thermostatically controlled air cleaner system

thermactor: An air injector type of exhaust emission control system used on Ford vehicles. See thermal reactor

thermactor II: Also called Ford's Pulse air system

thermactor air bypass solenoid: (TAB) an electrical solenoid that switch engine manifold vacuum to bypass the atmosphere

thermactor air control valve: Combines a bypass (dump) valve with a diverter (up/down stream) valve; controls the flow of the thermactor air in respond to vacuum signals to its diaphragms

thermactor air control solenoid vacuum valve assembly: Used on thermactor air control systems; consists of two normally open solenoid valves with vents

thermactor air diverter solenoid: (TAD) and electrical solenoid that switches engine manifold vacuum; when energized, switches Thermactor air from downstream (past the oxygen sensor) to upstream (before the oxygen sensor)

thermactor exhaust control system: (TEC) an air injector type of exhaust emission control system used by Ford

thermal: See British Thermal Unit thermal efficiency and thermal reactor thermal conduction: Heat transfer within a substance or to another substance by direct contact

thermal convection: Heat transfer by the combined mechanisms of fluid mixing and thermal conduction

thermal deterioration: Loss of strength of carcass cords due to heat generated in a tire.

thermal efficiency: The percentage of the heat developed in the burning fuel charge that is actually used to develop power determines thermal efficiency. When fuel is combusted in an engine not all the fuel is converted into power. Some is lost in overcoming friction and some escapes down the tail pipe in the hot exhaust gases so this percentage is always less than 100%. Efficiency will vary according to engine design, use, etc. If an engine uses a great deal of the heat to produce power, its thermal efficiency would be high. Also see adiabatic engine.

thermal equilibrium: The point at which the rate of cooling becomes equal to the rate of heat generation in a tire. Also called "heat balance."

thermal head:

The initial temperature of exhaust gas upstream of a catalytic converter

thermal ignition control: (TIC) device used by Chrysler that shifts the vacuum advance vacuum source from ported vacuum to manifold vacuum when coolant temperature exceeds 225° F

thermal inertia: The reciprocal of thermal response

thermal limiter: Fuse-like device that protects the low refrigerant protection system circuit on GM vehicles. Stops compressor operation when low pressure is sensed

thermal radiation: Heat transfer from one substance to another by means of electromagnetic waves

thermal reactor: (TR) [1] A high-volume thermally isolated chamber replacing the exhaust manifold and providing a place for high-temperature afterburning of exhaust pollutants. Found on all Mazda rotary engines and some piston engines (BMW for example) as well. [2] A device installed in the exhaust manifold of some air injection systems to promote HC and CO oxidation by providing long exhaust gas residence times in a localized area. [3] an emission control device that accepts raw exhaust gases from the engine and subjects them to extremely hi temperature to oxidize noxious emissions. Uses a specially designed exhaust manifold that uses heat and air to burn the unburned hydrocarbons in the exhaust gases to reduce pollution

thermal relay: A relay actuated by the heating effect of the current flowing through it

thermal response: The rate of temperature rise in a reactor if no heat is withdrawn by cooling. Its reciprocal is thermal inertia

thermal switch:

A bimetal switch that controls glow plug operation

thermal time valve: A valve which senses temperature, typically the temperature under the hood, and gives full vacuum advance when the temperature is below 10° above this temperature, the thermal time valve allows the distributor vacuum to be controlled by the thermal vacuum switch; includes a delay of typically 20 seconds to allow full spark advance for better hot starting

thermal unit: See british thermal unit

thermal vacuum switch: (TVS) [1] measures either air/fuel temperature, underhood temperature, or coolant temperature, or a combination of any two to regulate the EGR valve accordingly. [2] A temperature sensitive switch that shifts the source of the advance from ported to manifold vacuum when coolant temperature reaches approx 225 deg F

thermal vacuum valve: (TVV) A valve with the same function as a thermal vacuum switch. TVS units, which serve to interrupt exhaust gas recirculation when the temperature is too low, are located in the vacuum line between the ECR valve and inlet manifold or carburetor

thermal vent valve: (TVV) a temp-sensitive valve assembly located in the canister vent line. The TVV closes when the engine is cold and opens when it is hot to prevent fuel tank vapors from being vented through the carburetor fuel bowl when the fuel tank heats up before the engine compartment

thermistor: Resistor that changes its resistance inversely with temperature

thermocouple: An electrical temperature sensor. As opposed to a resistance thermometer, the thermocouple operates without an external voltage; it consists basically of two conductors of dissimilar metals, typically copper/constantan, iron/ constantan, nickel-chromium/nickel, which are connected at their ends; one joint, the hot junction, is exposed to the temperature to be measured, the other joint, the cold or

reference junction, is held at a fixed, known temperature; a thermoelectrical voltage is developed between the two junctions which is proportional to the temperature difference between the junctions

thermocouple spark plug: A spark plug with a thermocouple in the center electrode, used to measure the temperatures in the individual cylinders as a function of engine speed and load in order to select the correct heat range

thermoforming: The shaping of a polymer sheet while heating

thermometer: See resistance thermometer

thermoplastic: A plastic material with long chain-like molecules that can repeatedly be softened by heating and hardened by cooling; most plastic parts used on vehicles are made of thermoplastics

thermoplastic elastomers: Materials which are rubbery at room temperature but which on heating melt to viscous liquids that can be molded and otherwise processed; the change is reversible; on cooling, the melted material reverts to a solid material having rubbery properties

thermosetting: A polymer which sets at the same time as it is being molded

thermostat: A temperature sensitive device used in the cooling system of an engine to control the flow of coolant between the cylinder block radiator. It is set into the engine block and shuts off the circulation of water until the temperature of the water reaches the point at which the thermostat is set to open. Because automotive internal combustion engines operate more efficiently when their temperature is maintained within narrow limits, the thermostat closes off the flow of coolant from the engine to the radiator until the engine has reached the desired operating temperature. Other thermostats are used in the electrical circuit of the vehicle heating system to control the amount of heat supplied to the passengers, in the manifold heat control system

that preheats the air-fuel mixture going to the cylinders and in the automatic choke. See aneroid-type thermostat wax-type thermostat thermostatic air cleaner: (TAC) An air cleaner which also controls the temperature of the air entering the engine. A temperature control is necessary to optimize the air/fuel ratio with regard to minimum exhaust emissions; typically, the TAC regulates air intake temperature at about 27-46°C by means of a control damper that mixes pre-heated air from an inlet at the exhaust manifold with air from a cold air inlet; designs for actuating the damper range from simple thermostatic action to vacuum-motor and stepper-motor control

thermostatic coil choke: A sensing device mounted on the carburetor that automatically controls the choke butterfly valve by sensing the heat of the exhaust manifold. Also see choke.

thermostatic expansion valve: Metering device that removes pressure from liquid refrigerant, permitting it to expand and vaporize in evaporator

thermostatic interruptor: A bimetallic circuit breaker in a lighting circuits which switches to an alternative circuit in the event of a fault or short circuit

thermostatic spring choke: A sensing device that automatically controls the choke butterfly valve by sensing the heat of the exhaust manifold. Also see choke.

thermostatic vacuum switch: A temperature sensitive switch which allows spark advance when engine idles for long periods

thermo-switch: See oxygen sensor system thermo-switch

thermo-syphon:

A method of cooling an engine using difference in specific gravity and cold water. No pump is used, but the coolant passages are larger than in a pump-type system

thermosyphon cooling: A natural cooling, using the fact that two columns of liquid at different temperatures possess natural circulation because the hotter column weighs less on account of its lower density; thus the hot engine must be located at a lower level than the cool radiator

thermo-time switch: A switch in a continuous injection system that interrupts current from the starter solenoid to the coldstart valve solenoid when the engine is hot or after the starter has been operated for more than a few seconds, in order to prevent flooding

thermovalve: A valve which opens and closes as a function of temperature

thermowell: [1] A space which accommodates a temperature sensor. [2] The temperature sensing point or sensor rather than to the well itself

thick film integrated: (TFI) Ford electronic ignition system

thickness: See layer thickness

thief: See car thief

thin: To add thinners to paint in order to adjust the viscosity

thin needle-nose pliers: A needle-nose pliers with an extra long reach jaws without a wire cutter

thinner:

The solvent used to thin lacquers and acrylic products to the proper consistency for application and differs from a reducer which are used for synthetic enamel products. Thinners and reducers are not normally interchangeable, i.e., the corresponding type of thinner/reducer must be used for each type of paint; however, some generalpurpose thinners are available. Also see general purpose lacquer thinner

thinning out: The tendency of liquid paint to form much thicker coatings near the edge of a steel sheet, thereby causing the paint film thickness on the side opposite this edge to decrease

thin-wall casting: A weight-saving measure on oil filter housings

third: An intermediate gear used for increasing speed, climbing hills and sometimes for passing; but on a three speed transmission, it is the top gear.

third brush: A generator in which a third, movable brush is used to control current output.

third gear: An intermediate gear used for increasing speed, climbing hills and sometimes for passing; but on a three speed transmission, it is the top gear.

third hand: A tool used on bicycles to squeeze the brakes together against the rim so that adjustments can be made to the cable.

third motion shaft: See gearbox output shaft

third port induction: A design feature of a two-stroke engine that relies on the piston position to control induction of the fresh charge. A feature of this design is the use of the third port, i.e., the transfer port, to complement the intake and exhaust ports, e.g., as opposed to two-stroke diesels that have valve-controlled intakes and do not need transfer ports

third scavenging port: An additional transfer port located opposite the exhaust port of a two-stroke engine cylinder and connecting through the piston skirt to the region above the gudgeon pin and below the piston crown

thixotropic: Having the property of certain resins and paints that prevents them from running off vertical surfaces

Thompson rotovalve: A type of valve which rotates as it opens and closes.

thou: An abbreviation for "thousandth" or one divided by a thousand; a small measurement representing 1/1000th of an inch as in Ten thou (0.01) is equal to 0.25 mm."

thrash: A colloquial term for pushing an engine to its limits

thread: [1] The spiral grooves on a screw, bolt, or nut. See left-hand thread right-hand thread . [2] helical groove in a cylindrical hole, nut, etc., formed a tap or lathe tool (female or internal thread). See B thread buttressed thread class A thread class B thread coarse thread cut thread depth of thread external thread female thread

incomplete thread internal thread left-hand thread left hand thread male thread mating thread metric thread national coarse thread national fine thread nominal thread diameter nut thread right-hand thread right hand thread rolled thread unc thread unf thread V-thread thread angle: The angle between the adjacent flanks of a thread

thread crest: The highest point of a screw thread, opposite the root

thread-cutting screw: A British term for a self-tapping screw. A self-drilling fastener that drills its own hole, taps a mating thread, and then fastens, all in a single operation

thread diameter: The diameter measured from the crest of a thread to the corresponding crest on the opposite side of the bolt or screw. Also see nominal thread diameter

threaded: See cross-threaded

threaded insert: A threaded coil that's used to restore an original thread size hole that has damaged threads; the hole is drilled oversize and tapped, and the insert is threaded into the tapped hole

threaded rod: A shaft (usually fairly long) with threads from one end to the other. It is usually cut to the length required.

thread file: A tool for restoring internal or external threads by filing

thread gauge: See screw pitch gauge

thread height: The distance from root to thread crest, measured perpendicular to the axis of the thread

thread insert: A screw-thread system that allows the use of high-strength cap screws and studs in light soft metals, such as aluminum and magnesium, through the use of a phosphor bronze or stainless steel coil which is screwed into a threaded hole; the thread insert can also be used to repair damaged threads

thread pitch: See pitch

thread pitch gauge: See screw pitch gauge

thread root: The lowest point of a screw thread, where the thread joins the body. It is opposite of crest

three: See big three cross three three-chamber system: A test installation consisting of a salt spray chamber, a cold chamber, and a climatic chamber

three-door: A subcompact hatchback with two side doors and one liftgate

three-door hatchback coupe: Originally a small opening in the deck of a sailing ship, the term "hatch" was later applied to airplane doors and to passenger cars with rear liftgates. Various models appeared in the early 1950s, but weather-tightness was a problem. The concept emerged again in the early 1970s, when fuel economy factors began to signal the trend toward compact cars. Technology had remedied the sealing difficulties. By the 1980s, most manufacturers produced one or more hatchback models, though the question of whether to call them "two-door" or "three-door" never was resolved. Their main common feature was the lack of a separate trunk. "Liftback" coupes may have had a different rear-end shape, but the two terms often described essentially the same vehicle. === car-2hatch.jpg

three-link suspension: A variation on the four-link suspension. An upper link is typically removed. This arrangement was used on lower powered cars to reduce cost.

three-piece alloy wheel: A type of forged alloy wheel with a wheel spider or wheel disc and a divided rim consisting of an outer and an inner rim well; the rim is bolted to the spider or the disc

three-point seat belt: A combined lap-shoulder belt fastened at three points, usually with an automatic retractor

three-port engine: The traditional two-stroke engine design incorporating the intake port connecting the crankcase to the atmosphere, the transfer port connecting the crankcase to the combustion chamber, and the exhaust port to evacuate the spent gas from the combustion chamber. The term is used even if the three-port types are used in pairs

three-quarter cam: A type of camshaft for race car engines which increases lift of valve, speed of valve opening and closing, length of time valve is held open, etc. Also called full cam race cam or semi-race cam depending upon design

three-quarter floating axle: A rear axle assembly in which the weight of the vehicle is borne by the outer bearings of the axle shafts, mounted between the hubs and axle housing

three-quarter race camshaft: A description of the custom camshaft indicating the type of lobe grinding which, in turn, dictates the type of use. Other grinds are one-quarter race, full-race, streetgrind, etc.

3-spd: Abbreviation for "three-speed," either manual transmission or automatic transmission.

three speed: A transmission which has three forward gears.

three-speed: A transmission which has three forward gears.

three-speed transmission: A transmission which has three forward gears.

three-valve engine: An engine with two intake valves and one exhaust valve per cylinder. A fourcylinder three-valve engine is also called a "12-valve engine"

three-way catalyst: (TWC) A catalyst for the simultaneous conversion of the three exhaust pollutants HC, CO, and NOx three way catalytic converter: See three-way catalytic converter.

three-way catalytic converter: A pollution control device which reduces all three noxious substances: HC, CO, and NOx.

3-way catalytic converter: See single-bed 3-way catalytic converter

three-wheeler: [1] A light car with three wheels; formerly made popular by some British vehicles like the Morgan, the BSA, the Coventry Victor, and the Reliant Robin. [2] A modified motorcycle which has one wheel in the front for steering and two at the back driven by a Volkswagen engine.

throat: See actual throat carburetor throat and venturi throat depth: An indicator of the reach of welding clamps such as C-clamps

throat of a fillet weld: Distance from the weld root to the weld face.

throaty: A rough-sounding exhaust noise which is pleasant to some and irritating to others.

throttle: The device that controls the vacuum created in the venturi of the carburetor. The greater the vacuum, the richer the fuel-air mixture. The throttle enables the engine to run on a richer mixture and produce more power for high-speed driving. It consists of a throttle arm located on the outside of the carburetor and connected to the gas pedal (or throttle twist grip on a motorcycle), which in turn activates a throttle butterfly valve at the base of the carburetor barrel where it joins the intake manifold. See cranking On The Throttle depress the throttle pedal ease up on the throttle engaging the throttle full throttle enrichment

full throttle pumping the throttle pedal pump the throttle pedal wide open throttle throttle arm: The lever that actuates the throttle.

throttle body: A housing containing a valve to regulate the airflow through the intake manifold. The throttle-body is usually located between the air cleaner and the intake plenum.

throttle body fuel injection: A form of fuel injection in which the injectors are located at the engine's throttle body thereby feeding fuel to more than one cylinder. Such an arrangement saves money by using fewer injectors; but because it routes both fuel and air through the intake manifold it eliminates some of the tuning possibilities offered by port fuel injection. Also called single point injection

throttle body injection: See throttle body fuel injection

throttle butterfly: A valve in the throat of the carburetor which regulates the amount of the flow of gasoline. See throttle valve.

throttle enrichment: See full throttle enrichment

throttle gauge: A tool with straight calibrated measuring pins for determining throttle and choke valve gaps

throttle pedal: The gas pedal which operates the throttle butterfly through a series of linkages. See depress the throttle pedal ease up on the throttle pedal

pumping the throttle pedal pump the throttle pedal step on the throttle pedal take foot off the throttle pedal throttle position sensor: (TPS) A potentiometric fuel injection switch with two contacts for the two end positions of the throttle valve, which sends a signal to the electronic control unit when the throttle valve is closed (idle) or wide open (full load). The sensor wiper position is proportional to throttle position. The computer uses this information to control fuel flow

throttle return spring: A spring which forces the throttle valve closed when pressure is taken off the accelerator pedal

throttle shaft: A shaft on which the throttle valve disc pivots in a carburetor barrel or inlet tract

throttle solenoid: A solenoid which operates mechanically on the throttle lever; when energized, the solenoid stem extends and opens the throttle to establish the preset idle speed. Since the early 1970s, most manufacturers have used a throttle solenoid to prevent "runon" or dieseling

throttle spindle: A shaft on which the throttle valve disc pivots in a carburetor barrel or inlet tract

throttle stop solenoid: A device that maintains engine at speed over curb idle

throttle valve: [1] A valve in the carburetor. It is used to control the amount of air-fuel mixture that reaches the cylinders. Usually consists of a flat round disc mounted on a shaft so that it can be tilted at various angles in the carburetor throttle valve body. It is connected by suitable linkage to the accelerator pedal. [2] A modulator valve in an automatic transmission which is actuated either by the accelerator pedal, by the vacuum in the engine intake manifold, or by the carburetor throttle; it converts line pressure into an engine-load dependent pressure, which is directed to various valves

throttle valve switch: See throttle position sensor

throttling: Reducing the power output of an engine by closing the throttle, thus restricting airflow through the carburetor or intake tract. See poa suction throttling valve sonic throttling throttling valve: See POA suction throttling valve suction throttling valve through: See flow through ventilation

through bolt: [1] Any bolt which is inserted through the parts of an assembly and secured on the other side by a nut. [2] One of the two long bolts that holds the starter or alternator assembly together

through ventilation: See flow through ventilation

throw: [1] The offset portion of the crankshaft designed to accept the connecting rod. Also see crankpin. [2] The distance from the center of the crankshaft main bearing to the center of the connecting rod journal. The piston stroke is twice the throw distance. Also see crank throw

throwing: Elongating certain sections of a panel by hammering. Opposite to tucking. When making a section rounded along the inner and outer edges that is to be folded along the outer edge, the length of the outer edge must be increased. This is achieved by regular hammering, which causes the edge of the panel to stretch, reducing its

thickness by spreading the metal

throwing a rod: The action of breaking a connecting rod. Often the rod will force its way out of the side of the engine resulting in major damage which is expensive to repair. In most cases the rod breaks because of the lack of enough oil to cool the rod.

throwout: See throwout bearing clutch throwout fork. throw-out: See throwout bearing clutch throwout fork. throw-out bearing: See throwout bearing.

throwout bearing: A part of the clutch activated by the clutch pedal that allows the clutch to disengage. If you allow the vehicle to idle in gear with the clutch pedal depressed, instead of shifting to neutral gear, you can wear out the throwout bearing. The British term is "clutch release bearing." See free pedal play clutch throwout bearing throw-out fork: See clutch throwout fork.

throwout fork: See clutch throwout fork.

throwout lever: See clutch throwout fork

thrust: To surge powerfully upward or press outward. See camber thrust piston thrust thrust bearing thrust washer thrust bearing: A bearing with flanges on its two sides that prevents a shaft such as the crankshaft from moving endwise. In the engine crankshaft assembly these flanges are a close fit to the two sides of the crankpin. If the crankshaft tends to shift one way or the other the crankpin sides come up against the flanges preventing excessive endwise movement. See clutch release bearing clutch thrust bearing thrust belt: See steel thrust belt

thrusters: See bow thrusters

thrust plate: See driven plate

thrust washer: [1] A bronze or a hardened steel washer placed between two moving parts. The washer prevents longitudinal movement and provides a bearing surface for the thrust surfaces of the parts. [2] An axially loaded washer, e.g., of a shaft bearing

thumb nut: A nut or screw with projections enabling it to be turned by thumb and forefinger; a wing nut/screw

thumbscrew: A nut or screw with projections enabling it to be turned by thumb and forefinger; a wing nut/screw

thumbwheel: A small wheel for adjusting, which can be turned by using the thumb and forefinger

Thunderbird: A vehicle brand of which the 1955-57 and 1958-60 models are milestone cars.

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thyristor: A silicon-controlled rectifier which converts alternating current to a unidirectional current

thyristor ignition: A capacitor discharge ignition

TI: Acronym for transistorized ignition

TI-B: Acronym for breaker-triggered transistorized ignition

TIC: Acronym for thermal ignition control

ticket: See parking ticket

tickler: A carburetor starting aid. When starting at low temperatures, the float may be pushed below the fuel level in the float chamber by depressing the tickler, so that more fuel is supplied than is required for normal operation

tick over: [1] To run at low speed with the throttle control closed and the transmission disengaged.

[2] To idle

tick-over: The speed of an engine when it is turning over

tie-down: A device for securing a load usually made of straps and hooks.

tie-down system: Equipment which secures someone who uses a wheelchair to the floor of the van or bus. There are many kinds of devices used including brackets, straps, wheel locks, and belts.

tie rod: [1] Any connecting red or bar, usually under tension. [2] A rod, or rods, connecting the steering arms together. It links the pitman arm and the idler arm to the steering knuckle arms. When the tie rod is moved, the wheels pivot.

tie rod arm: See steering arm.

tie rod end: See tie rod ends.

tie rod ends: A type of ball joint which transfers the movements of the steering wheel to the wheels. Grease fittings or ball joints located on the ends of the steering linkage.

tie rod puller: A special automotive tool for forcing out joints on tie rod ends by screw action

tie rod separator: A special automotive tool for forcing out joints on tie rod ends by screw action

tier 1 Supplier:

manufacturer to the vehicle assemblers who are responsible for delivery of the finished assembly, product development and continued technology renewal.

tier 2 Supplier: producer of parts providing value-added to minor sub-assembly.

tier 3 Supplier: supplier of engineered materials and special services, such as rolls of sheet steel, bars and heat treating, surface treatments.

TIG: Term used to describe gas tungsten inert arc welding (tungsten inert gas).

tight: [1] A handling condition in which the car's front end wants to go straight when the wheel is turned. Also called understeer or push. [2] A description of a vehicle indicating its ability to easily negotiate curves at high speed. See finger tight gas-tight TIG welding: An inert arc welding method using a tungsten electrode

TI-H: Acronym for transistorized ignition with hall generator

TI-I: Acronym for transistorized ignition with inductive pick-up

tile setter hammer: A hammer used to secure tile

tilt: Abbreviation for "tilt steering wheel."

tilt column: A steering column that can be adjusted for height

tilt/slide sunroof: A sunroof, made of steel or glass, that slides and tilts and is operated either manually or electrically

tilt steering wheel: (tilt) A steering wheel which moves up or down or which can be set at a different angle. In this way, the driver can find the most comfortable position and also allows easier entry and exit from the vehicle.

time: See active braking time break time cure time curing time elapsed time flash time glow time soaking time straight time time delay relay: A relay which responds to a signal with a certain delay. In some ignition systems, a time delay relay allows for full vacuum advance 20-30 seconds after start-up, after which control is again taken up by the TCS; some cars have an additional time delay relay which delays vacuum advance about 30 seconds after the transmission has been shifted to high gear

timed fuel injection: See sequential fuel injection

timed injection: See sequential fuel injection

timer core:

A magnetic pick-up assembly. See trigger wheel

time valve: See thermal time valve

timing: One of the essential factors in a internal combustion engine (Fuel, Air, Proper proportion of mixture, compression Timing, spark). When the piston is in the compression stroke both valves must be closed. If one or more is open, the valve timing is out. Perhaps a timing belt or timing chain has jumped a tooth. If the spark does not arrive at the correct moment, the engine is out of time. If this ignition timing is only slightly off, the engine may run with less efficiency. See basic ignition setting basic ignition timing basic timing dynamic ignition timing electronic spark timing engine timing exhaust timing high energy ignition system with electronic spark timing ignition timing mechanical ignition timing microprocessor spark timing system reed valve induction timing spark timing static ignition timing static timing stroboscopic ignition timing valve timing variable valve timing timing belt: A toothed belt driven by the crankshaft and operates the camshaft. It causes the valves to open and close at the proper time. When an engine is rebuilt, it is important to line up the crankshaft sprocket camshaft sprocket before applying the belt. When the belt breaks, often a valve will remain open and be hit by the rising piston causing the valve to bend and other internal damage.

timing belt pulley: A spring-loaded jockey pulley or idler pulley designed to take up the slack in the timing belt

timing belt tensioner: A spring-loaded jockey pulley or idler pulley designed to take up the slack in the timing belt

timing chain: A drive chain driven by the crankshaft and operates the camshaft. It causes the valves to open and close at the proper time. When an engine is rebuilt, it is important to line up the crankshaft sprocket camshaft sprocket before applying the chain. When the chain often a valve will remain open and be hit by the rising piston causing the valve to bend and other internal damage. In OHC engines, it is called a camchain chain or cam chain

timing control: See vacuum timing control

timing diagram: A diagrammatic representation of the engine timing, i.e., the times during which the intake and exhaust valves are open and closed

timing gear: Both the gear attached to the camshaft and the gear on the crankshaft. They provide a means of driving the camshaft. This system is used where long life and hard service are expected as in commercial vehicles and race cars. Using gears is generally a noisier method than using a timing chain or a cog belt to drive the camshaft.

timing gears: See timing gear.

timing light: A stroboscopic unit that is connected to the secondary circuit to produce flashes of light in unison with the firing of a specific spark plug. By directing these flashes of light on the whirling timing marks the marks appear to stand still. By adjusting the distributor the timing marks may be properly aligned, thus setting the timing. Xenon timing lights have the advantage over neon lights because they are more visible in daylight.

timing mark:

See timing marks.

timing marks: [1] Marks or notches, usually located on the vibration damper used to synchronize the ignition system so that the plugs will fire at the precise time. [2] One tooth on either the camshaft or crankshaft gear will be marked with an indentation or some other mark. Another mark will be found on the other gear between two of the teeth. The two gears must be meshed so that the marked tooth meshes with the marked spot on the other gear.

timing rotor: A rotating part of the pick-up assembly, in the form of a drum with ferrite rods embedded vertically in the outer edge, used instead of a trigger wheel

timing shaft: See distributor shaft

timing system: See microprocessor spark timing system

timing valve: In Bosch CIS, a device that regulates pressure in the lower chamber of the differential-pressure valve, in response to a signal from the lambda (oxygen) sensor. Also called Lambda valve (Bosch's term) or a frequency valve

timing window: window through which it is possible to see the timing marks

Timken bearing: A type of taper roller bearing

Timken roller bearing: A type of taper roller bearing

tin immersion treatment: A formation of a thin tin deposit before electroplating

Tin Lizzie: An affectionate name for the Model T Ford of which 15,007,033 were built.

tinmen's shears: See snips

tinner's hammer: A hammer used to shape tin plates

tinners snips: See snips

tinning: Coating a piece of metal with a very thin layer of solder. This is a pretreating procedure before the application of body lead. To ensure that the body lead adequately covers and takes to the area to be repaired, a flux and a thin coating of tin or a special solder paint are applied

tin snips: See snips

tint: See graduated tint top tints tinted glass: A glass that has been specially colored to reduce glare from the sun

tinted windows: A glass that has been specially colored to reduce glare from the sun

tints: A colloquial term for glass that has been specially colored to reduce glare from the sun

tint tone:

A shade produced when a small amount of color is mixed with a large amount of white; this is required for formulating the ingredients of a certain paint tone

tip: The end of a spark plug insulator, nearest the electrode. See fork tip insulator tip tipper: See anti-tipper

tire: The rubber part of the wheel which contacts the ground. The construction can be bias-ply bias-belted or radial. The plies are made of rayon, nylon, and polyester. Belting can be fiberglass steel, or kevlar. The rest of the tire is hard rubber. See A-2 tire all terrain tire bald tire balloon tire beaded edge tire bead tire belted bias tire belted tire bias belted tire bias ply tire bias tire car tire clincher tire collapsible spare tire commercial tire continental tire conti tire system conventional spare tire conventional tire cross-ply tire denovo tire directional tire dual bead tire flat tire front wheel tire clearance green tire

grown tire industrial tire knobby tire lateral tire clearance longitudinal tire clearance low-profile tire low pressure tire m+s tire mileage tire mud and snow tire off-road tire overinflated tire pneumatic tire radial tire regrooveable tire rotate tires run-flat tire run-on tire separation solid tire sew-up tire snow tire solid tire space saving tire spare tire special mileage tire steel belted radial tire tubeless tire tubular tire underinflated tire undersize tire whitewall tire winter tire wired-on tire wired on tire x tire tire aging: The deterioration of rubber properties by oxidation over a period of time.

tire balance: Because tires turn at relatively high speeds, they must be carefully weighted so that they do not bounce or vibrate when they rotate. Two basic kinds of balancing are static balance dynamic balance.

tire bead: That portion of the tire that bears against the rim flange. The bead has a number of turns of steel wire in it to provide great strength.

tire bead lock: The tire bead and rim of a TD rim are designed so that an enlarged and reinforced toe on the tire bead engages in a small circumferential groove in the bead seat area of the rim; the bead thus remains locked in position under both inflated and deflated conditions

tire body: See carcass

tire carrier: See spare tire carrier

tire casing: The main body of the tire exclusive of the tread tube, etc.

tire chains: See snow chains

tire clearance: See front wheel tire clearance lateral tire clearance longitudinal tire clearance vertical tire clearance tire contact area: See contact patch

tire contact zone: See contact patch

tire deviation angle: An angle formed by the direction of travel of a vehicle and the steered direction (that which the wheels are pointing). It is produced by distortions within the tire,

due to external forces. Not to be confused by actual slipping or skidding. Also called slip angle.

tire dressing: Paint, black glossy or dull finish, to improve appearance of tire sidewalls.

tire gage: See tire gauge.

tire gauge: An instrument for determining the pressure in a tube or tire.

tier growth: The stretching of textile tire cord materials due to heat and loss of strength, resulting in the casing increasing in size.

tire iron: [1] A tool for removing a tire from the rim of a wheel. See spoon tire lever . [2] A tool for removing the nuts holding a wheel to the hub since one end is flat and the other has a socket. See wheelbrace

tire jack: A device which is used to lift one corner of a vehicle so that a wheel can be removed and replaced in the event of a flat tire. See jack.

tire kicker: A person who is just looking at a vehicle for sale but is not intending to buy.

tire lever: A British term for a tool used to remove and install tires by lever action or to pry off parts. See tire iron.

tire paint:

A black paint, compatible to tire bodies, used to enhance the appearance of a tire after retreading.

tire plies: The layers of nylon, rayon, etc., cloth that are used to form the casing. Most vehicle tires are two ply with a four ply rating. Two ply indicates two layers of cloth or plies.

tire ply: See tire plies.

tire pressure: The manufacturer's recommended pressure for a tire, dependent on load, speed, etc., usually given in bar or pound-force per square inch (psi). (1.8 bar = 26 psi; 2 bar = 29 psi; 2.2 bar = 32 psi; 2.4 bar = 35 psi; 2.7 bar = 39 psi)

tire pressure gauge: An instrument for measuring air pressure in a tire

tire roll-off: A condition in which the bead unseats because a tire was run while flat. Also, the sudden loss of air due to side forces, such as hard cornering, combined with underinflation. The safety ledge on passenger rims (a necessity for tubeless mountings) guards against a roll-off.

tire rotation: Moving the front wheels to the rear and the rear to the front to equalize any wear irregularities in the tires. Also see wheel rotation

tire scuff: Removal of some sidewall rubber as the tire drags along the edge of a curb. Also see tire wear

tire sidewall: That portion of the tire between the tread and the bead.

tire size designation:

A designation specified on the tire sidewall; e.g., P205160 R 15, where: P=Passenger car; 205 = tire width in millimetres; 60 = tire section height to width ratio; R = radial ply; 15 = nominal rim diameter in inches

tire Size Markings: Those designations that appear on the side of a tire to indicate its basic dimensions; width, and rim diameter.

tire slip angle: See slip angle

tire spreader: Any device, manual or hydraulic, used to spread tire beads for inspection, repair, service, etc.

tire squeal: The noise made by the tires when experiencing sudden acceleration or braking or when cornering too fast

tire store: retail outlet selling and installing tires and often offering other vehicle repair services.

tire system: See conti tire system

tire tread: That part of the tire that contacts the road.

tire tread gauge: See tread depth gauge

tire unbalance: A tire that is not weighted properly can cause vibration. The condition is exaggerated by centrifugal force which increases as speed is increased and by the distance the heave spot is from the wheel axis.

tire valve: A small valve, mounted on the wheel rim of a tubeless tire that allows air to be added to the tire with an air hose and allows air to be withdrawn from an overinflated tire by pressing on the little stem at the end of the valve. Some tire valves have little caps to protect against leaks and keep dirt from fouling the valve. On tires with inner tubes the tire valve is mounted on the inner tube. There are two kinds of valves used: Presta Schrader.

tire wear: The amount by which, for example, the tread of a tire is worn down, or the sidewall damaged by impact with the curb

tire width: The width of a tire measured across the carcass

TISC: The Industry Safety Council.

T-joint: Joint formed by placing one metal against another at an angle of 90 degree. The edge of one metal contacts the surface of the other metals.

TML: Acronym for tetramethyl lead

TMPH: Acronym for "Ton Mile Per Hour." A system devised to ascertain the working capacity of earthmover tires; it is a supplement to the normal load and inflation tables.

toe: See bead toe brake shoe toe heel and toe wear heel and toe toe-in toe-out toe-out on turns

toe control link tooth toe toe steer tooth toe. toeboard: The front vertical panel that provides support for the pedals and for the front passenger's feet, usually inclined towards the front and spot-welded to the floorboard at its bottom end and to the bulkhead at its upper end

toe control link: A lateral link in a multilink suspension designed to control a wheel's direction as the suspension moves up and down.

toe dolly: A flat slab of metal thinned down at one end and with a curved surface; useful for getting into awkward and narrow corners

toe in: See toe-in.

toe-in: An adjustment of the front wheels where the distance from the center of the left wheel to the center of the right wheel is less at the front of the wheels than at the back of the wheels. A slight amount of toe-in is usually specified to keep the front wheels running parallel on the road by offsetting other forces that tend to spread the wheels apart. The major force is the backward thrust of the road against the tire tread while the vehicle is moving forward. Other factors include play in the tie-rod assembly and allowance for angular changes caused by wheel bounce or variations in road conditions. Toe-in is measured in fractions of an inch or millimeters

toe-in angle: The angle formed by each front wheel plane and the longitudinal axis of the car, usually expressed as the difference in distance between right and left wheel rims at front and rear, measured at hub level

toe of weld: Junction of the face of the weld and the base metal.

toe out: See toe-out.

toe-out: An adjustment of the wheels where the front of the wheels is further apart than the back. Generally toe-out is not desirable. Toe-out is measured in fractions of an inch or millimeters. See toe-in.

toe out on turns: See toe-out on turns.

toe-out on turns: When the vehicle negotiates a curve, the inner wheel turns more sharply and while the wheels remain in this position, a condition of toe-out exists.

toe steer: The changes in the direction of a wheel that occur without driver steering input. Toe steer can be caused by ride steer or by deflections in suspension components caused by the stresses of cornering, accelerating, and/or braking on smooth and bumpy roads.

toe wear: See heel and toe wear

toggle switch: A switch that is actuated by flipping a small lever either up and down or from side to side.

toilet: See chemical toilet

tolerance: The amount of variation permitted from an exact size or measurement. The actual amount from the smallest acceptable dimension to the largest acceptable dimension. The difference between the permissible maximum size and the permissible minimum size of a measured quantity. Also see lead tolerance

toll:

Money charged for the use of a road or bridge -- especially for entering controlled highways and government parks

toll road: A road (usually a highway) where access requires the payment of a toll or fee. The opposite is a freeway

toll sticker: A label or sticker displayed on the windshield indicating pre-payment of a toll

TomasoPantera: A model of automobile manufactured in Italy

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tommy bar: [1] A rod that fits in a box spanner. [2] A short bar used as a lever to provide torque for tightening a box or socket spanner. Also called a crossbar

ton: See gross ton gross registered tons long ton short ton tone: See mass tone tint tone tongs: See lazy tongs

tongue weight: The amount of trailer weight supported by the hitch. Too much, and the rear of the tow vehicle will be overloaded; too little, and the trailer will wander and weave as it's towed. Tongue weight should be between 10 and 15 percent of the total trailer weight.

ton mile per hour: (TMPH) A system devised to ascertain the working capacity of earthmover tires; it is a supplement to the normal load and inflation tables.

tonnage: A measure of the internal volume of spaces within a vessel in which 100 cu.ft. is 1 ton. See international tonnage certificate net tonnage tonnage certificate: See international tonnage certificate

tonnage deadweight: See deadweight

tonnage gross: Gross tonnage includes a ship's internal volume, excluding such spaces as the peak, double bottom, deep tanks used only for water ballast, bridge, forecastle, openended poop, certain light and air spaces, skylights, anchor and steering gear spaces, toilets, the wheelhouse, and certain passenger spaces

tonnage net: Net tonnage is the gross tonnage less certain additional spaces such as crew and officer spaces, chart room, and a percentage of the propelling machinery spaces; also see deadweight, displacement, light and displacement, loaded

tonnage openings: Nonwatertight openings in the shelter deck and in the 'tween deck bulkheads immediately below in order to exclude spaces from tonnage measurement and thus obtain reduced gross and net tonnage. The openings could be closed by nonwatertight wood shifting boards or metal covers meeting the tonnage and load line regulations

tonneau:

See tonneau cover.

tonneau cover: A cover of leather or other soft pliable material used for protecting the interior of a convertible when the soft top is down. The cover snaps to the dash sides, and rear of the vehicle and often has a zipper allowing the driver to operate the vehicle while the passenger side of the vehicle remains covered.

tool: [1] As a noun, it is any device which assists in the installation or removal of a component. [2] To work material by turning, milling, grinding, polishing, drilling, punching, boring, shaping, shearing, pressing, or planing. [3] As a colloquial verb, it is the action of motion as in We were tooling down the highway when we saw you. See adjusting tool air tool automotive tool brake adjusting tool clutch aligning tool crimping tool drive tool electrode adjusting tool flanging tool flaring tool heated tool welding joint splitting tool magnetic pick-up tool pick-up tool pinstriping tool pushrod measuring tool retainer spring tool silencer-tailpipe tool striping tool taper-breaking tool trim panel release tool valve grinding tool tooling: Set of required standard or special tools needed to produce a particular part. It includes jigs, fixtures, gauges, and cutting tools; but excludes machined tools. Also see tool.

toolkit: See ignition toolkit

tool welding: See heated tool welding

tooth: See gear tooth hunting tooth radiator hose shark tooth pliers

toothed belt: A positive-action reinforced rubber or plastic belt in which parallel teeth engage with grooves in a driving and a driven wheel; commonly used for the valve timing gear as an alternative to a roller chain

toothed signal rotor: The component of an ABS system that rotates with the hub, driveaxle, axle, or ring gear, used along with the wheel speed sensors for generating impulses to the rear by the ABS electronic control unit (ECU). The ECU counts these impulses and determines if a wheel is decelerating too rapidly or not

tooth heel: The wider outside end of the tooth in the differential ring gear.

tooth pliers: See radiator hose shark tooth pliers

tooth toe: The narrower inside end of the tooth in the differential ring gear.

top: [1] a car roof, especially that of a convertible. [2] The highest gear of a transmission.

See canvas top convertible top electric top fabric top folding top hydraulic top piston top soft top sunroof top targa top top cap: When retreading a tire, new tread rubber is added to the buffed casing covering only the crown area. Also see full cap.

top carriers: A cage of chrome bars which attaches to the gutter rails on the roof of a car or van. It is used to secure loads on a vehicle roof, such as bulky containers, skis, or bicycles

top case: A top case sits behind the passenger seat of a motorcycle and may be large enough to hold two full-face helmets. Like the tank bag, a top case is meant to hold lightweight items. Overloading a top case puts more weight on the rear of the motorcycle, thus lightening the front wheel. Traction and steering suffer when the top case is overloaded.

top chop: A modification of the roof of custom cars. The roof pillars are cut off and shortened: when the roof is welded back on, the roof line is far lower than before and the screen and side window height may have been reduced to a minimum. Due to problems of rigidity and finding suitable glass panes, this modification is extremely difficult

top coat: A final paint coat

top coat drier:

An oven for drying or stoving the final paint coat

top coat oven: An oven for drying or stoving the final paint coat

top dead center: (TDC) Highest point of piston and connecting-rod travel in a cylinder; the ends of the compression exhaust strokes in a four-cycle engine. See after top dead center before top dead center top electrode: The ground electrode protruding above the center electrode of a spark plug, either full coverage type or set back slightly from the far edge of the center electrode

top end: [1] The upper range of engine revolutions. [2] The upper part of the engine from the base gasket to the valve cover

top end gasket kit: The gaskets that apply to everything from the base gasket up (e.g., base gasket, head gasket, manifold gaskets, carburetor mounting gaskets) as well as all the O-rings and replaceable spacers. Contrasts with the bottom end gasket kit.

top end speed: The maximum speed which a vehicle can attain. This may differ from the maximum speed allowed by the law and from the recommended maximum speed of a vehicle. In some vehicles, governors are installed to limit the speed so that top end speed is not attained. Others may use warning lights or flashing speedometer readings (i.e., on digital displays) or even warning sounds. See bury the needle red line. top feed gun: See gravity-feed spray gun

top gear:

The highest available gear

top hat section: A structural sheet metal member of U-section, but incorporating flanges for welding or assembling the section to a flat mating panel

top land: See head land

top off: Fill a partially filled container to full capacity.

top-of-the-line model: The most powerful and expensive model in a particular manufacturer's lineup of vehicles

top-of-the-range model: See top-of-the-line model. The most powerful and expensive model in a particular manufacturer's lineup of vehicles

toppers: See whitewall toppers

top ring groove insert: A piston ring that has a nickel-iron or comparable metal insert cast into the piston heads. The top ring groove is cut into this metal. As the top ring grooves in aluminum pistons pound out of shape, this insert groove will prolong the useful life of the piston and ring.

top speed: The maximum speed of a vehicle

top tints: The tinted stripe at the upper edge of the windshield

top tube:

On a bicycle the horizontal tube that connects the seat tube with the head tube.

top up: To raise the level of a liquid in a container to the required level

top up the battery: Determine if the electrolyte is at the correct level and add distilled water to bring it up if necessary

torch: [1] The mechanism which the operator holds during gas welding and cutting, at the end of which the gases are burned to perform the various gas welding and cutting operations. [2] A British term for a flashlight. See blow torch cutting torch Toronado: A vehicle brand of which the 1966-67 Toronado models are milestone cars. Sometimes you will see this car incorrectly spelled "Tornado" in classified ads.

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torpedo: An open sports vehicle generally with an unbroken design line from the hood to the back of the car.

torpedo body: An early type of touring car with a streamlined torpedo-like body

torque: [1] Turning or twisting force such as the force imparted on the drive line by the engine. Usually measured in lb-ft. It differs from work or power in that torque does not necessarily produce motion. Basically, the magnitude of a torque acting on a body is the product of the magnitude of a force and its force arm (perpendicular distance from the axis of rotation of the body to the line of action of the force). This product is called the moment of the torque about the axis or the torque. [2] To tighten a nut or bolt with a torque wrench. See bottom end torque

dial torque wrench hydrodynamic torque converter interchangeable head torque wrench lock-up torque converter lockup torque converter midrange torque self-aligning torque. torque arm: A T-shaped extrusion of the rear axle casing to take up forward thrust of the driven axle

torque converter: A unit in an automatic transmission quite similar to the fluid coupling that transfers engine torque to the transmission input shaft. It also cushions the flow of power. Unlike the fluid coupling the torque converter can multiply engine torque. This is accomplished by installing one or more stators between the torus members. In the torque converter the driving torus is referred to as the "pump" and the driven torus as the "turbine." The engine drives the impeller which in turn impels fluid against the vanes of a turbine connected through transmission gears to the driveshaft of the automobile. The stator redirects oil flow from the turbine to boost impeller action and multiply engine torque. See hydrodynamic torque converter lock-up torque converter lockup torque converter torque converter drive plate: See drive plate

torque converter housing: A bell housing

torque converter lock-up clutch: An automatically engaged clutch in a lock-up torque converter which prevents slipping losses

torque curve: A graph which shows the engine torque as a function of engine speed

torque limiter: A tool used in conjunction with a plug wrench which allows the controlled tightening of spark plugs by releasing automatically once a preset torque setting is reached

torque multiplication: Increasing engine torque in the automatic transmission through the use of a torque converter.

torque ratio: See stall torque ratio

torque rods: See stabilizer.

torque screwdriver: A screwdriver with a device that measures the amount of torque being applied

torque sensitive limited slip differential: A differential where the mechanism reacts to differences in torque when one wheel on an axle starts to slip, and limits the differential action to help maintain traction.

torque split: Distributing torque between wheels on the same axle or between front and rear axles in a 4WD vehicle

torque steer: A tendency for a car to turn in a particular direction when power is applied. Torque steer is common in front-drive cars because reaction forces created in the half-shafts can generate uneven steering forces in the front tires.

torque tube: A hollow forward extrusion of the rear axle casing incorporated in early live rear axle designs, both enclosing the drive shaft and providing a forward location of the driven axle, pivoting about a spherical joint either at the rear end of the gearbox or at the chassis frame

torque tube axle:

A live rear axle layout with a divided drive shaft and a T-shaped axle housing, the hollow forward extrusion of which carries the rear half of the divided drive shaft

torque tube drive: The method of connecting the transmission output shaft to the differential pinion shaft by using an enclosed driveshaft. The driveshaft is enclosed in a torque tube that is bolted to the rear axle housing on one end and is pivoted through a ball joint to the rear of the transmission on the other. The driving force of the rear wheels is transferred to the frame through the torque tube. This method was used on older cars in an attempt to get rid of the twisting forces of engine torque on the suspension driveshaft.

torque wrench: A wrench with a dial in the handle or a gauge with a needle for measuring the amount of torque applied to a nut or bolt. It is used for threaded fasteners with a critical tightening torque, such as cylinder head bolts, alloy wheel lugs, suspension links, etc. See click-type torque wrench dial torque wrench interchangeable head torque wrench torquey: An engine which develops high torque (i.e., it pulls well) at low speeds, relative to its power

torquing: See brake torquing

Torsen differential: A torque-sensing differential system incorporating a worm and roller mechanism

Torsen four-wheel drive: Based on the principle that a worm gear can drive a roller but not vice versa, the Torsen differential balances different wheel speeds due to different travel distances, whereas speed differences due to differing adherence situations are not balanced. A permanently engaged four-wheel drive incorporating a torsen differential

torsion:

The strain on a part or component produced by torque

torsional rigidity: The resistance against torsional loads, specified in newton-meter per angular degree of body twisting.

torsional stiffness: The resistance against torsional loads, specified in newton-meter (or lbs-ft) per angular degree of body twisting

torsional vibration: A twisting and untwisting action developed in a shaft. It is caused either by intermittent applications of power or load.

torsional vibration damper: [1] Any device that reduces torsional vibrations. [2] The small flywheel on the front end of a crankshaft

torsion bar: A long spring steel rod attached in such a way that one end is anchored while the other is free to twist. One end is fastened to the frame at one end and to a suspension part at the other. If an arm is attached, at right angles, to the free end, any movement of the arm will cause the rod or bar to twist the bar's resistance to twisting provides a spring action. The torsion bar replaces both coil leaf springs in some suspension systems. The main advantage of the torsion bar over the coil spring in the front suspension is the ease of adjusting front suspension height.

torsion bar suspension: A suspension system that makes use of torsion bars in place of the leaf or coil spring.

torsion damper: See torsional vibration damper

torsion spring: See torsion bar.

torus:

The inner surface of a hollow doughnut-shaped structure, especially found in automatic transmissions. See fluid coupling.

TORX: A special star-shaped screw recess or screw head top with six rounded corners to insert the tool. The TORX configuration on tools allows a very tight fit on the fastener and the application of high torque. The rounded corners also reduce wear of both the fastener and the tool

total hydrocarbons: (THC) A measurement of all the hydrocarbons emitted by the exhaust system

totalled: A car accident in which a vehicle has sustained severe damage so that the cost to repair it is more than what the vehicle is worth. In this case, it is written off

total loss: Ignition or lubrication system in which electricity or oil is used without being generated or recirculated. The ignition system uses power from a battery eventually running it flat. The lubrication system uses oil without returning it to a tank. Both systems were common on early motorcycles. Two-stroke engines use a total loss lubrication system. Scooters designed for the elderly or disabled use a total loss battery system because there is no alternator or generator to charge the battery as it is being driven

total-loss lubrication: The components of the conventional two-stroke engine with crankcase scavenging are lubricated by the oil added to the fuel; since the oil is burnt along with the fuel, fresh oil is constantly fed to the lubrication points inside the engine

Total Out-Of-Pocket Cost: This is the total of all monthly payments, any lease fees and deposits, and any capital cost reduction (except tax, license, and registration) from lease inception to closure.

total quality management: (TQM) A management technique to improve the quality of goods and services, reduce operating costs and increase customer satisfaction.

touch-dry: The condition after respraying a body when the paint coat has dried to an extent that foreign substances will not stick to the surfaces and light finger pressure will not leave any marks; the coat has not yet hardened completely, however, i.e., it cannot yet be sanded or polished

touch up: To repair minimal blemishes in the paintwork, e.g., those caused by stone chippings or scratches

toughened glass: See laminated windshield.

toughened windshield: A windshield made of toughened glass which, on impact, will not shatter like ordinary glass but fractures into small pieces and crazes over; laminated glass is now the preferred material

tour: See farewell tour

tourer: British term for touring car See loaded tourer sports tourer AC Buckland Open Tourer. Touring: See Grand Touring Prototype Grand Touring touring bike: [1] A motorcycle that comes from the manufacturer with saddlebags and a trunk. [2] A bicycle that has been equipped with saddlebags (often over the front wheels as well as the rear).

touring car:

A vehicle with a body longer than the phaeton style, but very similar to it. It permits the use of auxiliary seats in the rear passenger compartment. It was an open car with seats for four or more passengers. Early models had no side weather protection but later were fitted with detachable side screens and curtains. Made until about 1930.

Touring-injection: See grand Touring-injection

Touring Prototype: See camel Grand Touring Prototype

touring triple: A triple chainring crankset designed to provide the wide range of gears needed for loaded bicycle touring.

tourist: A cyclist who takes short or long excursions by bicycle often carrying several panniers containing clothing and camping equipment.

touristes-routiers: An older and slower category randonneur used in the 1901, 1911, and 1921 ParisBrest-Paris events. In 1931 the race organizers turned this segment over to touring clubs.

tow: [1] To pull a trailer behind a vehicle by means of a towing hitch. [2] To pull a disabled vehicle behind another vehicle by means of a rope, cable or rigid bar

towable: [1] A vehicle after an accident that is able to be towed. [2] An old vehicle which may be used for parts or to be scrapped that is still able to be towed

tow away: To remove unauthorized (e.g., illegally parked) vehicles, thus incurring a hefty fine for the owners

tow away zone: An area where unauthorized parking is not permitted. Unauthorized vehicles will be towed away

towball: A British term for a hitch ball

towbar: [1] A crossbar of a towing bracket on which the hitch ball is mounted. [2] A rigid bar used for towing disabled vehicles short distances. [3] A drawbar

tower: See coil tower distributor tower humidifying tower macpherson strut tower outer tower shock absorber tower terminal tower tower jack: A tower with a solid foot and an arm at right angles which fits into a slot in the side of a car and is wound up the tower to raise the vehicle

towing ball: A British term for a hitch ball

towing bracket: A structure attached to the rear of a car to enable a trailer to be towed. It consists of one or two brackets, a towbar and hitch ball

towing eye: A steel ring fitted to the chassis of a car to which a tow rope can be attached

towing hitch:

An inverted cup on the drawbar of a trailer which fits over a hitch ball

towing jaws: A coupling attachment on the rear of a truck cab into which the drawbar eye of a trailer fits to lock with a coupling bolt

towing lug: A steel ring fitted to the chassis of a car to which a tow rope can be attached

towing package: See trailer towing package

town car: The same as the Imperial sedan without the rear quarter windows or a roof over the front compartment.

tow rating: The amount of weight in pounds of an external trailer that a vehicle can pull.

towrope: A rope, or textile-covered or plastic-covered cable, usually no longer than 5 meters, used for towing another vehicle

Toyota: The largest car manufacturer in Japan and the third largest in the world (after GM and Ford)

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Toyota Avalon: A model of automobile manufactured by Toyota Click for books on Toyota Avalon Toyota Camry: A model of automobile manufactured by Toyota Click for books on Toyota Camry Toyota Carina: A model of automobile manufactured by Toyota Click for books on Toyota Carina

Toyota Celica: A model of automobile manufactured by Toyota Click for books on Toyota Celica Toyota Corolla: A model of automobile manufactured by Toyota Click for books on Toyota Corolla Toyota Corona: A model of automobile manufactured by Toyota Click for books on Toyota Corona Toyota Cressida: A model of automobile manufactured by Toyota

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Toyota Crown: A model of automobile manufactured by Toyota Click for books on Toyota Crown Toyota MR2: A model of automobile manufactured by Toyota

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Toyota Previa: A model of automobile manufactured by Toyota Click for books on Toyota Previa Toyota Starlet: A model of automobile manufactured by Toyota Click for books on Toyota Starlet Toyota Tercel: A model of automobile manufactured by Toyota Click for books on Toyota Tercel TPI: Acronym for tuned port injection

TPP: Acronym for tread pattern percentage

TPS: Acronym for throttle position sensor

TQM: Acronym for "Total Quality Management."

TR: Acronym for thermal reactor

TRA: Tire and Rim Association.

track: [1] Front track is the distance between the center of the left front wheel and the center of the right front wheel when the vehicle is set to its normal ride height and wheel alignment specifications. Rear track is the distance between the center of the left rear wheel and the center of the right rear wheel. They are not always the same. [2] A designated course or roadway where vehicles race. See axle track eight-track one-groove track oval track short track tri-oval track warning tracks track arc: The path travelled by a road wheel during a turn

track bar: See panhard rod

track control arm: See transverse link

tracked:

See crab-tracked

tracking: [1] The alignment of the vehicle with respect to axle centers of a vehicle being in the same plane, rear tires following front tires and trailer following the tractor, in the attitude designed. Correct tracking is when the rear wheels of a vehicle follow the same line as the front wheels. Also see straight-line tracking. [2] A line of carbon along which electricity leaks. See carbon tracking. [3] shunt firing of a spark plug.

tracking mark: A telltale sign on the distributor cover or ignition cables indicating a leakage of current

track rod: One of the transverse bars connecting the steering system to the steering arms; the link between the pitman arm and the steering-knuckle arm. See panhard rod tie rod tract: See intake tract

traction: [1] Pulling force. [2] The force of adhesive friction exerted by a body on the surface on which it moves. See electronic traction control liquid traction low-speed traction control traction avant: A French term for front-wheel drive

traction bar: An articulated bar or link attached to both frame rear axle housing to prevent spring windup (with resultant wheel hop) during heavy acceleration or braking. Also see panhard rod.

traction control, low speed: A system that helps prevent front-wheel spin on slippery or gravel surfaces during acceleration at speeds up to 40 kph (25 mph). See electronic traction control low-speed traction control traction control system: See anti-spin regulation anti-spin regulation traction control system

traction differential: See limited-slip differential.

traction engine: A steam or diesel engine used for hauling heavy vehicles on roads or over difficult terrain.

traction limited grade: Steepest negotiable grade where traction is the limiting factor.

tractive conversion: See stall torque ratio

tractor: Truck portion of combination or train. Also called "semi," "semi-tractor," "truck tractor," or "tractor-trailer." See semi-tractor truck tractor tractor-trailer: See tractor.

trade:

See agreement on Tariffs and Trade american Free Trade free Trade Agreement of the Americas general Agreement on Tariffs and Trade North American Free Trade Agreement trade agreement: See American Free Trade Agreement Canada-U.S. Free Trade Agreement free Trade Agreement of the Americas North American Free Trade Agreement Trade Agreement of the Americas: See Free Trade Agreement of the Americas

trade-in price: The price of your old car when you are selling it in part exchange for another one

Trade Organization: See world Trade Organization

traffic: A road with moving vehicles. See heavy traffic light traffic rush-hour traffic trafficator: See semaphore indicator

traffic circle: An intersection of several roads where the traffic goes around a central circle and goes out another road. Although it is a rapid way of negotiating an intersection, many people are intimidated by it because of its unfamiliarity. The British term is "roundabout"

traffic island: A raised area in the middle of a road designed to separate two flows of traffic and to provide a safe temporary stopping place for pedestrians crossing the road

traffic jam: A number of vehicles stopped behind one another on a road

traffic light: A series of red, amber, and green lights placed at the intersection to regulate the flow of traffic

trail: [1] A path used by pedestrians and smaller vehicles (e.g., bicycles, quads, snowmobiles, etc.). [2] The path that a wheel makes. See caster trail pneumatic trail trail bike: A dual purpose motorcycle for use on or off-road

trail braking: A driving technique in which the driver begins to brake before entering a turn and then continues to brake as he eases into the corner. As cornering forces build, the driver gradually feathers off the brakes -- trading braking power for cornering grip. By increasing the vertical loading -- and thus the traction -- at the front tires, trailbraking can improve a car's turn-in.

trail distance: The distance from the point at which the cornering force acts to the center of the wheel or steering axis.

trailer: [1] Platform or container on wheels pulled by a truck or tractor. [2] Distance between fifth wheel pin and center of rear axle (or center between tandems). [3] A unit which contains camping equipment and is pulled behind a vehicle. See

boat trailer camping trailer fifth-wheel travel trailer flatbed trailer folding camping trailer full trailer hard-sided trailer hard-top trailer maximum trailer weight semi-trailer soft-sided trailer soft-top trailer tractor-trailer travel trailer trailer towing package: See trailer-towing package.

trailer-towing package: An optional equipment which usually includes a heavy-duty suspension a larger radiator a transmission cooler and a rear bumper with a trailer hitch. This improves handling and allows a vehicle to haul a heavy trailer.

trailer weight: See maximum trailer weight

trailing: See parallel trailing link suspension

trailing arm: Type of independent rear suspension in which the pivot axis is exactly across the vehicle, or perpendicular to the longitudinal axis. This means the wheels are always upright relative to the body and hence leaning with the body in a corner. Widely used at the rear of front-wheel-drive cars. Also see semi-trailing arm.

trailing axle: See a dead axle

trailing brake shoe:

The brake shoe that is installed facing the rear of the vehicle. Also called secondary brake shoe or reverse brake shoe.

trailing edge: The rear edge (e.g., of a body panel). Compare leading edge

trailing link: A front suspension linkage that is aligned to resist longitudinal motions in a wheel; it is mounted to the chassis ahead of the wheel. The links pivot forward of the axle. Also see parallel trailing link suspension

trailing link suspension: See parallel trailing link suspension

trailing shoe: A British term for a secondary shoe -- a shoe of a brake drum system whose activated end faces away from the approaching drum

trailing throttle: An oversteer handling situation of rear drive cars. When the throttle is closed the engine applies compression braking so that the rear suspension alignment changes. This change causes the rear tires to lose traction which promotes a lateral slide.

train: See drivetrain gear train gross train weight member of the gear train powertrain road train strain in the drive train valvetrain wind trainer. trainer: See wind trainer.

train weight:

See gross train weight

tram: [1] A British term for a streetcar. [2] A small train used to haul ore at a smelter.

tramcar: A British term for a streetcar

tram gauge: An alignment tool -- a long bar that has two or three parallel pointers extending at right angles and attached so that they can be moved to any position along its length

tramline: The rails along which a tram runs

tramlining: The tendency of a vehicle's tires (often when of low profile) to follow a ridge or rut in the road's surface

tramp: See axle tramp wheel tramp tramway: The rails along which a tram runs

tramp: [1] A hopping or oscillating motion of the front wheels usually caused by incorrect balance or when a high inflation tire has been run empty. [2] The action of rapidly depressing the throttle pedal. See axle wind up axle tramp. tranny:

Colloquial name for "transmission."

trans: Abbreviation for "transmission."

transaxle: A drive setup in which the transmission gearbox clutch final drive, and differential are combined into a single unit connected directly to the driveshaft. It is used mostly in rear-engine cars like the Corvair, but is also found in some front-wheel drive cars and some performance cars where a front engine/rear transaxle gives better overall balance (such as the Alfa Romeo Alfetta). Also see rear-wheel drive transaxle

transceiver: A radio device which can transmit a signal and opposite to a receiver

transducer: A device for transferring power which is generated in one system to another system in the same or a different form, e.g., electrical to mechanical. Also see negative transducer EGR valve

transducer EGR: See negative transducer EGR valve

transducer EGR valve: See negative transducer EGR valve

transfer: See decal heat transfer load transfer weight transfer transfer box: See transfer case

transfer case:

An auxiliary device in a 4-wheel-drive vehicle that allows power to be delivered to both axles. Normally the transfer case incorporates a shifting device so that the front drive can be disconnected, if desired, for running on pavement. Also see four-wheel drive.

transference: See load transference

transfer molding: The development of compression molding where powder polymer is placed in a small chamber adjacent to a tool mold and when heated, is forced into the tool cavity. Also see molding

transfer moulding: British term for transfer molding

transfer passage: The passage connecting the crankcase of a two-stroke engine with the combustion chamber

transfer plate: An adapter plate in the control valve assembly of an automatic transmission, used to direct the fluid flow between adjacent valve bodies

transfer port: A channel in the block of a two-stroke engine where the air-fuel mixture enters the combustion chamber and exits out another transfer port after it burns.

transfer port cover: The transfer passages of most two-stroke engines are accessible from the outside to allow for maintenance, they are covered by the transfer port covers for regular engine operation

transfer ports: The holes that deliver fuel from the idle circuit during the transition from curb-idle to the main metering circuit. Located just above the throttle plates. At curb idle, offidle ports function as an extra air bleed for further emulsification of the idle mixture; but as vacuum moves up the carburetor bore when the throttle plates are opened, they become fuel discharge ports. Either one or more holes, or a single slot

(slots are usually used because they are cheaper to manufacture). Also called offidle discharge ports

transfer pump: An in-tank pump, used on many Bosch and some other fuel injection system, that boosts the fuel pressure slightly before the fuel is sucked into the main pump, in order to prevent cavitation. Also, part of the fuel injection pump for a diesel engine, boosts fuel pressure from around 20 psi to about 130 psi, depending on the pump and the engine speed

transformer: An electrical device with an arrangement of copper coils with an iron center, used to increase or decrease electrical voltage. A vehicle ignition coil transforms the voltage from 12 volts to upward of 20,000 volts. See air transformer ignition transformer voltage transformer transistor: See ignition transistor

transistor ignition: A form of ignition system which uses transistors and a special coil. The conventional distributor and point setup is used, but the points merely serve to trigger a transistor which switches the heavy primary current. With the transistor unit, the voltage remains constant, thus permitting high engine rpm without resultant engine "miss." Transistors are much more efficient switches at high engine speeds and in addition they don't burn, pit or change gap spacing. The advantages of these systems include greatly increased point life, generally better starting because of improved contact condition and voltage output not greatly affected by breaker point dwell time which results in better high-rpm performance. Also point life is greatly extended as the transistor system passes a very small amount of current through the points.

transistorized coil ignition: (TCI) See transistor ignition

transistorized coil ignition with Hall sensor:

(TCI-H) See transistorized ignition with hall generator

transistorized ignition: (TI) An ignition system using a transistor as a power switch; available as breakertriggered TI with contact breaker or as breakerless TI with magnetic pick-up or hall generator. Also see breaker-triggered transistorized ignition

transistorized ignition with inductive pulse generator: See transistorized ignition with inductive pick-up

transistorized ignition with Hall generator: (TI-H) There are two types of TI-H: in one version, the dwell angle is determined by the width of the rotor vanes in the distributor; the other version contains a circuit for automatic dwell angle control incorporated in the electronic control unit

transistorized ignition with inductive pick-up: (TI-I) A transistorized ignition system with a magnetic pick-up in the distributor and an electronic control unit for signal processing, with current and dwell angle control

transistorized ignition with magnetic pick-up: (TI-I) A transistorized ignition system with a magnetic pick-up in the distributor and an electronic control unit for signal processing, with current and dwell angle control

transit: See mass transit system

transit system: See mass transit system

transmission: A device (full of gears) that uses gearing or torque conversion to effect a change in the ratio between engine rpm and driving wheel rpm. When engine rpm goes up in relation to wheel rpm, more torque but less speed is produced. A reduction in engine rpm in relation to wheel rpm produces a higher road speed but delivers less torque to the driving wheels. See

automatic transmission auxiliary transmission belt transmission bevel gear transmission C-matic transmission continuously variable transmission dual-range transmission electronic transmission control electronic transmission five-speed transmission four-speed transmission high/low range transmission hydrostatic transmission infinitely variable transmission J gate transmission shifter manual transmission overdrive transmission planetary transmission powershift transmission progressive transmission selective transmission semi-automatic transmission six-speed transmission standard transmission stepless transmission synchromesh transmission three-speed transmission two-speed transmission variable belt transmission variable transmission variomatic transmission viscous transmission transmission adapter: A unit that allows a different make or year transmission to be bolted up to the original engine.

transmission, automatic: See automatic transmission.

transmission control: See electronic transmission control

transmission controlled spark: (TCS) A system to reduce the emission of nitrous oxides by which a vacuum solenoid and a switch in the transmission system prevents the distributor's vacuum advance mechanism from operating in the lower gears and at low speed

transmission control module: (TCM) An electronic automatic transmission control unit which computes data on the actual operating conditions of the vehicle and generates corresponding signal pulses for the solenoid valves of the hydraulic control system; may also exchange data with other electronic control units

transmission control system: A hydraulic or electro-hydraulic system which controls the changes of ratio in automatic transmissions corresponding to engine load, vehicle speed, positions of the selector lever, and shift mode button

transmission, conventional: See standard transmission.

transmission cover: A removable part of the floorpan usually located at the front end of the center tunnel in cars with a longitudinally mounted engine; provides better access to the top of the transmission for maintenance and adjustment purposes

transmission extension housing: A rear-wheel drive transmission housing enclosing an extended main shaft, sometimes accommodating the gear lever and associated mechanism

transmission fluid: (ATF) A superthin oil that fills the automatic transmission system so that it can run on hydraulic pressure. It can also be used in some power-steering pumps. It is sometimes used to clean the inside of a carburetor.

transmission governor: A governor on the output shaft of a hydraulically controlled transmission converts line pressure into governor pressure. In electro-hydraulically controlled transmissions, the governor is replaced by a sensor.

transmission housing:

The outer shell which contains the transmission gears.

transmission input shaft: A shaft which transmits power from the clutch to the gearbox

transmission output shaft: A shaft which transmits the power out of the transmission

transmission shifter: See J gate transmission shifter

transmission, standard: See standard transmission.

transmission tunnel: A semicircular or oval bulge along the longitudinal axis of the floorpan to accommodate the propeller shaft and, at its front end, the transmission, enabling the shaft and transmission mounting position to be raised to the floorpan level, thus providing better protection for the drive train against road dirt and obstacles

transmitter: A radio remote control system device that transmits electrical or radio signals. Also see emergency transmitter

transom: See stern transom

transom beam: The aftermost transverse deck beam

transom frame: The aftermost transverse side frame

transplants: An overseas production plant; in most cases, the term refers to automotive vehicles produced in the USA, Canada, or Europe at Japanese-owned factories (e.g., a Toyota plant in Cambridge, Ontario, Canada)

transporter: A large articulated truck for transporting several cars (on two or three decks)

transom stern: A square-ended stern used to provide additional hull volume and deck space aft and to decrease resistance in some high speed ships.

transverse arm: A suspension arm not split into two separate sections as is an A-arm. Often used as the bottom locating link with MacPherson strut suspension. Also called "lateral arm." Also see MacPherson strut.

transverse cable: See stirrup cable.

transverse engine: An engine that is mounted laterally (i.e., left to right) between the drive wheels (rather than longitudinally -- front to back), often found on cars with front-wheel drive. Also called "east-west layout"

transverse flow scavenging: See cross scavenging

transverse leaf spring: A leaf spring that is mounted so that it is at right angles to the length of the vehicle.

transverse link: Any suspension link that provides lateral support for wheels; on front suspensions, a typical design is the Y-shaped wishbone

transverse mount: The engine is mounted sideways. The fan belt will be over one of the tires rather than in the very front of the vehicle. This is common in front-wheel-drive cars. This enables the car to be more compact because the space under the hood is used more efficiently and provides better weight distribution. See transverse engine.

transverse rod: See panhard rod

trap: [1] The area over which the vehicle is raced for timing purposes. [2] A pedal on a bicycle into which the foot is locked in place. See rattrap . [3] A filter or separator. See activated charcoal trap flame trap oil trap pm trap trap oxidizer: In diesel particulate filters, a means of burning the particulate charge trapped in the filter element, to prevent the filter from clogging and to restore filtration capacity; usually a catalyst coating that promotes oxidation of carbon particulates to harmless carbon dioxide

trapped volume: A clearance volume

trapping efficiency: In a two-stroke engine, the mass of fresh charge in a cylinder actually retained, divided by the mass of fresh charge supplied per cycle

traps: See trap.

trauma fee: $6 per $1000 of car value levied annually in Washington State (and others) to support trauma units in hospitals that care predominantly for car crash victims.

travel: The distance an object can move.

See clutch pedal free travel direction of travel fifth-wheel travel trailer free travel pedal free travel pedal travel travel trailer: A unit which is pulled behind a vehicle. It is enclosed and contains all the conveniences of home: sleeping room, showers, toilets, cooking, dining, and relaxing. Some have a slide-out feature which enlarges the living, dining, sleeping, or cooking areas. Also see fifth-wheel travel trailer

tray: See battery tray draining tray tray table: A table that folds out of the back of the front seat (similar to those found on airplanes)

TR-Denioc rim: See TD rim

TR-Denioc wheel: See TD wheel

tread: [1] The distance between the two front or two rear wheels. [2] Portion of the tire which contacts the roadway. [3] The pattern of the outside circumference surface of a tire. See asymmetrical tread cracking tread directional tire directional tread new tread non-directional tread nu-tread

precured tread rubber self-cleaning tread symmetrical tire tread wide treads. tread bar: Raised portions of rubber that make up me tread of the tire, separated by grooves that are arranged laterally, providing traction in the forward or rearward direction.

tread block: Raised portions of rubber that make up part of the tread pattern They are often present in the shoulder area and are more or less rectangular in shape.

tread depth: The measurement from the bottom cm of the tread groove to the top of the tread expressed in millimeters or 32nds of an inch. The legal minimum amount of tread is 1.6 mm (2/32") across three-quarters of the tire width

tread depth gauge: A simple compact device for measuring the depth of tread, consisting of a springloaded plunger calibrated in millimeters or 1/32 of an inch

tread gauge: See tire tread gauge

tread groove: One of several channels cut in the tread that disperses road water or provides traction in mud and snow

tread pattern: Tread patterns differ according to the manufacturer of the tire but they all have in common the aim of dispersing water from the road, to enhance grip, to avoid aquaplaning, to disperse heat, and to reduce noise and wear

tread pattern percentage: (TPP) The percentage of grooves and sipes to the overall surface of the tread

tread profile: The shape of the tread as seen in cross section

tread rib: The continuous raised portions of rubber that run circumferentially (straight or in a zigzag pattern) making up the tread on the tire. Also called the tread bar

tread roller: A roller, either manual or power, used to help apply me tread rubber, remove trapped air and obtain adhesion. Also see stitching.

tread rubber: See precured tread rubber

tread separation: Pulling away of the tread from the tire casing.

tread squirm: The flexibility in the tire tread between the surface of the tread and the tire carcass. Snow tires, with their small, deep, unsupported tread blocks, have a large amount of tread squirm. Slick racing tires, which have no tread pattern, have very little squirm.

tread wear indicator: See tread-wear indicators.

tread-wear indicator: See tread-wear indicators.

tread wear indicators: See tread-wear indicators.

tread-wear indicators: Bars of hard rubber that appear across the treads of a tire. They are 1.5 mm (1/16") above the base of the tread (the legal limit. They become visible when the tread has been worn down so that only 1.5 mm (a sixteenth of an inch) of tread is left. The legal limit may be shown on the sidewall by a symbol or by the letters TWI

treatment: See anodic treatment anti-rust treatment chromate treatment exhaust treatment full dip treatment heat treatment mechanical surface treatment most-favoured-nation Treatment no rinse treatment phosphate treatment pvc underbody treatment tin immersion treatment zinc immersion treatment tree: See christmas tree triple tree wheel tree trial: See field trial

trials: A type of ATB bicycle or off-road motorcycle competition that tests riders not on speed but on ability to maintain balance while navigating around and over numerous obstacles such as rocks, trees, and steep, slippery terrain. Points are deducted if the rider puts his feet on the ground, goes outside the marked course, or fails to clear an obstacle. Also see sea trials

triangle: See front triangle main triangle rear triangle warning triangle triangle split system:

See dual brakes -- especially the picture.

triangle-split system: See dual brakes -- especially the picture.

triangular ground electrode: A ground electrode with three bridges attached to its end points, which form a link to the threaded shell

triangular safety reflector: See warning triangle

triangulation: The arrangement of the stabilizing tread plies whereby their cords form tiny triangles in the Michelin 'X. radial truck tire.

tricar: An old name for a three-wheeler

Tricarbonyl: See methylcyclopentadienyl Manganese Tricarbonyl

trichlorethene: (C2HCl3) A cleaning solvent trichlorethylene: (C2HCl3) A cleaning solvent trick: [1] A description of a whole motorcycle which is "really cool," "really hot," "really new" and unobtainable or expensive. [2] A component of a motorcycle which is unique

trickle charge: A continuous charging of a storage battery at a low rate to keep it in a fully charged condition for a period when no current is drawn from it

trickle charger: A small battery charger which delivers less than five amperes

tricycle: A three wheeled vehicle (usually pedal-powered) where there is a single front wheel and two rear wheels. A three-wheeled, early-type open automobile using bicycle wheels and a steel-tube frame. Also see trike.

tri-drive: A vehicle having three rear driving axles.

trigger box: See ignition control unit

triggering device: An electronic control unit that activates the air bag in a crash. It contains a deceleration sensor, a Hamlin switch and a check circuit

triggering unit: An electronic control unit that activates the air bag in a crash. It contains a deceleration sensor, a Hamlin switch and a check circuit

trigger wheel: [1] A rotor of a magnetic pick-up integrated into the distributor, with as many teeth as the engine has cylinders. [2] A Hall generator rotor with an outer ring interrupted by one or several Hall windows, depending on its purpose

trike: A tricycle. A motorcycle that has been converted to a three-wheeled unit. Sometimes the rear two wheels are powered by a small automobile engine.

trim: [1] Nonfunctional metal or plastic molding, frames and other decorative additions to vehicle bodies and interiors. Also called hard trim. [2] A vehicle's interior decoration, including the upholstery, roof and door linings. Also called soft trim.

[3] The difference between the draft forward and the draft aft. A ship is trimmed by adjusting the location of fuel, cargo, ballast, etc. See door trim edge trim hard trim head trim interior trim soft trim wheel trim trimaran: A triple hulled vessel

trim emblem: See wheel trim emblem

trim level: A vehicle designation assigned by vehicle manufacturers that represent specific equipment packages.

trim panel: The decorative interior panel

trim panel release tool: A fork-like tool used to pry out fasteners on interior panels without breaking them or damaging the car

trim rim: See wheel trim rim

tri-oval track: An oval track with an extra rounded corner. Daytona is a tri-oval track.

trip computer: A computer with a multifunction display; supplies the driver with trip information such as range, ETA, distance to destination, time, fuel economy, fuel consumption, average speed, accumulated trip miles, elapsed time since last reset

tri pin: A device which is attached to a steering wheel to allow disabled people to insert a hand into its bracket in order to steer a vehicle. triple: See touring triple

triple clamp: The devices which secure the handlebar to the triple tree on a motorcycle. Named because is has three clamping points -- one for each of the two front forks, and one for the steering tube.

triple tree: The yoke that supports the handlebar on a motorcycle.

triplex chain: A chain with three rows of rollers. See duplex chain simplex chain trip meter: An instrument which measures the distance a vehicle travels from the last time it was reset and runs in conjunction with the odometer

trip mileage counter: An instrument which measures the distance a vehicle travels from the last time it was reset and runs in conjunction with the odometer

tripod jack: A device for lifting a vehicle.

tripod joint: A constant velocity joint with three balls engaged in curved grooves

trip odometer:

An auxiliary odometer that may be reset to zero at the option of the driver. It is used for keeping track of the mileage on trips up to one thousand miles.

tripping bracket: Flat bars or plates fitted at various points on deck girders, stiffeners, or beams as reinforcements to prevent their free flanges from tripping

trip recorder: Incorporated in the speedometer, the trip recorder indicates the mileage (in miles or km) covered during a particular journey (trip), either mechanically or electronically; trip figures can be reset to zero by turning or pushing a reset button. Also called a trip meter trip mileage counter or trip odometer

Triumph: A vehicle brand of which the Dolomite 8 and Gloria 6 models only from 1925-1948 are classic cars. The 1953-63 TR2/TR3 models are milestone cars.

Click for books on Triumph

trk: See 8 trk

TR number: Code number of the tube valves and flaps set by Tire and Rim Association.

trolleybus: An electrically powered public transport bus that takes its power from overhead wires

trolley jack: A hydraulic jack with swivel wheels

trouble code: Engine self diagnosis. Electronic control module questions sensor reading and stores code for which circuit trouble is located

troubleshooting:

Diagnosing engine, transmission etc., problems by various tests and observations.

trouble-shooting light: A light with a long lead, used in garages to inspect the underside of cars and under the hood

trough: See wiring trough

troy weight: A system of measurement of weight used for gold, silver, and platinum

troy ounce: A measurement of weight where one troy ounce equals 31.10 grammes. In writing, it is often shortened to troy oz. after figures, e.g., 25.2 troy oz. Troy weight is divided into grains, pennyweights (24 grains = 1 pennyweight), ounces (20 pennyweights = 1 ounce) and pounds (12 troy ounces = 1 pound). Troy weights are slightly less than their avoirdupois equivalents; the troy pound equals 0.37 kg or 0.82 lb avoirdupois

TR rim: A safety rim developed by Michelin with a flattened rim flange and run-flat potential

Truarc retaining ring: An internal or external circlip of rectangular cross section with holes for easier installation and removal

truck: A general term for a vehicle designed to haul something. The British term is lorry. See articulated truck breakdown truck crew cab dump truck flatbed truck fork-lift truck heavy-duty truck lift truck light-duty truck

light truck medium-duty truck tanker truck utility truck truck camper: A camping unit which mounts on the bed of a pickup truck. Its advantage is that the vehicle can be used to drive into remote locations.

truck tractor: See tractor.

true: [1] Something that is accurately made or correctly adjusted. [2] To adjust something so that it is able to fit perfectly. Also see out of true

true up: To dress

truing: The act of cutting rubber off the tread of a tire while rotating on a "truing" machine to make the tire assembly round. A sometimes harmful practice which takes off tread rubber to allow for an out of round wheel, or for a tire not mounted properly.

trunion: A British term for kingpin -- a mechanical pivot located at the lower end of the suspension wheel upright.

trunk: The storage compartment of a vehicle. In older cars, a large suitcase (or trunk) was strapped to the back of the vehicle. In rear-engine vehicles, the trunk is located in the front of the vehicle (e.g., Volkswagen); but generally it is located at the rear of the vehicle. Also see escape trunk

trunk handle: A lever or handle for opening the trunk

trunk lid:

The cover of the trunk which is hinged

trunk model: A vehicle which may come as a hatchback or stationwagon is available in a style which has a trunk behind and below the backlight (i.e., rear window).

trunk rack: A luggage rack which is mounted to the surface of the trunk. Some are merely decorative.

trunk spoiler: A rear spoiler which is mounted to the lid of the trunk.

t-slot: A variation of the split skirt piston. The top of the "T" tends to retard the transfer of heat from the head to the skirt of the piston. The vertical slot allows the skirt of the piston to close when heated. TT: Tourist Trophy races held on the Isle of Man

tub: See body tub wheel tub tube: [1] A long, narrow, hollow cylinder for holding or passing liquids or gases. [2] A rubber doughnut-shaped object which is placed within the carcass of a tire and inflated. See axle tube bourdon tube capillary tube carburetor venturi choke tube curing tube distribution tube down tube emulsion tube

fuel filler tube glow tube head tube heat shrink tube inner tube japanese lantern-type jacket tube jet tube mini tube cutter neon tube pitot tube road-draft tube seat tube shrink tube steerer tube stern tube top tube torque tube drive torque tube venturi tube tube axle: See torque tube axle

tube bender: A tool for bending tubing without collapsing it

tube cutter: A tool used to cut tubing by passing a sharp wheel around and around the tube. Also see mini tube cutter

tubed: A tire which has an inner tube

tube drive: See torque tube drive

tube frame: A car frame made up of rigid tubing welded together. Tube frames are easier to manufacture in small quantities than unitized frames.

tubeless:

A tire with no inner tube

tubeless tire: A tire which does not have a tube. Air is sealed in the tire chamber because the bead of the tire adheres to the tire's rim. First developed by B. F. Goodrich in 1948.

tubeless tires: See tubeless tire.

tubing: See butted tubing plain gauge tubing seamed tubing seamless tubing tube. tubing reamer: A tool used to remove burrs on hard tubes (not inner tubes), e.g., after a tube cutter is used when servicing the brake line system

tubular: In the shape of a tube; cylindrical

tubular backbone frame: A backbone chassis with a tubular central spine

tubular frame: A frame construction that features members of tubular cross section; often used for racing cars, as this layout allows for weight-saving design with the use of aluminum

tubular nut driver: A nut driver with handle and tubular shank for driving hexagon nuts and bolts

tubular tire: A type of bicycle tire that has a tube sewn up inside the casing, also known as a sew-up.

Tucker: A vehicle brand of which the 1948 models are milestone cars.

tucking: Reducing the length of certain sections of a panel. Opposite of throwing. When making a panel with rounded edges that has to be folded along the inner edge, the radius along this edge must be increased and its length reduced; this is done by thickening the material in certain areas

tudor: A word coined by Ford for a 2-door sedan.

tug: A boat equipped with powerful engines for towing or pushing large ships or barges

tumblehome: [1] The severe inward (concave) curvature used on the sides of some cars. [2] The inboard slope of a ship's side above the designed waterline

tumbling: The smoothing of an aluminum surface by tumbling it in rotating barrels with metallic or ceramic shot but without any form of abrasive

tune: To adjust the engine controls (carburetor, timing, etc.) for optimum running. See out of tune

tuned exhaust: Intake and exhaust systems that harness the pressure pulses and resonances inside the various passages and chambers of the intake and exhaust manifolds. In this way they increase the flow of intake charge into and out of the combustion chambers. Although the exhaust port must be a smooth as possible, the intake port must not because the fuel must churn and mix with the air.

tuned for economy:

An engine (and often other components) which have been adjusted to use less fuel

tuned header: See high performance header

tuned port injection: (TPI) a GM fuel injection system that uses tuned air intake runners for improved airflow

tuner: That component/circuit of a radio which tunes to the frequencies of radio stations; (tuner + amplifier = receiver)

tune up: See tune-up.

tune-up: The intent of a tune-up is to obtain the maximum performance and economy of the engine with the lowest possible exhaust emissions so that the vehicle engine will meet the manufacturer's specifications. It involves checking the components of the ignition system and cleaning or replacing them; cleaning and adjusting the carburation or fuel injection system; adjusting the points and timing cleaning and gapping the spark plugs. Tune-ups should be performed according to the recommendation of each manufacturer.

tune up kit: See tune-up kit.

tune-up kit: A set of parts containing points, rotor condenser cam lube, and possibly a feeler gauge. Each vehicle make, model, and year has its own tune-up kit.

tungsten: A hard, malleable, greyish-white element used in lamp filaments, electrical contact points and, alloyed with steel, in high-speed cutting tools

tungsten-arc:

See gas tungsten-arc welding

tungsten-arc welding: See gas tungsten-arc welding

tungsten-halogen bulb: A quartz-halogen bulb with a tungsten filament

tuning: The adjustment of the carburetor, ignition timing, etc. to improve performance. See exhaust tuning performance tuning quartz tuning system tuning system: See quartz tuning system

tuning the exhaust: See exhaust tuning.

tunnel: See center tunnel transmission tunnel wind tunnel tunnel drier: A heated tunnel through which body shells are passed in painting lines, e.g., to dry their phosphate coatings

tunnel furnace: A heated tunnel through which body shells are passed in painting lines, e.g., to dry their phosphate coatings

tunnelling: Moving a component deeply into its surrounding sheet metal to give the appearance of being recessed, e.g., headlights, tall lights, and antennas

turbine: Turbine: A type of engine in which all the parts that are in regular motion are rotating, making for very smooth operation. The basic gas turbine operates as follows: air enters the compressor and is compressed. It is then delivered to the combustion chamber under pressure and here the fuel is introduced, mixed with the air and burned, the quantity injected determining speed and power output. The hot, high-pressure burning gases then proceed to the first turbine, which drives the compressor and continue to the power turbine, which delivers power to the output shaft through reduction gears. The gears are necessary because the speed of turbine rotation is measured in tens of thousands of rpm not thousands as with a typical piston engine. The turbine's attractions include its utter simplicity and directness in getting power from burning gas, its smoothness, easy cold starting and its ability to run on almost any hydrocarbon fuel. On the minus side are high cost, problems with materials because of the high temperatures and speed of rotation and relatively high NOx production. Also see gas turbine

turbine casing: The casing enclosing a turbine

turbine engine: An engine that uses burning gases to spin a turbine, or series of turbines, as a means of propelling the vehicle. Also see turbine.

turbine housing: The casing enclosing a turbine

turbine wheel: [1] A turbocharger wheel driven by exhaust gases, the turbine wheel spins at speeds up to 160,000 rpm and drives the compressor which is located at the opposite end of the turbine shaft; wheel and shaft are usually inseparable. [2] A driven member of a torque converter which transmits multiplied engine torque to the transmission input shaft

turbo: Abbreviation for "turbocharger." In computers the term is erroneously used to mean an increase in speed. Also see two-staged turbo

turbocharged engine:

An engine fitted with a turbocharger

turbocharger: An exhaust powered turbine super-charger. Turbochargers always use centrifugalflow compressors, which operate efficiently at the high rotational speeds produced by the exhaust turbine. See blower.

turbo charger: See turbocharger.

turbocharging: A method of increasing power and decreasing emissions by rerouting hot exhaust gases through a turbine which drives a pump that forces more air into the engine cylinders. Also see exhaust turbocharging

turbo-diesel: A diesel engine which is turbocharged

turbo gauge: A boost pressure gauge on turbocharged engines

turbo lag: Within a turbocharger's operating range, lag is the delay between the instant a car's accelerator is depressed and the time the turbocharged engine develops a large fraction of the power available at that point in the engine's power curve.

turbo-supercharger: See turbocharger

turbulence: Violent, broken movement or agitation of a fluid or gas. Also see swirl

Turismo: See gran Turismo

turn:

See handbrake turn right hand turn signal turn a lap: To drive one full circle around the race track.

turnbuckle: A device which allows the linkage to be lengthened or shortened. A threaded hole is found on each end of the turnbuckle. The linkage which attaches to the turnbuckle can be screwed in or out on each end to create the necessary length. Usually a lock nut secures the turnbuckle in place. In some instances, the turnbuckle may have a threaded hole at one end and a threaded stud at the other.

turner: See flywheel turner

turn-in: The moment of transition between driving straight ahead and cornering.

turning circle: The smallest circle in which a vehicle can turn, i.e., with the wheels on full lock. See turning radius.

turning over: See turn over.

turning radius: The diameter of the circle created by the outer front wheel when making a full turn. There are two ways of measuring the turning radius: curb to curb and wall to wall. The latter is always larger because it takes into account front-end overhang. As the vehicle turns, the inside wheels make a smaller circle than the outside tires. Also see Ackermann steering.

turn-in rate: The way a car steers into a bend; the roll-steer effect

turn into the skid:

To turn the steering wheel in the same direction as that in which the rear of the car is sliding, in order to counteract the skid

turn over: An engine is said to "turn over" when the starter has caused the crankshaft to begin to turn, which starts the pistons moving so that combustion can begin to take place in the cylinders providing power to move the vehicle.

turnpike: A US toll road, especially one that is an expressway

turns: See toe-out on turns

turn signal: See right hand turn signal

turn signal indicator: A light (usually accompanied by a click or chime) which flashes when the turn signal lever is engaged and the signal lights flash. Most are located somewhere on the dash in front of the driver, but Cadillac and others also mounted them on the upper edge of the front and rear fender or the rear headliner.

turn-under: The inward sloping of a car's body below the waistline

turnup: See ply turnup.

turret web: See suspension turret web

Click for books on TVR TV rod:

This refers to the throttle valve rod that extends from the foot throttle linkage to the throttle valve in the automatic transmission.

TVS: Acronym for thermal vacuum switch or temperature vacuum switch

TVV: Acronym for thermal vacuum valve or thermal vent valve

TWC: Acronym for three-way catalyst

tweak: [1] To adjust a screw or component by making a very slight adjustment. [2] To bend a component to such an extent that it will need to be replaced.

tween deck: The space between any two adjacent decks

twelve: See v-twelve

twelve-cylinder engine: An engine with twelve cylinders, e.g., a V-12

twelve-valve engine: A three-cylinder engine with four valves per cylinder (e.g., Daihatsu), or a sixcylinder engine with two valves per cylinder, or a four-cylinder engine with three valves per cylinder, i.e., two inlet valves and one exhaust valve

TWI: Acronym for tread wear indicators

twilight sentinel: A device found on Cadillac cars which controls the headlights so that they remain on for a set period of time after the engine is shut off.

twin: To construct a highway in which there are two lanes on each side of the road often with a center median dividing each pair of lanes. The British term is "dual." See flat twin offset twin parallel twin twin A-arm suspension: See double wishbone suspension

twin axle: See tandem axle

twin barrel carburetor: A carburetor with two identical barrels to feed two banks of cylinders

twincam: An engine with double overhead camshafts. See overhead cam DOHC. twin cam engine: An engine with double overhead camshafts.

twin camshaft: An engine with double overhead camshafts.

twin camshaft engine: An engine with double overhead camshafts.

twin carburetors: (TC) two carburetors on an engine, mechanically coupled and balanced

twin-choke carburetor:

A carburetor with two identical barrels to feed two banks of cylinders. See doublebarrel carburetor

twin diaphragm pump: A diaphragm pump with two diaphragms; if one fails the other takes over its function

twin exhaust system: An exhaust system with two tailpipes; either a complete exhaust system, as on performance cars and cars with V-engines, or simply two tailpipes emanating from the rear muffler. Also called dual exhaust system

twin fitment: See dual mounting.

twin front pipe: See Y-pipe

twin header: See Y-pipe

twin headlight: A headlight arrangement containing two headlights; the outer lights provide the low beams, the inner lights are for high beam

twin headpipe: See Y-pipe

twin ignition system: A distributor with two sets of contact points, each of which operates with its own coil in a separate primary circuit; the contact points open alternately, each set firing half of the cylinders

twin I-beam suspension: Used on most Ford trucks in the last 20 years. This variation does not link the wheels, but uses two long beams, each pivoting on the opposite side of the vehicle. Results in a smoother ride, but creates tire-wear problems.

twin ignition: See single-coil twin ignition

twin overhead camshaft: See double overhead cam twin-piston engine: An obsolete two-stroke engine design featuring two cylinder barrels plus two pistons per cylinder; the pistons are linked to the crankshaft via a forked con rod or a master/slave con rod assembly

twin planets: Two planet gears in mesh; one meshes with the sun gear and the other with the internal gear

twin-plate clutch: A clutch with two driven plates separated by an intermediate drive plate; gives higher torque capacity

twin plug ignition: See twin ignition system

twin port: A cylinder head design in which there are two exhaust ports

twins: A motorcycle with two cylinders

twin-spar frame: A motorcycle frame in which the steering head and the swingarm pivot are connected by two metal (usually alloy) members that wrap around the engine

twin spark ignition: See twin ignition system

twin swirl combustion chamber:

A special design of a four-stroke engine, in which the intake valves are arranged in such a way as to ensure that the gas flow ends in two separate swirls; this design improves swirl and thus enhances combustion of the fuel/air mixture within the cylinder

twin-tube damper: See double-tube shock absorber

twin wheel: [1] A double-rimmed wheel with two independently inflated tires; has good aquaplaning and run-flat properties. [2] Two wheels fitted to one hub

twist-beam rear axle: See semi-independent suspension

twist drill: A metal cutting drill with spiral flutes (grooves) to permit the exit of chips while cutting.

twisted frame: A type of frame damage often encountered as a result of the car rolling over. The left-hand and right-hand frame members are then no longer parallel and on a level when viewed from the side; instead, they are offset as if they had been turned on a horizontal axis at right angles to the frame members

twisty bits: The twisting back roads you can find in almost any state. The two lane roads that bring a sports car to life as you master the turns, curves and switchbacks.

two-coat system: See base and clear system

two-cycle engine: See two-stroke engine

two-door:

A vehicle with one door on each side; a body design typical of all two-seater sports cars (such as roadsters, spiders) and many subcompact cars

two-door club coupe: See two-door coupe

two-door coupe: Also called the two-door club coupe, the club coupe designation seems to come from club car, describing the lounge (or parlor car) in a railroad train. The early postwar club coupe combined a shorter-than-sedan body structure with the convenience of a full back seat, unlike the single-seat business coupe. That name has been used less frequently in the 1976-86 period, as most notchback two-door models (with trunk rather than hatch) have been referred to as just "coupes." Moreover, the distinction between two-door coupes and two-door sedans has grown fuzzy. === car-club.jpg

two-door fastback: By definition, a fastback is any automobile with a long, moderately curving, downward slope to the rear of the roof. This body style relates to an interest in streamlining and aerodynamics and has gone in and out of fashion at various times. Some (Mustangs for one) have grown quite popular. Others have tended to turn customers off. Certain fastbacks are, technically, two-door sedans or pillared coupes. Four-door fastbacks have also been produced. Many of these (such as Buick's late 1970s four-door Century sedan) lacked sales appeal. Fastbacks may or may not have a rear-opening hatch. === car-fast.jpg

two-door hatchback coupe: Originally a small opening in the deck of a sailing ship, the term "hatch" was later applied to airplane doors and to passenger cars with rear liftgates. Various models appeared in the early 1950s, but weather-tightness was a problem. The concept emerged again in the early 1970s, when fuel economy factors began to signal the trend toward compact cars. Technology had remedied the sealing difficulties. By the 1980s, most manufacturers produced one or more hatchback models, though the question of whether to call them "two-door" or "three-door" never was resolved. Their main common feature was the lack of a separate trunk. "Liftback" coupes may have had a different rear-end shape, but the two terms often described essentially the same vehicle. === car-2hatch.jpg

two-door hardtop: The term hardtop, as used for postwar cars up to the mid-1970s, describes an automobile styled to resemble a convertible, but with a rigid metal (or fiberglass) top. In a production sense, this body style evolved after World War II, first called

"hardtop convertible." Other generic names have included sports coupe, hardtop coupe, or pillarless coupe. In the face of proposed rollover standards, nearly all automakers turned away from the pillarless design to a pillared version by 1976-77. === car-2hard.jpg

two-door sedan: The term sedan originally described a conveyance seen only in movies today: a wheelless vehicle for one person, borne on poles by two men, one ahead and one behind. Automakers pirated the word and applied it to cars with a permanent top, seating four to seven (including driver) in a single compartment. The two-door sedan of recent times has sometimes been called a pillared coupe, or plain coupe, depending on the manufacturer's whim. On the other hand, some cars commonly referred to as coupes carry the sedan designation on factory documents. === car2sedan.jpg

two-door station wagon: Originally defined as a car with an enclosed wooden body of paneled design (with several rows of folding or removable seats behind the driver), the station wagon became a different and much more popular type of vehicle in the postwar years. A recent dictionary states that such models have a larger interior than sedans of the line and seats that can be readily lifted out, or folded down, to facilitate light trucking. In addition, there's usually a tailgate, but no separate luggage compartment. The two-door wagon often has sliding or flip-out rear side windows. === car-2wagon.jpg

two-pack filler: All polyester fillers in use today comprise a basic filler paste and a hardener or catalyst

two-pack paint: Paint prepared by mixing two constituents, such as pigment and an acrylic resin

two-piece alloy wheel: A wheel which consists of the rim and the wheel disc or spider bolted together. The word "forged" is optional, since multi-piece alloy wheels are always forged and not cast

two-piece forged alloy wheel: A wheel which consists of the rim and the wheel disc or spider bolted together. The word "forged" is optional, since multi-piece alloy wheels are always forged and not cast

2+2: See two plus two.

two plus two: See two-plus-two.

two-plus-two: (2+2) A two-door car with seating for the driver and a front passenger and only two people in the rear. It differs from a regular two-seater in that generally three people could sit in the rear seat and possibly three in the front. Usually the rear seats are very small and suitable only for children, small pets, or extra luggage.

two second rule: The minimum gap or distance between two vehicles travelling in the same direction. As the vehicle in front of you passes a particular mark on the road or sign along the road, count two seconds and your vehicle should pass the same mark or sign. If road conditions are poor, the gap should be extended to three seconds or more. If you are following less than two seconds, there is not sufficient time to react to emergency evasive manoeuvres to avoid the possibility of hitting the vehicle in front.

two-speed: An electric motor or transmission having two speed settings (e.g., fan, windshield wiper)

two-speed axle: Axle having two selective gear ratios.

two-speed gearbox: See dual-range gearbox

two-speed transmission: An automatic transmission with just two speeds (Drive and Low) such as the GM Powerglide popular in the 1960s

two-stage carburetor:

A compound carburetor

two-stage pump: A centrifugal pump with two impellers and diffusers arranged in series

two-staged turbo: Since there is often a lag while a turbine comes up to speed, some performance cars use two (or more) turbo units, large and small, driven by different legs of the exhaust. The smaller turbos speed up quickly giving rapid response, and the larger units provide the volume needed for high power at higher rpm's. Also see turbocharger.

two stroke cycle: See two-stroke cycle engine.

two stroke cycle engine: See two-stroke cycle engine.

two-stroke cycle: The operating principle of an internal combustion engine characterized by the fact that the intake, compression, combustion, and exhaust phases overlap and require only two cycles; used mainly by some motorcycle engines. On cars, the two-stroke engine was never very popular and was never produced in the USA (although Ford is experimenting with the engine); a new two-stroke engine concept with separate lubrication system and a valve system similar to four-stroke engines may combine the benefits of both the 2-stroke and the 4-stroke systems. Two-stroke engines have the advantage of rapid low-end torque (because it gets its power stroke twice as often) while 4-strokes are better at sustained high-speed.

two-stroke cycle engine: An engine requiring one complete revolution of the crankshaft to fire each piston once. See two stroke.

two stroke: A reciprocating engine cycle in which the piston takes over some of the valve functions in order to obtain a power stroke each revolution of the crankshaft. This involves the use of ports in the cylinders which are covered and uncovered by the movements of the piston. As the piston moves down, it clears these ports so that the exhaust gases can exit and a fresh charge of mixture can enter at the same time. In a typical two-stroke engine the fuel-air mixture enters the crankcase through a reed

valve. When the piston is at the bottom of the cylinder a port is uncovered. As prior movement of the piston has compressed the mixture in the crankcase it flows into the cylinder. Further compression in the cylinder starts as soon as the piston reverses and covers the ports. At the same time compression is occurring in the cylinder, movement of the piston has created a vacuum in the crankcase which draws a fresh charge of mixture from the carburetor into the crankcase. The compressed charge is fired as the piston reaches top dead center. As expansion of the burning charge forces the piston downward, the reed valve in the crankcase closes and the mixture in the crankcase is compressed. As the piston uncovers the ports at the bottom of the stroke, compressed mixture from the crankcase enters the cylinder again and is deflected by a baffle on the piston head into the outer end of the cylinder. This incoming fresh mixture then assists in pushing the burned gases out of the cylinder and the cycle is repeated.

two-stroke: See two stroke.

two-tone horn: Two horns whose diaphragms cause a column of air to resonate at two different frequencies

two-tone paint: A paint scheme where two different colors or two shades of the same color are used on a vehicle.

two-valve engine: An engine with two valves per cylinder

two-valve head: A cylinder head with two valves per cylinder

two-way: See mobile two-way radio

two-way catalyst: See oxidizing catalyst

two-way catalytic converter:

See oxidizing converter

two-way hammer: A hammer used for dual purposes

two-way radio: See mobile two-way radio

two-way system: A turbocharging system in which, as long as the charging pressure is insufficient, the air is drawn in from a prechamber via a diaphragm valve; with rising charging pressure, the valve closes and the turbocharger delivers air via the surge tank connected to a pressure regulator

two-wheel drive: (2WD) A vehicle's drive system in which two of the four wheels (either front or rear) are driven. Compare four-wheel drive

two-wheel driven: A vehicle with two-wheel drive; also written "4x2"

type: See motor wheel type

type A motorhome: A large, most luxurious motorized recreational vehicle. It is constructed on a bare, specially designed motor vehicle chassis. It is the most spacious and includes most luxuries: basement storage, washer & dryer, satellite dishes, VCRs, back-up cameras, hydraulic levelling, security systems, and even hot tubs.

type approval certificate: A British certificate issued by the Department of Transport denoting that a particular vehicle type meets official requirements

type axle: See elliot type axle

reverse-elliot type axle type B motorhome: Also called a "van camper," it is a customized cargo van which includes temporary sleeping, eating, and bathroom facilities. It is the most economical, versatile, and maneuverable of the motorized recreational vehicles. It is narrower than other RVs because it uses the space within the existing van body. However, most are equipped with a raised roof and sometimes a dropped floor to provide full stand-up room.

type C motorhome: Also called a "mini-motorhome," is built on the frame and front cab section of a manufacturer's van. A sleeping bunk is mounted above the cab as well as one in the back. It features full sleeping, kitchen, dining, and bathroom facilities.

type designation: A spark plug designation indicating seat and thread type, version, heat range code number, reach, spark position, and electrode material

type symbol: A spark plug designation indicating seat and thread type, version, heat range code number, reach, spark position, and electrode material

tyre: A British term for tire. The British smile when they see a sign saying "Goodyear tires" which implies lethargy in Goodyear.

TireX: A trade name for a form of rayon produced exclusively for tire cords.

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [Ub] [Uj] [Ul] [Um] [Un] [Up] [Ur] [Us]

UAIB: Acronym for "Union of Automobile Importers in Bulgaria"

u-bolt: U-shaped bolt for attaching leaf springs to the axle or securing exhaust pipes, ring bolts, and shackles

u brake: Heavy-duty centerpull mountain bike brakes that affix to frame posts.

u-brake: Heavy-duty centerpull mountain bike brakes that affix to frame posts.

u brakes: Heavy-duty centerpull mountain bike brakes that affix to frame posts.

u-brakes: Heavy-duty centerpull mountain bike brakes that affix to frame posts.

U-cylinder engine: See twin-piston engine

UDC: See upper dead center

UIC: Acronym for "universal integrated circuit"

UJ: See universal joint

u joint: See universal joint.

U-joint: Abbreviation for "universal joint." Ukravtoprom: Acronym for "Association of Ukrainian Motor Vehicle Manufacturers."

ULC: Acronym for "Underwriter's Laboratories."

ULCC: Acronym for Ultra Large Crude Carriers. Tankers larger than 300,000 dwt.

ULEV: Acronym for "Ultra Low Emission Vehicle Standards."

ULP: Acronym for "Ultra-Low Profile." A tire with a low aspect ratio

ultimate cornering force: The maximum steady-state cornering or side force generated by the tires when a vehicle is driven around a skidpad with the speed increased gradually until if it were increased further the vehicle would slide off course.

ultra Low Emission Vehicle Standards: (ULEV) State and federal governments set standards for automakers developing vehicles that will output lower emission levels. Each state determines their own levels as does the federal government. California and New York have some of the most stringent laws. Once the requirements are met for a specific vehicle, the automaker may call that car or truck a Low Emission Vehicle or LEV.

ultra 6:

A freewheel designed to allow six cogs to fit into the space normally taken up by five.

ultra 7: A freewheel designed to allow seven cogs to fit into the space normally taken up by six.

ultrasonic welding: A high-tech welding procedure used for metals (e.g., in wire bonding of integrated circuits) and plastics. Pressure is applied to the parts to be joined and ultrasonic vibrations are transmitted through the materials; frictional heat at the materials interface causes localized melting and coalescence; ultrasonic welding is fast and produces precise, strong welds

ultraviolet rays: Energy waves that emanate from the electrodes and the welding flames of such a frequency that these rays are in the ultraviolet ray light spectrum.

umbrella: An oil deflector placed near the valve tip to throw oil from the valve stem area. See valve umbrella.

unbalance: A condition of wheels which are not balanced. Also see tire unbalance

unburnt hydrocarbons: Pollutant (basically petrol vapor) released into the atmosphere as an exhaust gas, due to incomplete combustion

uncluttered: An orderly, neat instrument panel that is free of irrelevant detail

UNC thread: Acronym for Unified National Coarse thread; one of the screw threads used on British cars. See national coarse thread. Compare UNF thread

underbody:

The underside of a car. Also see PVC underbody treatment

underbody coating: A coating of the underbody of a vehicle, usually with organic coating materials (plastic, wax, bitumen-based products), to protect it from mechanical damage and corrosion

underbody protection: A coating of the underbody of a vehicle, usually with organic coating materials (plastic, wax, bitumen-based products), to protect it from mechanical damage and corrosion

underbody sealing compound: See underseal

underbody structure: The structural members and flat panels of the bodywork on the chassis. Also called substructure

underbody treatment: See PVC underbody treatment

underbrake: To run farther into the turns than normal without applying much brake

undercarriage: See underbody structure

undercoat: [1] All of the products used to prepare the surface to receive color coats (primers, surfaces, putties, sealers, etc.). [2] A rustproof coating with sound-deadening properties applied to the underbody

undercoating: The material sprayed on the underside of the automobile, under the hood, trunk lid, etc. which is designed to deaden sound and prevent the formation of rust.

undercoats: See undercoat.

undercure: A condition in which the vulcanization or curing has not been adequate.

undercut: A depression at the toe of the weld which is below the surface of the base metal.

underfilm corrosion: See creepage

underfloor: The underside of a car

underfloor mid-engine: A design, introduced on the Toyota Previa minivan, where the engine is located below the passenger compartment, between front and rear

underframe: The underbody backbone of a car, both for unitary or chassis designs

underhead collar: A washer fitted under the head of a bolt or screw

underhood area: The engine compartment

underinflated tire: A tire which has too little air in it, causing increased wear at the tread edge

underinflation: Insufficient air pressure in a tire for the amount of load carried.

underpowered:

A description of a vehicle with an engine that provides less power than is necessary for acceptable performance; especially noticeable when accelerating, passing, or going uphill

underseal: [1] A rustproof coating with sound-deadening properties applied to the underbody. [2] To apply underseal. See PVC underseal coating undercoat underseal coating: See pvc underseal coating

under seat panel: See seat well

undershield: A body accessory panel made from tough, oil-resistant plastic for fitting on cars that do not have a standard wheel housing panel. It is designed to protect the upper inside area of the fender and the door hinge area from splashes of water and mud deposits; it is also used as standard equipment on some modern cars to replace the traditional steel wheel housing panel

underside: The lower side of the underbody, i.e., the surfaces that face the road surface

underside panelling: A smooth cover on the underside of a car for improving aerodynamics below the vehicle, e.g., on the Porsche 911 and 928

under sill panel: A separate closing panel or section used on cars where the inner sill or side member consists of several separate parts; it forms the bottom of the inner sill and connects the sill area to the floor panel

undersize tire: The use of a tire having insufficient carrying capacity for the load. Also replacing original-equipment tire size with a smaller size of sufficient capacity, thus reducing

unladen weight.

underslung: suspended below a supporting member, e.g., of a chassis suspended below the axles

underslung frame: A frame design of the pre-war era whose characteristic feature is that the frame members run below the axles

undersquare engine: See under square engine

under square engine: An engine in which the bore diameter is smaller than the length of the stroke. Also called long stroke engine

under-square engine: An engine in which the bore diameter is smaller than the length of the stroke.

understeer: The tendency for a vehicle, when negotiating a corner, to turn less sharply than the driver intends. The front end wants to run wide in a turn. To correct this problem, the suspension needs to be stiffer in the front or softer in the rear. A front-engine vehicle has a natural tendency to plow straight ahead on turns (i.e., understeer) unless its suspension is adjusted to counteract it. Sometimes called "push." Also see roll understeer

undertray: The bottom panel of multi-layer or complex underbody panel assemblies, which faces the road surface

undertread: See breaker. A cushioning layer between the belt layers and the tread in radial tires.

unequal-length wishbone suspension: A double wishbone suspension system in which the upper wishbone is shorter than the lower one, with both converging slightly at the wheel hub; reduces tire wear due to variations in track and camber angle when cornering

unequal wishbones: A colloquial term for unequal-length wishbone suspension

UNF thread: Unified National Fine thread; one of the screw threads used on British cars. See national fine thread. Compare UNC thread

unibody construction: A manufacturing process where sheet metal body parts are combined with stressbearing elements to form the body and chassis as a single piece, as opposed to attaching body parts to a frame. See unitized construction unitary construction unicycle: A one-wheel cycle having pedals attached to the axle and a saddle attached to the upper end of the fork tubes.

unidirectional flow scavenging: A scavenging process of two-stroke engines. One of the characteristic features is that the flow of fresh charge does not follow a path opposed to that of the burnt charge; scavenging and exhaust ports are not located at the same stroke end of the piston but rather are staggered, i.e., the fresh charge flows along the length of the cylinder without its direction being reversed. This process is widely used in large engines, e.g., for ships

uniflow scavenging: A scavenging process of two-stroke engines. One of the characteristic features is that the flow of fresh charge does not follow a path opposed to that of the burnt charge; scavenging and exhaust ports are not located at the same stroke end of the piston but rather are staggered, i.e., the fresh charge flows along the length of the cylinder without its direction being reversed. This process is widely used in large engines, e.g., for ships

Unified National Coarse thread: See UNC thread

Unified National Fine thread: See UNF thread

uniform corrosion: Corrosion occurring over the entire exposed surface. The opposite is localized corrosion

union nut: A nut used to secure the connection between pipes or rods

uni-servo brake: A servo brake with one single-end wheel cylinder and two self-energizing brake shoes

unit: See airbag unit enrichment unit inflator unit lamp unit light unit metering unit unitary construction: A modern chassis layout with no separate frame, using the sheet metal parts of the vehicle body or floorpan as structural members which also carry all suspension parts; introduced by Citroëat&n in 1934 and by GM/Opel Olympia in 1935. Also called monocoque

unit body: Unit body: Type of body/frame construction in which the body of the vehicle, its floor plan and chassis form a single structure. Such a design is generally lighter and more rigid than a vehicle having a separate body and frame.

unit construction: Integrated unit consisting of the engine and gearbox within the same casing

united States Council for Automotive Research:

(USCAR) an organization founded by Chrysler, Ford, and General Motors to strengthen the technology base of the domestic automotive industry through research and co-operation.

unit engine: A term used for motorcycles where engine and gearbox are accommodated in one common housing

unitized construction: A type of body construction that doesn't require a separate frame to provide structural strength or support for the car's mechanical components. A unitized body can employ monocoque construction, or it can utilize strong structural elements as an integral part of its construction.

universal: See ball universal cardan universal hardy-spicer universal joint hooke universal impact swivel ball universal joint Rzeppa-type universal joint universal joint: (UJ) A flexible double-pivoted joint that allows driving power to be carried through two shafts that are at an angle to each other. It consists of two Yshaped yokes and a cross-shaped member called the spider. The four arms of the spider are assembled into bearings in the ends of the two yokes. With the normal cross-and-two-yoke universal joint there is some change in speed when the driveshaft and the driven shaft are at an angle to each other. The change in speed occurs because the driven yoke and driven shaft speed up and then slow down twice with every revolution of the drive line. The greater the angle between the drive and driven shafts, the greater the speed variation. To eliminate this speed variation, which results in increased wear of the affected parts, constant velocity joints are used on many cars. In front drive vehicles, it is called the constant velocity joint. Also called "Hooke joint" or "cardan joint." See ball universal joint constant velocity universal joint hardy-spicer universal joint impact swivel ball universal joint

Rzeppa-type universal joint universal joint socket: A socket with universal joint to reach into cramped working areas universally jointed shaft: See cardan shaft

universal spark plug socket: A spark plug socket with universal joint for reaching hard-to-get-at spark plugs

unladen weight: The actual weight of a vehicle or combination with no payload. See tare weight.

unleaded gas: Gasoline which has no tetraethyl lead. See lead free.

unleaded gasoline: See unleaded gas.

unloaded radius: See free radius.

unloader: See self-unloader

unloader valve: See delivery valve

unmanned machinery spaces: Engine room or space fitted with sensors and controls for monitoring and responding to machinery operating conditions. This makes it unnecessary for personnel to be present in the space at all times

unseating: See bead unseating

unsprung mass: See unsprung weight

unsprung weight: This refers to all parts of the vehicle that are not supported by the suspension system, wheels, tires, etc. Also see sprung weight.

updraft carburetor: A carburetor in which the air passes upward through the carburetor into the intake manifold.

updraught carburetor: See updraft carburetor

uph: Abbreviation for "upholstery."

upholstery: (Uph) The fabric used to cover the seats and other panels. See cloth upholstery full leather upholstery upper ball joint: A mechanical pivot located at the end of the upper suspension links.

upper-cylinder lubrication: A method of introducing a lubricant into fuel or intake manifold in order to permit lubrication of upper cylinder, valve guides, etc

upper dead center: See before upper dead center top dead center upright sitting position: Sitting straight up on a motorcycle with raised handlebars, where your hands are level with the bend in your elbows. It is the easiest and most comfortable position in

which to ride a bike because no part of your body is faced with undue stress based on position. On motorcycles where the rider is leaning forward or backward, backs and hands start to ache.

upset: [1] A widening of the diameter by pounding or compressing the ends of a pipe or rod. [2] Turning a vehicle over because of an accident.

upshift: Shifting to a higher gear. In Britain it is called "upward change."

upside-down forks: Telescopic forks on a motorcycle in which the lower section, on which the wheel is mounted, telescopes into the fixed upper tube. They are sometimes called inverted telescopic forks on earlier motorcycles

up-stroke: The ascending stroke of a piston, from BDC to TDC

upthrust: The upward force produced when an object is immersed in a liquid or gas.

upward change: A British term for shifting to a higher gear. In North America it is called "upshift"

urban driving: Driving in cities and towns where the common speed limit is 50 kph (30 mph) with traffic lights, etc. Also called metro driving

urban test cycle: A driving cycle that simulates driving in a town

USAC: Acronym for "United States Auto-Sound Challenge."

USB:

Acronym for "Universal Serial Bus."

USCAR: Acronym for "United States Council for Automotive Research"

U section: A sheet metal section often used on underbody structural members; it differs from a box section in that the fourth wall of the box is missing, i.e., its cross section more or less resembles the letter "U"

used car dealer: A proprietor who sells used cars. In some instances it is part of a new car dealership

used vehicle: vehicle that has been previously owned or driven. Also called preowned.

ute: An Australian term for a truck

utility truck: A pick-up truck

utility vehicle: See sport utility vehicle

UV absorber: Any substance that absorbs ultraviolet radiation, then dissipates the energy in a harmless form; used in plastics and rubbers to decrease light sensitivity

UV stabilizer: Any substance that absorbs ultraviolet radiation, then dissipates the energy in a harmless form; used in plastics and rubbers to decrease light sensitivity

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DICTIONARY OF AUTOMOTIVE TERMS [Home][A][B][C][D][E][F][G][H][I][J][K][L][M] [N][O][P][Q][R][S][T][U][V][W][X][Y][Z] [Va][Ve][Vi][Vo][Vu]

V: [1] A letter rating for tires to indicate that they are theoretically rated for speeds up to 210 kph (130 mph), as in P220VR15. The next higher rating is W and the one lower rating is H. [2] A letter indicating a valve configuration as in 16v meaning a 16 valve engine. [3] A letter indicating the configuration of the cylinders in an engine as in V-8

V-4: See V-four

V-6: See V-six

V-8: See V-eight

V-10: See V-ten

V-12: See V-twelve

V-16: See V-sixteen

VA: Value analysis.

vac:

See master vac master vac servo unit vac servo: See master vac servo unit

vac servo unit: See master vac servo unit

vacuum: An enclosed area in which the air pressure is below that of the surrounding atmospheric pressure. See air-valve carburetor constant vacuum manifold vacuum ported vacuum advance pulse vacuum hublock venturi vacuum vacuum advance: A mechanism on the side of the distributor that automatically varies the instant at which the spark occurs as a function of intake manifold vacuum. Vacuum advance provides the additional advance that is needed when the engine is operating at part throttle. At part throttle less air-fuel mixture gets into the cylinders and the mixture takes longer to burn after it is ignited. Because the mixture burns more slowly, the piston will be past top dead center and moving down before the mixture has a chance to burn and produce high power. As a result much of the power in the fuel will be lost. The vacuum advance mechanism consists of a flexible spring-loaded diaphragm connected by a linkage to the breaker plate on which the points are mounted. The sealed side of the diaphragm is connected by a tube to the carburetor. The throttle valve is below the vacuum passage in the carburetor air horn so there is no vacuum advance when the engine is idling because the throttle is closed. However, when the throttle is partly open, intake manifold vacuum pulls the diaphragm in and this causes the breaker plate to rotate a few degrees and advance the timing. With wide-open throttle there is very little vacuum in the intake manifold so there will be no vacuum advance. In most instances the vacuum advance is disconnected before checking the timing and point gap. See ported vacuum advance speed control vacuum advance

vacuum advance mechanism: See vacuum advance

vacuum advance unit: See vacuum advance

vacuum assisted brake: See brake booster.

vacuum assisted brakes: See brake booster.

vacuum booster: A small diaphragm vacuum pump, generally in combination with the fuel pump, that is used to bolster engine vacuum during acceleration so that the vacuum operated devices will continue to operate.

vacuum brake booster: A device directly connected to the master cylinder and mounted on the engine side of the bulkhead, which uses engine manifold vacuum to produce additional braking force

vacuum capsule: A pneumatic actuator that converts air pressure differences into a regulating shortstroke movement; the circular, flat capsule has a spring-loaded diaphragm with a lever attached

vacuum chamber: A pneumatic actuator that converts air pressure differences into a regulating shortstroke movement; the circular, flat capsule has a spring-loaded diaphragm with a lever attached

vacuum check valve: (VCK-V) a one-way valve used to retain a vacuum signal in a line after the vacuum source is gone

vacuum control:

A load-dependant mechanical ignition timing, controlled by the inlet manifold vacuum

vacuum control switch: A switch that monitors the vacuum signal enabling the ECU to recognize open or closed throttle (idle) operation

vacuum control unit: An assembly for load-dependent ignition timing controlled by the intake manifold vacuum, consisting of a vacuum capsule with a spring-loaded diaphragm linked to the breaker plate

vacuum control valve: (VCV) a ported vacuum switch, controls vacuum to other emission devices during engine warm up

vacuum delay valve: (VDV) a valve used by GM to bleed ported vacuum to the vacuum advance unit through a small orifice and control vacuum advance rate. Used to retard or delay the application of a vacuum signal. Also called delay valve

vacuum differential valve: (VDV) a device used in a Thermactor system with a catalyst that sense intake manifold vacuum and triggers the bypass valve to dump injection air to the atmosphere during deceleration

vacuum filter: A filter which removes electrical noise from the vacuum signal sent from the vacuum sensor to the ECU

vacuum gage: See vacuum gauge.

vacuum gauge: A gauge used to determine the amount of vacuum existing in a chamber.

vacuum hose:

A pipe which connects the intake manifold to the vacuum brake booster

vacuum hublock: See pulse vacuum hublock

vacuum ignition-timing control: See vacuum control

vacuum modulated EGR: An exhaust gas recirculation in which the amount of exhaust gas admitted to the intake manifold depends on a vacuum signal controlled by throttle position. When the throttle is closed, at idle or during deceleration, there is no vacuum signal to the EGR valve; as the throttle is opened, a vacuum signal is supplied causing the EGR valve to open

vacuum modulator: A small unit attached to the automatic transmission. If the vehicle tends to stay in low gear, shifts with difficulty or produces whitish smoke, has an automatic transmission, and is constantly low in transmission fluid, try replacing the vacuum modulator before undertaking major repairs. Most vacuum modulators simply screw into place. See modulator.

vacuum operated exhaust heat control valve: (VHC) a vacuum operated heat riser valve used by Ford to cause the exhaust to flow through the intake crossover passage for preheating of the air-fuel mixture

vacuum power motor: A device for use in opening doors in heating and air conditioning systems

vacuum power unit: A device for use in opening doors in heating and air conditioning systems

vacuum pump: A diaphragm type of pump used to produce a vacuum.

vacuum reducer valve: (VRV) A valve used by GM to limit the amount of vacuum governing the ignition advance mechanism of the distributor; on some ignition systems, a VRV is used to

reduce intake manifold vacuum when the coolant temperature is above 104°C (220°F), in order to prevent or reduce detonation

vacuum regulator valve three and four-port: (VRV) this type of vacuum regulator valve is used to control the vacuum advance to the distributor

vacuum regulator valve two-port: (VRV) this vacuum regulator provides a constant output signal when the input level is greater than a preset level. At a lower input vacuum, the output equals the input

vacuum reservoir: (VRESER) stores excess vacuum to prevent rapid fluctuations and sudden drops in a vacuum signal, such as during acceleration

vacuum restrictor: (VREST) controls the flow rate and/or timing in actions to the different emission control components

vacuum retard: A vacuum control unit for retarding the spark

vacuum retard delay valve: (VRDV) delays a decrease in vacuum at the distributor vacuum advance unit when the source vacuum decreases. Used to delay release of vacuum from a diaphragm -a momentary vacuum trap

vacuum retard unit: A vacuum control unit for retarding the spark

vacuum runout point: This refers to the point reached when a vacuum brake power piston has built up all the braking force it is capable of with the vacuum available.

vacuum sealing apparatus: A component in continuous zinc vapor deposition lines through which steel strips enter the deposition chamber and which prevents a build-up of pressure within the chamber

vacuum sensor: A sensor which detects changes in manifold pressure in comparison to barometric pressure; such changes indicate the need for an adjustment in air/fuel mixture and electronic spark timing to maintain efficient engine operation. Also called manifold pressure sensor, pressure differential sensor, or manifold vacuum sensor

vacuum servo: See vacuum brake booster

vacuum solenoid: On some engines, a vacuum solenoid controlled by an electrical sensor switch is used to control the EGR valve

vacuum suction cup: A hand tool for pulling out shallow body dents and for lifting flat, heavy objects such as windshields or sheet metal

vacuum suspended power booster: A type of power booster that contains vacuum in both chambers of the booster when the brake pedal is at rest. When the pedal is applied, the rear chamber is vented to the atmosphere, causing the diaphragm of the booster to move toward the master cylinder which assist the driver in the application of the brakes

vacuum switch: See thermal vacuum switch

vacuum switching valve: (VSV) an electrically controlled vacuum switching valve used to control emission control devices

vacuum tank: A tank in which a vacuum exists. It is generally used to provide vacuum to a power brake installation in the event engine vacuum cannot be obtained. The tank will supply several brake applications before the vacuum is exhausted.

vacuum timing control:

See vacuum control

vacuum transmitting valve: (VTV) a valve used to limit the rate of vacuum advance

vacuum unit: See vacuum control unit

vacuum valve: See thermal vacuum valve

vacuum vent valve: (VVV) controls the induction of fresh air into a vacuum system to prevent chemical decay of the vacuum diaphragm that can occur on contact with fuel

VAF: Acronym for vane air-flow meter

valance: A panel used to conceal structural detail or to provide extra protection. See rear corner valance rear quarter valance rear valance valet parking: The parking of your car by a parking attendant

valet switch: On some alarm systems, a switch to override the alarm system for valet parking, car washes, etc.

value: See actual cash value cd value duty paid value

expected residual value net sales value ph value residual value stated residual value value added: See census value added

value of shipment: summation of value of shipments produced by establishment, receipts of custom and repair revenue.

valve: A device used to either open or close an opening to allow or prevent the flow of a liquid or gas from one place to another. There are many different types. See abs relay valve accumultor valve air-valve carburetor air control valve air gulp valve air select valve air switching valve anti-backfire valve anti-percolation valve antibackfire valve antipercolation valve aspirator valve back pressure modulated valve back pressure valve ball valve bleeder valve bleed valve blow-off valve blowoff valve boost control valve boost valve brake proportioning valve burned valves butterfly valve bypass valve cam follower

change valve check valve choke valve combination valve compensator valve control valve delay valve delivery valve discharge valve disc valve diverter valve dropped valve dump valve eac Valve eas Valve economizer valve egr valve electric air control valve electric air switching valve exhaust valve opens exhaust valve expansion valve four valve frequency valve fuel injector nozzle fuel injector valve governor valve gulp valve hairpin valve spring heat control valve heat control valve high pressure relief valve hydraulic valve lifter idle stop valve inlet valve intake valve closes intake valve opens intake valve kickdown valve kneuter valve lightened valve load-sensitive proportioning valve manifold heat control valve manual valve metering valve modulator valve

mushroom valve needle valve negative back pressure modulated valve negative back pressure valve negative transducer EGR valve oil cooler bypass valve oil drain valve oil filter bypass valve oil filter oil filter bypass valve one-way valve outlet valve overhead valves overrun control valve oversize valve guide parallel valves PCV valve petcock poa suction throttling valve pop-off valve poppet valve power valve pressure limiting valve pressure regulating valve pressure regulator valve pressure relief valve Presta valve primary valve progressive valve spring progressively wound valve spring proportioning valve quick take-up valve RAVE valve reed valve reed valve induction timing regulated proportioning valve relay valve relief valve residual check valve residual pressure valve reverse inhibitor valve rotary disc valve rotary valve running-on control valve safety valve scavenging valve Schrader valve

shift valve shuttle valve sleeve valve slide valve sodium-cooled exhaust valve sodium-cooled valve solenoid valve sponge rubber valve spool balance valve spool valve suction throttling valve temperature valve thermal time valve thermal vacuum valve throttle valve tire valve unloader valve vacuum reducer valve valve-in-head engine valve clearance valve cover valve duration valve face valve float valve grinding valve guide valve keeper valve key valve lash valve lift valve lifter valve margin valve oil seal valve overlap valve port valve rotator valve seat valve seat grinding valve seat insert valve spring valve stem valve tappet valve timing valvetrain valve umbrella variable valve actuation

x-valve valve actuation: See variable valve actuation

valve adjusting screw: A screw at the end of a rocker which bears on a pushrod; used to tilt the rocker and thus adjust the valve clearance

valve and transducer assembly: This type of EGR valve consist of a modified ported EGR valve and a remote transducer. Works the same way as an integral backpressure transducer EGR valve

valve angle: A segment of the full circle of a rotary disc valve cut out to admit the fresh charge into the cylinder

valve aperture: See valve hole

valve assembly: A device through which a tire is inflated. It includes a valve stem, valve core, and valve cap. Also see control valve assembly

valve block: See control valve assembly

valve body: Part of the valve assembly containing plungers, pistons, springs, etc.

valve body housing: A housing which incorporates the bores in which the valve spools slide and the canals which channel the oil flow

valve body separator plate: A plate sandwiched between two gaskets which separates the upper and lower parts of the valve body

valve bounce: The bouncing of a valve on its seat due to the valve spring resonating at very high engine speeds. See bounce. Also called "flutter."

valve bushing: See valve guide

valve cap: A screw-on cap to prevent the entry of dirt and dust into the tire valve. It does not keep the air in -- the valve core does that.

valve carburetor: See air valve carburetor

valve clearance: The distance between the small end of the valve stem and the rocker arm or valve lifter. This gap is necessary to compensate for expansion due to heat. Also called valve lash.

valve clearance depression: A recess in the piston crown

valve closes: See exhaust valve closes and intake valve closes valve core: A check valve within a tire air valve which permits air pressure chucks without undue loss of air pressure. The core should not be considered a valve seal.

valve cover: A long metal lid located on the top of the cylinder head on vehicles with overhead camshafts. The valve cover is removed when the valves need adjusting. The British term is "rocker box" or "rocker cover."

valve cover gasket: A gasket between the cylinder head and the valve cover; usually either a flat paper or cork gasket or an O-ring. The British term is "rocker cover gasket."

valve crown: See valve head

valve cut-out: On some four-valve engines at low speed the main rocker arms open only two valves per combustion chamber in order to keep the energy of the gases at a high level; with increasing rpm, the energy of the gases becomes sufficiently strong for the remaining two valves to be opened via hydraulic locking bolts

valve diameter: Intake valves can be distinguished from exhaust valves by their larger diameter

valve duration: The length of time, measured in degrees of engine crankshaft rotation, that a valve remains open.

valve engine: See sixteen valve engine

valve extension: Extra length added to a tire valve stem for greater accessibility particularly on inside duals.

valve face: The outer lower edge of the valve head. The face contacts the valve seat when the valve is closed.

valve float: A condition where the valves in the engine are forced back open before they have had a chance to seat. Brought about (usually) by extremely high rpm. The valve lifters lose contact with the cam lobes because the valve springs are not strong enough to overcome the momentum of the various valvetrain components. The onset of valve float prevents higher-rpm operation. Extended periods of valve float will damage the valvetrain. Also called valve bounce

valve follower: See valve lifter.

valve gear: A mechanism that operates the intake and exhaust valves; includes the cams, pushrods, rocker arms, etc. but not the valves themselves

valve grinder: A special automotive tool consisting of a wooden shaft and rubber suction cup(s) for hand grinding valves. Also see suction valve grinder

valve grinding: Renewing the valve face area by grinding on a special grinding machine.

valve grinding compound: An abrasive compound used for refacing valve seats. The suction cup is placed on the valve head and the valve is pressed into the seat; turning the handle between one's hands will grind the valve into its seat; always use with grinding paste. Not to be confused with "valve seat cutter" which is used to cut worn valve seats to a specific angle

valve grinding tool: A special automotive tool consisting of a wooden shaft and rubber suction cup(s) for hand grinding valves

valve guide: The cylindrical hole which is located in the cylinder head or block through which the stem of the poppet valve passes. It is designed to keep the valve in proper alignment. It also serves as a bearing surface. Some guides are pressed into place and others are merely drilled in the block or in the head metal. Also see oversize valve guide

valve guide driver: A tool for installing valve guides

valve guide reamer:

A tool used to enlarge worn valve guides to accommodate oversized valve stems

valve guide remover: A drift punch for driving out valve guides

valve guide seal: See valve stem seal

valve head: The surface of the large end of a valve.

valve hole: The hole in the rim of a wheel for mounting tubeless tires. Tubeless car tires commonly have a snap-in valve consisting of a rubber molding bonded to the metal stem casing. The rubber molding has a groove formed at the base; when the valve is pulled through the valve hole, the pliable rubber base snaps into position. Commercial vehicle valves for tubeless tires are all metal; they are attached to the rim and the valve hole by an extended thread formed at the base and secured by a nut. Airtight sealing is achieved by either an O-ring or a fiat and flanged rubber washer. Commercial vehicle valve stems may have a single, double, or triple bend to accommodate different rim profiles and single and twin wheel combinations

valve induction: See reed valve induction timing

valve induction timing: See reed valve induction timing

valve in head engine: See valve-in-head engine.

valve-in-head engine: An engine in which both intake and exhaust valves are mounted in the cylinder head and are driven by pushrods or by an overhead camshaft. Also called "I-head engine" or "Overhead-valve engine."

valve job:

Replacing or regrinding old valves

valve keeper: A small unit that snaps into a groove in the end of the valve stem. It is designed to secure the valve spring, valve spring retaining washer and valve stem together. Some are of a split design, some of a horseshoe shape, etc. Also called "valve key" or "valve retainer."

valve key: Key, keeper, washer, or other device which holds valve spring cup or washer in place on valve stem See valve keeper.

valve lapper: a special automotive tool for grinding (lapping) valves into valve seats; some types are power-operated, thus allowing faster grinding compared with standard suctiontype valve grinding tools

valve lapping compound: See valve grinding compound

valve lash: Valve tappet clearance or total clearance in the valve operating train with cam follower on camshaft base circle. Also see valve clearance

valve lift: Distance a valve moves from the full closed to the full open position. It is usually about a quarter of the diameter of the port.

valve lifter: [1] The cylindrically shaped component that presses against the lobe of a camshaft and moves up and down as the cam lobe rotates. Most valve lifters have an oillubricated hardened face that slides on the cam lobe. So-called "roller lifters," however, have a small roller in contact with the cam lobe -- thereby reducing the friction between the cam lobe and the lifter. Also called "valve follower" or cam follower. [2] A tool that compresses valve springs for removal and replacement. Also see hydraulic valve lifter

valve lock:

Key, keeper, washer, or other device which holds valve spring cup or washer in place on valve stem

valve margin: The width of the edge of the valve head between the top of the valve and the edge of the face. Too narrow a margin results in preignition and valve damage through overheating.

valve oil seal: A neoprene rubber ring that is placed in a groove in the valve stem to prevent excess oil entering the area between the stem and the guide. There are other types of these seals.

valve opens: See exhaust valve opens intake valve opens valve overlap: A certain period in which both the intake and exhaust valve are partially open. The intake is starting to open while the exhaust is not yet closed. It is usually expressed in degrees of crankshaft rotation and determined by the valve timing, valve overlap is necessary for the efficient flow of gases in and out of the combustion chamber

valve plate: See valve body separator plate

valve port: The opening, through the head or block, from the intake or exhaust manifold to the valve seat.

valve principle: The original method of ABS control using an electrically operated valve to control the air pressure

valve retainer: See valve keeper.

valve rotator: A unit that is placed on the end of the valve stem so that when the valve is opened and closed, the valve will rotate a small amount with each opening and closing. This gives longer valve life. Also called roto cap

valve seat: The area onto which the face of the poppet seats when closed. The two common angles for this seat are forty-five and thirty degrees.

valve seat cutter: A special automotive tool with carting blades for use with power tools; used to cut worn valve seats with 30° or 45° angles

valve seat face: An annular part of a valve head located at the valve seat of the cylinder head

valve seat grinding: Renewing the valve seat area by grinding with a stone mounted upon a special mandrel.

valve seat insert: A hardened steel valve seat that may be removed and replaced. The use of valve seat inserts dispenses with the need for lead in the fuel to act as a lubricant between the valve head and seat Also see insert.

valve seat ring: A ring-shaped insert of a harder metal than that of the cylinder head; the use of valve seat inserts dispenses with the need for lead in the fuel to act as a lubricant between the valve head and seat

valve shim: A calibrated shim used to adjust valve clearance on OHV engines with bucket tappet assembly; for adjustment, a calibrated valve shim is placed or removed from between tappet and cam

valve shim pliers: A special automotive tool for the removal and installation of valve shims

valves-in-receiver unit: (VIR) a component used on GM system, in which the thermostatic expansion valve, POA suction throttling valve, the receiver-drier, and, if equipped, the sight glass are all combined into one assembly

valve slot: Tube-type tires require a valve slot instead of a valve hole to allow the tire valve to be removed from the rim; a thread adaptor is molded to a circular rubber patch vulcanized to the inner tube; the valve stem casing is then screwed onto the tube adaptor

valve spool: In an automatic transmission, a sliding cylindrical internal part of a valve with one or more sections of reduced diameter

valve spring: A small coil spring that closes the valve after it has been opened by the cam, and prevents the valve from bouncing on its seat. The action of the spring keeps the lifter in contact with the cam. If the spring is weak, noise will be generated and the valve, spring, lifter and cam will be subjected to hammer-like blows that cause metal fatigue. See hairpin valve spring progressively wound valve spring progressive valve spring valve spring cap: The retaining cap (of intake or exhaust valves) which secures the valve keeper on the valve stem

valve spring collar: The retaining cap (of intake or exhaust valves) which secures the valve keeper on the valve stem

valve spring compressor: A special automotive tool used to compress valve springs for removal and replacement; the most common type is a c-shaped clamp

valve spring depressor:

A lever-type tool used to depress valve springs, e.g., for removal and installation of valve stem seals

valve spring lifter: A pliers-type tool with two expanding jaws, used to lift and compress valve springs for removal and replacement

valve spring retainer: See valve spring cap

valve spring seat: A seat retaining the bottom of the valve spring

valve stem: The long cylindrical portion of the valve that moves up and down in the valve guide.

valve stem seal: The oil seal between the valve and the cylinder head which prevents excessive oil leakage from the top of the cylinder head into the combustion chamber

valve stem seal installer: A sleeve-type tool used to push down valve stem seals for installation

valve stem seal pliers: A special plier for removing valve stem seals on overhead camshaft engines

valve switch: See throttle valve switch

valve system: See vtec Valve system

valve tappet: An adjusting screw to obtain the specified clearance at the end of the valve stem (tappet clearance). The screw may be in the top of the lifter, in the rocker arm, or in the case of the ball joint rocker arm, the nut on the mounting stud acts in place of a

tappet screw.

valve timing: Adjusting the position of the camshaft to the crankshaft so that the valves will open and close at the proper time. Also see variable valve timing

valve tip: The upper end of the valve that contacts the rocker arm

valve train: See valvetrain.

valvetrain: The various parts making up the valve and its operating mechanism which causes the valves to open and close.

valve umbrella: A washer-like unit that is placed over the end of the valve stem to prevent the entry of excess oil between the stem and the guide. Used in valve-in-head installations.

van: [1] A covered road vehicle for carrying goods. [2] A recreational vehicle based on the body of a commercial van, usually with comfortable, plush interior trim, often with a bed. See box van cube van light van van camper: See type B motorhome

vane: A thin plate that is affixed to a rotatable unit to either throw off air or liquid, or to receive the thrust imparted by moving air or liquid striking the vane. In the first case it would be acting as a pump and in the second case as a turbine. See external vane pump

hall vane switch internal vane pump rotary vane pump vane air-flow meter: (VAF) a sensor with a moveable vane connected to a potentiometer calibrated to cause the amount of air flowing to the engine

vane air temperature sensor: (VAT) located inside the vane airflow meter housing; sense the temperature of the air flowing into the engine

vane-in-rotor pump: A sliding-vane pump

vane-in-stator pump: See external vane pump

vane pump: A type of rotary pump with either a slotted rotor and sliding vanes or a rotor with hinged vanes; typically used for air pumps in secondary air injection systems, as a compressor in air conditioning systems, and in some transmission systems. See external vane pump internal vane pump rotary vane pump vane switch: See hall vane switch

vane wheel impeller: An impeller with straight radial vanes

vanity mirror: A mirror on the inside of a sun visor

vanity plate:

A personalized licence plate

vapor: The gaseous form of a liquid which is usually created by heating the liquid. See fuel vapor fuel vapor recirculation system vapor canister: See activated carbon canister

vapor degreasing: A type of cleansing procedure to remove grease, oil, and loosely attached solids from metals; a solvent such as trichlorethylene is boiled, and its vapors are condensed on the metal surfaces

vapor deposition: A production of a surface film of metal on a heated surface, usually in a vacuum, either by decomposition of the vapor of a compound at the work surface, or by direct reaction between the work surface and the vapor. Also see zinc vapor deposition

vapor injection: See water injection.

vaporization: Breaking the gasoline into fine particles and mixing it with the incoming air.

vaporize: The action of converting a liquid into a mist or vapor by breaking it into small particles and mixing it with air. The design of the carburetor and fuel injectors vaporizes gasoline to produce a combustible fuel-air mixture. If it is not vaporized, the liquid gasoline may not burn properly and may even hydraulic.

vapor lock: This is an unwanted condition where bubbles of air form in the fuel line caused by boiling or vaporizing of the fuel in the lines from excess heat. The boiling will interfere with the movement of the fuel and the air bubbles which form will in some cases, completely stop the flow. Sometimes it will cause the float chamber to

overflow which floods the carburetor and result in an over-rich mixture that can cause stalling of the engine when the accelerator is depressed. Fuels containing alcohol have lower boiling points and many old-car owners have installed morepowerful electric fuel pumps which overcome vapor lock tendencies of these fuels by pushing them through the air bubble. A wet rag will cool the line and get rid of the problem. To prevent the problem in hot weather, some mechanics wrap tinfoil around the fuel lines to reflect the heat away.

vapor recirculation: See fuel vapor recirculation system

vapor recirculation system: See fuel vapor recirculation system

vapor recovery: An emission control system used by gasoline stations. A special filler nozzle seals the gap between the pump filler nozzle and the car's filler opening, preventing benzene vapors from escaping into the atmosphere; instead, they are recycled into the gas station's own fuel tank; the same system is also used when the gas station receives a new delivery of fuel from a gas tanker

vapor recovery system: A system that prevents the escape of gasoline vapors from the fuel system into the atmosphere. The basic system consists of a canister filled with activated charcoal and pipes connecting the canister to the fuel tank and carburetor. Any vapor-filled air that leaves the fuel tank because of expansion passes through special emission control pipes to the canister where the vapors are "grabbed" and stored by the charcoal. Then when the engine is started, intake manifold vacuum draws fresh outside air up through an opening in the canister. This moving air pulls the fuel vapor out of the charcoal and carries it to the carburetor and into the engine. In the meantime any gasoline that evaporates from the carburetor collects in the carburetor and air cleaner. As soon as the engine starts this vapor is drawn down through the carburetor and into the engine along with the entering fuel-air mixture. Also called evaporative emission control. See exhaust emission controls.

vapor recycling: An emission control system used by gasoline stations. A special filler nozzle seals the gap between the pump filler nozzle and the car's filler opening, preventing benzene vapors from escaping into the atmosphere; instead, they are recycled into the gas station's own fuel tank; the same system is also used when the gas station receives a new delivery of fuel from a gas tanker

vapor separator: A device used on cars equipped with air conditioning to prevent vapor lock by feeding vapors back to the fuel tank via a separate line.

vapor withdrawal: A system of piping and connection to operate an engine directly on vapor taken from the top of an LPG tank

VARI: Acronym for "Vacuum Assisted Resin Injection" -- a process for forming composite panels and bodywork with consistent, controllable results.

variable: See infinitely variable transmission input variable variable assist power steering: A power steering system that enables the stiffness or tension of the steering to increase at higher speeds for more control or to soften at low speeds when performing slower activities, such as parallel parking. See variable ratio steering

variable assist steering: See variable assist power steering

variable belt transmission: A continuously variable transmission using rubber V-belts on expandingcontracting pulleys, depending on engine speed and load; originally developed by van Doorne for DAF and then used on the Volvo 340

variable-choke carburetor: See variable-venturi carburetor

variable dwell: See dwell-angle control

variable exhaust port: See adjustable variable exhaust port.

variable hole cutter: A drill bit with a stepped cutting head used to drill holes into sheet metal and to enlarge the radii gradually by advancing from one step diameter to the next on the same drill bit

variable intake manifold: A setup in which the path through which air travels into the engine can be altered. Altering the path at a set point allows an engine to develop more power over its rev range.

variable limited-slip axle/center differential: A limited-slip axle/center differential with an electronically operated multiple-disc clutch as a slip-inhibiting device

variable pitch stator: A stator that has vanes that may be adjusted to various angles depending on load conditions. The vane adjustment will increase or decrease the efficiency of the stator.

variable rate springs: springs which become stiffer under compression; variable rate gas springs are a feature of air suspension systems

variable ratio steering: steering ratio characteristics in power steering systems providing different ratios for small and large steering angles

variable reluctance sensor: (VR or VRS) a non-contact transducer that converts mechanical motion into electrical control signals

variable spring: Spring providing variable effective length through cam action to suit load.

variable transmission:

See continuously variable transmission infinitely variable transmission. variable valve actuation: In older engines, the intake and exhaust valves operated in a fixed program of timed openings and closings. With variable valve actuation, these actions are varied for a better balance of low-speed, medium-speed, and high-speed operation.

variable valve timing: Through the use of computers, the precise time when the valves open and close can be altered. It may be better to change the timing slightly when the engine is at a higher RPM than when it is slower.

variable-venturi: See air-valve carburetor.

variable-venturi carburetor: The characteristic feature of this carburetor is the vacuum-operated piston which adjusts the cross-sectional area of the venturi and moves a jet needle in and out of a needle jet; typical designs are the SU and Stromberg carburetors

variable volume induction system intake configuration: A restrictor plate that opens and closes controlling the amount of oxygen that can go into the engine.

Variomatic transmission: A transmission which used rubber belts and expanding pulleys to provide an infinitely variable belt drive. Also see variable belt transmission

varnish: [1] A deposit on the interior of the engine caused by the engine oil breaking down under prolonged heat and use. Certain portions of the oil deposit themselves in hard coatings of varnish. [2] Residue formed when gasoline gets old and stale.

VAT:

Acronym for vane air temperature sensor

Vauxhall: A vehicle brand of which only the 25/70 and 30/98 models of Click for books on 1925-1948 are classic cars. Vauxhall V-band clamp: A clamp which connects the turbine housing and bearing housing a id="V-belt" name="V-belt"> V-belt: A drive belt with a V-shaped cross section, for transmission of low to moderate forces; typically used to drive generators, water pumps, air pumps, air conditioner compressor units and power steering pumps. Also see poly-V-belt

V-belt drive: A type of friction drive in which forces are transmitted from belt to pulley or vice versa by friction

VBRA: Acronym for Vehicle Builders And Repairers Association

VC: Acronym for viscous coupling

VCK-V: Acronym for vacuum check valve

VCV: Acronym for vacuum control valve

VDA: Acronym for "Verband der Automobilindustrie" (i.e., German Automakers Association)

VDOT: Acronym for "variable displacement orifice tube" air conditioning system

VDV: [1] Acronym for vacuum delay valve. [2] Acronym for vacuum differential valve

VE: Value engineering.

VECI: Acronym for Vehicle Emission Control Information which is on a decal placed on the windshield of a car.

vector: A physical quantity which has direction such as force and momentum.

Vee-belt: See V-belt

veeder root: The brand name of a common type of odometer.

vee engine: A type of engine with two banks of cylinders, each set at an angle to each other (in an end view) to form a "V".

Vega: See facel Vega

vehicle: [1] A conveyance on wheels or runners used to carry people or goods over land (e.g., bicycle, motorcycle, car, truck, sleigh, snowmobile). [2] A binder. See commercial vehicle concept vehicle controlled vehicle cross-country vehicle detoxed vehicle driver and Vehicle Licensing Agency

driver and Vehicle Licensing Center electric vehicle experimental Safety Vehicle gray Market Vehicles gross vehicle weight gross Vehicle Weight Rating heavy goods vehicle light vehicles low Emission Vehicle Standards, motor Vehicle Safety Act motor vehicle off-highway vehicle off-road vehicle passenger vehicle pre-converter vehicle pre-owned vehicle production vehicle recreational vehicle replacement vehicle sport utility vehicle used vehicle zero-emission vehicle Vehicle Builders and Repairers Association: (VBRA) A British trade association

vehicle dynamics: The behaviour of a vehicle in motion.

Vehicle Emission Control Information: (VECI) a label in the engine compartment, e.g., pasted to the radiator fan cover, providing information about the engine and emission controls

vehicle Identification Number: (VIN) Number assigned to a vehicle by the manufacturer primarily for registration and identification purposes (consisting of numerals and letters).

Vehicle Licensing: See driver and Vehicle Licensing Center

Vehicle Licensing Agency:

See driver and Vehicle Licensing Agency

Vehicle Licensing Center: See driver and Vehicle Licensing Center

vehicle registration document: A document which specifies the registered keeper(s) of a vehicle

Vehicle Safety: See Motor Vehicle Safety Act

Vehicle Safety Act: See Motor Vehicle Safety Act

vehicle speed sensor: (VSS) sensor in speedometer cluster which sends the vehicle speed information (i.e., how fast the car is travelling) to the electronic control module

Vehicle Standards: See Low Emission Vehicle Standards

vehicle system: See automated guided vehicle system

vehicle tax: See road tax

vehicle weight: See gross vehicle weight gross Vehicle Weight Rating Vehicle Weight Rating: See gross Vehicle Weight Rating

V-eight:

(V-8) An engine with eight cylinders in two rows of four cylinders with a common crankshaft and shaped in the letter V

V-eight engine: (V-8) An engine with eight cylinders in two rows of four cylinders with a common crankshaft and shaped in the letter V

velocipede: An early form of bicycle or tricycle propelled by thrusts of the feet against pedals.

velocity: The rate of motion in a particular direction.

velocity joint: See constant velocity joint.

velocity stack: A device mounted on the carburetor, typically made of polished or gold anodized aluminum, with or without a wire mesh filter; it looks good, provides greater air intake and increases engine performance but reduces engine life due to the intake of unfiltered or badly cleaned air

velocity universal joint: See constant velocity universal joint

vena contracta: The point of lowest-pressure and highest velocity that's located 0.030 inch below the venturi's throat (minimum diameter). The center of the discharge nozzle or the trailing edge of the booster venturi is placed at the vena contracta

V engine: See V-type engine.

V-engine: See V-type engine.

vent:

A small aperture designed to provide an outlet from a confined space or a inlet into it. Air vents (which are also used for heating and are sometimes called "louvres") are usually situated at the top of the dashboard pointing upward toward the windshield), in the center of the dashboard (directing the airflow out into the middle of the passenger compartment), on each side of the dashboard (sending the air back along the sides to the rear of the vehicle), and in the center underneath the dashboard (directing air into the front footwells). [2] A small triangular window for letting air into the passenger compartment. [3] To expel through a vent; e.g., when bleeding air (through a vent valve or bleed screw) out of a diesel fuel system alter running out of fuel.

ventilate: To provide with (fresh) air

ventilated brakes: A brake setup which allows air to enter to cool the rotor and caliper.

ventilated discs: Two discs in a disc brake system separated by ribs and channels to allow cooling air to disperse the heat between the discs

ventilation: A provision of a free or controlled circulation of air. See closed crankcase ventilation crankcase ventilation flow-through ventilation positive crankcase ventilation system positive crankcase ventilation ventilation slot: A series of gaps in the wheel disc which allow the passage of air to assist brake cooling

ventilation system: See positive crankcase ventilation system

venting: The act of perforating a textile bias ply tubeless tire above the beads during retreading. Thus air bleeding through the calendering can escape without forming

air pockets between plies.

ventiport: See porthole

vent port: See compensating port

vent slot: A series of gaps in the wheel disc which allow the passage of air to assist brake cooling

venture: See joint venture

venturi: That part of a tube, channel, pipe, etc., so tapered as to form a smaller or constricted area. A liquid, or a gas, moving through this constricted area will speed up and as it passes the narrowest point, a partial vacuum will be formed. The taper facing the flow of air is much steeper than the taper facing away from the flow of air. The venturi principle is used in the air horn throat of the carburetor. See air-valve carburetor carburetor venturi variable venturi. venturi tube: A short tube with a constricted passage that increases the velocity and lowers the pressure of a fluid conveyed through it. The venturi, or "choke tube," in a carburetor is used to suck the fuel from the float chamber through a discharge nozzle (fixed jet carburetor) or main jet (variable choke carburetor) into the barrel

venturi vacuum: A vacuum in the venturi of a carburetor which increases with the speed of the airflow passing through it; an exception are VV carburetors

venturi vacuum amplifier: (VVA) used with some EGR system so that carburetor venturi vacuum can control EGR valve operation; venturi vacuum is desirable because it is proportional to the

airflow through the carburetor

vent wing: A small triangular-shaped side window which is located in front of the main front side windows. Vent wings can be swung out into the air stream to improve ventilation inside the car. Also called wind wings.

VER: Acronym for "Voluntary Export Restraint."

vernier caliper: A short graduated scale that slides along a longer graduated instrument and is used to indicate fractional parts of divisions, as in a micrometer

vernier gauge: A short graduated scale that slides along a longer graduated instrument and is used to indicate fractional parts of divisions, as in a micrometer

version: See booted version entry-level version federal version manual version street version VERTAC-process: A process in which car bodies are transported horizontally through the surface treatment plant

vertical keel: See center vertical keel

vertical keiretsu: A keiretsu system with a production-oriented close partnership between a major company (such as Toyota) and many small suppliers which work exclusively and/or constantly for their giant customer within the just-in-time concept

vertical position: Type of weld where the welding is done on a vertical seam and on a vertical surface.

vertical tire clearance: The distance between the top of the tread and some part of the vehicle closest above it, after subtracting the axle stop clearance and any increase in tread depth from me existing tire.

vessel: See breakbulk vessel

veteran car: A car constructed before 1919, especially one made before 1905 Only the latter are permitted to take part in the London-Brighton Commemoration Run

V-four: (V-4) An engine with four cylinders in two rows of two cylinders with a common crankshaft and shaped in the letter V

V-four engine: (V-4) An engine with four cylinders in two rows of two cylinders with a common crankshaft and shaped in the letter V

vgc: A term used in advertisements, short for "very good condition"

VHV: Acronym for vacuum operated exhaust heat control valve

VI: Acronym for viscosity index

vibration: See angular vibration anti-vibration mounting

torsional vibration vibration damper: A round weighted device attached to the front of the crankshaft to minimize the torsional vibration. See harmonic balancer torsional vibration damper vibration mounting: See anti-vibration mounting

Vicat softening temperature: The temperature at which a flat-ended needle of 1 mm2 circular cross section will penetrate a thermoplastic specimen to a depth of 1 mm under a specified load, using a selected uniform rate of temperature rise

Vicat test method: A determination of the softening temperature of plastics

VICC: Acronym for "Vehicle Information Centre of Canada."

vice: A British spelling for a clamping device with adjustable jaws (usually mounted on a workbench) used to grip an object to be worked on. The American spelling is "vise." Also see bench vice

vice grips: See locking grips

Victoria: A model of automobile manufactured by Ford view:

Click for books on Ford Crown Victoria

See exploded view

VIN: Acronym for "Vehicle Identification Number."

vintage car: A car constructed in the period 1919-1930

VIR: Acronym for valves-in-receiver unit which is found in some air conditioning systems

virgin resin: A new resin material which has not been recycled before; needed for high-quality parts

vis-a-vis: A four-seater in which the two passengers faced the driver. Used around the turn of the century.

visco-control unit: See viscous coupling

visco-differential: See viscous coupling differential

viscoelastic materials: The most characteristic features of viscoelastic materials are that they exhibit a time-dependent strain response to a constant stress (creep) and a time-dependant stress response to a constant strain (relaxation). In addition, when the applied stress is removed the materials have the ability to recover slowly over a period of time

viscometer: See saybolt viscometer.

viscosimeter:

A device used to determine the viscosity of a given sample of oil. The oil is heated to a specific temperature and then allowed to flow through a set orifice. The length of time required for a certain amount to flow determine the oil's viscosity.

viscosity: A measure of an oil's ability to pour or be thick. Every container of oil is marked with the viscosity of the oil. Straight weight (also called "single viscosity" or "single weight") oil has a single number like 30 weight. A lower number means the oil is thinner and is particularly good for lower temperatures. A higher number is better for hotter temperatures. Multigrade (also called "multiviscosity" or "multiweight") oil has two numbers like 10W40. When the temperature is low, a multigrade oil like 10W40 will act like a 10 weight oil; but when the temperature increases, it will act like a 40 weight. In this way, a multigrade oil is excellent for all-around driving. Also see spraying viscosity

viscosity index: A measure of an oil's ability to resist changes in viscosity when heated.

viscosity cup: A special cup of conical shape with a calibrated bore at the bottom. When filled with paint, the paint will flow out at the bottom of the cup in a determined time. To adjust the viscosity, thinners are added to the paint until the cup contents flow out in the number of seconds indicated in the paint manufacturer's instructions

viscosity index: (VI) A measure of how the viscosity of a liquid (especially oil) changes with temperature: the higher the VI, the smaller the change of viscosity with temperature

viscosity index improver: An oil additive which reduces thinning at high temperature, thus improving the VI

viscous: Thick and sticky

viscous coupling: A particular kind of fluid coupling in which the input and output shafts mate with thin, alternately spaced discs in a cylindrical chamber. The chamber is filled with a viscous fluid that tends to cling to the discs, thereby resisting speed differences between the two shafts. Viscous couplings are used to limit the speed difference between the two outputs of a differential, or between the two axles of a car.

viscous coupling differential: A limited-slip differential using viscous couplings as slip-inhibiting devices

viscous mode: An operating condition in a viscous coupling with inner and outer parts rotating at different speeds, in which a torque is transmitted through the coupling, which corresponds to the value of the resultant shearing velocity

viscous transmission: (VT) A four-wheel drive with a viscous center differential

vise: An American spelling for a clamping device with adjustable jaws (usually mounted on a workbench) used to grip an object to be worked on. The British spelling is "vice." Also see bench vise

vise grips: See locking grips

visibility: Good visibility means that there are no blind spots for the driver in being able to see the traffic around him and that he is able to see the road in dark or adverse conditions.

visor: [1] A movable, perforated part of a helmet, covering the face but permitting sight and speech through the perforations. [2] The peak of a cap to shade the eyes from direct sunlight. Visors were also used above the windshield for the same purpose. See headlight visor main sun visor secondary visor sun visor viton-tipped needle: Special inlet valve carburetor needle with a hardened-rubber tip. Viton-tipped needles are resistant to dirt and conform to the seat even at low sealing pressures

vitreous enamel: A British term for porcelain enamel. A glassy material obtained by melting a mixture of inorganic materials; this can then be applied in one or more layers on a metal surface to which it is firmly bonded after firing; typical automotive applications are for badges and trim.

vitreous enamelling: An application of a glass coating to a metal by covering the surface with powdered glass frit and heating it until fusion occurs

VLCC: Acronym for "Very Large Crude Carriers." Tankers between 200,000 and 300,000 dwt.

VOC: Acronym for volatile organic compounds

voice alert system: A system in a car which audibly announces warning messages to the driver, e.g., "Warning! Oil pressure too low"

voice recognition: The ability of a computer to recognize a command spoken by the user; enables a driver to use a car phone without using his hands

Voisin: A vehicle brand of which the 1925-1948 models are classic cars.

voiture Legere: A light car, especially a racing car falling between the heavy cars and the voiturette. Term seldom used to describe production cars. Not used after 1914.

voiturette: Early two-seater touring car. Name first used by Leon Bollee and then applied to any small car.

volatile: Easily evaporated.

volatile organic compounds: (VOC) unburned hydrocarbon (HC) portions of gasoline

volatility: The property of gasoline, alcohol, etc., to evaporate quickly and at relatively low temperatures. For instance, gasoline is more volatile (has higher volatility) than kerosene because it evaporates at a lower temperature.

Volkswagen: (VW) A German car manufacturer

Click for books on Volkswagen

volt: A unit of electrical pressure or force that will move a current of one ampere through a resistance of one ohm.

voltage: A difference in electrical potential between one end of a circuit and the other. Also called "electromotive force (EMF)." Voltage causes current to flow. Measured in volts. See arc voltage back-voltage hall voltage ignition voltage induce a voltage low voltage circuit nominal voltage rated voltage regulator, voltage required ignition voltage spark discharge voltage spark voltage terminal voltage voltage circuit: See low voltage circuit

voltage drop: The lowering of voltage due to excess length of wire, undersize wire, etc.

voltage regulator: A device which maintains the correct voltage level in a vehicle's electrical system by preventing the circuit voltage from exceeding a predetermined safe value. When the battery needs charging the regulator cuts resistance out of the generator field circuit, thus increasing the flow of current in that circuit, with the further result that output is increased. When the battery becomes fully charged, the resistance is cut back into the field circuit so that the charging rate is decreased. As the engine speed increases, the alternator increases and generates more voltage. Unchecked, the alternator might put out so much voltage that bulbs and other electrical components might burn out. To a certain extent, the battery acts as a voltage regulator, but it too can be damaged by an electrical system which does not have an operating voltage regulator.

voltage reserve: See high-voltage reserve

voltage tester: A screwdriver for testing electrical current, with an insulated blade and handle; a bulb inside the handle lights up if the blade touches a live terminal

voltage transformer: An assembly for increasing the voltage supplied to the air bag system to 12 volts in case of a drop in battery voltage

voltammeter: A dual-purpose instrument for measuring either voltage or amperage

voltmeter: An instrument used to measure the voltage in a given circuit, in volts.

volume: The measurement, in cubic inches, cubic feet, liters, etc., of the amount of space within a certain object or area. See air volume clearance volume

combustion chamber volume displacement
volume control: See automatic volume control

volume control screw: An adjusting screw which controls the amount of air/fuel mixture supplied by the idling circuit of a fixed-jet carburetor

volume induction system intake configuration: See variable volume induction system intake configuration

volume sampling: See constant volume sampling

volumetric efficiency: A comparison between the actual volume of fuel mixture drawn in on the intake stroke and what would be drawn in if the cylinder were to be completely filled. In practice, a normally aspirated car engine does not take in an amount of an equal to the displacement, it passes only about 80% of the theoretical charge: i.e., volumetric efficiency is 80%; this can be increased by supercharging. Also see breathing capacity.

voluntary Export Restraint: (VER) In relation to Japanese manufacturers exporting to Canada (no longer in effect).

voluntary Restraint Agreement: In relation to Japanese manufacturers exporting to the United States (no longer in effect).

volute: A spiral-shaped case in which an impeller forces liquid in the direction it should go. Often used in pumps. Also see impeller.

volute casing: A progressively expanding pump casing proportioned to reduce the liquid velocity gradually so that some of the velocity energy of the liquid is converted into static pressure

Volvo: A model of automobile manufactured in Sweeden

Click for books on Volvo

vortex flow: The whirling motion of the oil in a torque converter as it moves around and around from the pump, through the turbine, through the stator and back into the pump and so on.

Volvo: A vehicle brand of which the 1961-67 P.1800S, 2-door Coupe models are milestone cars.

V-pulley: A pulley with a pair of adjustable cup-shaped discs, used on belt transmissions, to permit adjustment of the effective pulley diameter and transmission ratio. Also see primary V-pulley

VR: Acronym for variable reluctance sensor

VRA: Acronym for "Voluntary restraint agreement."

VRDV: Acronym for vacuum retard delay valve

VR engine:

A new engine design: a combination of in-line and V-engine, the V-angle being reduced (VR) to about 15°. This results in a block which is shorter than a fourcylinder unit of similar capacity. Unlike conventional V-8 engines, the VR engine is topped by a single cylinder head

VRESER: Acronym for vacuum reservoir

VREST: Acronym for vacuum restrictor

VRS: Acronym for variable reluctance sensor

VRV: Acronym for vacuum reducer valve

V-six: (V-6) An engine with six cylinders in two rows of three cylinders with a common crankshaft and shaped in the letter V

V-six engine: (V-6) An engine with six cylinders in two rows of three cylinders with a common crankshaft and shaped in the letter V

V-sixteen: (V-16) An engine with sixteen cylinders in two rows of eight cylinders with a common crankshaft and shaped in the letter V

V-sixteen engine: (v-16) An engine with sixteen cylinders in two rows of eight cylinders with a common crankshaft and shaped in the letter V

VSS: Acronym for vehicle speed sensor

VSV:

Acronym for vacuum switching valve

VT: Acronym for viscous transmission

VTEC Valve system: Variable Valve Timing and Electronic Lift Control. Changes intake and exhaust valve timing and lift so that it more closely matches the engine's changing air-fuel needs. The result is maximum torque at all engine speeds and under all driving conditions.

V-ten: (V-10) An engine with ten cylinders in two rows of five cylinders with a common crankshaft and shaped in the letter V

V-ten engine: (V-10) An engine with ten cylinders in two rows of five cylinders with a common crankshaft and shaped in the letter V

V-thread: A triangular screw thread

VTV: Acronym for vacuum transmitting valve

V-twelve: (V-12) An engine with twelve cylinders in two rows of six cylinders with a common crankshaft and shaped in the letter V

V-twelve engine: (V-12) An engine with twelve cylinders in two rows of six cylinders with a common crankshaft and shaped in the letter V

V-twin: Two-cylinder engine layout in which the cylinders form a "V"

V-type compressor:

A compressor with its pistons arranged in a V-shaped configuration

V type engine: See V-type engine.

V-type engine: An engine in which the cylinders occur in two rows set at an angle to each other with the crankshaft running through the point of the V. The single crankshaft is turned by both banks of cylinders. The angle of displacement is generally between 60 and 90 degrees. Although the most common engines are V-8 and V-6, manufacturers have used V-4, V-12, and even V-16

vulcanization: A chemical reaction which changes the physical properties of elastomers. Also see self-vulcanization

vulcanize: Process rubber by chemical means, usually in combination with heat, to improve its strength, hardness, elasticity, and to effect bonding to other rubber compounds. Used in the manufacture, repair, and retreading of tires.

vulcanizing: See room temperature vulcanizing sealer

vulcanizing sealer: See room temperature vulcanizing sealer

VVA: Acronym for venturi vacuum amplifier

VV carburetor: See variable-venturi carburetor

VVV: Acronym for vacuum vent valve

VW:

See Volkswagen

V-x engine: A V-type engine with a specific number of cylinders represented by the letter x

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DICTIONARY OF AUTOMOTIVE TERMS [Home] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] [Wa] [We] [Wh] [Wi] [Wo] [Wr]

W: A letter rating for tires to indicate that they are theoretically rated for speeds up to 270 kph (167 mph), as in P220WR15.The next higher rating is Y and the one lower rating is V

w/: Abbreviation for "with," as in black w/white top.

waddle: A side to side rocking movement of a vehicle in motion, caused by suspension or tire damage or excessive lateral runout

wad punch: A tool with a round cutting edge for cutting out holes in gaskets or other soft materials

wagon: See four-door station wagon liftback station wagon sag wagon space wagon station wagon two-door station wagon waistline: A British term for belt line. An imaginary or molded horizontal line below the bottom of the side window that separates the roof area from the bottom of the body

waiver:

See duty waiver

Walcker: See chenard-walcker

wall: See cylinder wall

walnut: See burr walnut

wander: A steering action where the vehicle moves or rambles from a fixed course without positive control.

Wanderer: The first Wanderer car with a 5/12 hp four-cylinder engine was test driven in 1912. It went into series production in 1913. This small Wanderer car had not been on the market very long when it became a stage star in the operetta "Puppchen" (which can be translated loosely as "darling") by Jean Gilbert. The title song was rather catchy: "Darling, you are the apple of my eye, darling, I think the world of you." From then on the little Wanderer was known simply by the name "Puppchen."

wandering: A condition in which the front wheels of an automobile tend to steer slowly one way and then another, and interferes with directional control of stability

wankel engine: A rotary internal combustion engine invented by Felix Wankel (1902-1988). It consists of an equilateral triangular member with curved sides orbiting about an eccentric on a shaft inside a stationary housing whose inner working surface is in the shape of an epitrochoid. The rotor is in sliding contact with the eccentric and imparts power to the eccentric shaft as a connecting rod does to a crankshaft. With one-third of a rotor revolution per shaft revolution and a power impulse for each of the three rotor sides, the Wankel generates one power impulse per revolution per rotor--twice that of what the four-cycle piston engine produces. Thus it has become accepted practice to multiply the geometry displacement of the Wankel by a factor of two for comparison with otto-cycle piston engines. The Wankel's advantages include compact size, light weight and smooth operation because there are no reciprocating parts. Its drawbacks include relatively high exhaust emission, possible

sealing problems and low fuel economy. Mazda, however, has made significant improvements in all three areas.

warding file: See key file

warm up: [1] To run an engine until it reaches normal operating temperature. [2] The laps taken on the track prior to the race used to warm up the tires, transmission, engine fluids and other components of the race car before the start of the event.

warm-up: The action of starting an engine and allowing it to idle until it reaches operating temperature before driving away.

warm-up control unit: A unit that produces the richer mixture needed for cold running and modulates fuel system pressure according to engine temperature; the unit includes an electrically heated thermostatic spring, which reduces the force on a spring-loaded control diaphragm

warm-up enrichment: A reduced enrichment of the air/fuel mixture following cranking and after-start enrichment. In the past, warming up an engine was thought to be good practice but now manufacturers recommend that motorists should drive off immediately, as this is the quickest way of heating up the engine and preventing oil being washed off the cylinder walls by partially burnt rich mixture (which causes engine wear)

warm-up regulator: On Bosch CIS, the original name for the control-pressure regulator

warning: See deflation warning system direction indicator warning light engine oil level warning light fluid level warning indicator handbrake warning light

hazard warning switch low oil warning light oil pressure warning light parkbrake warning light reversing warning signal warning indicator: See fluid level warning indicator

warning lamp: A small lamp on the instrument panel that lights up if there is a problem

warning light: A small lamp on the instrument panel that lights up if there is a problem. See brake warning light check engine warning light coolant level warning light direction indicator warning light engine oil level warning light handbrake warning light low oil warning light oil pressure warning light parkbrake warning light seat belt warning light signal light warning light SRS warning light warning signal: See reversing warning signal

warning switch: See hazard warning switch

warning system: See deflation warning system and talking warning system warning tracks:

The little ridges in the road that warn you of an upcoming tollbooth or another lane. Sometimes called "wake-up bumps" or "Bot's Dots" -- Mr. Bot got very rich off these.

warning triangle: A triangular red safety reflector that should be carried on all vehicles and be placed at the side of the road to warn of an obstruction ahead, such as a broken-down vehicle

warp: [1] A bending or twisting out of shape. [2] Threads in cloth that run along the length of the material. [3] To bend or twist out of shape

warranty: The promise made by both the vehicle manufacturer and the vehicle dealer to fix or replace parts on a new vehicle if there is a malfunction before a specific time or distance has elapsed. In some instances some manufacturers or dealers grant warranty even after the expiry of the designated time or distance. This is called "good will warranty." See anti-corrosion warranty corrosion warranty good will warranty warning tracks: A part of the race track which is off the main part of the section for driving.

wash: See automatic car wash and car wash washboard: A road surface which has a series of lateral grooves -- usually found on gravel roads and caused by water runoff.

washcoat:

An oxide layer on the catalyst substrate which increases with the active surface area

washer: A flat disc with a hole in the center. It may be made of metal, rubber, plastic, or leather. It is often placed under a nut to even out pressure and prevent damage to the part on which it rests. See bridge washer crush washer cup washer dish washer flat washer helical spring lock washer protector washer split washer spring lock washer spring washer tab washer thrust washer windshield washer fluid windshield washer washer fluid: A fluid added to the water in the windshield washer and rear window washer reservoirs/bottles to improve the cleaning action and lower the freezing point. Also see windshield washer fluid

washer pump: See windshield washer pump

wash/wipe: See headlight wash/wipe rear wash/wipe system wash/wipe switch: A switch on the instrument panel that operates the rear wash/wipe system

wash/wipe system: See

windshield wash/wipe system rear wash/wipe system wastegate: See waste gate

waste gate: A valve used to limit the boost developed in a turbocharger. A waste gate operates by allowing some of the engine's exhaust flow to bypass the turbocharger's turbine section under certain conditions.

waste spark method: In distributorless ignition systems, dual-spark coils fire two spark plugs at the same time; one of these sparks is in a cylinder during its exhaust stroke, where the spark has no effect (waste spark); the other spark occurs in the cylinder near the end of the compression stroke

water: See de-ionized water distilled water oil and water extractor water column: A reference term used in connection with a manometer

water-cooled: An engine which is cooled by antifreeze in contrast with an air-cooled engine.

water cooling system: The normal cooling system used on most cars and trucks to keep the temperature of the engine down to a desirable level; engine heat is removed via water acting as a coolant which surrounds the cylinders in a water jacket; the system typically includes water passages, coolant pump, thermostat, hoses, and radiator

water extractor: See oil and water extractor

water injection: In an attempt to improve performance and allow the use of lower octane gasoline, water injection was developed. The cooling of the water vapor charge suppresses detonation. A small amount of water or alcohol-water fluid is injected into the fuelair mixture as it enters into the carburetor. Theoretically, as the water evaporates it should cool the incoming charge which then becomes denser, leading to higher volumetric efficiency. This in turn should lead to improvements in performance and economy and allow the use of lower octane fuel because cooling of the charge suppresses detonation.

water jacket: The area around the cylinder block and head or intake manifold that is left hollow so that water may be admitted for cooling. Also called "cooling jacket." Also see cooling system.

water jet cutter: A stream of water under great pressure (50,000 psi) which is controlled by a computer and is used to acurately cut plastic and fiberglass, etc.

waterline: The line of the water's edge when the ship is afloat. Also see load waterline

water marking: Stains on the paintwork caused when a drop of water evaporates, leaving behind an outline of the drop

water passage: A passage within the water jacket designed to prevent the formation of pockets of steam

water pump: A device that circulates the liquid through the cooling system by pumping it from the engine water jackets to the radiator. The pump is usually mounted at the front of the engine and is driven by a belt from a pulley on the front end of the crankshaft. Also called a "coolant pump."

water separator: A device found on diesel cars which removes any water that may have contaminated the diesel fuel.

water splash: See salt water splash

water spotting: Stains on the paintwork that occur when a drop of water evaporates from the painted surface and leaves a white spot behind. See water-spotting.

water-spotting: Drops of water that mar the finish before it is thoroughly cured.

water temperature gauge: A gauge on the instrument panel which indicates coolant temperature

waterways: See international waterways

watt: The international unit of measurement of power. One watt equals one joule per second.

watt linkage: A suspension linkage which has three-bars to locate the De Dion or live axle. There are two usual methods for arranging a Watt linkage: frame to pivot on axle housing to frame or axle to pivot on frame to axle. In either arrangement, this link structure restrains all movement of the axle to a vertical plane.

Watts link: A device used to control side to side motion in a ladder bar, torque-tube, or 4-link rear suspension. A watts link has a pivot point in the center of the axle and a rod that runs to each side of the car. This design eliminate the side to side motion of a panhard rod.

wave: See full wave rectifier half wave rectifier

pressure wave supercharger pressure wave waveband: A series of wavelengths forming a group

wave rectifier: See full wave rectifier half wave rectifier wave supercharger: See pressure wave supercharger

wax: [1] A substance resembling beeswax in appearance and character, and in general distinguished by its composition of esters and higher alcohols, and by its freedom from fatty acids; used for underbody sealing, cavity sealing, and paintwork care. [2] To treat with wax. See car wax hot wax release wax waxing: [1] The formation of wax crystals in diesel fuel in freezing conditions, thus clogging the fuel filter and stopping the engine; avoided by the use of a fuel heater or fuel additives. [2] The application of a wax finish on the paint surface of a vehicle to preserve the paint and maintain its beauty

wax injection: The injection of corrosion-inhibiting wax into car body cavities

wax lancing: The injection of corrosion-inhibiting wax into car body cavities

wax-type thermostat: A thermostat in which the expansion of melting paraffin wax (in a rigid cylinder) deforms a molded rubber membrane and displaces a piston/pin from the cylinder; this has the advantage of being insensitive to sudden temperature fluctuations or to the pressure in the system

way: See oil way one way clutch way catalytic converter: See three way catalytic converter

way clutch: See one way clutch

ways: The machined abutments on which a sliding brake caliper rides

WD-40: A proprietary water-repellent spray

weak: See lean

wear: The progressive loss of substance from the operating surface of a body occurring as a result of relative motion at the surface; rubbing away. See heel and toe wear tire wear wear adjuster: See automatic wear adjuster

wear and tear: The condition of a vehicle where some parts are damaged from normal use

wear bars:

See tread wear indicators

wear-in: As the piston slides up and down the cylinder of a new engine, the rings rub against the rough cylinder walls. The roughness smooths out in time so that a near perfect fit is achieved. Also called "broken-in."

wear indicator: See brake pad wear indicator tread wear indicator wear pattern: A pattern of wear visible at the point where two parts touch

wear resistance: The ability to withstand conditions which cause a progressive loss of substance

wear ring: A ring on a pump used to prevent costly wear of the casing and impeller at the running joint. It is secured to both the casing and the impeller

weather cracking: A visual sidewall condition which appears as cracking of the rubber. Also see ozone checking.

weather deck: Uppermost continuous deck and having no overhead protection having watertight openings

weathering: The change in appearance of paint caused by exposure to the elements. The physical disintegration and chemical decomposition of materials on exposure to atmospheric agents. Also see natural weathering

weather resistant: The ability to withstand natural climatic conditions which cause surface deterioration

weatherstrip: A rubber seal fitted to the body, e.g., along a door aperture or trunklid, to prevent water, air, and moisture from getting into the interior of the body. Also see window weatherstrip

web: [1] An internal reinforcement between panels. [2] A crank web. [3] A supporting structure across a cavity. See crank web suspension turret web webbing: A woven nylon strap used for seat belts. Also see belt webbing

webbing grabber: A device in an inertia reel seat belt that grips the belt webbing tightly in the event of sudden braking or impact

weber carburetor: A well-known Italian brand, used on many high-performance Italian, German, and other vehicles during its heyday. Weber carburetors were famous for their adjustability

wedge: [1] Engine using wedge-shaped combustion chamber. The combustion chambers are flatter on one end than the other. [2] A simple machine consisting of a triangular shaped block, that can be forced into a gap, giving a greatly increased force. Also see hydraulic wedge

wedge block: Combustion chamber design in which the top of the piston and the surface of the block form an angle

wedge combustion chamber: A combustion chamber using a wedge shape. It is quite efficient and lends itself to mass production and as a result is widely used. The valve is in the longer sloping

surface and the spark plug in the shorter; the tapered part of the wedge forms a squish zone

wedge end: The flat peen of a peen and finish hammer, shaped like a wedge

wedge expander: A part of a mechanical drum brake system which forces the shoes apart into contact with the drum

weekly earnings: See average weekly earnings

weep: Fluid leakage which stains the outside of the container, but does not actually drip. Generally oil weeping is not a serious problem.

weighbridge: A device for measuring the weight of vehicles (especially trucks), consisting of a metal plate set into the road surface

weigh scale: A roadside scale which determines the weight of transport trucks and their load.

weight: The force of gravity acting upon a body. It is measured in Newtons. Click on the camera to see how to determine the weight of your vehicle. See advance weight, axle weight balance weight balancing weight centrifugal weight clip-on weight counterweight curb weight distributor weight dry weight flyweight

governor weight gross axle weight rating gross combination weight gross Combined Weight Rating gross train weight gross vehicle weight gross Vehicle Weight Rating horsepower weight factor horsepower-weight factor laden weight lead weight light weight mass maximum trailer weight molecular weight multiweight power-to-weight ratio power to weight ratio sliding weight sprung weight straight weight tape weight tare weight tongue weight troy weight unladen weight unsprung weight weightlessness wheel weight weight engine oil: See straight weight engine oil

weight factor: See horsepower weight factor

weightlessness: A condition when an object is in free fall. It does not mean that the object is completely out of the Earth's gravitational field.

weight per unit area: An indication of the thickness of metallic paint coatings in grams per square meter of surface area

weight rating: See axle weight rating combined weight rating gross axle weight rating gross Combined Weight Rating gross Vehicle Weight Rating weight ratio: See power to weight ratio

weight tool: See wheel weight tool

weight transfer: The transfer of load from one end or side of the vehicle to the other when accelerating, braking, or cornering

weight transfer effect: Because the center of gravity of a vehicle is located above the centers of wheel rotation, a sudden stoppage of the vehicle tends to cause the center of gravity to move forward, thus throwing more weight onto the front wheels and less on the rear wheels

Weissach axle: A special double wishbone rear suspension developed by Porsche for the 928S to minimize the problems of oversteering

welch plug: [1] A concave disk generally about 10 mm (3/8 inch) diameter used to plug a hole in a carburetor. [2] A core plug

weld: To join two pieces of metal together by raising the area to be joined to a point hot enough for the two sections to melt and flow together. Additional metal is usually added by melting small drops from the end of a metal rod while the welding is in progress.

See arc welding axis of a weld butt joint continuous weld convex weld face of weld fillet weld groove weld inside corner weld intermittent weld leg of fillet weld outside corner weld plug weld reinforcement of weld rosette weld spot weld tack weld throat of a fillet weld toe of weld weld face: The exposed surface of the weld. Also see concave weld face

welding: Art of fastening metals (or plastic) together by means of interfusing them. They are heated to a suitable temperature. In some cases pressure is used to bond them together. In other cases a filler material (solder) is used to join them. Among the approximately 40 different welding methods, the resistance welding processes, and especially spot welding, are most relevant for automobile production, whereas arc welding methods are most relevant for servicing and repair. See arc welding atomic arc welding automatic welding back-step welding backhand welding backward welding braze welding bronze welding downhand welding flat position welding forward welding friction welding

gas metal-arc welding gas tungsten-arc welding gas welding hammer welding heated tool welding hot gas welding inert arc welding inert gas-arc welding leftward welding mig welding oxyacetylene welding oxygen-acetylene welding percussion welding plastics welding plug welding projection welding puddle welding pulse arc welding resistance welding sigma welding spot welding tack welding tig welding ultrasonic welding welding clamp: A locking clamp with U-shaped jaws (which allow more visibility and working space), used to hold panels, bars, tubes, etc. for welding

welding jig: A special type of frame gauge used to establish the correct position of structural parts on the body prior to welding them in

welding rod: Wire which is melted into the weld metal.

welding sequence: Order in which the component parts of a structure are welded.

welding wire:

A welding electrode fed into the handset from a reel

weldment: Assembly of component parts joined together by welding.

weld metal: Fused portion of base metal or fused portion of the base metal and the filler metal.

weld-through primer: A special paint used along spot welds or seams; it does not burn off during welding and thus offers good protection on the back of welded panels that would normally be inaccessible once welding is completed

well: See door well rim well rim well base seat well spare wheel well wheel well well base: See rim well base

well-base rim: A wheel rim with a central channel or recess into which one side of the tire bead can drop; the other side can then be forced over the rim for fitting or removal. Wheels with well-base rims are commonly used on passenger cars because they enable easy installation and removal of the tire; the seats of the rim on which the tire sits (rim flanges) have a 5° taper so that, as the tire is inflated, the beads are forced up the taper to give a wedge fit and a good seal for tubeless tires; safety bead seats must also be incorporated, however

well-base wheel: See one-piece wheel

well depth:

Vertical distance from bead seat to bottom of drop center rim.

welting: Piping -- a rubber or plastic strip inserted between two removable panels, i.e., between a bolt-on fender and the body, to cover up the joint and to prevent water getting in; with the piping inserted, only the round bead along the upper edge of the piping is visible

W-engine: A rare engine design, basically similar to a V-engine, but using three instead of two cylinder rows. The W-engine is less perfectly balanced than a V-engine, but this is compensated by balancer shafts; the main advantage of the W-engine is its short crankshaft which results in a very short block; the compact construction permits a 12-cylinder W-engine to be installed transversely in a mid-engine sports car

wet: See grip in the wet

wet boiling point: The boiling point of brake fluid when it has absorbed some water. See boiling point DOT 3 wet clutch: A friction clutch that uses an oil bath to dissipate heat

wet friction: wet friction exists when the rubbing parts have some other substance between them such as oil or grease. Opposite to dry friction.

wet galvanizing: A galvanizing method in which the flux is deposited in molten form on the zinc bath, and the metal to be galvanized is introduced into the bath by passing it through this layer of flux

wet grip:

A roadholding ability of a tire on a wet surface

wet liner: A cylinder sleeve application in which the water in the cooling system contacts a major portion of the sleeve itself. Also see liner.

wet manifold: An intake manifold that caries coolant through integral passages

wet motor: A pump whose motor compartment is filled with liquid; submersible pumps are generally classified as wet motor types

wet-on-wet application: A paint application by which a second coat of paint is applied over a first coat before it is dried or stoved; in the case of metallic paint systems, the clear coat is applied over the wet base coat

wet sanding: Sanding with wet-and-dry sandpaper that has been wetted with water to prevent the paper from clogging; commonly used for final sanding

wet setting: The addition of the float with the carburetor mounted on engine and the float bowl full of fuel

wet sleeve: A cylinder sleeve application in which the water in the cooling system contacts a major portion of the sleeve itself. The sleeve is supported by the block only at the top and bottom of the sleeve. The sleeve must be thicker than a dry sleeve. See wet liner.

wet sump lubrication: The usual engine lubrication system in which the oil is carried in a pan below the crankshaft. Such a system relies on gravity draining the circulated oil and needs no return pump

whale tail:

A colloquial term for a large, rear spoiler

wheel: A circular device, thin in relation to its face area, usually able to rotate about a central axle or pivot, with a durable but elastic rim or with regular teeth cut on the rim and for lightness often supported by spokes joined to the hub instead of being left solid. The invention of the wheel enabled loads to be transported with relative ease, because rolling friction is always much less than sliding friction. The use of cogged wheels also enabled power to be transmitted from one component to another. See alloy wheel aluminum wheel bogie wheel buffing wheel burred wheel california wheel car wheel cast-alloy wheel chain wheel chopped wheel cross-spoke wheel crown wheel custom wheel degree wheel disc wheel disc wheel type drag wheel driven wheel driving wheel fifth wheel fixed wheel flared wheel arch four-way wheel wrench four wheel alignment four wheel disc brakes four wheel steering free rolling wheel front wheel drive front wheel tire clearance grinding wheel horn rim steering wheel jjd wheel jockey wheel knock-off wheel

light-alloy wheel lockable wheel magnesium wheel mag wheel minilite alloy wheel mini spare wheel motor wheel type negative wheel dish negative wheel dishing negative wheel offset one-piece wheel passenger car wheel plain disc wheel planet wheel rear wheel skirt rear wheel spat safe stop wheel safety wheel sheet wheel single-piece wheel solid disc wheel space-saving spare wheel space saver wheel spare wheel spoke wheel sprocket wheel standard wheel star wheel steel wheel steering wheel sun wheel td wheel telescoping steering wheel tempa spare wheel temporary spare wheel three-piece alloy wheel tilt steering wheel tr-denioc wheel trigger wheel turbine wheel twin wheel two-piece alloy wheel two-piece forged alloy wheel well-base wheel wire spoke wheel wire wheel

worm wheel wheel adapter: A spacer ring that adapts hubs to wheels with a different number of lugs, e.g., 4-lug hubs to 5-lug wheels

wheel aligner: A device used to check camber, caster, toe-in, etc.

wheel alignment: See alignment four wheel alignment wheel alignment gauge: A gauge used to measure the distance between the rims of the front wheels

wheel and brake lock: See steering wheel and brake lock

wheel and pinion: See crown wheel and pinion

wheel arch: The edge of the fender around the wheel cutout; sometimes also used with reference to the entire wheel housing. Also see flared wheel arch

wheel arch extension: A roughly square extension of the wheel arch; the areas in front of and behind the wheel cutout, as well as a strip above the cutout, are angled sharply outward to increase the width of the wheel arches to allow wider tires to be installed

wheel arch protector: See undershield

wheel assembly:

A unit on a turbocharger consisting of the compressor, shaft, and turbine wheel

wheel balancer: A machine used to check the wheel and tire assembly for static and dynamic balance. Also see steering wheel balance

wheel balancing: A procedure that ensures that the weight of the wheel is distributed evenly to improve performance and cut tire wear. Static balancing distributes the weight of the wheel evenly around the axle or spindle and is done with the wheels off the vehicle. Dynamic balancing distributes the weight evenly as the wheel and tire hang vertically down, also balances the brake drum, and can be done with the wheels on the vehicle. Smaller wheels need more frequent balancing than larger wheels because the speed of rotation is greater in smaller wheels.

wheel balancing machine: See wheel balancer

wheelbase: The distance between the front and the rear axles on a vehicle, motorcycle, or bicycle. In a few cars (e.g., Renault 5), the wheelbase is longer on one side of the vehicle.

wheel bearings: The bearings in wheel hubs: ball bearings for drive shafts and taper roller bearings for driven hubs

wheel bolt: Bolts which are screwed into threaded holes in the wheel hub or at the axle flange; common on passenger car wheels and one-piece commercial vehicle wheels

wheel bolt hole: The holes through which bolts are inserted to secure the wheel to the hub. To secure the correct wheel, it is necessary to measure the diameter of the bolt hole

wheel bolt hole circle: The diameter of a circle scribed through the bolt hole centers of a wheel.

wheelbrace: A cranked socket wrench for wheel nuts

wheel camber: See camber

wheel center bore: The diameter of the opening in a disc which allows for protrusion of the axle hub.

wheel centering: See steering wheel centering

wheelchair lift: A platform which is deployed from a vehicle, allowing people who use wheelchairs or have trouble stepping up easy access. These platforms or lifts are run by electricity or hydraulics but can always be manually operated in the event that one of the previously-mentioned power sources fail.

wheel changing: Changing a defective wheel involving: stop the car on firm, level ground and put on the handbrake; turn on the four-way warning light; put a chock against the wheel in the opposite corner to prevent vehicle movement; place a warning triangle or flare a short distance behind the vehicle; loosen the wheel bolts or nuts while the wheel is still on the ground; jack up the car so that the wheel is no longer on the ground; remove the nuts or bolts; pull the wheel off; put on the spare or the repaired wheel (you may have to raise the car a little more since the flat tire sat lower on the ground); tighten the bolts or nuts evenly, giving them a final tightening once the jack has been removed

wheel chock: A wedge-shaped block put under a wheel to prevent a vehicle from rolling

wheel clamp: A Denver boot -- a device attached to the wheel of a parked car to prevent its being driven away; used as an anti-theft device if attached privately, and a means of ensuring payment of a fine (to the authority to have the device removed) if parked illegally

wheel cover:

A hubcap which covers the entire wheel (but not the tire, of course).

wheel cutout: The open area described by the wheel arch, which determines to what extent the wheels are visible

wheel cylinder: [1] A small cylinder located at each wheel brake that uses brake fluid to exert hydraulic pressure, which forces the brake shoes against the brake drums and stops the vehicle. [2] That part of the hydraulic brake system that receives pressure from the master cylinder and in turn applies the brake shoes to the drums. Also see brake backing plate. wheel damper: See steering wheel damper

wheel disc: A part of the wheel that connects the rim to the hub; its design is governed by specific rim type, axle connection, brake contour, brake cooling, hub cap fixing, load capacity, and attractive styling. Also see four wheel disc brakes

wheel disc brakes: See four wheel disc brakes

wheel dish: See negative wheel dish

wheel dishing: See negative wheel dishing negative wheel dishing wheel dolly: A trolly that supports the front wheels when a disabled vehicle is being towed. Also called just a dolly

wheel drive:

See all wheel drive front wheel drive wheeler: See three-wheeler

wheel flutter: See wheel wobble

wheel hop: A hopping action of the rear wheels during heavy acceleration. Traction is lost and regained in rapid cycles after power is applied to the rear wheels. It indicates a need for different tires, better shock absorbers, better springs, better axle control, different driving technique, or all of the above. The British term is "wheel patter"

wheel house: The inner area behind the fender described by the inner and outer fender panels; the term is occasionally used for the inner fender panel

wheel housing: The inner area behind the fender described by the inner and outer fender panels; the term is occasionally used for the inner fender panel

wheel house panel: A steel panel inside the wheel housing that is shaped similar to the wheel cutout and protects the upper inside areas of the fender from splashes and gravel

wheel hub: See hub

wheelie: An acceleration phenomenon of rear drive vehicles (especially motorcycles) in which the front wheel(s) lift off the ground. Most automobiles are too heavy and lack the proper balance to accomplish this feat; but bicycles, motorcycles, and even wheelchairs can perform it.

wheelie bar:

A bar incorporating little wheels, mounted behind the rear axle of a dragster to reduce the effect of a wheelie. On wheelchairs it is called antitippers

wheelie bars: Short arms attached to the rear of a drag racer to prevent the front end from rising too far off the ground during heavy acceleration. Arms are usually of spring material and have small wheels attached to the ends that contact the ground.

wheel imbalance: See imbalance

wheel impeller: See vane wheel impeller

wheeling machine: A special shop tool used to shape steel and aluminum panels. No electric, pneumatic, or hydraulic power is used; the base takes the form of a large C and the parts used to do the shaping are fastened at the open end of the frame. A flat-faced steel wheel is bolted to the top of the C; the lower wheels, called anvils are smaller in diameter and have a curved surface. To shape the metal, the steel sheet is moved back and forth between the two wheels

wheel judder: See shimmy

wheel load: That part of the vehicle weight resting on a single wheel

wheel lock: [1] A condition in which the wheels stop turning as a result of excessive braking; leads to a skid. [2] Any anti-theft device for expensive (alloy) wheels. [3] The brakes on a wheelchair so named because of a bar or rod that presses against the tread of a tire

wheel lug bolt: The bolts used to fasten the wheel to the hub. Also called "lug bolt."

wheel marking: All disc wheels are marked (generally on the front side of the disc in the stud hole area) with the manufacturer's trademark, the wheel number, rim size, and date of production

wheel mounting: The attachment of a wheel on a hub

wheel nut: A British term for lug nut -- one of several nuts which hold the wheel and tire assembly on the car and are screwed on the studs

wheel nut wrench: A cross-shaped wrench with four socket heads

wheel offset: A measurement in inches from the center of the rim (between the flanges) to the outside face of the disc. Also see negative wheel offset

wheel panel: The panel area around the wheel cutout in the fender; this term often also refers to a repair section for this area, as this is a common rust spot on many cars

wheel patter: A British term for wheel hop. A vertical oscillation of a wheel making it hop up and down rapidly, either because of imbalance or because the tire is faulty or badly secured

wheel puller: See steering wheel puller

wheel rim: The outer part of the wheel on which the tire is mounted

wheel rotation: Swapping wheels around to compensate for unequal tire wear and increase tread life; moving them from front to rear is generally recommended and is the only safe method on vehicles with directional tread tires

wheel shimmy: See shimmy

wheel shudder: See shimmy

wheel skirt: See rear wheel skirt

wheelslip: See wheelspin

wheel spacer: An obsolete circular metal plate having a bolt hole circle and center bore and fitting between the faces of disc wheels to provide additional dual clearance. Also see between wheel spacer

wheel spat: See rear wheel spat

wheel speed sensor: An electronic device for picking up the rotational speed of a wheel in order to inform the processing unit of an ASR or ABS system

wheel spider: A part of a cast/forged wheel which connects the rim and the wheel hub and incorporates a spoke design

wheel spin: The effect of too much throttle making the driven wheels turn too fast to grip the road surface; easily done on a wet or icy surface and leaves a telltale trace of rubber on a dry one

wheel spin sensors:

Sensors used in the anti-lock brake systems to determine the rate of wheel rotation

wheel steering: See four wheel steering

wheel stud: One of several threaded bolts projecting from the wheel disc to which the wheel is secured by a lug nut

wheel tire: See front wheel tire clearance

wheel tire clearance: See front wheel tire clearance

wheel tramp: See radial run-out

wheel tree: A special stand for wheels, e.g., for a complete set of summer or winter tires, designed to prevent condensation and tire deformation over extended storage periods

wheel trim: See wheel cover

wheel trim emblem: A plastic emblem with logo; self-adhesive backing adheres to hub cap or wheel cover center cap

wheel trim rim: An aluminum or stainless steel recessed ring, chrome-flashed or polished for added lustre; improves the looks of old steel wheels

wheel tub: A part of the wheel housing visible on the inside of the car body to either side of the rear seats

wheel type: The styling of the wheel disc: e.g., disc wheel with holes, plain disc wheel, styled disc wheel with ribs, disc wheel with flange openings, spoke wheel, rim type. See disc wheel type motor wheel type wheel weight: Small weights (usually made of lead) attached to the wheel to balance the wheel and tire assembly. Most have a lip which attaches to the flange of the rim; others are pasted on the smooth side of a rim -- particularly on mag wheels; and others are wrapped around the spokes of a wheel (such as a motorcycle wheel). They are marked in fractions of an ounce or in grams.

wheel weight tool: A special automotive tool for use when balancing wheels; installs, trims and removes all types of clip-on wheel weights with a hammerhead and pliers for installation and removal and a cutter for trimming

wheel well: See rim well spare wheel well wheel wobble: The oscillation of the front wheels caused by unbalanced wheels, defective steering gear, etc.

wheel wrench: See four-way wheel wrench

whip: See chain whip

whip aerial: A long, thin, flexible aerial

whip antenna: A long, thin, flexible aerial

whiplash: An injury to the head and neck of an occupant of a vehicle. The action is somewhat prevented by head restraints.

whiplash injury: Neck injury resulting from a violent forward and backward jerking of the head, as in a vehicle collision

whipping: The tendency of a long rotating shaft (like a drive shaft) to bend at high speed, like a bow or whip

whirling: The tendency of a long rotating shaft (like a drive shaft) to bend at high speed, like a bow or whip

whiskering: See plug whiskering spark plug whiskering white: See body-in-white

white checkered flag: See black and white checkered flag

white flag: The white flag is the flag shown to the race leader and the pursuing drivers telling them that there is one lap to go before the end of the race and the finish line. This final lap is almost always one of the most exciting as lead drivers vie for the best possible position -- making that last ditch, all-out effort to win.

white lithium grease:

A type of grease that will not freeze, melt, or wash off; used for speedometer and brake cables, door and hood hinges, door stop latches, boot springs, seat slide tracks, distributor cams, windshield wiper mechanism, etc.

white metal: Any of various (tin-based) alloys (e.g., tin, lead, and antimony), such as Babbitt metal, still occasionally used for bearings because it had a low melting point and a low coefficient of friction

white rust: A loose, porous oxidation products formed on zinc when a lack of carbon dioxide occurs and water condenses on the surface of the work

whitewall: Tires that have a concentric white line. Some are up to four inches wide and called "wide whitewall."

whitewall rings: Narrow or wide rubber rings that snap on between tire and rim to give the effect of a whitewall tire

whitewall tire: A tire with white sidewalls

whitewall toppers: Narrow or wide rubber rings that snap on between tire and rim to give the effect of a whitewall tire

Whitney: See pratt and Whitney key

Whitney key: See pratt and Whitney key

Whitworth: See British Standard Whitworth

wholesaler: An intermediary which sells to other intermediaries, such as a firm that buys from a manufacturer and sells to a retailer.

wick: The action of flicking or blipping the throttle rapidly.

wicking: A capillary act of air escapement from the tire casing during retreading.

wide-nose peen hammer: A peen and finish hammer with an extra-wide wedge end well suited to shaping of sharp corners and beads in panels

wide open throttle: (WOT) A term describing full throttle

wide ovals: See wide treads.

wide range gearing: See wide-range gearing.

wide-range gearing: A gearing system in which the step between the two chainrings is considerably greater than that found in most other systems.

wide step gearing: See wide-step gearing.

wide-step gearing: A gearing system in which the step between the two chainrings is considerably greater than that found in most other systems.

wide treads: Wide tires. Tire height, bead to tread surface is about 70 percent of tire width across outside of carcass.

widget: Any small gadget, device or mechanism that is unknown or temporarily forgotten; a car is full of them

width: See bandwidth crown width nominal rim width rim width section width tire width will: See good will warranty

Wills Sainte Claire: A vehicle brand of which the 1925-1948 models are classic cars.

will warranty: See good will warranty

Willys-Knight: A vehicle brand of which the Series 66 for 1925-1948 with required application are classic cars.

Willys: A vehicle brand of which the 1948-51 Overland Jeepster models are milestone cars.

Click for books on Willys

Wilson gearbox: An early preselector epicyclic gearbox still used in buses. Named after British inventor Walter Gordon Wilson, 1874-1957

winch: Manual or power device employing a drum with cable or rope for pulling objects where great power is required. Power generated by vehicle engine and transmitted

through power take-off on transmission.

wind: See crosswind

windage tray: On some high-performance engines, another pan within the oil pan, up near the crankshaft, that insulates the crankshaft from the windage phenomenon, which causes oil, in the form of tiny droplets, to become airborne within the crankcase of an engine running at high rpm. At high rpm, it is possible for as much as two quarts of oil to be airborne within the crankcase. This oil, if it comes in contact with the crankshaft, will cause additional friction and rob horsepower

windchill: The perceived temperature in winter when wind is blowing or when riding an open vehicle (motorcycle, snowmobile, etc.). It is calculated with the following formula: Windchill Temperature = 0.045*(5.2735*SQROOT(W) + 10.45 - 0.2778*W)*(T 33.0)+33 WCF = 1.1626*(5.2735*SQROOT(W) + 10.45 - 0.2778*W)*(33.0 - T) where: ET = equivalent temperature (degrees Celsius) WCF = wind chill factor (Watts per square metre) SQROOT = square root function W = wind speed (Km/hr) T = air temperature (degrees Celsius)

wind deflector: See air shield

wind drag: The amount of force a ride feels from the wind. If the rider sits upright and is broad, the wind drag is going to greater than it would be for a narrow rider, and even greater than it would be for a rider who "crouches" or tries to fit behind the handlebars. A windshield helps reduce significantly the drag that a rider feels.

winder: See window winder

winding: The wrapping of wire around a core.

See excitation winding exciter winding field winding high-tension winding hold-in winding holding winding inductive winding primary winding pull-in winding secondary winding shunt winding winding the engine: Running the engine at top rpm.

windlace: A type of piping covered with fabric; often used along the outlines of convertible tops, etc.

window: See electric windows frameless window heated rear window hinged quarter window lambda window manual-crank window manually operated window power window lock-out switch power window quarter window filler panel quarter window rear side window rear window heater system rear window heating rear window louvres rear window sliding side window timing window wind-up window window channel:

A British term for glass channel -- a U-shaped draft excluder, often fitted with a steel core, along wind-up door window edges inside the door frame

window etching: A security measure whereby the glass panes of a car's windows are permanently marked by etching a number (such as the registration number) into the glass surface

window filler: See quarter window filler panel

window filler panel: See quarter window filler panel

window heater: See rear window heater system

window heater system: See rear window heater system

window heating: See rear window heating

window lift: British term for the switch or mechanism used to raise or lower a side window.

window line: See waistline

window lock-out: See power window lock-out switch

window lock-out switch: See power window lock-out switch

window louvres:

See rear window louvres

window regulator: The mechanism used to raise and lower window glass. The regulator can be either manual or electric

window weatherstrip: A rubber or moquette sealing strip fitted in the gap on either side of a sliding door window to seal the door gutter and prevent water getting into the interior of the door frame

window winder: A handle on the inside of a door panel with which the window is manually wound up and down

windscreen: British term for windshield.

windshield: The primary piece of glass in front of the driver and front passenger. In some older vehicles, there were two pieces of glass. Both are considered the windshield, left and right side. In Britain, it is called the windscreen. See emergency windshield heated windshield laminated windshield panoramic windshield toughened windshield windshield header wrapround windshield windshield aperture: The open area into which the windshield fits, determined by the windshield panel

windshield corner panel: A separate panel that extends the scuttle to the left-hand and right-hand top rear corners of the fenders and closes off the area towards the bottom windshield corners; on many cars, it is part of the one-piece scuttle extending from the lefthand to the right-hand fender

windshield glass: See laminated windshield glass

windshield header: The bar or metal that goes between the two A-pillars that form the windshield framing.

windshield header panel: A box-section or double panel at the front end of the roof panel above the windshield aperture that helps to reinforce the roof frame

windshield mounting flange: The spot-welded flanges of the panels which together form the windshield aperture

windshield panel: The panel around the windshield that links the roof panel above the windshield to the scuttle below the screen

windshield pillars: The front posts of the body shell which together with the scuttle and header panel form the windshield aperture

windshield shadeband: See sunvisor sunshield windshield support panel: See scuttle

windshield surround: A molded rubber insulating strip round the windshield

windshield washer:

[1] An apparatus for spraying windshield washer fluid on the outside surface of the windshield and removing the solution with the windshield wipers and thereby removing contaminants from the windshield. [2] A person who washes windshields

windshield washer fluid: A soapy solution used to remove dirt and bugs from the windshield. In colder climates this solution must not freeze.

windshield washer pump: A pump which forces the windshield washer fluid to the windshield washer nozzles so that the fluid is sprayed on the windshield.

windshield wash/wipe system: A system operated by the same lever on the control stalk that operates the wipers, which directs a jet of water onto the windshield and activates the wipers for a short period

windshield wiper: A squeegee attached to an arm in front of the windshield. When activated, it sweeps across the windshield to remove any moisture such as rain or windshield washer fluid.

Windsor experiment: Chrysler Canada, in partnership with government and educational institutions, has launched a number of initiatives collectively referred to as the Windsor Experiment. The Windsor Experiment conducts studies to benchmark "best practice" training and education in Europe, and applied the results in various skills development programs.

wind trainer: A training device consisting of a frame in which a bicycle is fastened for stationary riding and a fan that creates wind resistance to simulate actual road riding.

wind tunnel: A tunnel-like chamber in which a current of air can be maintained at a constant velocity and in which motor vehicles (and aircraft, etc.) are tested to determine their aerodynamic properties and the effects of wind pressure

windup: See axle windup" spring windup wind-up window: A window that is manually operated with a winder

wind wing: See vent wing.

wing: [1] An aerodynamic device attached to a vehicle to cause a downward force on the front or rear of the vehicle. It is often found in the shape of an inverted airplane wing. [2] A window wind deflector. [3] A Honda Goldwing motorcycle. [4] British term for airfoil. bolt-on wing, fender, front wing, vent wing, wind wing, and wiper wing

wing arch: British term for fender arch

wing beading: A British term for fender beading

wing bumping hammer: British term for fender bumping hammer

wing extension: British term for fender extension

wing landing section: British term for fender landing section

wing mirror:

British term for fender mirror

wing mounting: British term for fender mounting

wing nut: A nut with two flat projections (i.e., wings) to be turned by thumb and finger. Also called a butterfly nut.

wing punch: A British term for a fender punch

wing shield: A small curved panel in front of the front side window which deflects wind and reduces draft with the window open; typically made of transparent acrylic, clear or smoked

wing splash apron: British term for fender splash apron

wing stock: Tread rubber that is tapered to a feathered edge on each side of a retread tire in order that it may be applied to the shoulder of the tire. Used only on a full retread.

wing strengthening buttress: British term for fender strengthening buttress

wing support bracket: British term for fender support bracket

winker: Japanese (especially Honda) term for a signal light.

winter tire: A tire with a deep tread suitable for winter conditions

wipe: See headlight wash/wipe

wipe system: See rear wash/wipe system windshield wash/wipe system wiper: A metal or plastic device with a rubber blade that scrapes across the windshield to clean the windshield from rain or other moisture. Also called delay wiper, hidden wiper, hideaway wiper, intermittent wiper control, linear wiper system, rear wiper, self-parking wiper, and windshield wiper

wiper control: See intermittent wiper control

wiper system: See linear wiper system speed-sensitive wiper system wiper wing: A molded attachment to the back of the windshield wiper arm, intended to increase the pressure of the wind on the blade to provide effective cleaning at high speeds

wire: See bead wires coil wire control wire earth wire ground wire hot wire lead wire live wire primary wire secondary wire shredded wire spark plug wire

welding wire wire brush: A brush with wire bristles for removing loose paint, dirt, carbon, or rust from metal surfaces. Wire brushes come in a variety of shapes, e.g., with an extremely thin head for cleaning parts in very tight places (such as brake rotors or calipers), or they can be attached to power tools to remove carbon and deposits from cylinder heads, transmissions, etc. e.g., as knotted or crimped rotary wire brushes, wire cup brushes, or wire end brushes. Also see cup-shaped wire brush

wire cover strip: See spark plug wire cover strip

wired on tire: See wired-on tire.

wired-on tire: A tire with a wire bead edge that fits inside a trough-shaped rim; the type of tire often inaccurately referred to as a "clincher."

wire feeder: The handle and gas nozzle through which the steel wire electrode is fed by an electric motor in a MIG welding system

wire glow plug: A double-pole glow plug with an unsheathed wire loop; now superseded by sheathed-type glow plugs

wire loom: See spark plug cable loom spark plug wire loom wire marker: See spark plug wire marker

wire mesh:

In catalytic converters with a ceramic monolith, a stainless-steel fabric used as a shock-absorbing support for the honeycomb

wires: Wire-spoked wheels or wire-spoke hubcaps.

wire separator: See spark plug wire separator

wire spoke: A part which connects the hub of a wire spoke wheel to the rim. All loads are transmitted from the rim to the hub by steel spokes; individually, they have little resistance to bending stresses and therefore have to be laced in a complex crisscross pattern. Due to their complicated design (each spoke is hooked at one end into the hub, and the other end is pushed through a hole in the rim, where a tapered nut is screwed down to pull the spoke tight) and their reduced stiffness and poor stress resistance (if the spokes are too loose or too tight, the relatively flimsy rim will distort), wheels with wire spokes are expensive and rarely used on automobiles; but they are common on bicycles and some motorcycles

wire spoke wheel: A wheel designed in such a way that its rim is joined to the center member by a series of wire spokes

wire stripper/crimper tool: A multi-purpose electricians' pliers for cutting and stripping wire and crimping insulated or non-insulated solderless terminals when servicing the electrical system. Also see automatic wire stripper

wire strippers: Pliers used for removing insulating material from the ends of electrical wire

wire wheel: A wheel designed in such a way that its rim is joined to the center member by a series of wire spokes

wiring an edge: Rolling the edge of a panel, e.g., a wheel opening of a fender, around a wire to provide additional stiffness of the panel edge

wiring diagram: A drawing showing the various electrical units and the wiring arrangement necessary for them to function properly.

wiring harness: The collection of color-coded wires which connects all the vehicle's electrical components. Sometimes refers to the main bulk of wires, not the secondary wires which are plugged into the main collection.

wiring loom: See wiring harness

wiring pigtail: A short length of wire, usually with connector, permanently attached to an electric component, such as an oxygen sensor

wiring trough: A longitudinal molding that guides and conceals wiring

wishbone: The radius rod setup used in many of the older ford cars to keep the axle square with the frame. See A-arm control arm double wishbone unequal wishbones wishbone suspension: See double wishbone suspension unequal-length wishbone suspension withdrawal: See liquid withdrawal.

withdrawal fork:

See clutch fork

witness mark: A punch mark or scratch used to position or locate some part in its proper spot. The mark is made on each half of the assembly so that upon reassembly the marks can be lined up.

witness marks: See witness mark.

w/o: Abbreviation for "without," as in excellent condition, w/o body damage.

wobble: Side to side movement -- usually unwanted. Also called "lateral runout." See caster wobble wheel wobble wobble extension bar: A special extension with a unique male end that enables the user to drive the socket up to 15° from vertical

wobble plate: See swash plate

wood alcohol: See methanol.

woodie: [1] A shooting brake. [2] A wood-bodied vehicle, especially station wagons of the '30s and 40s.

Woodill: A vehicle brand of which the 1952-58 Wildfire models are milestone cars.

wood mallet:

A hammer with a wooden head

Woodruff key: a half-moon shaped piece of metal used to secure something to a shaft which has a notch cut in the shaft to accommodate the key.

woody: A station wagon with wood sides. It was made popular by the surf-board crowd

work: Production of an effect by exertion of a force. Energy is needed to do work and work is measured in joules. Also see chrome work

work capacity: The maximum ability to perform. See energy.

work ceiling: See joiner work ceiling

working cycle: A recurring sequence of events in the combustion process, e.g., a four-stroke cycle

working cylinder: The inner cylinder of a double-tube shock absorber

work week: See standard work week

world Trade Organization: (WTO) Created by the Uruguay Round and successor to the GATT, this new organization began operations on January 1, 1995.

worm: A short, rotating shaft on which a helical groove has been cut, as in a gear arrangement in which such a shaft meshes with a toothed wheel. See

ball worm recirculating ball worm and nut worm-and-lever steering: See cam-and-lever steering

worm and nut: See ball worm and nut recirculating ball worm and nut worm-and-nut steering: A steering system in which rotation of the worm causes a nut, which encloses it, to move up or down, thus turning the rocker shaft

worm-and-peg steering: See cam-and-lever steering

worm and roller: A type of steering gear using a worm gear on the steering shaft. A roller on one end of the cross shaft engages the worm.

worm-and-roller steering: See cam-and-roller steering

worm and sector: A type of steering gear using a worm gear engaging a sector (a portion of a gear) on the cross shaft.

worm-and-sector steering: A type of steering system in which rotation of the worm moves a V-shaped section of a toothed wheel at the top of the rocker shaft

worm and taper pin: A type of steering gear using a worm gear on the steering shaft. The end of the cross shaft engages the worm via a taper pin.

worm gear: A coarse, spiral shaped gear cut on a shaft. It is used to engage with and drive another gear or portion of a gear. As used in the steering gearbox, it often engages the cross shaft via a roller or by a tapered pin.

worm wheel: A gearwheel driven by a worm

worry: To bend something like a wire or a bar back and forth with the intention of breaking it apart.

worthiness: See sea worthiness

WOT: Acronym for wide open throttle

wound: See progressively wound valve spring

wound valve: See progressively wound valve spring

wound valve spring: See progressively wound valve spring

wow: See bow wow

wrap: See outer wrap

wrapped pin: See spiral wrapped pin

wrapround: Curving around in one continuous piece

wrapround bumper: A modern bumper style that extends around the front and rear of the body right up to the wheel cutouts to offer maximum protection of the body panels

wrapround dash design: An instrument panel design introduced on volume cars by BMW which, in contrast to the classic flat panels, is curved to provide optimum driver access to all controls

wrapround windshield: See panoramic windshield

wrecker: See auto wrecker

wrench: [1] A device for removing nuts, bolts, and other fasteners. [2] A colloquial term for a mechanic or someone who is handy repairing engines. [3] To use a wrench tool. See adjustable wrench Allen wrench box wrench brake adjusting wrench brake wrench chain filter wrench chain pipe wrench chain wrench click-type torque wrench combination wrench crescent wrench cross-shaft lug wrench dial torque wrench distributor wrench double-ended wrench drain plug wrench filter wrench flare nut wrench four-way wheel wrench

grip wrench heavy-duty ring wrench heavy-duty wrench hex wrench ignition wrench impact wrench interchangeable head torque wrench left-handed monkey wrench lug wrench miniature offset open-end wrench mole wrench monkey wrench obstruction wrench offset wrench oil filter wrench open-ended wrench pin wrench pipe wrench plug wrench socket wrench spanner spark plug socket spark plug wrench spoke wrench stillson wrench strap wrench tappet wrench tap wrench torque wrench wheel nut wrench wringing-fit: A fit with less clearance than for a running or sliding fit. The shaft enters the hole by means of twisting and pushing by hand

wrinkling: The top coat tends to wrinkle to a smaller or greater degree if the outer paint coat dries too rapidly, preventing the underlying coats from drying properly; this also occurs if the paint film is too heavy

wrist pin: See piston pin.

wrist pin circlip: A circlip which is used on either end of the wrist pin to hold the pin in place.

wrist pin end: The small end of the connecting rod through which the wrist pin is inserted

write off: [1] To damage a car beyond repair or, for insurance purposes, so as to be not worth repairing. [2] To consider a vehicle to be a total loss

write-off: A car damaged beyond repair or so badly damaged as to be not worth repairing for insurance purposes

written off: When a vehicle has sustained a severe accident so that it would cost more to repair it than what it is worth, it is said to be written off.

writer: See service writer

WTO: Acronym for "World Trade Organization."

WW: Acronym for "whitewall," as in ww tires.

WWW: Acronym for "wide whitewall," as in www tires.

x: [1] Originally this letter indicated "experimental" vehicles, but later came to indicate an "exotic" or unusual vehicle. [2] Also see Michelin "X"

x engine: See X-type engine.

x-engine: See X-type engine. xenon : A colourless, odourless gas used in electric luminescent tubes to provide a bright light; a xenon stroboscope for ignition timing is strong enough to use in daylight

X-flow cylinder head: See crossflow cylinder head

x. Liter Engine: The total displacement of an engine expressed in liters. This is the total volume within an engine devoted to the combustion which produces power.

x tire: Michelin "X" Radial tires.

x-type engine: An engine in which the cylinders occur in four rows set at an angle from each other with the crankshaft running through the intersection of the X. The single crankshaft is turned by all banks of cylinders.

X-type frame: A frame design shaped like an elongated letter X that narrows to a strong junction at the center section; it usually has three or more crossmembers to provide torsional stability but there are no crossmembers in the center section of the vehicle

x-valve:

There are two kinds of valves in a car, intake and exhaust. The intake valves allow oxygen and fuel into the cylinder head and the exhaust valves allow the used-up gases to exit.

Y: A letter rating for tires to indicate that they are theoretically rated for speeds up to 300 kph (186 mph), as in P220YR15.The next higher rating is Z and the one lower rating is W yard : See breaker's yard scrap yard yaw: The rotation about a vertical axis that passes through the car's center of gravity.

yaw acceleration: A steady increase in the yaw angle

yaw angle: The angle of deviation between a vehicle's longitudinal axis and its true direction of motion, i.e., the difference between the direction a vehicle is pointing when cornering and the direction in which it is actually moving Y-belt : A Y-shaped belt design used to restrain babies in a baby seat Y-configuration : A Y-shaped connection of the three stator windings of an alternator

y-connector: Any connector in the shape of the letter "Y" -- often referring to a hollow unit. For example, the line coming from the windshield washer pump is connected to the bottom part of a "Y" and the two tubes going to the windshield nozzles are connected to the upper part of the "Y". It differs from a T-connector in that the Vshape is straight across. year : See model year

yellow boot:

Colloquial term for a Denver boot

yellow flag: A solid yellow flag is used to slow down the racers in the case of a crash, debris on the course (like car parts), slick fluids on the track or the weather has become a factor with rain. During a yellow flag the pace car, with the top lights flashing, joins up with the race leader and sets a slower speed on the track. This is done to preserve the driving order on the track as cars cannot pass one another under a yellow after crossing the start/finish line. Drivers generally use this time to hit the pits for refueling, new tires and adjustments. It is an advantageous time to make the race car faster on the track.

yellow shoe: Colloquial term for a Denver boot

yield strength: Stress in psi at which a specimen assumes a specified limited permanent set.

yoke: [1] A triangular metal piece used to connect the main brake cable with the stirrup cable in a centerpull brake system. Also known as a "saddle" or "pickup." [2] A bracket or coupling. [3] A forked parts of a U-joint connected by the spider.

Y-pipe : A Y-shaped down pipe connecting a two-branch exhaust manifold to a single exhaust pipe

Yugo: A model of automobile manufactured in Yugoslavia

Click for books on Yugo

Z: A letter rating for tires to indicate that they are theoretically rated for speeds over 300 kph (186 mph), as in P245/50ZR16. There is no higher rating, but the one lower rating is Y

Zahnradfabrik Friedrichshafen: See ZF ZAP : See aia-zap

Z-axle: A rear axle introduced with the BMW Z1 in 1988, consisting of a trailing arm, one upper lateral link, one lower diagonal link, and a coil spring at each side; also included is an anti-roll bar

zebrano: A striped hardwood used for interior trim as a cheaper alternative to burr walnut

zebrawood: A striped hardwood used for interior trim as a cheaper alternative to burr walnut

Z'ed: When a frame is cut, usually in front of the rear wheels, and a section is welded in to raise the axle so large tires can be used at stock body heights, racers say their car has been z'ed [pronounced ZEED, not ZED], referring to the new appearance of the frame.

Zener diode: A semiconductor used on British motorcycles for many years as a voltage regulator. When the voltage across the Zener diode reached a certain point, the element would begin to conduct current, routing it to ground, thus preventing the battery from overcharging.

zerk fitting: A small valve that allows grease to be added to a ball joint with a grease gun and prevents the grease from leaking out when pressure is placed on the area. Incorrectly pronounced "zert." Also called grease fitting

zero absolute pressure: A total vacuum. Zero on the absolute pressure scale

zero-emission vehicle: (ZEV) A vehicle which itself produces no emissions, such as electric powered vehicles. The concept does not take into account the fact that electric cars use the electric power of batteries that are normally charged by power supplied by electric power plants (which generally do produce certain emissions); Californian laws require that from 1998, 2% of new cars must be ZEVs

zero offset: See center point steering

zero-offset steering: A steering system whose geometry has a scrub radius of zero. This configuration minimizes the steering effects produced during acceleration (with front drive) or braking on varying traction surfaces.

ZEV: Acronym for zero-emission vehicle

ZF: An acronym for "Zahnradfabrik Friedrichshafen," which is a German company that manufactures transmissions and transaxles used in many exotic, high performance, and racing cars.

zinc: A metallic element used in galvanizing metals, die casting, as a constituent in various alloys, as a battery electrode, etc. Also see layer of pure zinc, low zinc technology, and normal zinc technology

zinc alloy: An alloy whose main component is zinc

zinc bath:

See galvanizing bath

zinc electroplating: See electrogalvanizing

zinc immersion treatment: A pretreatment before electroplating a thin zinc deposit forms by immersion of aluminum in a zinc solution which prevents further oxidation of the aluminum and provides a key for the galvanic coating

zinc-iron alloy layer: An alloy layer formed on iron and steel during hot-dip galvanizing as a result of the diffusion of atoms from the molten zinc into the work and vice versa

zinc phosphate coating: A zinc-rich conversion coating produced by phosphating

zinc plating: The application of a zinc coating by galvanizing or electrogalvanizing

zinc-rich paint: Paint containing an extremely high proportion of metallic zinc dust in the dry film (about 95% by weight), applied to iron and steel as an anti-corrosive primer; the application of zinc-based primer may be regarded as a less durable form of cold galvanizing

zinc-rich primer: Paint containing an extremely high proportion of metallic zinc dust in the dry film (about 95% by weight), applied to iron and steel as an anti-corrosive primer; the application of zinc-based primer may be regarded as a less durable form of cold galvanizing

zincrometal: The trademark of a special type of coil-coated steel sheet with plastic and zinc dust coating, which is proving increasingly useful in automobile manufacture

zinc spraying:

A process for applying zinc coatings to iron and steel. Particles of molten zinc are sprayed on the surface to be coated; the coating metal, usually in the form of wire, is fed into a spray gun, in which it is melted by the combustion of a fuel gas, e.g., a mixture of oxygen and acetylene. The molten metal is atomized by compressed air and precipitated on the surface to be coated at high velocity zinc technology : See low zinc technology and normal zinc technology

zinc vapor deposition: (ZYD) A process in which zinc vapor is deposited in a vacuum on the pieces being worked on

zirconia: zirconium oxide, used in enamels and ceramic coatings

zirconium: A metallic element. Symbol: Zr; atomic number: 40

zone: See crumple zone, deformation zone, heat-affected zone, preheating zone, splash zone, squish zone, tire contact zone, tow away zone, and quench zones

ZVD: Acronym for zinc vapor deposition