Glossary of Automotive Terms – W

Letter W – Dictionary of Automotive Terms

  1. A letter rating for tires to indicate that they are theoretically rated for speeds up to 270 kph, as in P220WR15.The next higher rating is Y and the one lower rating is V
  2. Abbreviation for Watt
Abbreviation for with, as in black w/white top.
  1. Abbreviation for Wide Open Throttle A/C Cutoff Relay
  2. Abbreviation for Wide Open Throttle A/C Cutout Relay
Abbreviation for A/C Wide Open Throttle Cutout Relay Monitor
A side to side rocking movement of a vehicle in motion, caused by suspension or tire damage or excessive lateral runout
Wading plugs
Oil drain holes are provided in the bottom of the clutch housing (and the camshaft drive-belt housing on Tdi and 2.5D engines) to preclude the possibility of the clutch or cam belts becoming contaminated in the event of oil leaks from the adjacent bearings. Wading plugs should be fitted to block these holes when driving through water over 30 cm deep and subsequently removed.
Wad punch
A tool with a round cutting edge for cutting out holes in gaskets or other soft materials
A thin sheet of semiconductor (photovoltaic material) made by cutting it from a single crystal or ingot.
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 rest of the body.
Walked over
Trucker slang for Over powered by a stronger c.b. signal as in ‘Come back on that someone walked all over you.’
Walk-in cooler
Larger. commercially refrigerated space kept below room temperature. Often found in supermarkets or wholesale meat distribution centers.
Walking Beam Suspension
A type of truck and tractor rear suspension consisting of two beams, one at each side of the chassis, which pivot in the center and connect at the front to one axle of a tandem and at the rear to the other axle.
Walking Floor
A type of dump trailer with a conveyor belt or chain running down the center of the floor of the trailer to unload the cargo. Also called live bottom
A steering action where the vehicle moves or rambles from a fixed course without positive control.
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.
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
Warm Air
Warm Air Furnace
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.
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 Flasher
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.

Warning light valve
A valve in the hydraulic circuits of a dual brake system that switches on an instrument panel warning light when one system fails.
Warning signal
Warning switch
Warning Switch Assembly
Warning system
Warning tracks
  1. 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.
  2. A part of the race track which is off the main part of the section for driving.
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
  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
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.

A road surface which has a series of lateral grooves — usually found on gravel roads and caused by water runoff. Also called corrugations
An oxide layer on the catalyst substrate which increases with the active surface area
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.

Washer face
A circular rim or boss on the underside of the head of a bolt (i.e., the bearing surface) or on one side of a nut to give a flat surface for the bolt or nut to sit on. A smooth washer face takes away any burrs or imperfections caused by the manufacturing process.
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.

Washer pump
Wash/wipe switch
A switch on the instrument panel that operates the rear wash/wipe system
Wash/wipe system
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 materials
Otherwise discarded combustible materials that, when burned, produce energy for such purposes as space heating and electric power generation. The size of the waste may be reduced by shredders, grinders, or hammermills. Noncombustible materials, if any, may be removed. The waste may be dried and then burned, either alone or in combination with fossil fuels.
Waste oil
Petroleum-based materials that are worthless for any purpose other than fuel use.
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
Waste tar
Petroleum-based materials that are worthless for any purpose other than fuel use.
Watchdog timer
A device that detects controller malfunction and initiates independent action to safely deactivate the equipment operated by the failed controller. The device accomplishes failure detection, by monitoring a periodic update signal from the controller, and activation, if this periodic signal does not occur within a specified time period.
Water bar
A diversion ditch and/or hump installed across a trail or road to divert runoff from the surface before the flow gains enough volume and velocity to cause soil movement and erosion, and deposit the runoff into a dispersion area. Water bars are most frequently used on retired roads, trails, and landings.
Water column
A reference term used in connection with a manometer
An engine which is cooled by antifreeze in contrast with an air-cooled engine.
Water-cooled condenser
  1. Heat exchanger designed to transfer heat from hot gaseous refrigerant to water.
  2. Condensing unit which is cooled through use of water flow.
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
A definite channel with bed and banks within which concentrated water flows continuously, frequently or infrequently.
Water defrosting
Use of water to melt ice and frost from evaporator during off-cycle.
Water extractor
Water fade
A delay in brake application caused by water contamination that reduces friction between the brake linings and drum or rotor.
Water gauge
A device, often a glass tube, which shows the level of water.
Water hammer
Noise generated by back pressure of water when a valve is closed.
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 fuel-air 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
  1. 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.
  2. Channels in the engine through which water and coolant circulate to cool the engine.
Water jet cutter
A stream of water under great pressure (50,000 psi) which is controlled by a computer and is used to accurately cut plastic and fiberglass, etc.
The line of the water’s edge when the ship is afloat.


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
Water spotting
Stains on the paintwork that occur when a drop of water evaporates from the painted surface and leaves a white spot behind.

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
Water turbine
A turbine that uses water pressure to rotate its blades; the primary types are the Pelton wheel, for high heads (pressure); the Francis turbine, for low to medium heads; and the Kaplan for a wide range of heads. Primarily used to power an electric generator.
Water valve
  1. A shut-off valve, mechanically or vacuum operated, for stopping the flow of hot coolant to the heater.
  2. In most water cooling units, a valve that provides a flow of water to cool the system while it is running.
Water vapor
Water in a vaporous form, especially when below boiling temperature and diffused (e.g., in the atmosphere).

  1. The international unit of measurement of power. One watt equals one Joule per second.
  2. The unit of electrical power equal to one ampere under a pressure of one volt. A Watt is equal to 1/746 horsepower.
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 AC Current
A series of wavelengths forming a group
Wave rectifier
Wave supercharger
  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. Ingredient in many lubricating oils which may separate from the oil if cooled enough.
  3. A solid or semi-solid material at 25°C consisting of a mixture of hydrocarbons obtained or derived from petroleum fractions, or through a Fischer-Tropsch type process, in which the straight chained paraffin series predominates. This includes all marketable wax, whether crude or refined, with a congealing point (ASTM D 938) between 80 (or 85) and 116°C and a maximum oil content (ASTM D 3235) of 50 weight percent.
  4. To treat with wax.
  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 clutch
  1. The machined abutments on which a sliding brake caliper rides
  2. Special sliding surfaces machined into the anchor plate and caliper body where these parts of a sliding caliper make contact and move against one another.
Abbreviation for Wheelbase
WB-EGO Sensor
Abbreviation for Wide Band EGO sensor which can be used to derive real AFR data with mixtures from 10:1 to 20:1, i.e. anything you are likely to be interested in.


A proprietary water-repellent spray

A diluted mixture


The progressive loss of substance from the operating surface of a body occurring as a result of relative motion at the surface; rubbing away.

Wear adjuster
Wear and tear
The condition of a vehicle where some parts are damaged from normal use
Wear bars
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.

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
A projection on the inner brake pad that contacts the disc and creates a squealing noise when pad replacement is necessary. Gradually being replaced by an electrical sensor that illuminates a warning lamp.

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
Wear Sensor
Weather caulking
Any of several kinds of crack-filling material around any windows or doors to the outside used to reduce the passage of air and moisture around moveable parts of a door or window. Weather stripping is available in strips or rolls of metal, vinyl, or foam rubber and can be applied on the inside or outside of a building.
Weather cracking
A visual sidewall condition which appears as cracking of the rubber.

Weather deck
Uppermost continuous deck and having no overhead protection having watertight openings
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.

Weather resistant
The ability to withstand natural climatic conditions which cause surface deterioration
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.

Weather stripping
Any of several kinds of crack-filling material around any windows or doors to the outside used to reduce the passage of air and moisture around moveable parts of a door or window. Weather stripping is available in strips or rolls of metal, vinyl, or foam rubber and can be applied on the inside or outside of a building.
  1. An internal reinforcement between panels.
  2. A Crank web.
  3. A supporting structure across a cavity.
A woven nylon strap used for seat belts.

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
  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.
Wedge block
Combustion chamber design in which the top of the piston and the surface of the block form an angle
Wedge combustion chamber
Wedge combustion chamberClick image to supersize
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. The squish produces swirling turbulence as the piston forces the mixture away from the narrow area of the wedge. Turbulence keeps the fuel and air mixed thoroughly for even burning. Squish also cools the mixture in the corners to reduce hot spots. It has a short Flame path which reduces the tendency of the burning fuel to knock or pre-ignite.

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
Fluid leakage which stains the outside of the container, but does not actually drip. Generally oil weeping is not a serious problem.
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.
  1. The force of gravity acting upon a body. It is measured in Newtons.
  2. The mass of an object under the influence of gravity. Unlike mass, the weight changes with the location of the object. As the force of gravity is relatively constant on earth, we use the terms weight and mass interchangeably.
Weight Arrestance
Weight bias
An element of vehicle design that results in either the front or rear suspension having to support more than half of the vehicle’s weight. Most cars have a forward weight bias.
Weight engine oil
Weight factor
(WIM) Technology for determining a vehicle’s weight without requiring it to come to a complete stop.
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 metre of surface area
Weight rating
Weight ratio
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
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.

Welded Rail Joint

A device used to Weld (usually) two pieces of metal

Weld face
The exposed surface of the weld.

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.

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 hammer
Welding hammerWelding hammer

A special type of tool with high tensile strength head and a spring handle (to reduce shock/vibration) used to chip excess slag and splatter during welding process. It has a blade at one end and a point at the other. Also called straight head chipping hammer

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 Stud
A ‘drive screw’ having a flat fillister head, used as an anchorage for welding.
Welding wire
A welding electrode fed into the handset from a reel
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 Screw
Projection welding applied to screws offer a means of providing attached treated members in sheet metal construction. Welding lugs on the head of the screw reduce the amount of current required for surface welding and provide fusion of metal at predetermined points.
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 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
Well depth
Vertical distance from bead seat to bottom of drop center rim.
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
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
Werner Frame
Western hand truck
A device used to transport goods manually with wheels within the side rails. Compare Eastern hand truck
Wet boiling point
The Boiling point of brake fluid when it has absorbed some water.

Wet bulb
Device used in measurement of relative humidity. Evaporation of moisture lowers temperature of wet bulb compared to dry bulb temperature of same air sample.
Wet bulb hygrometer
Instrument for measuring the relative humidity of atmospheric air. Also called psychrometer.
Wet bulb temperature
Measure of the degree of moisture. It is the temperature of evaporation for an air sample.
Wet cell battery
Cell or connected group of cells that converts chemical energy into electrical energy by reversible chemical reactions.
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 heat
Heating system using hot water (hydronic) heat or steam heat.
Wet liner
A cylinder sleeve application in which the water in the cooling system contacts a major portion of the sleeve itself.


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 natural gas
A mixture of hydrocarbon compounds and small quantities of various nonhydrocarbons existing in the gaseous phase or in solution with crude oil in porous rock formations at reservoir conditions. The principal hydrocarbons normally contained in the mixture are Methane, ethane, Propane, Butane, and Pentane. Typical nonhydrocarbon gases that may be present in reservoir natural gas are water vapor, carbon dioxide, hydrogen sulfide, nitrogen and trace amounts of helium. Under reservoir conditions, natural gas and its associated liquefiable portions occur either in a single gaseous phase in the reservoir or in solution with crude oil and are not distinguishable at the time as separate substances. Note: The Securities and Exchange Commission and the Financial Accounting Standards Board refer to this product as natural gas.
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.


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
The ability of an adhesive, coating or sealer compound to wet or adhere to a surface immediately on contact even when the film is extremely thin.
Whale tail
A colloquial term for a large, rear spoiler
What’s your 20?
Trucker slang for asking for location as in ‘What’s your 20 there New Penn.’
Wheatstone bridge
Electronic circuit consisting of resistors and thermistor. A temperature change on thermistor causes the bridge to become unbalanced, which sends a signal to the output device.
  1. 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.
  2. To drive a vehicle
  3. To propel a wheelchair
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
The position of the wheels relative to the car body. Proper wheel alignment reduces tire wear and improves driving control.

Wheel alignment gauge
A gauge used to measure the distance between the rims of the front wheels
Wheel and brake lock
Wheel and pinion
Wheel arch
The edge of the fender around the wheel cutout; sometimes also used with reference to the entire wheel housing.

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
Wheel assembly
A unit on a turbocharger consisting of the compressor, shaft, and turbine wheel
Wheel Balance
Wheel balancer
A machine used to check the wheel and tire assembly for static and Dynamic 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
  1. 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 than the other.
  2. For a three axle vehicle, the distance from the front axle center to the midpoint between the rear tandem axle centers
  3. For a truck tractor and semitrailer combination, wheelbase refers to the distance from the center of the front tractor axle to the center of the rearmost trailer axle.
Wheel bearings
  1. The bearings in wheel hubs ball bearings for drive shafts and taper roller bearings for driven hubs
  2. The inner and outer bearings found at each wheel cushion the contact between the wheel and the spindle it sits on. They’re packed with grease to prevent wear from the friction produced by the turning wheels.
Wheel bearing seals
Rubber or leather seals used at wheel hubs to keep wheel bearing grease from getting into a brake drum or onto a brake disc.
Wheel beauty side
The side of the wheel that is exposed to the exterior of the vehicle rather than the side that is attached to the axle. Also called Wheel face.
Wheel bolt
Wheel boltWheel bolt

A securing fastener which is screwed into threaded holes in the Wheel hub or at the Axle flange; common on some 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.
A cranked socket wrench for wheel nuts
Wheel camber

Wheel Carrier
Wheel center bore
The diameter of the opening in a disc which allows for protrusion of the axle hub.
Wheel centering
Wheelchair lift
Van liftWheelchair 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
Denver BootWheel 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 cover key
A special tool (unique to the vehicle) for installing and removing wheel covers
Wheel cutout
The open area described by the wheel arch, which determines to what extent the wheels are visible
Wheel cylinder
Wheel cylinderWheel 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.
Wheel cylinder pushrod
The rod that transmits the movement and force of the wheel cylinder piston to the brake shoe.
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.

Wheel disc brakes
Wheel dishing
The act of offsetting a bicycle rear wheel to accommodate the gear cluster so the circumference runs equally between the axle.
Wheel dolly
A trolley that supports the front wheels when a disabled vehicle is being towed. Also called just a Dolly
Wheel drive
Wheel face
The side of the wheel that is exposed to the exterior of the vehicle rather than the side that is attached to the axle. Also called Beauty side.
Wheel flutter
Wheel friction assemblies
The axle-mounted components of a brake system that create the friction necessary to stop a vehicle.
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
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
Wheel hubWheel hub

The component upon which the wheel mounts. It fits over the wheel bearings and is also mounted to the brakes.


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
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

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 lockup
A condition of 100% wheel slip.
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, mountain
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.
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
Wheel rim
The outer part of the wheel on which the tire is mounted
Wheel, road
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
A pair of matching bicycle wheels (front and rear).
Wheel shimmy

Wheel shudder

Wheel slip brake control system
A system which automatically controls rotational wheel slip during braking.
Wheel slip sensor
When used in combination with the wheel slip brake control system, a unit which senses the rate of angular rotation of the wheel(s) and transmits signals to the logic controller.
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.

Wheel spat
Wheel speed sensor
  1. 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
  2. The component of an anti-lock brake system that picks up the impulses of the toothed signal rotor, sending these impulses to the ABS ECU.
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 spindle
A flange that holds the wheel bearing assembly. It may be the end of the driveshaft
Wheel spin sensors
Detection devices used in the anti-lock brake systems to determine the rate of wheel rotation
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
Wheel tire clearance
Wheel tramp
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, triathlon
Wheel trim
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 luster; 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.

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
Wheel wobble
The oscillation of the front wheels caused by unbalanced wheels, defective steering gear, etc.
Wheel wrench
Whip aerial
A long, thin, flexible aerial
Whip antenna
A long, thin, flexible aerial, usually over 2 meters (6 feet). It is rarely seen on modern cars. Most were mounted on the rear fender and waved in the air when in use; but the tip was secured to the front fender when not in use. See Antenna
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
The tendency of a long rotating shaft (like a drive shaft) to bend at high speed, like a bow or whip
The tendency of a long rotating shaft (like a drive shaft) to bend at high speed, like a bow or whip
White Balance
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 line
Yellow lineClick to supersize dictionary author

A line painted on a road to mark one on-going lane from another lane going in the same direction. Also used to mark the shoulder on the side of the road.

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
White Smoke
  1. The exhaust color emitted during a cold start from a diesel engine, composed mainly of unburnt fuel and particulate matter.
  2. The exhaust color emitted from an engine with a blown head gasket so that coolant is entering the combustion chamber.
  3. The normal color of exhaust seen on very cold days caused by normal combustion process meeting cold air to create a fog-like substance.
White spirit
A highly refined distillate with a boiling point range of about 150°C to 200°C. It is used as a paint solvent and for dry-cleaning purposes.
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 key
Whitworth Thread
A screw thread, also known as the British Standard Whitworth, used principally in Great Britain.
An intermediary which sells to other intermediaries, such as a firm that buys from a manufacturer and sells to a retailer.
  1. The action of flicking or blipping the throttle rapidly.
  2. To remove moisture from clothing through capillary action.
  1. A capillary act of air escapement from the Tire casing during retreading.
  2. The capillary action of removing moisture from clothing.
A type of fabric where the polyester undergoes a special Visa treatment process, which greatly enhances the wicking properties of the fabric. Extremely hydrophobic Wicktec keeps you dry and cool.
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 open throttle switch
  1. Switch that disengages the automotive compressor circuit during periods of high acceleration.
  2. A switch which senses a wide open throttle condition. Existing methods of sensing this condition are manifold vacuum and mechanical travel of the throttle.
Wide ovals
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
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.
Any small gadget, device or mechanism that is unknown or temporarily forgotten; a car is full of them
Width Modulation Valve
Wiggle bus
A colloquial term for an articulated bus
Wilcox Boiler
A model of automobile manufactured by Buick Division of General Motors from 1962-70
Wills Sainte Claire
A vehicle brand of which models from 1921-1948 are classic cars.
A vehicle brand of which the Series 66, 66A, 66B Custom bodied for the classic era of 1925-1948 with required application are classic cars.
WillysClick image for books on

A vehicle brand of which the 1948-51 Overland Jeepster models are milestone cars.

Willy weaver
Trucker slang for Drunk driver as in ‘Watch out for the willy weaver in the granny lane.’
Wilson gearbox
An early preselector epicyclic gearbox still used in buses. Named after British inventor Walter Gordon Wilson, 1874-1957
Abbreviation for Weigh-In-Motion — A technology for determining a vehicle’s weight without requiring it to come to a complete stop.
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.

Winch Truck
A winch is a powered spool wound with cable. Winches are used to lift or to pull heavy objects. Winches vary in size from those on the front of small vehicles to heavy equipment which may weigh tons.
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
Wind Chill
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
Wind Chill 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)
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
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.
Wind energy
Kinetic energy present in wind motion that can be converted to mechanical energy for driving pumps, mills, and electric power generators.
The wrapping of wire around a core.

Winding the engine
Running the engine at top rpm.
Trucker slang for Blabbermouth trucker as in ‘That Reimer driver was a real windjammer.’
A type of piping covered with fabric; often used along the outlines of convertible tops, etc.
The windows on an automobile are called the greenhouse

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
Window filler panel
Window heater
Window heater system
Window heating
Window lift
British term for the switch or mechanism used to raise or lower a side window.
Window line
Window lock-out
Window lock-out switch
Window louvers
Window regulator
The mechanism used to raise and lower window glass. The regulator can be either manual or electric
Window unit
Air conditioner which is placed in a window.
Window wash
Trucker slang for A rainstorm as in ‘The news said we can expect a window wash later today.’
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
Logging debris and unmerchantable woody vegetation that has been piled in rows to decompose or to be burned; or the act of constructing these piles.
British term for 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.

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 left-hand to the right-hand fender
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
Windshield support panel

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.
Windstopper Fleece
A composite fabric with an ultralite Windstopper membrane laminated between a lightweight performance fleece and a wicking mesh. The membrane creates a windproof barrier, yet freely allows perspiration to escape.
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
Wind turbine
Wind energy conversion device that produces electricity; typically three blades rotating about a horizontal axis and positioned up-wind of the supporting tower.

Wind-up window
A window that is manually operated with a winder
Wind 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. A second plow attached to the side of a truck that extends the total plowing surface area beyond the reach of a front-mounted plow
  5. 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
Wing nutWing nut

A nut with two flat projections (i.e., wings) to be turned by thumb and finger. Used where frequent removal and replacement or adjustment are required. Also called a Butterfly nut.

Wing punch
A British term for a Fender punch
Wing Screws
Special screws with projection heads. Widely used in industry and home where a finger tightened screw is needed for frequent adjustments or for knock-down assembly applications. This piece is produced by pressing, forming, machining, welding or die casting. (Also available as 2 piece wing nut and studs, peened or welded together.
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
Retaining walls attached to the bridge abutment to support the roadway.
Japanese (especially Honda) term for a signal light.
Winter coolant
A fluid of ethylene glycol and special additives that when mixed with water lowers its freezing point in winter.
Winter tire
A tire with a deep tread suitable for winter conditions
wipe Switch
Wipe system
A metal or plastic device with a rubber blade that scrapes across the windshield to clean the windshield from rain or other moisture.

Wiper blade judder
Excessive vibration so that the blade does not make proper contact due to a bad wiper motor, worn wiper blade, wind lifting the blade, debris on the windshield. Also called wiper blade shudder
Wiper blade shudder
Excessive vibration so that the blade does not make proper contact due to a bad wiper motor, worn wiper blade, wind lifting the blade, debris on the windshield. Also called wiper blade judder
Wiper control
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 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.

Wire Circuit
Wire cover strip
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 Gauge
Wire glow plug
A double-pole glow plug with an unsheathed wire loop; now superseded by sheathed-type glow plugs
Wire loom
Wire marker
Wire mesh
In catalytic converters with a ceramic monolith, a stainless-steel fabric used as a shock-absorbing support for the honeycomb
Wire rope
Flexible 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 Hoisting rope
Wire-spoked wheels or wire-spoke Hubcaps.
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 criss-cross 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
Wire spoke wheelWire 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.

Wire strippers
Pliers used for removing insulating material from the ends of electrical wire

Wire System
Wire wheel
Wire wheelWire 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 harness connector
A single connector with many terminals for electrical wiring connections
Wiring loom
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
The Radius rod setup used in many of the older Ford cars to keep the axle square with the frame.

Wishbone suspension
Withdrawal fork
Withdrawal System
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
Abbreviation for without, as in excellent condition, w/o body damage.
Side to side movement — usually unwanted. Also called lateral runout.

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
Wobble plate-swash plate
Type of compressor designed to compress gas, with piston motion parallel to crankshaft. Often used in automobile air conditioning systems.
WolseleyClick image for books on

An automobile manufactured by British Leyland

Wood alcohol

Wood chisel
Wood chiselWood chisel

A tool for cutting or carving soft material like wood or plastic.

  1. A shooting brake.
  2. A wood-bodied vehicle, especially station wagons of the ’30s and 40s.
A vehicle brand of which the 1952-58 Wildfire models are milestone cars.
Wood mallet
A hammer with a wooden head
Woodruff key
Woodruff keyWoodruff 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.

Wood screw
Wood screwWood screw

  1. A tapered shaft fastener with wide spiral threads like a sheet metal screw and a variety of head shapes. Used to secure wood or plastic. Wood screws have a smooth shank that allows the screw to pull the two pieces of wood together for a tight joint. Wood screws also taper along the threaded portion optimizing the screws holding power in wood.
  2. A metal screw having a driver head, a gimlet point, and a sharp- crested, coarse pitch thread, for insertion in wood or resilient materials. It produces its own mating thread.
A station wagon with wood sides. It was made popular by the surf-board crowd
Production of an effect by exertion of a force. Energy is needed to do work and work is measured in Joules.

Work capacity
The maximum ability to perform.


Work ceiling
Work hardened
An increased level of hardness caused by cold forming fasteners.
Work Hardness
Hardness developed in metal as a result of cold working.
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
Working pressure
Work vehicles
Vehicles used at sites or roadworks that usually do not drive on the road
Work week
Work zone
An area within highway construction, maintenance or utility work activities.
World Trade Organization
(WTO) Created by the Uruguay Round and successor to the GATT, this new organization began operations on January 1, 1995.
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.

Worm-and-lever steering
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
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 gearbox
Worm and roller gearboxWorm and roller gearbox

A gearing system used with parallelogram steering linkage. Threads on the worm gear engage the threads of the roller. Both ends of the worm gear are supported by ball bearings to reduce friction. When the steering wheel is turned, the roller moves along the worm gear, swiveling the Pitman shaft (arm).

Worm-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
To bend something like a wire or a bar back and forth with the intention of breaking it apart.
Abbreviation for Wide open throttle
Abbreviation for Wide-Open Throttle Valve (Ford)
Wound valve
Wound valve spring
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
Wrapped pin
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
A truck designed for hoisting and towing disabled vehicles.

  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.
Wrench Head
A head on a fastener designed for driving or holding by means of an externally applied wrench to the sides of the head.
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
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
Wrist pinWrist 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 piston pin, gudgeon pin, or Floating piston pin.

Wrist pin circlip
A Circlip which is used on either end of the wrist pin to hold the pin in place. Also called a snap ring
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
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.


Abbreviation for Wheel Speed Sensor

Abbreviation for World Trade Organization.
W-type engine
W-type Engine
W-type engine
An engine configuration in which there are three rows of cylinders in the shape of the letter W. The center row is vertical while the other two are at an angle much like a V-type engine.
Abbreviation for Warm Up Oxidation Catalytic Converter
Abbreviation for Warm Up Three Way Catalytic Converter
Abbreviation for Whitewall, as in ww tires.
Abbreviation for wide whitewall, as in www tires.