Auto Parts Glossary

 

ABS sensor
Part of the ABS system. An electronic sensor used to control brake system to prevent driver from locking wheels and skidding, and instead allowing the vehicle to achieve a controlled stop using electrical pulses.

AC belt
A v-belt or serpentine belt used to drive an AC compressor.

AC compressor
A refrigerant pump which uses compressed air to pump refrigerant through a refrigeration system.

AC compressor clutch
A component utilizing a magnetic solenoid used to engage and disengage an AC compressor on command from the climate control system.

AC compressor seal kit
A kit containing the necessary seals and o’rings to rebuild or repair an AC compressor.

AC hose
Any of several rubber and metal hoses used to circulate refrigerant through an AC system.

AC o’ rings
Any of a number of rubber o’rings installed at various connections or joints throughout an AC system in order to prevent refrigerant leaks.

AC relay
Generally, the relay which powers the AC compressor.

AC switch
Any of several switches used to control various functions of an AC system.

AC tensioner pulley
A circular pulley used to set the tension on the AC belt.

Air cleaner mounts
A rubber mount, usually having a metal stud on each end which is used to cushion the natural vibration of an engines’ air filter housing.

Air filter
The filter which filters the outside air coming into an engine.

Alternator
An electrical device which is driven by a fan belt or serpentine belt which generates DC electrical current and sends that current to the battery so as to keep it charged.

Alternator belt
A v-belt or serpentine belt used to drive the alternator.

Alternator tensioner pulley
A circular pulley with a bearing which is used to tighten and keep the correct tension on an alternator belt.

Auxiliary fan
An additional cooling fan used to cool an AC condenser.

Axle
The part that connects the transmission or trans-axle to the wheel, thereby transferring power.

Axle nut
A threaded nut used to hold the outer end of an axle against a hub.

Axle seal
The seal which prevents the trans-axle (front wheel drive), or the differential (rear wheel drive) from leaking oil.

Ball joints
A steel ball socket with a threaded shaft attached to the control arm and to the steering knuckle giving a solid basis for the steering system.

Brake caliper
The part that, when the brake is applied, it receives brake fluid pressure and causes its hydraulically driven pistons to push against the brake pads which then push against the rotor and stops the car.

Brake dust shields
A pie-shaped disc that fits inside a wheel like an inside wheel cover and virtually eliminates brake dust from getting onto wheels.

Brake hose
With disc brakes, the hose that connects to the brake caliper on one end and the steel brake supply line on the other. With drum brakes, the hose that connects the wheel cylinder to the steel supply tube.

Brake lines
A series of small steel lines which deliver brake fluid from the brake master cylinder to the brake calipers or wheel cylinders via rubber hoses.

Brake pads
The parts that when pushed by the brake caliper pistons against the rotor, stop the car.

Brake pad spring
The part that cushions the brake pad and helps to limit noise due to the pads shifting.

Brake pins
The part that is driven through the brake caliper in order to hold the brake pads in place (fixed caliper design).

Brake rotor
The disc-shaped part that connects to the wheel and when pressed against by the brake pads causes the car to stop.

Brake sensor
An electrical sensor which is attached to a brake pad for the purpose of notifying the driver via a light , when brake pads get to a minimum thickness, thereby preventing a possibility of pads wearing down to a metal on metal situation against the brake rotor.

Brake shim
A metallic shim which is used between the brake pad and the brake caliper piston for noise reduction.

Brake shoes
Steel semi circular parts which have a layer of friction material that are used in pairs, two per drum, to stop a vehicle that has drum type brakes. When the brake pedal is pressed, the shoes push outward against the drum causing the vehicle to stop.

Brake shoe springs
The part that holds the brake shoe to the backing plate, and also to the other brake shoe.

Breather hose
One of several hoses used in the distribution of air as part of the engine breathing system.

By-pass hose
A rubber coolant hose which directs coolant from the thermostat housing to the water pump.

Cabin filter
A paper or carbon filter which filters and cleans the air within a vehicles’ interior.

Cam gear
The gear which drives the camshaft.

Camshaft position sensor
An electrical sensor which reports the position of the camshaft to an on-board computer.

Catalytic Converter
That part of the exhaust emission system that is designed to help reduce carbon emissions.

Clima relay
The relay which powers the climate control system.

Climate control panel
A push button panel that allows a driver to alter the cabin temperature. The panel controls various heating and air condition components to achieve the desired temperature.

Clutch disc
A metal disc with carbon fibers on each side used to smoothly transmit power from the engine to the transmission.

Clutch cable
A cable with a flexible shaft that when the clutch pedal is depressed, disengages the clutch.

Clutch kit
A kit usually containing all necessary components for replacing a clutch, including clutch disc, pressure plate, release bearing, pilot bearing and sometimes the pilot shaft tool.

Clutch master cylinder
A hydraulic cylinder which is activated by pushing the clutch pedal (hydraulic type clutch) and in turn sends hydraulic pressure to the clutch slave cylinder, thereby disengaging the clutch.

Clutch slave cylinder
A hydraulic cylinder which serves a master cylinder in a hydraulic type clutch system. When the clutch is depressed fluid is pushed from the master cylinder down to the slave cylinder.

Compressor
A vapor pump which pumps vapor from evaporator into a condenser.

Computer
The electronic device that monitors all of the vehicles systems and notifies of any system malfunction.

Condenser
A finned part, similar to a radiator, through which AC refrigerant circulates and as air passes through the fins, the refrigerant is cooled and then phase changes from a vapor to a liquid.

Condenser motor
The electric fan motor used as an additional cooling fan for the AC condenser when the system gets above a certain temperature, or pressure.

Control arm

(front) A part of the suspension system which connects the frame and the steering knuckle or front axle carrier. (rear) Connects rear frame to rear axle carrier.

Control arm bushing
The bushing that fits in either end of the control arm.

Crankshaft gear
The gear which sits on the front of the crankshaft and is used to drive all other timing and auxiliary gears.

Crankshaft position sensor
An electrical sensor which reports the position of the crankshaft to an on-board computer.

Crankshaft seal
A circular seal which prevents oil from leaking from the front end and rear end of the crankshaft.

CV Boot
The rubber boot which keeps grease around the CV joint.

CV Joint
(front inner) A spherical device which connects and delivers power to the axle from the transmission or transaxle output flange. (front outer) Similar in design to the inner, but delivers power to the output flange which drives the wheels.

Cylinder head
A cast iron or aluminum part which sits directly on top of an engine block. The cylinder head’s functions are basically to house the engines’ intake and exhaust valves and guides and on (OHC) overhead cam engines, the camshaft as well, and provides the upper half of the combustion chamber in which a series of controlled explosions take place so as to create horsepower.

Differential seal
The seal usually located on the side of the differential and prevents oil from leaking out of the differential.

Distributor assembly
Central to an ignition system on gasoline engines, an electro-mechanical device which receives a high voltage spark via an ignition coil and transmits that spark, in a firing order, to each of the engines’ spark plugs.

Distributor cap
The phenolic cover on the top of a distributor assembly, whose job it is to send fire to each spark plug via a set of spark plug cables, according to the in a sequential firing order.

Distributor rotor
A phenolic part which sits just underneath the distributor cap and whose duty it is to receive a spark from the ignition coil via a cable usually connected to center of the cap and transmit that spark according to the vehicles’ firing order, to the terminals located inside the distributor cap and on to the spark plugs via the spark plug wires.

Driveshaft center support
A metal and rubber part used to connect the front and rear sections of the drive-shaft which provides stability for the drive-shaft and a smooth transition from front to rear.

Door check aka door brake
A metal strap which, when a door is opened, only allows the door to open the appropriate distance, thereby preventing the door from hitting the fender.

Door handle
The handle on a vehicle’s doors used for entry or exit of the vehicle.

Drag Link aka Center Link
That part of the steering on a conventional steering system that connects the left and right outer tie rod assemblies.

Door seal
A rubber gasket which seals out wind noise and water around the perimeter of a vehicles’ doors.

Drive belt
A serpentine or “ribbed” belt used to drive most or all pulleys in a drive belt system.

Driveshaft center support
A metal and rubber part used to connect the front and rear sections of the drive-shaft which provides stability for the drive-shaft and a smooth transition from front to rear.

Driveshaft drive disc
A rubber circular part which connects the transmission output flange to the front of the drive-shaft and provides a smooth power transfer.

EGR valve
The exhaust gas recirculation valve recirculates unburnt fuel gases back into the intake or turbo.

EGR valve gasket
The gasket which fits between the intake or turbo and the EGR valve.

Emblems
Any of a number of insignias on a vehicle which represent the vehicles’ make or model.

Emergency brake shoes
The parts which, when the emergency brake is applied, push outward against the interior of the rear brake rotor, so as to prevent the car from moving.

Evaporator
A finned part, similar to a radiator, through which AC refrigerant passes and as warm interior air passes over the fins, the refrigerant is phase-changed from a liquid to a vapor and is recirculated back to the compressor.

Exhaust gasket
The gasket or gaskets that are used between exhaust system components to seal off leaks and exhaust noise.

Exhaust manifold gasket
The gasket that seals between the cylinder head and the exhaust manifold.

Exhaust valve
A circular part with a stem usually several inches long which is part of the combustion system, and when opened allows hot exhaust gases to escape the combustion chamber resulting in combustion power.

Expansion valve
A metering device which allows a refrigerant to phase change from a liquid into a vapor.

Fan belt
A v-belt driven by the crankshaft pulley used to drive a fan blade and water pump, both used to cool the engine.

Fan switch
A switch which activates a cooling fan based on engine temperature.

Flasher relay
A relay which delivers power to a turn signal and four way flasher system.

Fog light assembly
A fog light lens and housing assembly usually including the mounting point.

Fog light lens
A glass lens which covers the fog light bulb. In most late model cars the lens is casted as part of the fog lamp assembly.

Fuel injector
An electrical or mechanical device which meters tny amounts of fuel into a combustion chamber.

Fuel injector o’ rings
The rubber o’rings used to prevent fuel from leaking around the injector.

Gas cap
A metal or plastic cap which is used to fill a fuel tank when removed.

Gas cap gasket
A rubber gasket which seals between the gas cap and the fuel filler tube.

Glow plug
An electrical heating element which heats usually for a few seconds and enables a diesel engine to achieve combustion when the engine is cold.

Glow plug fuse
Usually an aluminum strip fuse used to prevent damage to a glow system. When the system draws too much current, the fuse blows, circumventing any further damage to the electrical system.

Glow plug relay
A relay which powers a glow system in a diesel vehicle.

Grille
A decorative part located on the front of a vehicle whose purpose is purely cosmetic.

Grille moulding
An aluminum or plastic strip used to embellish a grille.

Head gasket
The gasket which provides a seal between the engine block and cylinder head, thereby preventing the engine coolant and engine oil to mix.

Head gasket set
The set of gaskets which usually contains the head gasket, valve cover gasket, exhaust manifold gasket, the valve seals, the plenum gasket, and other gaskets and o’rings needed to remove and replace the cylinder head.

Headlight assembly
A combination of headlight lens, lens housing and mounting structure.

Headlight lens
A glass or plastic covering for the headlight bulb.

Heater control valve
A mechanical or electromechanical valve which controls the flow of coolant to the heater core and which, depending on the temperature called for by the driver, will be open, closed or partially open.

Heater hose
A rubber hose which, directly or indirectly, provides a coolant supply to the heater core and a return to the engine.

Heater motor
The electric motor used to blow either heat or AC air generated by a climate control system.

Hood release handle
A handle inside a vehicle used to release a hood latch.

Hub
A round steel which houses the wheel bearing and the part to which a wheel fastens.

Hub bolts
The bolts used to hold a rotor onto a hub.

Idler arm
A part of the steering system which helps to stabilize it by providing a pivot point for the left and right motion of the tie rod assemblies and the center link.

Idler arm bushing
The bushing that fits inside the idler arm.

Idler pulley
A circular stationary pulley with a bearing which is used to assist a fan belt, drive belt or timing belt in running straight.

Igniter
An electronic device which supplies power to an ignition system.

Ignition coil
A device which upon receiving a low amount of voltage, using a magnetic coil, creates a powerful spark which is used to start an engine and to keep it running.

Ignition control unit
An electronic device which receives, adjusts and then transmits voltage to the ignition system.

Ignition Rotor
A part inside the distributor cap whose function it is to receive a spark from the ignition coil via a cable and sequentially in the firing order , deliver spark to each distributor terminal, which then delivers a spark to each spark plug wire.

Ignition wires
Electric cables that receive a spark from an ignition coil via a distributor cap, or directly from an ignition coil, and then transmit a high voltage spark to the engines’ spark plugs.

Intake hose
A hose, which is usually plastic that delivers outside air to the engine’s intake system.

Intake manifold gasket
The gasket that seals between the cylinder head and the intake manifold.

Intake valve
A circular part with a stem usually measuring several inches long which is part of the combustion system. It allows oxygen to enter into the combustion chamber enabling the explosions to occur which creates combustion power.

Intermediate gear
A gear which is used to indirectly drive a device such as an oil pump or injection pump.

Main bearings
Thin semi-circular aluminum or copper parts used in pairs. One upper and one lower. These fit between the crankshaft and the main bearing journals.

Mass air sensor
A part that monitors and regulates air flow to the fuel system. Mirror A reflective part that is used to enable a driver to see on either side or behind the vehicle.

Motor Mount
The rubber mounts which give cushion and reduces vibration between the engine and the frame.

Muffler
That part of the exhaust system that muffles or quietens and reduces the noise coming from the engine, located at center and or rear of the vehicle.

Oil cap
A metal or plastic cap on top of an engine which is used to add engine oil when removed.

Oil cap gasket
A rubber gasket which seals an oil cap to a valve cover.

Oil dipstick
A metal shaft which is submerged into a vehicles’ oil pan used to measure the crankcase oil.

Oil level sensor
An electrical sensor which uses a floating rheostat to monitor and report the current engine oil level.

Oil pan
On the bottom of the engine, a cavity which holds the engine oil.

Oil pan drain plug
A threaded plug at the bottom of an oil pan which enables the oil to be drained out and changed.

Oil pan drain plug washer
A washer, usually either copper, aluminum or rubber which seals between the oil drain plug and the oil pan.

Oil pan gasket
The gasket that seals the oil pan to the engine block.

Oil pressure switch
An electrical switch that monitors and reports to a light or gauge, the engine’s oil pressure. If a light is used, the light will come on if engine’s oil pressure is dangerously low.

Oil pump
A mechanical pump consisting of a housing , gears and a wire screen. This pump circulates engine oil through a series of orifices ports and arteries scattered throughout an engine, providing life-sustaining lubrication for the engine.

Parking pawl
A small curved “catch” used in automatic transmissions so that when the vehicle is placed in park, this lever prevents the vehicle from rolling.

Pilot bearing
A ball or needle bearing situated in the center of a flywheel through which the transmission main-shaft protrudes so as to prevent any side to side or up and down movement of it.

Piston
A circular part that moves in an up and down motion in a cylinder bore, which together with the other pistons and the engines valves delivers power to the engine.

Plenum gasket
The gasket which seals between the intake manifold and the plenum.

Power steering belt
A v-belt or serpentine belt used to drive a power steering pump.

Power steering filter
A filter, usually located inside the power steering pump, for the purpose of filtering particulate matter out of the power steering fluid.

Power steering pump
A hydraulic pump used to pump power steering fluid through a closed system in order to keep the internal parts from being damaged from the heat that is generated.

Power steering pump repair kit
A kit containing seals,o’rings and washers used to rebuild or repair a power steering pump.

Pressure plate
A metal spring loaded part used to disengage the transmission when the clutch pedal is pushed down and when the pedal is allowed to come up, to reengage the transmission and deliver power to the wheels.

Radiator fan motor
A cooling fan motor which gives the radiator additional cooling when the coolant reaches a certain temperature.

Radiator hose
One of, usually two hoses, connecting the radiator to the engine. Also usually consisting of a supply hose and a return hose, or one upper and one lower hose.

Radiator mounts
Rubber mounts used to cushion and insulate between the radiator and the radiator frame.

Rear glass seal
The weatherstripping around the rear glass that seals out air and water.

Release bearing
Working with the pressure plate, when the clutch pedal is depressed , disengages the pressure plate and clutch disc and reengages them when the pedal is allowed back up.

Receiver drier
A round metal cannister that contains desiccant and uses it to remove small amounts of moisture and particulate matter from AC refrigerant.

Reference sensor
An electrical sensor which reports the position of a camshaft or a crankshaft to an on-board computer for the purpose of ensuring that an engines’ valve timing is correct.

Relay
An electromechanical switch which controls electrical loads.

Rocker arm
A part which is used by camshaft movement to open and close the intake and exhaust valves.

Rod bearings
Thin semi-circular aluminum or copper parts which are used in pairs. An upper “shell” and a lower shell. These fit inside the connecting rod, between the connecting rod and the rod journal on the crankshaft.

Serpentine belt
A belt which is characterized by a series of ribs running parallel with the belt, and one that drives usually several pulleys.

Shifter bushing
A circular bushing, usually rubber or plastic, which attach to a transmission linkage and insulate between the linkage and the transmission.

Shifter knob
The handle which attaches to the transmission shifter to facilitate the shifting of the transmission.

Shock absorbers
Telescoping cylinders located on each corner of a suspension system which absorbs small bumps and rough surfaces on a road thereby limiting damage to the suspension system and providing a smoother ride.

Spark plug
A threaded electrode which screws into a combustion chamber whose job it is to provide a spark at the appropriate time in order to create a controlled explosion in the chamber, therefore delivering horsepower to a vehicle.

Spark plug connector
A metal and rubber boot used to deliver a spark from an ignition wire or coil to the spark plug.

Speedometer cable
A cable with a flexible shaft that runs from a speedometer gear inside the transmission up to the speedometer, to indicate current speed.

Spindle
A part attached to the control arm(s) on which a wheel bearing hub mounts.

Spindle nut
A threaded nut used to hold a rotor and hub assembly on a spindle.

Starter
The electric motor used to start a vehicle. When the ignition switch is turned to the start position, voltage is delivered to the starter causing a gear to run up a shaft which engages the flywheel and therefore spins the engine over, at which point the ignition and fuel systems work in tandem to cause the engine to start.

Steering box
A cast iron box which connects to the various steering components via a pitman arm, and is also attached to the steering shaft which is controlled by the use of the steering wheel.

Steering box repair kit
A kit containing various seals o’rings and washers used to rebuild or repair a steering box.

Steering knuckle
A part to which the bearing hub mounts.

Steering Rack
The main component of a rack and pinion steering system. A set of worm gears inside a steel an cast iron housing which facilitates the left and right steering of the vehicle.

Sunroof seal
Usually a rubber (sometimes felt) gasket used to prevent noise around a sunroof.

Sway bar bushings
Those bushings which help secure the sway bar to the frame, usually consisting of outers and inners.

Sway bar link
The links, usually having a swivel socket on each end that connect the sway bar to the frame.

Tail light assembly
A tail light lens and housing with mounting structure.

Tail light lens
A plastic cover which covers the tail light bulbs.

Tensioner assembly
A device which keeps tension on a belt or a chain.

Thermostat
A mechanical device which opens and closes doe to engine temperature. It opens as an engine warms up, stays open while engine is at operating temperature and closes when engine cools back down.

Thermostat housing gasket
A paper or rubber gasket which seals between the engine block and the thermostat housing.

Thermostat o’ring
A round rubber seal which seals the thermostat cover to the thermostat housing.

Thrust bearings
In an engine, the bearings or usually shaped like a semi-circular washer which provides the proper spacing and clearances for the front to back movement of a crankshaft.

Tie rod end
That part of the steering which, with conventional steering, connects to the steering knuckle on one end and the center link on the other. With rack and pinion steering it connects to the outer end of the steering rack.

Timing chain
A chain, similar to a bicycle chain, used to drive various engine gears, the power originating from the crankshaft gear.

Timing chain kit
A kit containing all necessary components for replacing the timing chain. Usually including the timing chain, timing gears, front crank seal, timing guide rails and the tensioning rail.

Transmission drain plug
A threaded screw plug on the bottom of the transmission which enables the transmission fluid to be drained out and changed.

Transmission drain plug washer
The washer, usually copper, aluminum or rubber which seals between the transmission drain plug and the transmission.

Transmission filter
The filter, usually a paper filter inside a metal case, which filters particulate matter.

Transmission pan gasket
A cork or rubber gasket which seals the transmission pan to the transmission.

Transmission mount
The steel and rubber mount which gives cushion and reduces vibration between the transmission and the transmission cross member.

Transmission seal
A circular double-lipped seal for the front or rear of a transmission.

Trunk seal
A rubber gasket which seals out wind noise and water from the trunk area.

Turbo
A device which, by utilizing a small turbine, increases horsepower by introducing additional air pressure to boost compression and performance.

Turn signal lens
A plastic cover which covers the turn signal bulb.

Turn signal light assembly
A lamp usually located next to the headlamp which gives a directional signal indicating the intentions of a driver turning in a particular direction.

U joint
A cross-shaped part that depending on position, connects a yoke to a transmission, a flange to a differential or a front driveshaft section to a rear section.

Vacuum pump
A mechanical or electrical pump which delivers vacuum to a vacuum system via a set of plastic line and rubber hoses.

Vacuum pump repair kit
A kit which contains the parts needed in repairing or rebuilding a vacuum pump.

Valve cover
A metal or plastic cover that covers the valve train area of the top of the engine.

Valve cover gasket
A gasket that is used to seal the mating surfaces of the valve cover and the cylinder head.

Valve seals
Circular seals made of rubber, nylon, or a combination,which fits at the base of a valve guide and which prevents oil from leaking down the inside of the guide and into the combustion chamber.

Warm-up regulator
A device which controls fuel pressure based on engine temperature.

Water pump
A mechanical pump which is driven by a belt and uses an impeller to circulate coolant through an engine.

Wheel bearing
A ball or roller bearing used which allows the wheel to roll without resistance or friction.

Wheel bolts
The bolts which are used to hold a wheel to a vehicle.

Wheel cylinders
The hydraulic cylinders used in conjunction with brake shoes. When brake pedal is pushed, the brake fluid travels inside the wheel cylinders which causes the pistons inside the cylinders to push outward against the brake shoes, therefore stopping the vehicle.

Wheel seal
A double-lipped seal which keeps the grease inside the wheel bearing from leaking out.

Window motor
The electric motor which controls the up and down movement of the window regulator.

Window regulator
Usually a scissors shaped part which mechanically raises and lowers the door glass. Some regulators utilize a cable type raising and lowering system.

Windshield seal
The rubber weatherstripping that seals around the windshield and prevents air and water from entering into the vehicle.

Wiper arm
A metal part that extends off the wiper motor linkage, used to hold wiper a blade in place.

Wiper blade
A metal and rubber part with a soft rubber strip used to wipe a windshield or rear glass.

Wiper blade refills aka wiper blade inserts
A soft rubber strip which fits into a rubber frame used to wipe a windshield or rear glass.

Wiper motor
The electric motor used to operate windshield wiper blades.

Wiper relay
The relay which powers the wiper motor.