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GLOSSARY
A

A/C
The cooling and dehumidification of a vehicles cabin air. Short for Air Conditioning.

A/C Accumulator
A component used in a fixed-orifice tube system that protects the compressor from excess liquid refrigerant by means of desiccants, or the drying agents that remove moisture from the refrigeration system.

A/C Compressor
An engine-driven pump in the air conditioning system that increases the pressure of the refrigerant.

A/C Condenser
A tube-and-fin heat exchanger that is exposed to outside airflow. As refrigerant vapor flows through the tubes, it condenses to liquid and releases heat that the air stream carries away. The condenser is on the high side.

A/C Driver
Integrated Computer Output Circuit for the air conditioning system.

A/C Gauge
A tool used for measuring the air conditioning system's atmospheric pressures.

A/C High Side Fitting
Located on the discharge side, the high pressure line, contains a port for servicing and checking high side pressures.

A/C Hose
A hose used to carry refrigerant throughout the air conditioning system.

A/C Idler Pulleys
An adjustable pulley used to keep tension on the air conditioning drive belt.

A/C Inline Filters
A device that removes contaminants from external air entering the ventilation system.

A/C Leak
A leak in the air conditioning system that regulates cool air flow and temperature to the interior of your vehicle; usually a refrigerant leak.

A/C Leak Detection
A fluorescent dye that is added to the air conditioning system in order to track a leak.

A/C Low Side Fitting
Located between the evaporator and compressor, the lower pressure line, which is the suction side, contains a port for servicing and checking low side pressures.

A/C O-Ring
A round rubber-like ring used to seal particular components of the air conditioning system.

A/C Pipe
A tube that connects components within the air conditioning system.

A/C Power Module
A computer or module used in order to switch the A/C system on and off.

A/C Receiver
A component of the air conditioning system, also known as the receiver drier, containing desiccants that remove moisture

A/C Valve Core
A removable stem inside the high and low side fittings that holds pressure for the air conditioning system.

Absorbed Glass Mat (AGM)
AGM is an advanced battery technology that allows the electrolyte (acid) to be uniformly distributed across the battery plate active material, allowing the battery to tolerate repeated deep discharges and provide an overall longer service life. AGM batteries are safer because there is no free acid to spill and they are highly resistant to failure from vibration.

Absorption Charge
Many automatic battery charges will charge a battery in stages, beginning with the initial or bulk charge phase, which brings the battery to about 3/4 of a full charge. During the Absorption charge phase, the charger reduces the charge amperage but holds the voltage at a relatively high set point of around 14.5 volts DC. A final maintain or float phase follows, whereby the battery is retained in a fully charged condition at about 13.5 volts.

Active Material
Also known as paste, active plate material is an absorbent lead-based substance that coats the plates and converts chemical energy to electrical energy (current) within the battery.

Acrylic Lacquers
From late 1950s to 1980s, acrylic lacquer was the most sought-after automobile paint and it was mostly on luxury and expensive vehicles like Rolls Royce. If you want the absolute highest possible gloss or shine on your vehicle, acrylic lacquer paint is the best choice.

Air Conditioning
The system that regulates cool air flow and temperature to the interior of your vehicle.

Air Conditioning System
The system that regulates cool air flow and temperature to the interior of your vehicle.

Air Shock
A suspension system that uses air pressure as its spring source.

Air Suspension
Air suspension is a type of suspension engineered by an electrical or engine driven air pump or compressor. This pump pressurizes the air, using compressed air as a spring.

Air Suspension Kit
A suspension system that uses contained compressed air for vehicle springing. The air suspension kit is used to restore vehicle’s suspension system that the air suspension is a type of vehicle suspension powered by an electric or engine driven air pump or compressor.

Alignment
When referring to wheel alignment, it is the proper adjustment of a car's front or rear suspension for camber, toe, caster, and ride height.

Alignment Bolt
Various bolts types used on the vehicles chassis system used to make varying degrees of adjustment for caster, camber or toe.

Alignment Shim
Metal or plastic spacers used in the alignment process to alter camber, caster and/or toe. On rear-wheel drive applications, shims may be added to or removed from stacks of shims on the front control arms to change camber and/or caster. On front-wheel drive applications, partial shims or full contact shims may be positioned behind the rear axle spindle to vary rear toe and/or camber. Camber shims are also available for 4x4 axle applications. Some shims are adjustable or can be indexed various ways to provide incremental alignment corrections.

All Wheel Drive
A vehicle transmission system that delivers power to all four wheels at the same time.

Alternating Current
(AC) An electric current that first flows one way in the circuit and then the other at regularly recurring intervals. This is the type used in homes. It contrasts with direct current. It is also the type of current produced by a vehicle's alternator. Since the rest of the vehicle uses direct current, the current coming from the alternator must be changed by the rectifier.

Alternator
An alternator is an electrical generating device that produces an alternating current (AC). In transportation applications, the alternator uses diode rectification to transform the AC voltage produced be the winding.

Amp Hour
Amp-Hour is a measure of electrical charge and more specifically the amount of electrical charge potential that can be transferred from a battery in a period of one hour.

Analog Computer
An analog computer is a form of computer that uses the continuously changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved.

Angular Sensor
A type of sensor that replaced a mechanical part.

Articulated Steering
Articulated steering is a system by which a four-wheel drive vehicle is split into front and rear halves which are connected by a vertical hinge. The front and rear halves are connected with one or more hydraulic cylinders that change the angle between the halves, including the front and rear axles and wheels, thus steering the vehicle.

ATV Cover
Fabric that provides all weather protection to your ATV and protects against harmful pollutants and UV rays.

Automotive Paint
A liquid mixture, usually of a solid pigment in a liquid vehicle, used as a decorative or protective coating.

Axle Flange Gaskets
Axle drive flange gaskets are designed to fit between your axle tube housing end and the bearing retainer plates. They are made from quality materials and are available for most rear-wheel drive applications.

Axle Flange
An axle flange is the part of an axle that has the wheel studs coming through it in order to mount a wheel to the axle.

B

Backing Plate Gaskets
Backing plate gaskets protect your car's rear axle and keep water and debris out of it. It also helps prevent metal-to-metal contact and seal off any gaps between the metal surfaces.

Ball Joint
Ball joints act as the pivot point for suspension articulation. Ball joints are designed to allow the suspension to move independently without interfering with the action of the wheel. This independent motion isolates the movement of the car or truck wheel from the chassis of the vehicle, creating a smooth and quiet ride.

Ballast Resistor
A resistor inserted into a circuit to swamp or compensate changes, e.g., those arising through temperature fluctuations. One similarly used to swamp the negative resistance of an arc or gas discharge. Also called ballast tube. A resistor constructed of a special type wire, the properties of which tend to increase or decrease the voltage in direct proportion to the heat of the wire.

Basecoat Paints
A liquid mixture, usually of a solid pigment in a liquid vehicle, used as a decorative or protective coating.

Battery
A battery is a vessel containing one or more cells, used for the storage and transfer of electrical energy.

Battery Discharge
Battery discharge is the amount of electrical energy drawn from a battery over a specified period of time and for which immediate replenishment does not occur.

Battery Life
Battery life is the amount of time, generally measured in months, that a battery will perform within the design specification of the product. Useful automotive battery life averages about four years.

Battery Plates
Battery plates are lead-based grids that are stacked in an alternating negative-positive-negative fashion inside each battery cell. Plates in a conventional lead-acid battery are interconnected by a metal strap, allowing current to be conducted across cells and between the positive and negative terminals.

Battery Shelf Life
Battery shelf life is the amount of time, generally measured in months, that a battery is considered serviceable in storage. Generally, a battery will discharge at a rate of several percent per month. Left to discharge without boosting, battery shelf life is typically about 6 months and upwards of one year if maintained with a battery charger.

Battery Solution (Electrolyte)
Battery electrolyte is usually a mixture of sulfuric acid and water and acts to conduct the electrical charge across the plates within a cell. Electrolyte level must be maintained within a battery so as not to allow the active material to dry.

Battery Testing
Battery testing is a process by which the condition of a battery is verified using any of a variety of test equipment ranging from a simple voltmeter to highly accurate capacitive and load testing. Battery testing is critical to avoid impending battery failure during operation and possible damage to charging system components.

Battery Vents
Battery vents are opening typically located in the filler caps or cap manifold of a battery. Vents are necessary to evacuate excessive hydrogen gas that may have built up inside the battery during charging. Without venting, dangerous vaper pressure may be allowed to build inside the battery.

Bellcrank
A bell crank is a type of crank that changes motion through an angle. The angle can be any angle from 0 to 360 degrees, although 90 degrees and 180 degrees are common.

Belt Tensioner
Tensioner is a device that applies a force to an object to maintain it in tension. Often the amount of force is adjustable. There are tensioners for applying a tensioning force to drive belts and chains, fibers, and bolts.

Blower Motor
The motor that regulates the fan in the heating and air conditioning system.

Blower Wheel
The fan that propels air in the heating and air conditioning system.

Breakerless Ignition
An ignition system using electronic switching devices to assist or eliminate the mechanical parts.

Breakers
Breathers are a part of your vehicles emission system. Breathers allow air movement between the atmosphere and the component it is installed in and relieves heat in the engine to increase performance.

Bulk Charge
Bulk charge is considered to be the first stage in automatic battery charging. This occurs when the battery charger applies a powerful amperage and voltage that is above the nominal to the battery. This first stage is responsible for about 3/4 of the battery charge.

Bumper Paint
Designed to renew and revitalize your worn-out chrome or plastic bumper trims, giving them a like new shine and defending them against future wear and tear.

Bushing
Bushings isolate and reduce transmitted noise, road shock, and vibration.

C

Cable Hook Up
Cable hook up as applies to vehicle batteries refers to the polarity of the battery cable or jumper cable with respect to that of the host battery. The positive battery cable is to be attached to the positive (generally labeled +) battery post, and the negative cable is to be attached to the negative (generally labeled -) battery post.

Cam
A stepped or curved eccentric wheel mounted on a rotating shaft. As a cam is turned, objects in contact with it are raised or lowered.

Camber
A wheel alignment adjustment of the inward or outward tilt on the top of the wheel when viewed from the front of the vehicle. Correct camber improves handling and cuts tire wear.

Canvas Car Cover
Made for indoor use and can help protect garage vehicles from dust and scratches.

Capacitance Discharge
A type of ignition system. It can be either all-electronic or breaker point controlled.

Capacitor/Condenser
Electrical device made of dry metal and dry insulation; used to store electrons.

Capacity Offset
Capacity offset refers to a correction factor programmed into many more sophisticated battery testers, chargers and maintainers. Simply stated, the ability of a battery to take and hold a charge is influenced by atmospheric temperature. The charge rate is corrected or offset according to the ambient temperature.

Car Covers
A car cover protects your vehicle from dust, direct sunlight, tree sap and more.

Caster
A wheel alignment adjustment that positions the wheels like the casters on a chair or shopping cart, so the tires follow naturally in a forward straight line.

Catalytic Converter
The catalytic converter is a vital part of your vehicle emissions control system. Its job is to reduce toxic air by converting harmful pollutants into less harmful emissions, such as water, carbon dioxide and nitrogen.

Cathode
The negatively charged cell from which current flows in an electrolytic cell.

Cell Change
A battery cell is a container within the battery case that holds a prescribed number of positive and negative battery plates, their separators and the electrolyte. In a conventional 12 volt battery, there are 6 cells, each producing just over 2 volts. Each cell within a battery is connected in series via a metal strap.

Chameleon Paints
Paints that provide an illusion of sparkling or changing colors.

Charge Control
Charge control for batteries is the regulation of charge current and / or voltage used to charge or maintain a battery.

Charging Cycle
Charging cycle is a program or series of programs used by battery chargers for replenishing a discharged battery.

Chassis
Generally, chassis refers to the frame, engine, front and rear axles, springs, steering system, and fuel tank .

Clamp
A mechanical coupling used to join and grip mating parts.

Clear Coat Finishes
An automotive painting technique in which a coating of clear lacquer or other synthetic liquid is applied over the base color to enhance the shine and durability of the paint.

Clear Coat Paint
Clear coat paint, or a clear coat finish as it is commonly referred to, is paint that does not contain any pigment or color.

Coachwork
Coachwork is the body of a motor vehicle. The term is usually reserved for bodies built on a separate chassis, rather than being of unitary or monologue construction.

Coil on Plug
A coil for each spark plug.

Coil Primary
An alternating current in the primary side of the ignition coil.

Coil Spring
A suspension spring made from coiled wire having a cylindrical or conical outline.

Cold Cranking Amp
Cold cranking amps (CCA) is the amount of current that a battery can deliver at 0 degrees Fahrenheit. Specifically, it is the number of amps that a battery can deliver for a period of 30 seconds while maintaining a minimum of 1.2 volts per cell (7.2 volts for a 12 volt battery). CCA has been the generally accepted standard for battery power.

Combustion Chamber
The volume of the space in the cylinder above the piston with the piston at top dead center (TDC) in the compression stroke. The head of the piston, the cylinder walls, and the head form the chamber. Combustion of the fuel-air mixture.

Compression Cycle
It is the squeezing of the fuel-air mixture in the cylinder of a spark-ignition engine or the squeezing of the air in a diesel engine. Compression makes the process of combustion more effective and increases engine efficiency.

Condensation
the collection of moisture removed from ambient air.

Constant Current
Constant current is an older technology method for charging batteries. It is also known as trickle charging when the application is a small amount of current. Constant current means that the charge current does not change regardless of the batteries state of charge.

Contact Breaker
A mechanical switch in the distributor with two metal Contact points (usually made of silver, platinum, or tungsten) that open and close. When the points are closed, energy is stored in the Primary windings of the Coil. When the breaker points open, this energy is transferred to the secondary windings of the coil and stepped up, resulting in a high voltage to fire the plugs.

Control Arm
The primary function of a control arm is to provide the connection point between the body of the vehicle and wheel. This allows the wheel to move up and down while the body frame and passengers stay smooth and level. Key components that are normally found on a control arm include the control arm bushing and the ball joint.

Conversion Gasket Set
The lower engine gasket set.

Corrosion
Corrosion, as pertains to batteries, is a chemical reaction that occurs both inside and outside the battery. Internally, the sulfuric acid electrolyte acts to corrode the plates over time, eventually reducing the strength and density of the plates. Externally, acid spillage or fumes acts to chemically corrode metals in contact or near the battery. Specifically, corrosion is commonly known to occur on the battery cable ends and cable wire.

Covers
Battery covers are often specified by the original equipment vehicle manufacturer in order to insulate the battery from engine heat and/or protect adjacent components from the battery.

Crab Steering
Crab steering is a special type of active four-wheel steering. It operates by steering all wheels in the same direction and at the same angle. Crab steering is used when the vehicle needs to proceed in a straight line but under an angle, or when the rear wheels may not follow the front wheel tracks.

Crank Angle Sensor
A detection device which picks up signals to locate the position of a part and sends the information to the ECU.

Cranking Amp
Cranking amps (CA) is the amount of current that a battery can deliver at 32 degrees Fahrenheit. Specifically, it is the number of amps that a battery can deliver for a period of 30 seconds while maintaining a minimum of 1.2 volts per cell (7.2 volts for a 12 volt battery). CA is often referred to as marine cranking amps.

Crankcase
The lower section of the engine that supports the crankshaft, confined by the lower block casting and the oil pan.

Cranking Amp
Cranking amps (CA) is the amount of current that a battery can deliver at 32 degrees Fahrenheit. Specifically, it is the number of amps that a battery can deliver for a period of 30 seconds while maintaining a minimum of 1.2 volts per cell (7.2 volts for a 12 volt battery). CA is often referred to as marine cranking amps.

Crankshaft
A main rotating shaft running the length of the engine. The crankshaft is supported by main bearings. Portions of the shaft are offset to form throws to which the connecting rods are attached.

Custom Fit Cover
Car cover that is designed to fit the exact make and model of your vehicle.

Cycle Life
Cycle life is the amount of discharge and recharge cycles that a battery can tolerate before it fails to meet the design specifications of output. The depth of discharge are carefully controlled during determination of cycle life.

Cylinder
The round chamber or hole in the cylinder block that houses the pistons and where combustion takes place. Also called bore or barrel.

D

Damper
A damper is a device that deadens, restrains, or depresses the impact of shock.

Deep Cycle Battery
A deep cycle battery is a specific design that allows the battery to be deeply discharged and recharged many times without substantial degradation to performance or battery life. Typical applications for deep cycle batteries are marine trolling motor batteries, motor homes and campers and solar power systems.

Desiccant
Drying agents that absorb and remove moisture from the air conditioning system.

Differential
A differential is a device, usually using gears, which is connecting three shafts or chains, through which it transmits torque and rotation.

Differential Cover
To protect the intricate moving parts of your differential, an aluminum differential cover is the perfect answer, adding an extra layer of protection to your vehicle's underside.

Differential Cover Gaskets
Differential gaskets seals the differential housing and protects the rear-end gears and axles from exposure to the elements.

Differential Steering
Tracked vehicles such as bulldozers and tanks usually employ differential steering - that is, the tracks are made to move at different speeds or even in opposite directions, using clutches and brakes, to bring about a change of course or direction.

Discharge Rate
The discharge rate is the amount of amperage drawn from a battery over a specified amount of time.

Distributor
A unit in the ignition system designed to make and break the ignition Primary circuit and to distribute the resultant high voltage to the proper cylinder at the correct time.

Distributor Cap
An insulated cover containing a central terminal or tower with a series (one per cylinder) of terminals or towers that are evenly spaced in a circular pattern around the central terminal or tower, the secondary voltage travels to the central terminal or tower where it is then channeled to one of the outer terminals or towers by the rotor. The cap also keeps dirt and moisture out of the distributor.

Direct Ignition
A system where each spark plug has its own ignition coil, thus eliminating the need for a distributor.

Dual Purpose Battery
A dual purpose battery typically refers to a unit that performs the function of both a starting and deep cycling battery. Many AGM batteries perform this dual function.

Dupli-Color
Dupli-Color is known for its 'Perfect Match' in touch-up automotive paints.

Dynamo
A British term for a generator producing direct current.

E

ECM
Abbreviation for Electronic Control Module which is the master computer responsible for interpreting electrical signals sent by engine sensors and for activating automated engine components and processes accordingly in order to produce optimum performance.

ECU
Electric power steering (EPS or EPAS) uses an electric motor to assist in steering the vehicle. Sensors detect the position and torque of the steering column, and a computer module applies assistive torque via the motor, which connects to either the steering gear or steering column.

Electric Power Steering
Electric power steering (EPS or EPAS) uses an electric motor to assist in steering the vehicle. Sensors detect the position and torque of the steering column, and a computer module applies assistive torque via the motor, which connects to either the steering gear or steering column.

Electric Spark
An electric spark is a type of electrostatic discharge that occurs when an electric field creates an ionized electrically conductive channel in air producing a brief emission of light and sound. A spark is formed when the electric field strength exceeds the dielectric field strength of air.[1] This causes an increase in the number of free electrons and ions in the air, temporarily causing the air to become an electrical conductor through dielectric breakdown.

Electrolyte
Electrolyte is the fluid medium by which electrical energy is transferred between the positive and negative plates within a battery cell. Electrolyte is more commonly referred to as battery acid.

Electronic Ignition
An ignition system using electronic switching devices to assist or eliminate the mechanical breaker points.

Enamel Paints
Due to heavier body, these paints are harder for application. Enamel paints dry slowly as they have a heavy body. If filtered air supply doesn’t exist in working area, they may receive lint, dust or other imperfections. But due to same heavy body, they deliver excellent performance.

Engine Management System
(EMS) An electronic engine control system which covers at least the functioning of the fuel injection and ignition, but may also include emission controls and self-diagnostics.

Evacuate
Using a vacuum pump to remove all atmospheric air and moisture from inside the air conditioning system.

Evaporation
The act of changing a liquid to a vapor.

Evaporator
A component of the air conditioning system that removes heat from the air located within the evaporator housing.

Expansion Valve
A term used for the thermal expansion valve.

Exhaust Gaskets
A metal ring used on the exhaust to seal pressure. A piece of thin compressible material such as cork, rubber, or soft metal, placed between two mating surfaces to form a seal.

Exhaust Manifold Gaskets
Exhaust manifold gaskets seal gaps to keep exhaust fumes out of the emissions system, as well as reduce engine noise and improve fuel efficiency.

Exterior Car Paint
If you have ever considered repainting your vehicle, there are various types of exterior car paints that are available. Achieving the perfect car paint finish usually involves several different types of paint or finish to ensure proper bonding of the paint to the metal surface of the vehicle and to create a glossy shine that is attractive.

F

Flannel Car Cover
A flannel car cover’s material is 100% cotton or cotton/polyester blends. Flannel covers are not water resistant and should not be used outside for long periods of time. For indoor use, the 100% cotton flannel cover is the gentlest on the paint and probably the best choice. If you store your car over the winter, or drive your pride and joy infrequently, a 100% cotton cover may be a wise investment.

Float Step
Float step is a breakpoint in a non-linear battery charger whereby the charge current is either ramped up or down depending upon the state of charge.

Flooded Lead (Lead Acid Battery; Wet Cell Battery)
A flooded battery is a considered to be a conventional battery. It is constructed of lead plates, coated with active material and contained within cells in the battery case. Each cell is flooded to approximately the top of the plates with sulfuric acid.

Four-Stroke Engines
A four-stroke engine (also known as four-cycle) is an internal combustion engine in which the piston completes four separate strokes - intake, compression, power, and exhaust - during two separate revolutions of the engine's crankshaft, and one single thermodynamic cycle.

Freon
The registered trademark for several different types of refrigerants.

Front Wheel Drive
Front-wheel drive (FWD) is a form of engine/transmission layout used in motor vehicles, where the engine drives the front wheels only. Most modern front-wheel-drive vehicles feature a transverse engine, rather than the conventional longitudinal engine arrangement generally found in rear-wheel-drive and four-wheel-drive vehicles.

Front Ride Height
Ride height (also called ground clearance or simply clearance) is the amount of space between the base of an automobile tire and the underside of the chassis; or, more properly, to the shortest distance between a flat, level surface, and any part of a vehicle other than those parts designed to contact the ground (such as tires). Ground clearance is measured with standard vehicle equipment, and for cars, is usually given with no cargo or passengers.

Fuel-Air Mixture
A combination of Vaporized fuel and air which is brought into the cylinder through the carburetor or fuel injectors. When it is compressed and ignited, it produces the power needed to drive the engine. A mist consisting of fuel and air that's compressed in the cylinders and ignited to drive the pistons in a car's engine.

G

Gasket Paper
Gasket sheets are used for areas where extreme heat and pressure sealing are required such as exhaust gaskets.

Glowplug
An electrical element located in the combustion chamber of a diesel engine which helps to heat up the air in the chamber so that the diesel fuel will be ignited more quickly. Often they are connected in series so that when one becomes defective the others are inoperative. Also called a 'heater plug'.

Grids
Grids are another name for battery plates, because the plates are perforated in such a manner as to form the appearance of a grid.

Ground
Ground, also known as earth, negative or return. Ground carries electrical energy to complete the electrical circuit through a substitute for earth, in the case of a vehicle normally through the chassis.

H

HC12a
A hydrocarbon refrigerant blend.

Head
An alignment head is a device which clamps to a wheel, to give a technician the ability to check the condition of the vehicle's wheel alignment.

Head Bolts
The bolts that fasten the cylinder heads to the engine block.

Head Gaskets
A head gasket is a gasket that sits between the engine block and cylinder head(s) in an internal combustion engine. Its purpose is to seal the cylinders to ensure maximum compression and avoid leakage of coolant or engine oil into the cylinders.

Heater
A device used to heat the interior of a vehicle.

Heat Sink
A finned housing, normally made of aluminum, that is used to dissipate heat.

High-pressure line
The discharge side for the air conditioning system that carries high pressure vapors, liquid, or air.

Hot Cranking Amp
Hot cranking amps (CCA) is the amount of current that a battery can deliver at 80 degrees Fahrenheit. Specifically, it is the number of amps that a battery can deliver for a period of 30 seconds while maintaining a minimum of 1.2 volts per cell (7.2 volts for a 12 volt battery).

Housing Gasket
Both external and internal oil filters attach to the housing, which mounts to the engine and requires a gasket to keep engine oil from leaking out around it.

Hydraulic Cylinders
An actuation device that makes use of a pressurized hydraulic fluid is known as a hydraulic pump. This mechanism is used for producing in linear motion and force in applications that transfer power.

Hydraulic Power Steering
Power steering helps drivers steer vehicles by augmenting steering effort of the steering wheel. Hydraulic or electric actuators add controlled energy to the steering mechanism, so the driver needs to provide only modest effort regardless of conditions. Power steering helps considerably when a vehicle is stopped or moving slowly.

Hydrometer
A hydrometer is a device used to measure the specific gravity of the battery electrolyte or acid. Specific gravity of the electrolyte changes in proportion to the amount of electrical energy (voltage) in the battery.

I

Idler Arm
The purpose of the idler arm is to support the center link and to ensure the center link is always at the proper height. The position of steering linkage must be parallel with the control arm. Optional steering linkage position maintains directional stability and minimizes wear on the tires.

Ignition Coil
A step-up pulse transformer which is a part of the ignition system. It receives a small amount of electrical voltage from the battery and steps up the low primary voltage and amplifies it into a big jolt of secondary voltage of volts, and sends it to the spark plugs. It is made of two windings and a core of iron. Also called just coil.

Ignition Module
A transistorized component in an electronic ignition that triggers the ignition coil to fire high voltage. It replaced the breaker points on older cars.

Ignition Sensor
A sensor that sends information back to the various computers on a vehicle.

Ignition Spark
The combustion of the compressed air/fuel mixture in the combustion chamber that is ignited by an electric spark from a spark plug.

Ignition Switch
A control device that is generally operated with a key that closes and opens an electrical current to connect and disconnects the ignition system from the battery so that the engine can be started and stopped as desired.

Ignition System
The system that provides the electrical current or spark to ignite the air-fuel mixture in the combustion chambers.

Ignition Timing
The relationship between the time a spark plug is fired and the position of the piston in terms of degrees of crankshaft rotation.

Ignition Wires
High tension lines (spark plug wires) to the spark plugs where it ignites the air-fuel mixture. The high voltage wires that go to each of the spark plugs are called spark plug wires or high tension leads.

Included Angle
Included angle is the angle formed between the SAI and the camber. Included angle is not directly measurable. To determine the included angle, you add the SAI to the camber. If the camber is negative, then the included angle will be less than the SAI, if the camber is positive, it will be greater. The included angle must be the same from side to side even if the camber is different. If it is not the same, then something is bent, most likely the steering knuckle.

Independent Rear Suspension
Independent suspension is a broad term for any automobile suspension system that allows each wheel on the same axle to move vertically (i.e. reacting to a bump in the road) independently of each other.

Indoor Car Cover
Designed to help protect garage vehicles from dust, scratches, and insects.

Induction Coil
Same as a ignition coil. A pulse-type transformer for increasing the voltage to fire the spark plugs.

Intake Manifold Gaskets
The intake manifold is an aluminum, steel or plastic cover that sits on top of the engine. It is attached to the top of the engine by an intake manifold gasket that is made of plastic and rubber. The intake manifold directs the air-fuel mixture in the engine to the corresponding cylinder where it is burned to produce power.

Intercell Connections
The intercell connections are often referred to as the strap. It is generally a flat metal plate that connects each of the cells inside a battery so as to provide continuity through the battery.

Internal Combustion Engine
(ICE or IC) An engine that burns fuel within itself as a means of developing power (unlike an External combustion engine such as a steam engine).

J
K

Kingpin
The kingpin is the main pivot in the steering mechanism of a heavy truck. It usually consists of a machined steel bolt, washers, bearings and seals.

Knuckles
In an automotive suspension a steering knuckle is the part which contains the wheel hub or spindle, and attaches to the suspension components. It is variously called a steering knuckle, spindle, or hub as well.

L

Lacquer-Based Automobile Paints
Due to fast drying process and thin body, lacquer based paints flow smoothly. Lacquer-based finishes and paints can easily be sprayed and dried with gloss finish.

Lash
Clearance in the valve operating train with cam follower on camshaft base circle.

LC Circuit
An LC circuit can store electrical energy oscillating at its resonant frequency.

Leaf Spring
A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Each leaf (or leaves) are rectangular flat pieces that can be singular or stacked on each other to support increasing loads.

Lift Support
A hydraulic cylinder that restores the original opening and closing speeds of your hood, hatch or trunk.

Load Bearing
Is a Bearing that handles the stress of a wheel. It used to enable rotational or linear movement, while reducing friction and handling stress.

Load Tester
A load tester, often called a resistance tester or carbon pile, is a battery tester that applies an electrical load to the battery to simulate the effect of a starter or other large electrical load within a vehicle. Load testing is a dynamic test that often reveals battery problems that a simple voltage tester would not.

Low-pressure line
The return side of the air conditioning system that carries low pressure vapors, liquid, or air.

M

Magnet
A piece of magnetized steel that will attract all ferrous material. The Permanent magnet does not need electricity to function and will retain its magnetism over a period of years. Often shaped into the letter U.

Magnetic Pickups
A pulse generator consisting of a stator with a permanent magnet and a rotor, which induces an AC voltage in the inductive winding by the periodic change of the air gap between stator and rotor. Magnetic pick-ups attached to the distributor for ignition triggering have as many teeth on the pole piece (stator) and on the trigger wheel (rotor) as the engine has cylinders. Some magnetic pick-ups have a bowl-like rotor with ferrite rods inserted in the walls. Magnetic pick-ups on the crankshaft flywheel act as reference mark sensors.

Manifold Vacuum
As the pistons move down on the Intake stroke, they create a suction or vacuum in the intake manifold.

Marine Cranking Amp
Marine cranking amps (MCA) is the amount of current that a battery can deliver at 32 degrees Fahrenheit. Specifically, it is the number of amps that a battery can deliver for a period of 30 seconds while maintaining a minimum of 1.2 volts per cell (7.2 volts for a 12 volt battery). MCA is better known as cranking amps.

Matte Finishes
Matte is a dull non-gloss finish. Matte (or flat paints) diffuses light in a range of angles, making the paint have no shine effect. It’s not common to see matte finishes, but some niche vehicles are available in a variety of matte colors, usually grey or black.

Memory Effect
Memory effect refers to the conditioning of a battery, whereby the discharge pattern repeats for each subsequent time that the battery is charged and discharged.

Metallic
Metallic paints are effectively the same as solid paints, only with a small quantity of powdered metal added. The size and type of metal added varies depending on manufacturer choices, but it’s commonly about 1 part in 50 of aluminum powder.

Misalignment
The state of your vehicle's wheels when they are out of alignment. This can lead to uneven and rapid treadwear resulting in the need to replace tires sooner.

Moisture
Damp or wet areas of water.

N

Negative Charge
Negative charge simply means that one source has a lower electrical potential than another.

Negative Grounded
In a negative ground electrical system, current travels from the positive to negative using the chassis as a current return path to the battery. The vast majority of road vehicles in use today are negative grounded.

O

OE Touch Up
Paint specially formulated to exactly match the color of the original factory applied coating. Ideal for use on all OEM paint surfaces.

Ohm
An ohm is a measure of electrical resistance that causes one volt to produce a current of one ampere.

Oil Drain Plug
A drain plug is a plug which is taken out to allow a fluid to be drained from a tank such as an engine oil pan or sump.

Oil Filter
A component, located near the oil pump, that removes abrasive particles from the motor oil by a straining process as the oil circulates through the lubrication system.

Oil Pan Gaskets
An oil pan is a metal container that contains the engine oil. The oil pan gasket seals the oil pan to the bottom of the engine.

One-Part Paint
The single/one or two-part component paints are also known as 1K or 2K and these distinctions simply refer to the need or non-need of an activator for the paint to dry. You can spray one or single part products instantly, although they might need a solvent like thinner so it can go through a spray gun properly. This kind of paint is not usually used to paint a whole car.

Open Circuit Voltage
Open circuit voltage (OCV) in reference to a battery is the voltage as measured across the battery terminals with no load applied.

Orifice Tube
A component of the air conditioning system that controls the flow of liquid refrigerant to the evaporator.

Outdoor Car Cover
Created for outdoor use against the elements that can damage your car’s paint and finish.

Out-Of-Alignment
The state of your vehicle's wheels when they are out of alignment. This can lead to uneven and rapid treadwear resulting in the need to replace tires sooner.

Overcharge
Overcharge is the continuous introduction of charging current through a battery after all the active material has been converted chemically to a charged state. Overcharge by definition is the exceeding of 100% state of charge.

Over Discharge
Over discharge is an excessive discharge applied to a battery and can be damaging.

Oversteer
The tendency for a vehicle, when negotiating a corner, to turn more sharply than the driver intends.

P

Paint Classification Systems
Paint classification systems are used to individualize paint in single-stage, undercoat, mid-stage, clear-coat and base-coat products. With these systems, automobile paints are classified into usage instead of composition in the process of painting.

Pan Gaskets
The pan gasket is a mechanical seal between the transmission oil pan and the transmission itself.

Parasitic Drain
Parasitic drain, also referred to as parasitic draw, is the unintended discharge of a battery through applied electrical loads that typically remain on continually. Typical parasitic drain can be the keep-alive memory in the vehicle computers, but can also be an unintended load such as a glove box light left on.

Passive Rear Wheel Steering
The passive steering system uses the lateral forces generated in a turn (through suspension geometry) and the bushings to correct this tendency and steer the wheels slightly to the inside of the corner. This improves the stability of the car, through the turn.

PCM
Abbreviation for Powertrain Control Module A computer that controls the operation of the engine's fuel, ignition, and emission-control systems as well as the transmission on vehicles with automatic transmission.

PCV
Positive Crankcase Ventilation.

Pearlescent
Pearlescent paints use ceramic crystals that don’t just reflect light but refract it too, splitting it into different colors by allowing some light in and slowing it down as it passes through. This gives the paint not just a sparkle, but a deep color that can vary depending on how you look at it, making for interesting effects where the car’s bodywork creases or changes direction.

Petrol Engine
Gas Engine. A British term for gasoline.

Pigment
the pigment or what is also known as the tint is the one responsible for the color of the paint.

Pitman Arm
A short lever arm splined to the steering gear cross shaft , the pitman arm transmits the steering force from the cross shaft to the steering linkage system.

Plastic Car Cover
Designed to be waterproof and a temporary solution for outdoor protection.

Plasti Dip
Plasti Dip is a multi-purpose, air dry, specialty rubber coating. It can be easily applied by dipping, brushing, or spraying. Plasti Dip protective coating is ideal for a broad array of do-it-yourself projects around the home, garage, garden, and elsewhere. It protects coated items against moisture, acids, abrasion, corrosion, and skidding/slipping, and provides a comfortable, controlled grip. Plasti Dip remains flexible and stretchy over time, and will not crack or become brittle in extreme weather conditions. It has been tested and proven in temperatures from -30F to 200F.

Plenum Chamber
An area, filled with air at a pressure that is slightly higher than the surrounding air pressure, such as the chamber just before the blower motor.

Plenum Gaskets
A piece of thin compressible material such as cork, rubber, or soft metal, placed between two mating surfaces to form a seal within the plenum chamber.

Plenum
A chamber containing air under pressure.

Polarity
Polarity is the electrical condition of positive or negative charge.

Polarization
Polarization is the change in electrical potential in a battery cell that is caused by current flow through the battery.

Positive Charge
Positive charge refers to introduction of electrons toward the electrode or terminal with a shortage of electrons.

Power Cylinder
A linear actuator consisting of a piston in a cylinder, driven by pneumatic or hydraulic fluid under high pressure.

Power Steering
A system for steering used on vehicles, where the torque applied to the steering wheel is augmented by engine power.

Power Steering Belt
Is a belt used to transfer energy between the engine and the power steering pump to drive the power steering system.

Power Steering Control Valve
A power steering pump contains a pressure-relief valve to make sure that the pressure does not get too high, especially at high engine speeds when so much fluid is being pumped.

Power Steering Filter
Is an aftermarket device used when replacing a rack & pinion or power steering pump to remove contaminants usually found in the fluid after a previous system failure. Enables the replacement part to work more efficiently having clean fluid throughout the system.

Power Steering Gear Box
A gear box refers to the mechanism by which energy output of an engine or a high speed motor is redirected into another mechanical component in the same machine at a higher torque and at a lower rotational speed. The mechanism is also known as gear shifter.

Power Steering Pipe
A device used on a hydraulic system for the passage of hydraulic fluid to pass through the system to and from the pump. Similar in nature to a power steering hose, but is 100% metal.

Power Steering Pressure Switch
The Power Steering Pressure switch feeds information about the demand on power to the Engine Control Module.

Power Steering Pulley
A power steering pulley is a pulley used to drive a power steering pump on an automobile or truck. Usually is attached to the Power Steering Pump which attaches to a belt and is driven by the engine.

Power Steering Pump
The power steering pump transfers power steering fluid under pressure to other power steering system components, allowing the driver to steer with minimal effort.

Power Steering Hose
Power steering hoses are grouped into two parts, high pressure hose and low pressure hose. High pressure hose is required to supply the fluid under high pressure and hence it is used with compression fittings. Hoses are made up of reinforced synthetic compound and are highly resistive against the high pressure and temperature of the fluid passing through it. The low pressure hose is used to bring back the fluid from the gearbox to the reservoir and is not usually applied with compression fittings as the pressure of oil is comparatively low.

Premix Paint
Ready-to-spray system that requires no mixing or reducing, and with no re-coat window.

Prep Finishes
Prep finishes are referred to as primers. Car paint primers are usually available in either grey or black and are used to 'prime' the surface of the vehicle and make it ready for painting. Primer is designed to help car paint better adhere to the vehicle by creating a binding layer that can bond to paint easier and more consistently than bare metal.

Pressure Gauge
A device used to measure the amount of pressure in a given system.

Primer
Primer is designed to help car paint better adhere to the vehicle by creating a binding layer that can bond to paint easier and more consistently than bare metal.

Primary Angles
The primary angles are the basic angle alignment of the wheels relative to each other and to the car body. These adjustments are the camber, caster and toe. On some cars, not all of these can be adjusted on every wheel.

Pushrod Cover Gaskets
A piece of thin compressible material such as cork, rubber, or soft metal, placed between two mating surfaces to form a seal between the valve lifter and rocker arm.

Pushrod
A solid or hollow rod which serves as a link between the valve lifter and rocker arm. The pushrod transmits the movement and force of the driver from the brake pedal lever to the master cylinder.

Q
R

R-12
A chlorofluorocarbon refrigerant, also known as CFC-12, which was once the common chemical compound used in older refrigerant systems.

R-134a
The refrigerant that is now used in automotive air conditioning systems today, which can be converted from R-12.

Rack and Pinion
A rack and pinion is a type of linear actuator that comprises a pair of gears which convert rotational motion into linear motion. A circular gear called 'the pinion' engages teeth on a linear 'gear' bar called 'the rack'; rotational motion applied to the pinion causes the rack to move, thereby translating the rotational motion of the pinion into the linear motion of the rack.

Radiator
A heat exchanger used to remove heat from the coolant in the cooling system containing a vertical or horizontal-finned tubing section connected between two tanks.

Ratings
Ratings, as applies to batteries, are determined through a prescribed and precise series of tests. Ratings include cranking amperage, reserve capacity and voltage.

Rear Wheel Drive
Rear-wheel drive (RWD) is a form of engine/transmission layout used in motor vehicles, where the engine drives the rear wheels only. Most rear-wheel-drive vehicles feature a conventional longitudinal engine arrangement.

Rear Ride Height
Ride height (also called ground clearance or simply clearance) is the amount of space between the base of an automobile tire and the underside of the chassis; or, more properly, to the shortest distance between a flat, level surface, and any part of a vehicle other than those parts designed to contact the ground (such as tires). Ground clearance is measured with standard vehicle equipment, and for cars, is usually given with no cargo or passengers.

Receiver
Also known as drier, receiver drier, or dehydrator. A storage component of the A/C system for liquid refrigerant and desiccants.

Recharge
The action of refilling the air conditioning system once a leak is fixed or repair is made.

Recirculating Ball
The recirculating ball steering mechanism contains a worm gear inside a block with a threaded hole in it; this block has gear teeth cut into the outside to engage the sector shaft (also called a sector gear) which moves the Pitman arm. The steering wheel connects to a shaft, which rotates the worm gear inside of the block.

Refrigerant
The substance used in the air conditioning system in order to create a cooling effect; its chemical compound can be changed from liquid to gas.

Refrigeration Cycle
The process in which the air conditioning system recycles refrigerant.

Reluctors
A ferrous metal piece attached to the distributor shaft. Made up of teeth of which the number are the same as the number of engine cylinders. As the reluctor teeth pass through the pick-up magnetic field, an alternating current is generated in the pick-up coil. Also called an Armature.

Reserve Capacity
Reserve capacity is the number of minutes a battery can maintain a specified voltage under a 25 ampere discharge load.

Resin
The resins in automotive paint are usually made up of one of three elements namely urethane, enamel or lacquer. In general though, enamel and urethane are the common terms for the chemical combination of hydrocarbon polymers that formulates the resins in paints. This chemical combination impacts the durability and look of a paint’s finish, the manner by which it is applied and its costs.

Resistance
Resistance, also known as impedance is the restriction to electrical current flow within a battery.

Reversal
A computer or module used in order to switch the A/C system on and off.

Rolling Chassis
Is an assembled working frame & Chassis of the automobile, including the wheels and suspension.

Rotor (Ignition)
A small rotating cap-like unit at the end of the distributor shaft. It is located on the breaker cam inside the cap. It connects between the center electrode and the various outer spark plug terminals as it turns, thus distributing the high voltage from the ignition coil secondary winding to the proper spark plug. Also called rotor arm.

RPM
Abbreviation for revolutions per minute. The number of times a rotating object turns every minute.

RTV Sealants
Seals, bonds, repairs, mends and secures glass, metal, plastics, fabric, vinyl, weather stripping and vinyl tops.

S

Safety Vent
A safety vent is also referred to more commonly as a vent cap, and is designed to vent excess hydrogen gas from the inside of a battery in the event of buildup in gas volume or pressure.

Secondary Angles
The secondary angles include numerous other adjustments other than Caster, camber & toe, such as steering axis inclination, included angle, max turns, track width, etc.

Separators
Separators are comprised of paper, plastic or fiber batting and are used to separate the negative and positive plates within a battery cell, such that they are not permitted to touch one another.

Setback
Setback is a measurement referencing the wheels to a line placed perpendicular to the vehicle centerline. This line would be parallel to a line drawn through the centers of the spindle. If a vehicle has setback, one front tire/wheel assembly is farther back from this imaginary reference line across the front of the vehicle than the other.

Shock
A component using friction to dampen and control a vehicle's suspension up and down movement. Modern shocks are of the hydraulic type, using an oil to dissipate the heat of friction to the outside air. They contribute to your vehicle's ride quality.

Shock Absorber
A component using friction to dampen and control a vehicle's suspension up and down movement. Modern shocks are of the hydraulic type, using an oil to dissipate the heat of friction to the outside air. They contribute to your vehicle's ride quality.

Short Circuit
A short circuit refers to the direct and generally unintended connection of a battery negative and positive terminal using an electrical conductor. Short circuiting a battery may result in rapid battery discharge, causing formation of hydrogen gas, sparks, heat and a generally dangerous situation.

Shorted Cell
A shorted cell refers to a condition where one or more negative plates within a cell come in contact with the positive plates. This condition generally results in a zero voltage or dead cell.

Sleeves
Adjustable connecting sleeves attaching to the outer tie rods allow for directional changes from the Pitman arm to be transmitted equally to both sides, making them turn in unison.

SLI
SLI is an abbreviation for starting, lighting and ignition, and is the designation of most automotive batteries.

Snaking Effect
The 'Snaking effect' is a term experienced while towing a travel trailer. In order to move the hitched vehicle in one direction, you must steer the vehicle in the other direction.

Solid Paint
Almost all cars are available in a no-cost basic, solid color. The most common options are white, red, blue or black.

Spark Plug
A device containing two electrodes across which electricity jumps to produce a spark to fire the fuel charge. The center electrode is insulated from the spark plug shell by means of a molded insulator resembling Porcelain. The side electrode protrudes from the bottom edge of the spark plug shell and is so positioned that there is a gap between it and the center electrode.

Spark Timing
Timing of ignition spark.

Speciality Paints
Also known as custom paints. Examples include, metallic finish paints or chameleon paints. There are many other types of specialty paints that a professional paint shop may be able to recommend to you.

Starting Battery
A starting battery is a specific construction and design, where a large amount of momentary current is permitted to be drawn from the battery for starting purposes without consequential damage to the battery.

State of Charge
State of charge refers to the condition of a battery with respect to its design voltage and capacity.

Stator
A self-contained unit of the magnetic pick-up, consisting of a permanent magnet, an inductive winding, and the pick-up core; the stator can be a disc-shaped pole piece with stator tooth or a simple pole piece. The fixed electrical windings on a magneto, alternator, or generator. It turns within the rotor.

Steering Arm
Arms, either bolted to, or forged as an integral part of the steering knuckles . They transmit the steering force from tie rod to the knuckles, thus causing the wheels to pivot. Also called tie rod arm.

Steering Axis Inclination
The angle between the centerline of the steering axis and vertical line from center contact area of the tire (as viewed from the front). SAI is typically not adjustable, but deviations from specification can indicate vehicle damage. A maximum variation side to side of ± 1.0° may also indicate vehicle damage. This topic is covered in detailed charts later.

Steering Column
A shaft connecting the steering wheel to the steering gear assembly. Also called the steering shaft.

Steering Shaft
A shaft connecting the steering wheel to the steering gear assembly. Also called the steering shaft.

Steering System
The mechanism that allows the driver to guide the vehicle down the road and turn the wheels as he desires. The system includes the steering wheel, steering column, steering gear, linkages, and the front wheel supports.

Steering Wheel
The steering wheel is the part of the steering system that is manipulated by the driver; the rest of the steering system responds to such driver inputs.

Stop Leak
A product specifically designed to stop leaks in air conditioning system.

Strut
Struts are part of your vehicle's suspension, and do the same job as a shock absorber. A vehicle will either have struts or shock absorbers, or a combination of both (i.e. struts in the front, and shock absorbers in the rear). They regulate how much your vehicle can move up and down, and keeps the tires in contact with the road surface after going over a bump.

Strut Mount
Strut mounts connect the vehicle’s suspension system to the vehicle body, and are located between the strut and the chassis at the upper strut attachment point. For the front fitting applications, the mount includes a bearing that serves as a steering pivot. Because these are load-bearing, worn strut mounts can affect a vehicle’s handling and safety.

Sulfation
Sulfation is a condition where lead sulfate crystals form in a battery, typically through a prolonged discharge condition. The lead sulfate precipitates to the bottom of the case, where it impedes electrical flow through the battery.

Surface Charge
Surface charge is the indicated state of voltage with a battery sitting at equilibrium and is not an indicator of the true condition of the battery. Before testing, it is necessary to remove the surface charge through momentary loading.

Suspension System
A system that cushions the passenger compartment of the vehicle from the bumps and shocks caused by the wheels moving over irregular road surfaces. Includes springs, shock absorbers , steering linkage, upper and lower control arms, torsion bars, and stabilizers.

System Evacuation
Evacuating a refrigeration system serves two primary objectives: To remove noncondensables and to dehydrate the air conditioning system (remove water vapor). If noncondensables such as air are not removed, the system will operate at higher than normal condensing pressures. If water vapor is not removed, it can cause a freeze at the expansion device, causing a block in the refrigeration process.

T

Thermostat
A driver-operated device used to cycle the clutch to control the rate of refrigerant flow as a means of temperature control. Also known as a temperature-sensitive component that is located in a housing at the coolant outlet of the engine that restricts coolant flow to the radiator to maintain the desired engine-operating temperature.

Thermal Expansion Valve
A component of the refrigeration system that regulates the rate of flow of refrigerant in the evaporator; as the refrigerant enters the TXV, as a high-pressured liquid, it expands reducing its pressure to become a low-pressure liquid. It then is able to enter the evaporator.

Terminal Type
Terminal type refers to the design of the attachment point of the battery to the electrical system. Most automotive batteries are either a post style terminal or a threaded side terminal; however some today use a threaded design that resembles a flag.

Thermistor
A thermistor is a temperature compensating resistor and generally refers to the charge level compensation in an alternator regulator that is used to replenish the battery.

Thermostat
A driver-operated device used to cycle the clutch to control the rate of refrigerant flow as a means of temperature control. Also known as a temperature-sensitive component that is located in a housing at the coolant outlet of the engine that restricts coolant flow to the radiator to maintain the desired engine-operating temperature.

Throttle Body Base Gaskets
The body throttle gasket is the seal the keeps outside air from entering the space between the intake manifold and the throttle body.

Throttle
The device that controls the vacuum created in the Venturi of the carburetor. The greater the vacuum, the richer the fuel-air mixture. The throttle enables the engine to run on a richer mixture and produce more power for high-speed driving.

Tie Rod
A rod, or rods, connecting the steering arms together. It links the pitman arm and the idler arm to the steering knuckle arms. When the tie rod is moved, the wheels pivot.

Tiller Steering
A steering device present on some very early automobiles before the steering wheel became the only car steering utility.

Toe
Toe relates to the difference in the distance between the front of the tires and the rear of the tires on the same axle, or to the vehicle centerline. Toe-in, or positive toe, is defined as the front of the tires being closer together than the rear of the tires. Toe-out, or negative toe, is when the rear of the tires are closer together than the front of the tires.

Toe out on Turns
When the vehicle negotiates a curve, the inner wheel turns more sharply and while the wheels remain in this position, a condition of toe-out exists.

Torque
A force that turns or tends to turn an object.

Track Width Difference
The measurement of the center of tire to center of tire or outer edge to outer edge.

Transfer Case Gaskets
A piece of thin compressible material such as cork, rubber, or soft metal, placed between two mating surfaces to form a seal.

Transfer Case
A small transmission used on four-wheel-drive vehicles to transfer engine torque to the front and/or rear axles.

Transmission Filter
Transmission filters prolong the life of the transmission and its fluid by trapping potentially harmful particles and abrasives. A properly functioning filter ensures that transmission fluid is free from contaminants.

Transmission Gaskets
Transmission gasket is a mechanical seal between the transmission oil pan and the transmission itself.

Transistor
Electronic device commonly used for amplification. A small semi-conductor electronic component, with no moving parts, that functions as a switch, amplifier, or detector by controlling the flow of current.

Trickle Charge
A trickle charge is a steady battery charger current that does not vary with the battery state of charge. Trickle charges are considered to be old technology and have largely given way to automatic battery maintainers.

Tune-Up
The intent of a tune-up is to obtain the maximum performance and economy of an engine with the lowest possible exhaust emissions so that the vehicle engine will meet the manufacturer's Specifications. It involves checking the components of the ignition, fuel, and emmission system and cleaning, adjusting, or replacing them. Tune-ups should be performed according to the recommendation of each manufacturer.

Turning Radius
The turning radius or turning circle of a vehicle is the diameter of the smallest circular turn (i.e. U-turn) that the vehicle is capable of making.

Twist Beam Suspension
The twist-beam rear suspension, also known as torsion-beam axle is a type of automobile suspension based on a large H or C shaped member. The front of the H attaches to the body via rubber bushings, and the rear of the H carries each stub-axle assembly, on each side of the car. The cross beam of the H holds the two trailing arms together, and provides the roll stiffness of the suspension, by twisting as the two trailing arms move vertically, relative to each other.

Two-paint Paint
Two-part paint products are those that need activators or hardeners to stimulate chemical bonding between the paint and the car’s surface, which is commonly known as drying or evaporating. Without activators, two-part paints have longer shelf life because they do not dry by themselves. They are also non-porous and weatherproof. You can apply a 2K primer on your car and leave it without having to worry about the rusting of your sheet metal.

U

Undercoat Finishes
Undercoat finishes are referred to as primers. Car paint primers are usually available in either grey or black and are used to 'prime' the surface of the vehicle and make it ready for painting. Primer is designed to help car paint better adhere to the vehicle by creating a binding layer that can bond to paint easier and more consistently than bare metal.undercoat-finishes.

Understeer
The tendency for a vehicle, when negotiating a corner, to turn less sharply than the driver intends.

Universal Joints
A coupling between rotating shafts set at an angle to one another, allowing for rotation in three planes.i.e. the shaft and 2 wheels.

Urethane Paints
These paints are known for their heavy-body base and they last longer than enamel or lacquer based paints. Urethane paints are usually applied on engine parts and those parts which receive high temperature.

V

Valve Cover Gaskets
The valve cover is a metal cover that is found on very top of the engine. The valve cover is attached to the engine by a gasket made of rubber or cork.

Valve Stem Seals
Valve stem seals are engineered to allow a small amount of oil to pass through their oil-metering to lubricate the valve stem interface of an engine.

Valve Stem
A device mounted in the rim or inner tube to provide a method of increasing or decreasing air pressure inside a tire.

Vent
Any opening serving as an outlet or inlet for air.

Ventilation
The circulation of flow of air through openings; the direction of ambient cabin air through openings to other sections of the vehicle.

Voltage
Voltage is a measure of electrical pressure. All batteries are rated in volts DC (Direct Current).

Voltage Delay
Voltage delay is the time required after an electrical load is applied for a battery to deliver the requisite voltage.

Voltage Depression
Voltage depression is an unexpected drop in battery voltage below anticipated values during the discharge of a battery.

Voltage Regulator
A voltage regulator is a device that controls the charging output of an alternator or generator so as to maintain charge volts within defined parameters.

Voltmeter
A volt meter is a device that measures and indicates the voltage within an electrical system or electrical circuit.

W

Waterborne Enamels
Due to the rise of environmental concerns, the water-based acrylics, waterborne and urethane paints are developing faster. You can apply waterborne enamels on primers or bare metal or present coatings. For DIY car finishers, these paints are safe and widely-known option to work from personal garage.

Water Resistant Car Cover
Treated for moisture repellency. These types of covers will repel most of the water yet allow air to circulate, preventing condensation. Most have ultraviolet screens woven into the mesh to help them withstand sunlight degradation and are usually mildew resistant.

Waterproof Car Cover
Waterproof car covers are usually plastic film or a plastic-coated fabric and will keep the rain off your car, but will also trap condensation between the cover and your car. The plastic type of car cover is useful if you store your car over the winter in a garage and use a flannel cloth cover against the surface and the plastic one as an outer protective shield.

Weatherproof Car Cover
Fabric sheds water as soon as it hits the car cover, leaving your vehicle dry.

Water Inlet
A pipe that brings water into a machine or a room.

Water Pump Gaskets
The water pump gasket is a simple sheet comprised of gasket paper, rubber, silicone, metal, felt, and fiberglass or plastic polymer. It fills the gap between the engine and the water pump in your vehicle.

Worm and Sector
A type of steering gear that looks like a bolt & nut, but the sector of this type looks like a gear instead of a nut. The teeth of the sector are machined in an arc or curve to look like a section of the gear.

Wheel
A wheel is a round object that is intended to rotate on a bearing. Wheels, in conjunction with axles, allow heavy objects to be moved easily moved or rolled.

Wheelbase Difference
The wheelbase of a vehicle equals the distance between its front and rear wheels. At equilibrium, the total torque of the forces acting on a vehicle is zero.

X
Y

Y Pipe
A Y pipe is an exhaust pipe designed improve exhaust flow and increase horsepower by splitting the I pipe from the exhaust manifold. Y pipe can also refer to a two-into-one fitting for air intake systems.

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