Engine balancing: A process that involves static and dynamic balancing of all reciprocating and rotating engine components. The advantage of balancing an engine is to reduce vibration which leads to reduced wear and increased horsepower and reliability.

Tires: See Wheel balancing.

A ball and socket assembly that connects upper and lower suspension arms to a vehicle's steering knuckle. The ball portion acts as a pivot point to allow the steering knuckle to turn (as the wheels are steered) and also allows the suspension to flex as a vehicle encounters road bumps.

Ball joints carry the weight of the vehicle as well as road shock and wear over time, requiring replacement after many miles (usually 100,000+). Many modern vehicles are equipped with ball joints that are non-serviceable, meaning they are greased at the factory and cannot be regularly re-greased. More frequently on modern vehicles, ball joints are pressed into or part of the construction of suspension arms requiring that the whole suspension arm be replaced. On other vehicles, they may simply be riveted in place.

The ends of most steering linkages, tie rod ends, center links, drag links, etc. also incorporate ball joints (which are non-replacable).

The primary air passage at the base of a carburetor where the throttle is located. Air goes through these passages on it's way to the cylinders. Many carburetors have one opening, while larger carburetors may have two or 4 openings (also known as venturies), leading to the common carburetor descriptions such as one-barrel, two-barrel and four-barrel.

A "classic" four-barrel carburetor, for example, has four throttle plates (air valves) at it's base, and four venturies (fuel outlets) where fuel is delivered to passing air entering the engine. The four barrels are usually grouped in pairs to what is referred to as primaries and secondaries. A fuel metering jet (four in total) is located inside the carburetor for each venturi. During normal cruising, two barrels are used to provide good economy. When the accelerator is pressed hard, such as during passing or accelerating, the secondary jets are activated either by vacuum or linkage to provide increased fuel for more engine power.

A molded plastic insert that fits into a pickup box. Used to protect the metal sides and bottom of the truck bed. Prevent dings and scratches and protects from corrosive materials such as fertilizer. Easy to wash out. Also helps preserve a truck's resale value. One downfall of hard plastic bedliners is they tend to allow objects to slide around.

Spray-on bed liner. A new type of bed liner which is permanent. A durable urethane or rubber coating is applied to the inside of a prepared truck box to the thickness of about 1/4" thick. Once hardened, the coating makes tough, waterproof, non-slip surface which prevents rust. Another unique feature of spray-on bed liner is they can be tinted to about any color to match vehicle color. The same material can also be sprayed on the inside floorboards of trucks in place of carpeting for easy washing out of the interior floor.

A heavy-duty, bell-shaped device usually made of cast iron or aluminum that connects the transmission to the engine and provides space between for the clutch, flywheel or torque converter. The bell housing can either be an integral part of a transmission body or a separate bolt-on unit.

Auto restorers, street rodders and racers who swap different engines and transmissions into vehicles often use special aftermarket bell housings which allows the mating of otherwise incompatible engines and transmissions to each other; for example, installing a 350 ci. Chevy motor into a Ford street rod which is equipped with a Ford C-6 transmission.

Often referred to as a drive belt or accessory drive belt. Made of rubber reinforced with fiberglass or nylon cord. Drive belts connect to a motor's crankshaft pulley and use engine power to drive various pumps and an alternator.

Can also be a reinforcing band used in tires. Tire belts are typically constructed of steel but fiberglass and textile bands are also sometimes used. Many belts are placed in the tire to add strength to a tire's tread area and to help the tire maintain form while under heavy load and rotating at road speeds. A broken belt may result in a tire deformity leading to vibrations or tire failure.

Originally a trademark name but now a general term for the one-way gear/drive mechanism used on the end of a starter motor. In general terms, a bendix is a tiny one-way drive-gear mechanism that pops out when the starter motor is engaged. The gear on drive mechanism lock tight tight in one direction (to apply torque to the motor) but can spin freely in the other direction. When the starter is engaged, the bendix 's teeth mesh with and spin the engine's flywheel (start the engine). Once started, the flywheel begins to spin faster than the starter motor. The bendix gear drive mechanism allows the gear to freely spin faster than the starter motor can safely turn to prevent damage to the starter. When the ignition key is released from the "start" position, the bendix retracts from the rapidly spinning flywheel. A lever and solenoid (engaged by the start position on the ignition key) push the bendix out to mesh with the flywheel.

A bendix's one-way clutch can wear out. When that happens, the bendix drive will usually pop out to meet the flywheel but not be able to turn it. It will often spin and "kick out" causing a high-pitched whining sound. A new bendix can often be replaced reasonably (rather than replacing the entire starter motor).

A thin strip of metal which is a combination of two metals with differing expansion rates bonded together. When heated, the metal strip bend or curls because the side of the strip with the metal with the greater expansion rate expands more.Used as the primary component of an automatic choke system.When the engine is cold, the choke pull-off spring is tightly coiled which closes the air flap on the carburetor and moves a small choke cam under the accelerator which causes the engine to operate at fast idle. The closed carburetor air flap creates a richer air/fuel mixture needed to make a cold engine run well. As the engine warms up, heat from the exhaust manifold, heater hose, or electric current (depending on system used) causes the metal strip to unwind which opens the choke flap and moves the accelerator off the fast idle cam position. The open flap allows more air in which leans out the air/fuel mix.

A process of removing air or contaminated fluid from hydraulic brake or clutch lines. Air is compressible, hydraulic (brake) fluid is not. Air in the brake/clutch lines can cause "brake pull" and "spongy pedal". Brakes and clutch systems must be bled anytime the system is "opened" and air is allowed to enter (such as replacing a new brake cylinder or caliper). The process of bleeding the brakes, for example, involves pumping up the brakes (to create pressure) and holding them on, and loosening a bleeder screw with a wrench to release the air/fluid. The pressure forces fluid and air out of the system. The fluid reservoir must be replenished by adding new fluid.

Air needs to be bled from the engine's cooling system on some vehicles -- usually accomplished by loosening a special bleeder screw located at a high point in the cooling system such as on the intake manifold, or loosening a heater hose until air escapes.

A bubble in the tread of a tire usually the result of internal separation of the tread and belts. Often caused by excessive heat or faulty construction.

Also, bubbles in a coat of paint due to poor surface preparation, insufficient drying time (of previous coat), too heavy of paint, or painting in excessively humid conditions. Can also be caused by incompatibility between topcoat and primer.

A term used in racing, by engine-builders and automotive enthusiasts that refers to careful selection of engine parts and custom assembly of a motor to achieve the lowest tolerances possible (according to the manufacturers design -- blueprints) in an effort to produce a more powerful and smoother running motor. During the process of blueprinting, pistons and connecting rods are typically individually weighed (and some weight removed if needed) for evenness and all journals and tolerance are measured and adjusted to be as "tight" as possible.

The term was originally used by racers to make an engine more powerful by careful assembly but still keeping it technically 'stock' as was required by some racing classes.

A process of shortening a tail section of a vehicle.

A body modification performed on four-wheel-drive vehicles, particularly pickup trucks, which involves cutting a length (usually ~12") out of a truck box's rear overhang and shortening the frame; then re-welding the tail section back on the box to produce a shorter, but stock-looking pickup box for purposes of reducing rear overhang and increasing the vehicle's departure angle. Increases a vehicle off-road worthiness allowing it to descent steeper hills and traverse larger boulders without becoming hung up on the rear box or bumper.

A term used with turbochargers to designate the amount of pressure (above atmospheric pressure) which air is forced into an engine. Normal atmospheric pressure is 14.7 psi. If turbo boost is 10, air forced into the engine would be 24.7 psi. Forcing air into an engine increases engine performance.

Sometimes boost is referred to as atmospheres. One atmosphere equals 14.7, two atmospheres equals 29.4

A flexible cover used around a gear shifter to keep out road and engine noise.

Any rubber or flexible covering used on automotive components such as CV joints, spark plug wires or wire connectors to keep out moisture, dust, and dirt, etc.

British term for trunk

The liquid used in a brake system to transmit force from the brake pedal (your foot) to wheel cylinders and calipers at each wheel -- which force brake pads/shoes against moving parts and slow the vehicle down. Brake fluid has special properties. It must not be allowed to thicken, freeze or easily boil. It must also lubricate moving brake parts as well as absorb moisture (to keep from rusting other brake parts).

All brake fluids must meet DOT 3 specifications. Most brake fluids are petroleum-based, however, a special-silicon based brake fluid is often used for high-performance applications because it resists boiling more than normal brake fluid and does not absorb water. Standard and silicon brake fluids are incompatible and generally switching to silicon brake fluid requires flushing the entire brake system and installing different seals. Silicon and petroleum based brake fluids should never be mixed.

An electrical switch connected to the brake light circuit and usually mounted above the brake pedal which activates the brake lights when the brake pedal is applied. Pushing the brake pedal releases the tang of the switch, when the pedal returns to it's resting position the switch is pushed back in (lights go off).

Classic automobiles used a pressure switch similar to an oil sending unit which was mounted in the brake's hydraulic system, usually on the master cylinder or in a brake line. When the brakes were engaged, pressure activated the brake lights. The principle downfall of this system is that subtle brake action would not always produce enough pressure to switch on the brake lights. In addition, replacing a faulty switch required bleeding the brake system.

The friction material on brake pads and shoes that contacts moving discs or brake drums to slow a vehicle down. Friction between the lining and moving drum/disc produces large amounts of heat. Asbestos was once widely used as a key component to the friction material due to it's resistance to heat, but has since been replaced with other, safer, organic compounds.

Semi-metallic linings, another type of lining material, have metal particles imbedded into the friction material and hold up better under higher brake temperatures and helps reduce brake fade. Brake linings are typically fastened to the metal brake shoe or brake pad backing plate with rivets or cement.

In the "old days" brake linings were once commonly replaced. A technician would remove the old brake shoe lining by drilling out the retaining rivets, and re-riveting a new piece of lining (which came in a large roll) onto the brake shoe frame. However, that practice has long since been abandoned and shops always replace the whole shoe or pad assembly.

A mechanical switching device used to distribute electricity to spark plugs in engines until the mid 1970's. Breaker points contain a movable arm with a set of electrical contacts on the end. The arm rides against a multi-lobed cam which rotates with the distributor shaft (turned by the camshaft and therefore timed to the engine's crankshaft/valves/pistons). As the engine runs and distributor turns, the breaker arm moves according to the distributor lobes causing the electrical contacts to open/close. When the points are closed, energy is stored in the primary windings of the ignition coil. Once the points are opened, the energy field in the coil collapses and is transferred to the coil's secondary windings where it is stepped up to a much higher voltage -- enough to jump the gap (produce a spark) at the end of a spark plug, and ignite the air/fuel mix in the combustion chamber.

The gap between the electrical contacts on the points is critical. If the gap is too wide, the timing will be retarded. If the gap is too narrow, the timing will be advanced. A dwell meter and a set of feeler gauges should be used to set the proper gap. The contact surfaces of the points wear out from the effects of electrical sparking and require frequent adjusting and replacing.