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Unit

1. One. 2. An assembly or device that can perform its function without outside interference or assistance.

Unit Body

A form of vehicle construction that includes the chassis, frame, and body in one unit.

Unit Cable

A cable having pairs of cables placed into groups (units) of a given quantity, then these groups form the core.

Unit Distributor

A breakerless ignition distributor used by General Motors containing the ignition coil, magnetic pickup coil, and timer core.

United Nations Environment Program (UNEP)

A program or agreement mandating the scheduled phaseout of CFC refrigerants.

United States Customary System (USC Measurements, USCS)

The type of measuring system used in the United States, such as gallon, inch, mile, and pounds.

Unitized Construction

A type of vehicle construction whereby the frame and body parts are welded together to form a single assembly.

Unitized Distributor

An electronic ignition-system magnetic-pulse distributor, that combines the distributor, electronic module, pickup coil, cap, and coil into one compact assembly.

Universal Flexible Hose

A flexible radiator hose.

Universal Joint

A joint connection in the drive line that permits the driving angle to change. Also known as U-joint.

Unleaded Fuel

Fuel that does not contain tetraethyl lead.

Unleaded Gasoline

Gasoline that contains less than 0.0018 ounces (0.05 grams) of lead per gallon (3.785 liters).

Unloader

A device linked to the throttle valve to open the choke valve when in the wide-open throttle position.

Unobtanium

A mythical alloy that is lighter, stronger, more flexible and, at the same time, more rigid than anything available.

Unscheduled Deployment

A term used when referring to air bag system that could be set off without the vehicle being involved in a crash.

Unsprung Weight

The vehicle weight not supported by the springs, including the steering knuckle, brake assembly, tire and wheel.

Updraft

A device or system having an upward airflow.

Updraft Carburetor

A carburetor having an updraft airflow.

Upper A-Arm

A term used for upper-control arm.

Upper Control Arm

A front-suspension component bolted to the frame between the pivoting attachment point on the vehicle-frame crossmember and the upper ball joint, which is fastened to its outer end having bushings that are attached to the control arm.