Glossary “unibody design” Definition:
Chassis design that has a floorpan and a small subframe section at the front and the rear.
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unicast
Glossary “unicast” Definition:
Component or part cast as a single unit.
unicast rotor
Glossary “unicast rotor” Definition:
Type of rotor used on man late-model cars having the rotor and hub cast as one integral component, often from gray iron rather than cast iron.
unidirectional
Glossary “unidirectional” Definition:
When a scan tool can read data, but can not give commands to the computer.
unibody
Glossary “unibody” Definition:
Short term for unit body. Type of construction where body parts are welded and bolted together to form an integral frame. Lighter, thinner, high-strength steel alloys or aluminum alloy is used.
UNEP
Glossary “UNEP” Definition:
United Nations Environment Program.
unequal A-arms
Glossary “unequal A-arms” Definition:
A suspension system where one arm is larger than the other.
unequal length control-arm suspension
Glossary “unequal length control-arm suspension” Definition:
Front suspension-control arms of unequal length to compensate for jounce and rebound.
UNF
Glossary “UNF” Definition:
Unified National Fine. Identifying a standard thread pitch and count.
understeer
Glossary “understeer” Definition:
Condition where the front of the vehicle tends to break out and slide toward the outside of a turn.
undertread compound
Glossary “undertread compound” Definition:
Blend of synthetic rubbers used in the material under the tire tread.
underspeed mode
Glossary “underspeed mode” Definition:
Control mode that prevents the engine from stalling in the event it stumbles while running. Also used during engine crank.
undersquare
Glossary “undersquare” Definition:
When the bore is less than the stroke.
undersized bearing
Glossary “undersized bearing” Definition:
Bearing made thicker than standard. It has a smaller inside diameter to fit an undersized crankshaft.
underslung suspension
Glossary “underslung suspension” Definition:
A suspension system in which the spring is positioned under the axle.
undermasked
Glossary “undermasked” Definition:
An area that must be cleaned with solvent or polishing compound to remove overspray.
undersize (US)
Glossary “undersize (US)” Definition:
Part of item that is smaller than that specified.
undercut
Glossary “undercut” Definition:
A weld condition where the base metal is burned away, below the surrounding area.
undercutting
Glossary “undercutting” Definition:
Removing too much primer-surfacer when sanding.
underfill
Glossary “underfill” Definition:
Depression on the weld face or root surface extending below the adjacent surface of the base metal.