Glossary “urethane adhesive” Definition:
Any of several strong polymer adhesives that are used to intall auto glass. Urethane adhesives are necessary to meet federal standards for windshield retention in most late model passenger vehicles.
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urethane enamels
Glossary “urethane enamels” Definition:
Requires an isocyanate hardener for curing. The ingredients have toxins that can effect a person coming in contact with them. Protective clothing and a NIOSH-approved respirator are required when applying materials containing isocyanate hardeners. The material is available in colors and in clear form, and provides a glass-smooth finish approximately two and half times harder than ordinary actylic enamels.
urethane plastic
Glossary “urethane plastic” Definition:
As used on bumpers, filler panels, and quarter extension panels, urethane plastic is of the thermoplastic type. It is tough and flexible. This material can be plastic-welded. Parts made of it require flexible plastic paint finishes.
upshift
Glossary “upshift” Definition:
Shifting from a lower gear to a higher gear ratio.
upstream
Glossary “upstream” Definition:
Secondary air flow sent by the AIRD to ports in the exhaust manifold. Also refers to placement of oxygen sensors that are upstream (ahead of) the catalytic converter. Also see downstream.
UPS
Glossary “UPS” Definition:
Uninterruptible Power Supply; a power supply that includes a battery to maintain power in the event of a power outage.
upr
Glossary “upr” Definition:
Acronym form of Upper.
upper A-arm
Glossary “upper A-arm” Definition:
Term used for upper-control arm.
upper control arm
Glossary “upper control arm” Definition:
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.
upper end
Glossary “upper end” Definition:
Parts of the engine that include cylinder heads and valvetrain.
upper radiator hose
Glossary “upper radiator hose” Definition:
Radiator hose from the engine coolant outlet to the radiator inlet.
unscheduled deployment
Glossary “unscheduled deployment” Definition:
Term used when referring to air bag system that could be set off without the vehicle being involved in a crash.
unsprung weight
Glossary “unsprung weight” Definition:
Vehicle weight not supported by the springs, including the steering knuckle, brake assembly, tire and wheel.
updraft
Glossary “updraft” Definition:
Device or system having an upward airflow.
updraft carburetor
Glossary “updraft carburetor” Definition:
Carburetor having an updraft airflow.
unloaded caliper
Glossary “unloaded caliper” Definition:
Bare rebuilt caliper with no pads or hardware.
unloader
Glossary “unloader” Definition:
Device linked to the throttle valve to open the choke valve when in the wide-open throttle position.
unloading solenoid
Glossary “unloading solenoid” Definition:
Electrically controlled valve for operating the throttling valve or bypass valve in some applications.
unobtainium
Glossary “unobtainium” Definition:
A mythical alloy that is lighter, stronger, more flexible and, at the same time, more rigid than anything available. Also refers to any part that is unobtainable.
unleaded fuel
Glossary “unleaded fuel” Definition:
Fuel that does not contain tetraethyl lead.