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One-way Clutch

1. A friction or ratcheting device that permits motion in only one direction. 2. A mechanical holding device that prevents rotation in one direction, but overrun to allow rotation in the opposite direction. One-way clutches may be either roller or sprag clutches.

One-way Roller Clutch

A term used for one-way clutch or overrunning clutch.

One-way Sprag Clutch

A device that consists of a hub and drum separated by a number of sprags.

One-way Valve

A type of switching valve that allows fluid to pass in one direction and only when the pressure is sufficient to unseat the valve.

One-wire System

An electrical system using body and/or chassis metal as a grounded circuit.

Oodle

To operate an engine at idle speed.

Op-amp

Short for Operational amplifier. 1. A high-gain analog amplifier with two inputs and one output. 2. Used in circuits to control and amplify digital signals.

Open Circuit

1. A circuit in which there is a break in continuity. 2. An open circuit is any circuit that is not complete and in which no current flows.

Open Course

That part of a race track that extends beyond the finish line into a shut-off area.

Open Loop

A mode of computer operation in which fuel delevery calculations are based primarily on preprogrammed values, not Oxygen sensor input 2. The Oxygen sensor value is not considered when in Open Loop.

Open Structural Member

A flat body panel having an open access from the rear.

Open System

A crankcase, emission-control system having no tube from the crankcase to the air cleaner; drawing air through the oil filter cap only.

Open The Tap

Increase the speed.

Open-chamber Head

A cylinder head in which the cylinders have no quench area.

Open-end Spring

A coil spring having its end loops apart from the spring coils.

Operational Control Valve

A device used to control the flow of compressed air through the brake system.

Operational Specifications

Specifications used to show how the vehicle operates, such as acceleration, tire inflation, and other general information.

Operational Test

A term used for performance test.

Opposed Engine

An engine with cylinder banks at 180 degrees, such as the Volkswagen flat four.

Opposite Lock

Turning the steering wheel in the opposite direction of a turn to control or correct oversteer.