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Overcord

The covering bonded to the tensile member of a synchronous belt that protects it form frictional wear if a backside idler is used or if power is transmitted from the backside of the belt.

Overdrive

A transmission having a ration of less than 1.

Overdrive Band

A transmission brake device that is engaged in overdrive.

Overdrive Ratio

A ratio identified by the use of a decimal point, such as 0.80, indicating less than one driving input revolution compared to one 1.0 output revolution of a shaft, or 0.85.

Overflow

1. The spilling of the excess f a substance. 2. To run or spill over the sides of a container.

Overflow Tank

1. A tank at the top of a radiator to receive heated coolant and vent trapped air due to expansion. 2. A device bound in some fuel tanks to prevent gas escaping due to expansion. 3. A term used for expansion tank.

Overhaul

To rebuild a device or an assembly, such as an engine or a transmission.

Overhaul And Maintenance Specifications

Specifications used to service vehicle components such as an engine, differential, or transmission.

Overhead Cam (OHC)

A term used for overhead camshaft or overhead camshaft engines.

Overhead Camshaft

A camshaft mounted in the cylinder head.

Overhead Camshaft Engine

An engine in which the camshaft is mounted over the cylinder head.

Overhead Position

The position in which welding is performed from the underside of the joint.

Overhead Valve (OHV)

An I-head arrangement where the valves are located over the piston in the cylinder head.

Overhead-valve Engine

An engine in which the valves are mounted in the cylinder head over the combustion chamber.

Overheat

1. To become excessively hot. 2. A general term used if the engine exceeds design operating temperature.

Overinflation

The condition of a tire that is inflated to more than the recommended pressure, decreasing the contact area, increasing the rolling diameter, and stiffening the tire resulting in excessive wear at the center of the tread.

Overlap

The interval of valve timing when the intake valve starts to open before the exhaust valve is fully closed.

Overlay Cam

A camshaft having a hard face material welded to the nose and flank of the lobes to help decrease wear and increase lift.

Overload

Excess current flow in a circuit.

Overload Spring

Spring in the end of the cable in cable-operated adjusters that lets the cable move without breaking if the pawl or star wheel is jammed.