TRANSMISSION: Describes a geared device that uses torque conversion to effect a change in the ratio between engine rpm and driving wheel rpm.
AUTOMATIC TRANSMISSION: Describes a major function of a vehicle drivetrain whose role it is to take the power from the engine and transfer it to the driveshaft through a torque converter and fluid coupler to change the gear ratio through a series of oil operated clutches and bands.
AUTOMATIC TRANSMISSION FLUID (ATF): Describes a liquid of very thin viscosity designed for use in an automatic transmission system whose function it is to transfer the movement of the torque converter to the driveshaft.
BAULK RING: Describes a friction-regulated pawl or plunger used to make the engaging gears smoother
BAND: Describes a circular shaped metal belt where the two ends are close, but do not meet. The band wraps around parts inside the transmission called drums, which house the gears and clutches and freewheel until a certain gear needs to be applied.
BEVEL GEAR DRIVE: Describes a transmission used to drive one or more shafts that do not line up with the output shaft.
CENTRAL GEARCHANGE: Describes the usual arrangement with the gear lever in the centre of the floor.
CHANGE-SPEED GEARBOX: Describes a transmission housing a set of gears which move into various configurations in order to produce different output ratios.
CHANGE VALVE: Describes a valve in an automatic transmission that raises the oil pressure as the vehicle speed increases.
CLOSE-RATIO GEARBOX: Describes a transmission in which there is little difference between one gear ratios making for very rapid shifting.
COLUMN CHANGER: Describes the gear changer lever and mechanism which located on the steering column below the steering wheel.
CONSTANT MESH GEARBOX: Describes a type of transmission where all or most of the gears are always in mesh with one another, as opposed to a sliding-gear transmission, in which engagement is obtained by sliding some of the gears along a shaft into mesh.
CONVERTER CASE: Describes an assembly containing the converter fluid and vane wheels that is part of a vehicle’s automatic transmission, connected to the crankshaft by means of the drive plate and revolving at engine speed.
CONVERTER COVER: Describes a part in the automatic transmission welded to the pump and makes up the converter case.
COUNTERSHAFT: Describes the shaft in a manual gearbox that carries power by means of gears from the clutch shaft to the driveshaft, turning opposite to them.
CROSS SHAFT: Describes the shaft in the steering gearbox that engages the steering shaft worm, the cross shaft is splined to the pitman arm.
CROWN WHEEL: Describes the larger of two gears in a bevel gear drive with teeth around its periphery facing sideways.
DRIVESHAFT: Describes the shaft, found primarily on rear-drive vehicles, that connects the transmission output shaft to the differential pinion shaft in the process transmitting power from the transmission to the differential
DRIVE PINION: Describes a shaft that transmits power from the clutch into the gearbox.
DRIVE PLATE: Describes a light plate found in a vehicle with automatic transmission that is bolted to the crankshaft and on to the torque converter.
DRIVESHAFT SAFETY STRAP: Describes a metal strap that surrounds the driveshaft to prevent the shaft from becoming completely disconnected in the event of a universal joint or shaft failure.
DRIVETRAIN: Describes all of the individual components situated beyond the engine up to the wheels (clutch, drive shaft, differential, driven axles) although not the engine or transmission.
DIRECT DRIVE POWERTRAIN: Describes a propulsion system in which the engine, transmission, and propeller shaft rotate at the same pace.
DRAINING TRAY: Describes the container used to catch oil when draining a vehicle’s transmission.
DRIVE LAYOUT: Describes the arrangement of the order of the transmission in either front-wheel drive, rear-wheel drive, mid-engine drive, four-wheel drive or two-wheel drive.
DUAL-RANGE TRANSMISSION: Describes a transmission system designed foe use in a four-wheel drive vehicle.