A highly common, clipped shop term for the transmission assembly. It refers to the entire gearbox unit, whether automatic or manual, that transfers engine power to the driveline. Mechanics use it constantly in spoken shorthand when discussing fluid changes, rebuilds, or swaps.
Heard on the job
Grab the jack, we need to drop the tranny out of this truck before lunch.
Related terms
Transmission
The mechanical or hydraulic assembly that adapts engine power to drive the wheels.
Automatic transmission
A gearbox that changes gear ratios independently without a manual clutch pedal.
Manual transmission
A gearbox requiring the driver to manually select gear ratios using a shift lever and a clutch.
Transmission fluid
A specialized hydraulic fluid and lubricant used to operate and protect gearboxes.