Gearbox, axle, cardan

This section covers the whole path of power from the engine to the wheels: gearboxes, clutch assemblies, cardan shafts, transfer boxes and axles. Both single parts and complete units are listed - new ones and units pulled from dismantled cars.

Gearbox and clutch

Gearboxes here come in both kinds - automatic and manual - and in a listing the transmission code matters more than the model name alone. On manuals the clutch wear parts are replaced together: the disc, the pressure plate and the release bearing are sold as a clutch kit for exactly that reason, and the flywheel is inspected at the same time so the job is not done twice.

Cardan, transfer box and axle

Rear- and all-wheel-drive cars add the cardan shaft, the transfer box and the axle. Vibration and hum at speed often come from the cardan support bearing or the universal joint - before buying the whole assembly it is worth confirming that these smaller parts are not the actual culprit.

Buying a used gearbox - what to clarify

The gearbox is one of the most searched-for used units, and a well-chosen one runs for years. A matching model is not enough - the transmission code is tied to the engine, the production year and the driven wheels. Ask the seller:

• the transmission code and which engine it was paired with
• which car it came off and with what mileage
• whether it was tested working before removal
• the state of the oil - dark fluid with a burnt smell betrays wear

Installation and inspection are best left to a specialist - gearbox repair services have a section of their own.