Manual Transmission (Manual Gearbox)

Most manual gearboxes have five or six forward gears and one reverse. Gears are constantly meshed and are locked to their shafts by sliding collars. Gear oil lubricates the gears and bearings. Front-wheel-drive cars usually combine the gearbox and differential in one unit called a transaxle. Some gearboxes have a dual-clutch automatic version based on the same gears.

Moving the lever slides a selector fork, which moves a collar to lock the chosen gear to its shaft. Synchronisers match shaft speeds first so the change is smooth.

Grinding, jumping out of gear or hard shifting can mean worn synchros, clutch problems or low gear oil. Gearbox oil is often described as "lifetime", but changing it can help shifting quality on older cars. Use the specified oil; the wrong type can damage synchromesh rings.