Manual transmission

A manual transmission (also known as a manual gearbox; abbreviated as MT and sometimes called a standard transmission in Canada and the United Kingdom) is a multi-speed motor vehicle transmission system, where gear changes require the driver to manually select the gears by operating a gear stick and clutch (which is usually a foot pedal for cars or a hand lever for motorcycles).

Manual transmission for a four-wheel-drive vehicle- viewed from the engine side
Internals of a manual transmission for a front-wheel-drive vehicle

Early automobiles used sliding-mesh manual transmissions with up to three forward gear ratios. Since the 1950s, constant-mesh manual transmissions have become increasingly commonplace and the number of forward ratios has increased to 5-speed and 6-speed manual transmissions for current vehicles.

The alternative to a manual transmission is an automatic transmission; common types of automatic transmissions are the hydraulic automatic transmission (AT), and the continuously variable transmission (CVT), whereas the automated manual transmission (AMT) and dual-clutch transmission (DCT) are internally similar to a conventional manual transmission, but are shifted automatically.

Alternately, there are transmissions which facilitate manual clutch operation, but the driver's input is still required to manually change gears; namely semi-automatic transmissions. These systems are based on the design of a conventional manual transmission, with a gear shifter, and are mechanically similar to a conventional manual transmission, with the driver's control and input still required for manually changing gears (like with a standard manual transmission), but the clutch system is completely automated, and the mechanical linkage for the clutch pedal is completely replaced by an actuator, servo, or solenoid and sensors, which operate the clutch system automatically, when the driver touches or moves the gearshift. This removes the need for a physical clutch pedal.