Manual Transmission (MT)

Torque from the engine is transmitted through the clutch to the input shaft of the gearbox. This input (drive) shaft carries six gears (including reverse), which are in constant mesh with six gears on the output shaft. These gears rotate freely until one of them is locked to its shaft when a particular gear is selected. The ratio of the teeth on the meshing gear pair produces the required gear ratio. Like all passenger cars, the Audi 80 has fully synchronized gears for forward travel. Reverse gear is also synchronized to prevent grinding when it is engaged.

The gears on the input and output shafts are mounted on needle bearings. Therefore, there is no rigid connection between the shafts and the gears. As mentioned above, the gears always remain in mesh.

When shifting gears, the connection is made not between the gears, but between the gear and the shaft. To synchronize the speeds of the shaft and the gear, the following method is used: one part is pressed by friction elements against the other part of the shaft.

Friction slows the faster component until both run at the same speed and a torque-transmitting connection can be made. Because synchronization still takes a fraction of a second, the driver should not force the shift lever, especially when starting a cold engine with thick transmission oil.