Mercedes-Benz cars are equipped with 4- or 5-speed automatic transmissions.
The automatic transmission consists of a torque converter, an epicyclic gear train, as well as a hydraulic clutch and brakes.
Torque from the engine to the gearbox is transmitted through a torque converter, which functions as a fluid clutch and acts as an automatic clutch, also providing torque transfer during acceleration.
An epicyclic gear train provides forward movement in one of four or five gears or reverse. The gear train components are controlled by brakes and clutches which are actuated hydraulically. A pump located in the gearbox provides the necessary hydraulic pressure to operate the brakes and clutch.
The gearbox is controlled by a selector lever and two switches. Position D provides automatic selection of one of four or five gears. The automatic KICK DOWN·mechanism forces downshifts when the accelerator pedal is fully depressed. This mode should be used when maximum vehicle acceleration is required. If the selector lever is in position 3, the vehicle will move only in the first three gears, and in position 2 - only in the first two gears, etc. Lower gears are desirable when engine braking, when driving downhill, or to prevent unwanted selection top gear on winding roads.
With the help of additional switches, two driving modes can be set: economical (E) or standard (S).
Due to the complexity of the automatic transmission, any repair must be done at a service station.