The gearbox includes a torque converter, planetary gear, hydraulic clutch and brakes.
The torque converter provides fluid engagement between the engine and transmission, acts as a clutch, and also provides the degree of conversion under acceleration.
Depending on which of the parts is held stationary or can rotate, the planetary gear provides a gear ratio of four forward gears or one reverse gear. The parts of the planetary gear are held or released by brakes or clutches, which are activated by a hydraulic control unit. A fluid pump inside the gearbox provides the necessary pressure for the brakes and clutches to operate.
The driver controls the gearbox by switching the gear selector lever and the two-position switch.
The pressure control cable, actuated by the movement of the accelerator pedal, changes the hydraulic control pressure in the gearbox in accordance with the position of the throttle valve. The gear selector lever has a "drive" position and a "hold" mode of operation in 2nd and 3rd gears. Position "drive" ("D") provides automatic shifting throughout the entire forward gear range and is the normal driving position. Automatic downshifting automatically changes down a gear when the accelerator pedal is fully depressed. The "hold" position is similar to the "drive" position but limits the number of available gears - i.e. if the gear selector lever is in position "3" then only the first three ratios can be selected; if position "2", only the first two gears can be selected, etc. A low "hold" ratio is useful when driving downhill or to prevent upshifting on a winding road. There are two drive programs, which can be selected using the switch; "Economy" or "Standard". With the switch in the "Economy" ("E") position, the car will start off in 2nd gear with a small throttle opening or in 1st gear with the throttle fully open. With the switch in the "Standard" ("S") position, the car will always start off in 2nd gear and shifting between gears will occur at lower speeds.
(Publication reprinted from this resource: «MercedesMan.ru»)
Due to the complexity of the automatic transmission, any repairs should be carried out at the company's service station "Mercedes-Benz", which has all the necessary equipment for diagnostics and repair. Therefore, the content of the following paragraphs is limited to the presentation of basic information and maintenance information and instructions that can be used by the owner of the machine.