Note: To make work easier when installing the gearbox, engage first gear before removing it.
To remove the gearbox, you must perform the following operations:
Raise the vehicle and place it on jack stands.
Disconnect the ground wire from the battery. Disconnect and remove the entire exhaust system.
Disconnect the adjusting shaft (3) (see arrow).
Support the gearbox with a jack and, working under the car, unscrew the mounting bolt to the cushion (see arrow) in the rear cover of the gearbox.
Remove the rear transmission support and crosspiece. Remove the exhaust bracket from the rear of the transmission, noting the position it was in (see arrows).
Remove the exhaust pipe clamp and bracket.
Remove the heat-insulating screen.
Disconnect the speedometer cable, having first unscrewed the drive gear (see arrow), and secure it to the side.
Loosen the propeller shaft lock nut.
Remove the propeller shaft.
Caution: The flexible coupling must remain on the shaft.
Remove the clutch slave cylinder, having first unscrewed the hydraulic line fastening.
Remove the starter and disconnect the gear shift mechanism.
Remove the bolts securing the gearbox to the engine, then, with someone's help, lower the gearbox to the floor and pull it out from under the car.
Caution: Before lowering the gearbox, make sure that the input shaft has come out of the driven clutch disc, otherwise the disc may be damaged.
(Original source of information: MercedesMan.ru)
Check that the car is securely fastened as it may require some rocking of the transmission to get it moving.
The gearbox is installed in the reverse order.
It is necessary to ensure that the clutch release lever and bearing do not stick, and that the functional disk is aligned with the drive shaft of the gearbox.
Lubricate the splines of the gearbox drive shaft with molybdenum-based grease, check and, if necessary, add oil to the gearbox.