Extension Housing: Service and Repair

Note: Remove complete exhaust system.

After completing work, top up ATF level.
Check/top up fluid level in automatic transmission, refer to Automatic Transmission Fluid, Testing and Inspection.

Caution:
It is absolutely essential to use the approved automatic transmission fluid in this automatic transmission.
Failure to comply with this requirement will result in serious damage to the automatic transmission!

Caution: On E39 cars with M57 engines, the automatic transmission must be removed completely.

The affected automatic transmissions are generally provided with a sticker on the transmission extension at the rear (see Fig.).
To avoid damaging the automatic transmission, set up the transmission for the entire work sequence vertically (output flange facing upwards) on the assembly stand.
Remove and install automatic transmission, refer to Automatic Transmission/Transaxle, Service and Repair.

Remove heat shield (1).

Support transmission with special tool 00 2 030 24 5 301 245305.

Unfasten screws.
Remove cross-member (1).

Installation:
Tightening Torque, refer to Automatic Transmission/Transaxle, Specifications.

Unfasten screws.

Installation:
Replace self-locking nuts.
Tightening Torque, refer to Automatic Transmission/Transaxle, Specifications.

Grip propeller shaft and release nuts.
Bend propeller shaft downwards at center mount (1), detach from transmission output flange and tie back to one side on underbody of vehicle.

Installation:
Tightening Torque, refer to Automatic Transmission/Transaxle, Specifications.

Caution: On E39 cars with M57 engines, the automatic transmission must be removed completely.

To avoid damaging the automatic transmission, set the automatic transmission vertically (output flange facing upwards) on the assembly stand throughout the entire work operation.

Note: The affected automatic transmissions are generally provided with a sticker on the transmission extension at the rear (see Fig.).

Version 1 without spring washer
Grip output flange (1) with special tool 23 0 020.
Release hexagon nut.
Detach output flange (1).

Installation:
Replace 0-ring in output flange (1).
Tightening Torque, refer to Automatic Transmission/Transaxle, Specifications.

Version 2 with spring washer
Release nut (1) on output flange (2).

Installation:
Tightening Torque, refer to Automatic Transmission/Transaxle, Specifications.

Version 2 with spring washer
Remove spring washer (1).
Remove output flange (2).

Installation:
Note installation direction of spring washer (1).

Withdraw radial seal (1) with special tool 00 5 010.

Release screws on transmission extension (1).
Carefully remove transmission extension (1).
Tightening Torque, refer to Automatic Transmission/Transaxle, Specifications.

Replace gasket between transmission housing (1) and end cover.

Caution: Existing shim (2) remains fitted and is not recalculated.

Caution: If shim is lost: Calculate new shim.

Calculate measurement between contact face (1) and parking gear (2) with special tool 00 2 550.

Calculate the new shim with this measurement from the table.

Installation:
Coat sealing lips of new radial seal with automatic transmission fluid.
Drive in radial seal with special tool 24 1 090 until flush.