Removing and Installing Automatic Transmission

Removing and installing automatic transmission (A4S 270R/310R)

Caution! First read fault memories with tester and print any faults as disconnecting the negative lead will cancel the fault memories in control units.

Disconnect battery.
Remove propshaft from transmission and center mount and fasten to one side.

Note: On version with two center mount, only disconnect front center mount.




Drain oil
Never reuse drained ATF.

Note: Replace the transmission if the fluid smells burnt and is black.

Caution! Clean oil cooler and pipes with compressed air and flush twice with ATF if the transmission is faulty.




Move selector lever into setting "P"
Unscrew nut (1).

Caution: Always brace bolt with special tool 24 5 210 to avoid deformation of the cable.

Note: Special tool 24 5 210 can only be fitted in position "P".

Unscrew cable from holder.
Pull out cable.
Tightening torque: Mechanical Specifications

Installation instructions:
Adjust selector lever. Adjustments




Turn bayonet lock (1) counterclockwise.
Pull off plug (2).
Lift wire harness out of holder.

Installation:
Connect plug (2) that marks are aligned.




Pull plug (1) off speed sender.




Lift off cover from opening (1) on side of crankcase.
Using special socket 24 1 110, release three screws securing torque converter to drive flange.
Turn flywheel for this step.




Installation:
Install screw, using special socket 24 1 110.
Tightening torque: Mechanical Specifications

Caution: Only use original bolts.




Preassemble special tool 24 5 300 (fixture) to suit transmission THM-R1 as marked.




Support transmission with special tool 24 5 300 (fixture in conjunction with special tool 00 2 020 (lifting fixture).




If applicable, remove center of gravity suspension.




Unscrew cross member.

Installation:
Centering transmission.
Tightening torque,: Mechanical Specifications
Lower transmission, until the cylinder head or manifold no longer abuts the engine fire wall or the heating connections (visual inspection).





Release oil cooler pipe clamps from crankcase and oil pan.





Unscrew front oil cooler pipe.

Installation:
Check O-ring (1), replacing if necessary.
Tightening torque: Mechanical Specifications





Unscrew rear oil cooler pipe.

Installation:
Check seals, replacing if necessary.
Tightening torque: Mechanical Specifications





Unscrew transmission on engine (Torx screws).





Installation:
Check that washers are fitted to Torx screws.
Tightening torque: Mechanical Specifications





Secure converter from slipping by fitting and securing tool 24 4 080 to transmission housing with flat side of retaining element (1) facing converter.
Pull transmission off engine.

Caution: A lifting fixture with mounted transmission may be moved only in completely lowered position.





Check that dowel sleeves (1 and 2) are not missing.
If necessary convert or replace dowel sleeves. Ensure correct position of cover plate.

Installation:
Check drive plate for breaks and cracks, replacing if necessary.





Engine M50:
Version with Sheet Metal Flywheel (2):

Caution: Keep to sequence of installation. Sheet metal flywheel (2) has three indentations for the torque converter mounting tabs.

When guiding the engine and transmission together the three mounting tabs on the torque converter must be aligned with the three indentations in the sheet metal flywheel. Non-conformance leads to follow-up damage on the automatic transmission.
Turning on the torque converter, or engine, is no longer possible after guiding the engine and transmission together and would lead to damage.





Turn the torque converter on the transmission until bore (1) faces down perpendicular to the tab. Screw special tool 24 2 300 into the tab.





Bore (3) on drive plate must point perpendicularly to centre of opening in oil sump.





Lift automatic transmission until bore (3) in drive plate is reached.
Guide transmission in carefully with special tool 24 2 300 in bore (3) on the drive plate.
Bolt transmission housing to engine.
Unscrew special tool 24 2 300 from the tab towards the front.
Mount torque converter.





All:
After the transmission has been refitted, the oil level must be checked and topped up if necessary.

Versions with oil filler pipe:
Take out oil dipstick.

Caution: Oil dipstick has detent.

Tilt handle to unlock oil dipstick for removal.
Run engine in selector lever setting "P" or "N".
Car must be unloaded and stationary on a level surface Interrogate ATF temperature with Service Tester or MoDiC.





Take out oil dipstick and measure ATF level.





Compare measured level with values in the table. Never wipe off oil dipstick with a cloth which loses lint.





Top up ATF only using special tool 24 0 080.

Version without oil filler pipe:
Oil filler pipe was discontinued as of 2.91.
Replenish ATF through filler opening on underside of of pan.





Check the actual level, and top up if necessary.
Car must be unloaded and stationary on a level surface
Only check oil level at a transmission oil temperature of 30 - 55°C.
Interrogate ATF temperature with Service Tester or MoDiC.
Run engine in selector lever setting "P" or "N".
Unscrew filler plug (1).





Allow too much oil to escape or top up with insufficient oil.
To top up ATF, attach filler neck (2) to filler aperture.
Add ATF until it runs out. Screw in and tighten filler plug.

Installation:
Check sealing ring, replacing if necessary.
Tightening torque: Mechanical Specifications
ATF level too high
Strong foaming, loss through splashing, high temperatures at high speeds.
Oil lost through vent.

ATF level too low:
Rattling of valves, foaming, spinning of engine.
General malfunction.