11 31 051 Replacing timing chain (N18)
Special tools required:
The timing is not determined at firing TDC of cylinder no. 1.
All pistons are in the 90° position.
Observe direction of rotation (direction of rotation always clockwise when viewed towards timing drive side).
Necessary preliminary work:
- Remove CYLINDER HEAD COVER .
- Remove all SPARK PLUGS .
- Remove VIBRATION DAMPER .
- Remove CHAIN TENSIONER .
- Remove VANOS UNIT .
- Remove PTFE RING at front.
- Remove BELT TENSIONER .
- Remove FRICTION GEAR .
Crankshaft is positioned with special tool 11 9 590 .
Do not remove special tool 11 9 590 during repair work.
Move front panel into WORKING POSITION .
Suspend engine with engine crane (1) from lifting eye (2).
Remove ADAPTER PLATE .
Remove right ENGINE MOUNT .
Release upper ALTERNATOR BOLTS .
Secure special tool 11 9 630 with standard bolts (1 and 2).
Do not remove special tool 11 7 440 .
Fit special tool 11 9 280 on hub for vibration absorber with screws (2).
Release central bolt (1).
Release central bolt in direction of arrow.
Release bearing journal (1 and 2).
Tightening torque: 11 31 1AZ .
Sprocket (1) of timing chain.
Sprocket (2) of oil pump.
Secure chain module (1) with rubber part (3) to facilitate assembly.
Pull timing chain (2) upwards until sprocket (4) rests against chain guide (1).
Install timing chain (2) and sprocket (4) in this position.
Installation note:
Always keep timing chain (2) tensioned; it is possible for timing chain (2) to jam on chain module (1).
Installation position of both sprockets.
Sprocket (1) of oil pump.
Guide rail (2) of timing chain.
Hub (3) on crankshaft.
Sprocket (4) of timing chain.
Check oil pump sprocket (2) is in correct installation position.
Insert chain module with timing chain and secure.
Attach crankshaft hub.
Screw in central bolt.
Remove special tool 11 9 280 from hub.
Secure central bolt with special tool 00 9 120 .
Tightening torque: 11 21 1AZ .
Install VANOS UNIT .
Crank engine twice.
Check TIMING .
Install PTFE RING .
Assemble engine.