Timing Belt: Service and Repair

Toothed belt, removing and installing

Removing
- Remove ribbed belt. Service and Repair





- Unscrew bolts -arrows- and remove engine cover panel -C-.





- Remove pressure hoses -arrows- between charge air coolers and pressure pipes (left and right sides).





- Remove pressure pipes -1-.

Note: Watch position of retaining strips -2-.





- Remove tensioner-1- for ribbed belt.
- Remove left and right toothed belt guards -2-.
- Remove center toothed belt guard -3-.





- Turn crankshaft to TDC by hand. Marks -A- and -B-must be aligned.

Note: Turn over the engine at the central bolt on the crankshaft.

- Check position of camshafts: larger holes in securing plates on camshaft sprockets must align opposite one another on the inside. If not, turn crankshaft one revolution further.
- Remove sealing plug from cylinder block, left.
TDC drilling in the crankshaft must be visible (or able to be felt) in line with the sealing plug hole.

CAUTION: Injury risk - do not turn engine while feeling for TDC drilling.





- Screw clamping bolt 3242 for crankshaft into sealing plug hole and tighten.





- Remove vibration damper on crankshaft.

Note: The central bolt does not have to be loosened to remove the vibration damper.





- Remove idler wheel for ribbed belt -arrows-.
- Remove toothed belt guard behind vibration damper -arrows-.

Notes:
^ Mark the direction of rotation of the toothed belt with chalk or felt pen before removing. A used belt can break if it rotates in the wrong direction when reinstalled.
^ The toothed belt tensioning element is oil damped and can therefore only be compressed slowly by applying constant pressure.





- Using a hex key, turn toothed belt tensioning roller-1- clockwise 8 mm in direction of arrow until tensioning lever-2- compresses tensioning element -3- sufficiently to enable special tool T 400 11 to be fitted in drilling and in plunger.
- Insert special tool T 400 11, release toothed belt tensioning roller.
- Remove toothed belt.

Installing
- Insert camshaft clamp 3391 in securing plates of two camshafts.
- Loosen both camshaft bolts and unscrew approximately 5 turns.
- Take out camshaft clamp 3391.





- Pull off both camshaft sprockets with special tool T40001.
- Refit both camshaft sprockets with securing plates and tighten hand-tight again.

Note: The camshaft should be just tight enough on the camshaft tapers so that they can still be turned but do not move axially.





- Fit toothed belt on all sprockets as illustrated.
- Fit camshaft clamp 3391.





- Using a hex key, turn toothed belt tensioning roller-1- clockwise 8 mm in direction of arrow until special tool T 400 11 can be removed.





- Pre-tension toothed belt by turning in direction of arrow with a torque of 15 Nm using a torque wrench.
- Tighten bolts on camshaft sprockets.





- Install idler wheel for ribbed belt -arrows-.
- Install toothed belt guard behind vibration damper-arrows-.





- Install vibration damper. Note positions of locating lugs -arrows- on belt sprocket.
- Install toothed belt guard.
- Install ribbed belt. Service and Repair

Tightening Torques (Part 1 Of 9):

Tightening torques