Timing Chain: Service and Repair

11 31 051 - Replacing timing chain





Special tools required:
- 11 2 000 11 2 000 Puller
- 11 8 250 11 8 250 Pin Wrench
- 11 8 300 11 8 300 Puller Plate
- 11 8 370 11 8 370 Support Bracket





Necessary preliminary tasks:
- Unscrew all spark plugs Service and Repair.
- Remove cylinder head cover.
- Remove pulse generator on camshaft Service and Repair.
- Remove hydraulic chain tensioner.
- Remove timing chain cover.
- Remove left engine mounting Replacing Right Engine Mount.





Fit special tool 11 8 370 11 8 370 Support Bracket on cylinder block (1) and engine mounting (2).





Release camshaft retaining bolt (1) and hold camshaft gear with special tool 11 8 250 11 8 250 Pin Wrench.
Unscrew plugs (2).





Unscrew retaining bolt for camshaft gear, then remove gear wheel and chain.
Remove camshaft gear from timing chain.

Caution!
Protect timing chain to prevent it from dropping into timing case.

Unscrew retaining bolts (1) of chain guides and remove both guides (2).





Installation note:
If the timing chain is replaced, the camshaft gear and crankshaft gear must also be replaced.

Remove crankshaft gear using special tool 11 8 300 11 8 300 Puller Plate together with 11 2 000 11 2 000 Puller.





Installation note:
Shrink-fit crankshaft gear (1) onto crankshaft.
Check correct position of locating pin (2).
Use a hotplate to heat crankshaft gear to a maximum temperature of 150°C.

Caution!
Do not exceed the specified temperature.





Install timing chain.
Install clamping rail and guide rail (2).
Install retaining screws (1) of chain guides.
Tightening torque: 11 12 12AZ 11 12 Cylinder Head and Cylinder Head Cover.
Place timing chain on camshaft gear.
Fit camshaft gear onto camshaft.
Fit central bolt for camshaft gear.
Tightening torque 11 12 5AZ 11 12 Cylinder Head and Cylinder Head Cover.





Installation note:
Triangular adjustment mark (1) on camshaft gear must be aligned with copper-colored timing chain links (2).





Installation note:
The two triangular adjustment marks (1) on crankshaft gear must be aligned with copper-colored timing chain links (2).





1. Camshaft adjustment mark lines up with colored chain link.
2. Camshaft gear.
3. Left timing chain guide.
4. Right timing chain guide.
5. Tensioning device for timing chain.
6. Crankshaft gear.
7. Chain.
8. Crankshaft adjustment mark lines up with the two colored chain links.





Assemble engine.