Removing and Installing/Replacing Left Exhaust Camshaft

11 31 036 Removing and installing/replacing left exhaust camshaft (N74)

Special tools required:

(cylinder bank 7 to 12)





Necessary preliminary tasks:
^ Remove left cylinder head cover.
^ Check timing.
^ Remove left inlet adjustment unit.





Release bolts of camshaft bearings in sequence (1 to 14) in 1/2 turns.

Set down all bearing caps in a tidy and orderly fashion on special tool 11 4 480.

Remove exhaust camshaft in upward direction.





Important!
Used rocker arms (1) may only be reused in the same position.

Note:
Rocker arms (1) are freely accessible after exhaust camshaft has been removed.

Do "not" remove rocker arms (1) on exhaust side.





Important!
Plain compression rings (1) can easily break.

Press compression ring (1) on one side into groove, pull up on other side and remove catch.

Carefully pull plain rectangular compression ring (1) apart and remove towards front.

Modify plain rectangular compression ring on new camshaft.

Ends of compression rings (1) point upwards

Make sure compression rings (1) are engaged at ends.





Note:
Exhaust camshaft (1) of cylinder bank 7 to 12 is marked with "A and 712".





Important!
Rocker arms (1) slip slightly when exhaust camshaft is fitted.
Make sure rocker arms (1) are secured as illustrated on hydraulic valve clearance compensating elements and on valves.

Align all rocker arms (1) straight.

Coat all bearing points with engine oil.





Install exhaust camshaft (1).

Insert exhaust camshaft (1) so that cams point to side at cylinder 5 as shown in picture.

Coat all bearing points with engine oil.





Important!
Do not mix up the bearing caps of cylinders 1 to 6 and 7 to 12.
All bearing caps are coded and can only be installed in one position.

All bearing caps are marked:

L = Cylinders 1 - 6.

R= Cylinders 7 - 12.

E = Intake side

A = Exhaust side

1 = Designation from 1 to 7





Coat all bearing points with engine oil.

Insert all bolts.

Tighten down bolts in sequence (14 to 1) in 1/2 turns.

Tightening torque: 11 31 1 AZ.





Preload exhaust camshaft (1) with an open-end spanner (2) towards left.





Block exhaust camshaft with special tool 11 9 893.





Install inlet adjustment units.

Adjust valve timing.

Assemble engine.