Part 2

11 31 001 - Replacing camshaft (M52TU/M54/M56)

Continued from Part 1.





Automatic transmissions only:

Illustration does not show automatic transmission.

Important!
On engines with automatic transmissions, there is shortly before the special tool bore (1) a large bore (2) which can be confused with the special tool bore.

If special tool 11 2 300 11 2 300 Plug Mandrel is secured in the correct bore (1), the engine can no longer be cranked at the central bolt.





Position sensor gear on inlet camshaft.





Fit thrust washer and tighten down with dowels.

Tightening torque 11 31 11AZ 11 31 Camshaft.





Feed chain wheel onto timing chain so that arrow on chain wheel faces separating face of upper side of cylinder head.





Insert special tool 11 4 220 11 4 220 Chain Tensioner in cylinder head and bring adjustment screw into contact with tensioning rail, but do not pretension timing chain yet.

Check arrow on chain wheel to separating face of upper side of cylinder head, reposition chain wheel if necessary.





Insert and tighten down screw-in pin.

Tightening torque 11 31 11AZ 11 31 Camshaft.





Install secondary chain tensioner.





Fit toothed sleeve (6) and align to toothed shaft in camshaft so that tooth gaps are opposed.





Secure toothed shaft (5).

Insert pin of toothed shaft (5) into tooth gaps of splines on camshaft and toothed sleeve (6).





Push in toothed shaft (5) until the longitudinal holes in the toothed sleeve (6) are positioned centrally with respect to the thread.





Place chain wheels in special tool 11 6 180 11 6 180 Fixture, position tooth gap on inlet chain wheel as shown in illustration and feed on chain.





Important!
Do not alter position of chain wheels with respect to chain when removing from special tool 11 6 180 11 6 180 Fixture.

Remove chain with sprocket wheels positioned from special tool 11 6 180 11 6 180 Fixture and so that tooth spaces oppose each other on inlet side.





Align chain with sprocket wheels so that tooth spaces are positioned exactly over each other on inlet side.





Secure toothed shaft (4).

Insert pin of toothed shaft (4) into tooth gaps of splines on camshaft and chain wheel.





Push in toothed shaft (4) until approx. 1 mm of splines can still be seen.





Note installation direction of corrugated washer (7), "FRONT" lettering must be visible.

Install corrugated washer, tighten nuts by hand but do not tighten down fully yet.





Insert screws on exhaust side, initially tighten to approx. 5 Nm and then slacken off again half a turn.





Fit thrust washer (3).





Note installation direction of cup spring (2), "F" lettering must be visible.

Note:
If "F" lettering is no longer visible on an engine that has been run:

Install cup spring (2) so that small locating diameter of spring (2) points to sensor gear.

Fit cup spring (2) in position.





Position sensor gear (1) so that arrow on sensor gear faces separating face of upper side of cylinder head.

Install nuts and tighten by hand but do not tighten down fully yet.





Withdraw toothed shaft (5) up to stop.





Press down secondary chain tensioner at top and remove special tool 11 3 292.





Preload tensioning rail with special tool 11 4 220 11 4 220 Chain Tensioner by rotating adjusting screw with special tool 00 9 250 00 9 250 Torque Wrench with Flexible Extension or standard torque wrench to 0.7 Nm.





Preload cup spring slightly by pressing on sensor gear (1) and tighten nuts by hand.

Important!
Do not tighten down nuts fully.





Remove gasket.

Check dowel sleeves (1) for damage and correct installation position.

Keep sealing face clean and free of oil.





Important!
Fit special tool 11 6 150 11 6 150 Adjusting Plate "without gasket" only.

If gasket remains underneath special tool 11 6 150 11 6 150 Adjusting Plate, camshaft timing will be "incorrectly" set.

Attach special tool 11 6 150 11 6 150 Adjusting Plate "without gasket", tighten nuts by hand and then tighten down uniformly until special tool 11 6 150 11 6 150 Adjusting Plate is in full contact with cylinder head.





Insert screws (1) on exhaust side and initially tighten to approx. 5 Nm.





Initially tighten nuts (2) on exhaust side and nuts (3) on inlet side to approx. 5 Nm.





Tighten down screws (1) on exhaust side.

Tightening torque 11 31 3AZ 11 31 Camshaft.





Tighten down nuts (2) on exhaust side and nuts (3) on inlet side.

Tightening torque 11 31 11AZ 11 31 Camshaft.





Pull special tool 11 2 300 11 2 300 Plug Mandrel back until flywheel is no longer secured in position.





Remove special tool 11 3 244 11 3 240 Locking Fixture and special tool 11 3 240 11 3 240 Locking Fixture.





Crank engine twice in direction of rotation until cam tips on inlet and exhaust camshafts on 1st cylinder face one another.





Secure crankshaft in firing TDC position with special tool 11 2 300 11 2 300 Plug Mandrel.

Important!
Do not turn the engine back.

Remove special tool 11 2 300 11 2 300 Plug Mandrel before switching on the engine.





Fit special tool 11 3 240 11 3 240 Locking Fixture to camshafts.





Note:
The timing is correctly set if the special tool 11 3 240 11 3 240 Locking Fixture rests without a gap on the cylinder head or protrudes up to 1 mm to the inlet side.

The timing must be reset if the special tool 11 3 240 11 3 240 Locking Fixture protrudes to the exhaust side.





Remove special tool 11 6 150 11 6 150 Adjusting Plate.

Install VANOS adjustment unit Service and Repair.

Assemble engine.