Part 2

WM 150520 Removing and installing camshafts (includes setting timing)


12. Check axial bearing clearance by pulling and pressing on the camshaft controller and sprocket.
12.1. There must be perceptible clearance because otherwise the shafts will have to be fitted again.
13. Screw in and tighten chain tensioner with a new seal.
=> Tightening torque: 80 Nm (59 ftlb.)

Set the timing, cylinder bank 4-6:
14. Check cam position for cylinder 4 -arrows- again.





Cam position for cylinder 4 at overlap

Data matrix code -inset- is facing the observer.





Marking on camshafts 4-6 at overlap

15. The adjusting device is positioned on the reconditioned dihedron of the camshafts -arrows-.





Position of dihedron of camshafts 4-6

15.1. Check the position of the intake and outlet side -arrows-.





Fitting position of staking tool for cylinder bank 4-6





16. Fit special tool staking tool 9772 -1- on the cylinder head and camshafts.
16.1. Tighten four screws (M6 x 25) -2- on the cylinder head hand-tight.





Staking tool screws for cylinder bank 4-6

17. Tighten adjusting screw -arrow- on the staking tool by turning it clockwise using a torque wrench -1-.
=> Tightening torque: 10 Nm (7.5 ftlb.)





Tightening adjusting screw on staking tool

18. Turn the crankshaft clockwise (running direction of engine) to the TDC marking at the vibration damper.
18.1. This position is marked TCD 1/4 on the surface.
18.2. Fix in place using a long locating pin 9595/1 -2-.





TDC marking on cylinder 1/4 at vibration damper

19. Tighten central screws on sprocket and camshaft controller to the prescribed initial tightening torque.
19.1. Tighten central screw on sprocket -1- initially, countering with a holding wrench 9775.
=> Initial tightening: 30 Nm (22 ftlb.)
19.2. Tighten central screw on camshaft controller -2- initially, countering with a long open-ended wrench (a/f 32) at the driver -3-.
=> Initial tightening: 35 Nm (26 ftlb.)





Central screws on camshaft timing gears

Information

Before final tightening (torque angle) of the central screws, the special tool staking tool 9772 must be removed.

20. Staking tool 9772 must now be removed.
20.1. Loosen the adjusting screw. A creaking noise is normal due to the tension in the tool.
20.2. Unscrew fastening screws on the cylinder head and remove the tool.
21. Tighten central screws on the sprocket and camshaft controller to the prescribed final torque using a torque angle wrench.
21.1. Tighten central screw on sprocket, countering with a holding wrench 9775 -1-.





Outlet sprocket threaded joint

=> Torque angle: 60°
21.2. Tighten central screw on camshaft controller, countering with a long open-ended wrench (a/f 32) -1-.





Camshaft controller threaded joint

=> Torque angle: 120°

Installing camshafts, setting timing - cylinder bank 1-3

NOTICE

Dirt and contamination

- Risk of damage to units or components

-> Protect components from dirt and contamination.
-> Clean or replace dirty components.

Information

Specifications for wrench sizes (a/f specifications) for screw heads are described as follows:

- Torx screws: (E.) for external Torx, (T.) for internal Torx.

- Hexagon-head bolts (internal and external hexagon): Wrench size (a/f)

1. Continue to turn the crankshaft clockwise (running direction of engine) to 60° before TDC at the vibration damper.
1.1. This position is marked U 3/6 on the surface.
1.2. Fix in place using a long locating pin 9595/1 -1-.





Position U 3/6 (60° before TDC)

2. Turn the engine on the assembly support until cylinder bank 1-3 is at the top.
3. Fit lower part of bearing saddle -1-.
3.1. Check position of oil bores and position and fit the component on the dowel sleeves.





Lower part of bearing saddle 1-3

4. Oil the bearing surfaces of the camshafts with new engine oil.
4.1. When rebuilding the engine, apply a light coating of Optimol Optipit grease (Part No. 000.043.204.17) on the bearings.
4.2. Check that all hydraulic tappets are installed correctly.
5. Lightly coat the sealing surface of the central screws for the sprocket and camshaft controller with new engine oil.
6. Fit the outlet camshaft and sprocket.





Outlet camshaft and sprocket (view of cylinder bank 1-3)

6.1. Check that the (new) friction plate is fitted in the sprocket.





Friction plate in sprocket

6.2. Screw in the central screw but make sure that the sprocket can still turn slightly.
6.3. Lift the timing chain and position the camshaft and sprocket at the overlapping position of cylinder 1. The cams must be facing outwards -arrows- at an angle with respect to the cylinder head wall and the camshaft must lie loosely in the bearings.





Cam position on cylinder 1 at overlap

6.4. Another feature is the data matrix code marking on the reconditioned surface next to the dihedron -inset-. These markings must be facing the observer at overlapping position.





Marking on camshafts 1-3 at overlap

Information

The outlet sprocket must be positioned correctly in order to build up the pressure of the high-pressure pump correctly when starting the engine.

7. 3.4-litre DFI engine only: After fitting the outlet camshaft, the sprocket must be aligned as follows with the driver for the high-pressure pump.
7.1. Cylinder head is vertical: The sprocket -1- must be positioned towards the top left using the deeper recess on the driver (15 mm) -2- at approx. 15 degrees with respect to the sealing face of the cylinder head.





Driver for high-pressure pump pre-positioned

8. Fit the intake camshaft.
8.1. Check that the (new) friction plate is fitted on the shaft.





Position of friction plate on intake camshaft

8.2. Lift the timing chain and engage and secure the camshaft controller. Guide the intake camshaft into the controller and set it to the overlapping position of cylinder 4. The cams must be facing downwards at an angle with respect to the spark-plug recess and the camshaft must lie loosely in the bearings.





Intake camshaft with camshaft controller

8.3. The square marking (data matrix code) on the camshaft must be facing the observer at the overlap.
8.4. Screw in the internal Torx central screw (T55, M12 x 1.5 x 110) by hand until the controller can still turn.
9. Check cam position of cylinder 1 before fitting the bearing saddle and bearing covers. The cams must be facing the outer cylinder head wall and must point downwards at an angle.
9.1. Check the position of the outlet sprocket again (position of driver for high-pressure pump).

CAUTION

Timing chains positioned incorrectly

- Too much wear on sprockets and timing chains
- Engine damage

-> Perform a visual inspection to check the position of the timing chains on the tensioning and guide rails.

10. Use a torch to check that the timing chains are on the tensioning and guide rails between the guide pins -arrow-.





Guide pins on tensioning and guide rails

11. Oil the bearing surfaces of the camshafts with new engine oil.
11.1. When rebuilding the engine, apply a light coating of Optimol Optipit grease (Part No. 000.043.204.17) on the bearings.
12. Fit bearing saddle and bearing covers (observe matching numbers).
12.1. Position bearing saddle and bearing covers.
12.2. Fit four external Torx screws (E10, M6 x 55) on the bearing saddle.
12.3. Fit two external Torx screws (E10, M6 x 37) on each of the bearing covers.
12.4. Fit and tighten screws according to the specified tightening sequence -1 to 16-.
=> Initial tightening torque for bearing covers and bearing saddle: 5 Nm (3.5 ftlb.)
=> Final tightening torque angle for bearing covers and bearing saddle: 50 °





Tightening sequence for mounting camshafts 1-3

13. Check axial bearing clearance by pulling and pressing on the camshaft controller and sprocket.
13.1. There must be perceptible clearance because otherwise the shafts will have to be fitted again.
14. Screw in and tighten chain tensioner with a new seal.
=> Tightening torque for chain tensioner: 80 Nm (59 ftlb.)

Set the timing, cylinder bank 1-3: Essentially, the timing for cylinder bank 1-3 is set in the same way as for cylinder bank 4-6.
15. Check cam position for cylinder 1 -arrows- and data matrix code position -inset- again.





Cam position for cylinder 1 at overlap





Marking on camshafts 1-3 at overlap

16. The adjusting device is positioned on the reconditioned dihedron of the camshafts -arrows-.





Position of dihedron of camshafts 1-3

16.1. Check the position of the intake and outlet side.





Fitting position of staking tool for cylinder bank 1-3





17. Fit special tool staking tool 9772 -1- on the cylinder head and camshafts.
17.1. Tighten four screws (M6 x 25) -2- on the cylinder head hand-tight.





Staking tool screws for cylinder bank 1-3

18. Tighten adjusting screw -arrow- on the staking tool by turning it clockwise using a torque wrench -1-.
=> Tightening torque for adjusting screw: 10 Nm (7.5 ftlb.)





Adjusting screw on staking tool

19. Turn the crankshaft clockwise (running direction of engine) to the TDC marking at the vibration damper.
19.1. This position is marked TCD 1/4 -inset- on the vibration damper.
19.2. Fix in place using a long locating pin 9595/1 -2-.





TDC marking on cylinder 1/4 at vibration damper

20. 3.4-litre DFI engine only:Check position of the outlet sprocket -1-.
20.1. The driver must be positioned towards the top left with the deeper recess on the driver (15 mm) -2- at approx. 45 degrees with respect to the sealing face of the cylinder head.
20.2. If this is not the case, the outlet camshaft must be re-aligned once again with the sprocket.





Positioning driver for high-pressure pump

21. Tighten central screws on sprocket and camshaft controller to the prescribed initial tightening torque.
21.1. Tighten central screw on sprocket -1- initially, countering with a holding wrench 9775.
=> Initial tightening torque for central screw on outlet sprocket: 30 Nm (22 ftlb.)
21.2. Tighten central screw on camshaft controller -2- initially, countering with a long open-ended wrench (a/f 32) at the driver -3-.
=> Initial tightening torque for central screw on camshaft controller: 35 Nm (26 ftlb.)





Central screws on camshaft timing gears

Information

Before final tightening (torque angle) of the central screws, the special tool staking tool 9772 must be removed.

22. Remove special tool staking tool 9772.
22.1. Loosen the adjusting screw. A creaking noise is normal due to the tension in the tool.
22.2. Unscrew fastening screws on the cylinder head and remove the tool.
23. Tighten central screws on the sprocket and camshaft controller to the prescribed final torque using a torque angle wrench.
23.1. Tighten central screw on sprocket, countering with a holding wrench 9775 -1-.
=> Final torque angle for central screw on outlet sprocket: 60 °





Outlet sprocket threaded joint

23.2. Tighten central screw on camshaft controller, countering with a long open-ended wrench (a/f 32) -1-.
=> Final torque angle for central screw on camshaft controller: 120 °





Camshaft controller threaded joint

24. Then check the position of the camshafts on both sides again (pay attention to overlapping position).
24.1. It must be possible to screw in the adjusting screw by hand at the staking tool 9772.
24.2. Remove the tool and complete the engine.

Subsequent work

1. Install cylinder head cover.
-> 158219 Removing and installing cylinder head cover Service and Repair.
2. Fit cover for positive crankcase ventilation.
2.1. Fit cover for cylinder bank 1-3 -1- with a new O-ring and moulded seal and secure with three external Torx screws (E10, M6 x 25) -4-.





Cover on positive crankcase ventilation 1-3

2.2. Fit cover for cylinder bank 4-6 -1- with a new O-ring and secure with two external Torx screws (E10, M6 x 25) -3-.





Cover on positive crankcase ventilation 4-6

=> Tightening torque: 13 Nm (9.5 ftlb.)
3. 3.4-litre DFI engine only: Install high-pressure pump.
-> 246319 Removing and installing high-pressure pump Service and Repair.
=> Tightening torque: 13 Nm (9.5 ftlb.)
4. 2.9-litre SRE engine only: Fit a new plastic cap (brown) on cylinder head 1-3.
4.1. Dry the cap and tap in using a plastic mallet.
5. Install vacuum pump.
-> 477619 Removing and installing vacuum pump Service and Repair.
=> Tightening torque: 13 Nm (9.5 ftlb.)
6. Fit spark plugs.
-> 287020 Removing and installing spark plugs Service and Repair.
7. Fit bar ignition modules.
7.1. Fit and tighten one internal Torx (T30) countersunk screw (M6 x 16) on each.
=> Tightening torque: 10 Nm (7.5 ftlb.)
7.2. Attach cable plugs for bar ignition modules, hall sender and solenoid hydraulic valve (for valve lift adjustment) and screw on two ground cables for each.
=> Tightening torque: 10 Nm (7.5 ftlb.)
8. Fit heat shield.
8.1. Fit and tighten four external Torx screws (E10, M6 x 12) -1-.
=> Tightening torque: 10 Nm (7.5 ftlb.)





Screws on heat shield

9. Install the engine.
-> 100119 Removing and installing engine 100119 Removing and installing engine.