11 31 028 Removing and installing/replacing exhaust camshaft (N54/N54T)
Special tools required:
It is absolutely essential to follow an exact procedure for removing and installing the exhaust camshaft.
Top and bottom bearing strips must be pre-tensioned with a total of six special tools 11 8 553 .
Necessary preliminary tasks
- Remove CYLINDER HEAD COVER .
- Remove EXHAUST ADJUSTING UNIT for exhaust camshaft.
- Adjust VALVE TIMING .
Release bearing cap screw connections from outside inwards.
Lift out lower and upper bearing strips (1) with camshaft.
Mixing up the two camshafts will result damage .
A Exhaust camshaft.
E Intake camshaft
Metal plain rectangular compression ring
Only replace plain rectangular compression rings (1) when they are broken.
The plain rectangular compression rings have catches at the joint.
Press the plain rectangular compression rings (1) apart forwards and towards the rear and remove towards the front.
Make sure plain rectangular compression rings (1) can move freely.
Installation note:
When exhaust camshafts are inserted, no joint must point to a separating joint.
Illustration shows N12 engine
Plastic plain rectangular compression ring
Installation note:
The plastic plain rectangular compression ring is maintenance free and does not have to be replaced.
Insert plastic rectangular compression ring (1) into groove of exhaust camshaft (2) (see arrow).
Lightly oil plastic rectangular compression ring (1) and rotate in direction of arrow until compression ring (1) is positioned on the exhaust camshaft.
Make sure plain rectangular compression ring (1) can move freely.
Engine at cylinder no. 1 firing TDC position.
Removed cylinder head:
When using special tool 11 9 000 , it will be necessary to remove the aluminium strip.
Installation note:
Before installation of exhaust camshaft, make sure roller cam follower is correctly fitted on hydraulic valve clearance compensating element and valve!
Installing camshaft bearing strip
Preassemble special tool 11 8 551 on 2nd cylinder.
Observe markings E and A
E: Intake side
A: Exhaust side
Insert special tool 11 8 552 in screw connection of cylinder head cover.
Press down roller cam follower (1) on 2nd cylinder with spindle nut of special tool 11 8 551 .
Lay lower bearing strip (1) on cylinder head.
Installation note:
Lubricate all bearing positions with engine oil.
Insert exhaust camshaft (1) in lower bearing strip.
Installation note:
Lubricate all bearing positions and cams with engine oil.
Installation position (1) of exhaust camshaft (2) at cylinder no. 1.
Join exhaust camshaft to lower and upper bearing strips with torque wrench from inside outwards to 8 Nm .
Release all screws of bearing strip (1) from outside inwards by 90°.
Check position of exhaust camshaft (2) at cylinder no. 6.
Roller cam follower (1) is not actuated.
Installation note:
Lower and upper bearing strips must be aligned to each other at ground surfaces (1 and 2).
Bring thrust piece and shanks of special tools 11 8 553 into contact at milled surfaces.
Position special tool 11 8 553 over screw connection of bearing strips.
Position screw of special tool 11 8 553 on ground surfaces of bottom bearing strip (2) and top bearing strip (1).
Pretension all special tools 11 8 553 only with special tool 11 4 350 .
Fit special tools 11 8 553 with screw (1) to the inside of the cylinder head.
On 2nd cylinder fit special tool 11 8 553 with screw (1) facing outwards.
Position special tools 11 4 350 so that screw connections (2) of bearing strip are easily accessible.
Tighten lower and upper bearing strips with special tool 00 9 120 .
Position special tool 11 8 553 over screw connection of bearing strips.
Tightening torque 11 31 1AZ .
Assemble engine.