Removing and Installing/Replacing Exhaust Camshaft
11 31 028 Removing and installing/replacing exhaust camshaft (N51)Special tools required:
Important!
It is absolutely essential to follow an exact procedure for removing and installing the exhaust camshaft.
Risk of damage!
The upper and lower bearing strips must be pre-tensioned with a total of six special tools 11 4 461.
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.
Remove upper bearing strip (1).
Remove exhaust camshaft from lower bearing strip.
Important!
Both camshafts have different identifications.
Mixing up the two camshafts will result in engine damage.
A Exhaust camshaft.
E Intake camshaft
Important!
Plain compression rings (1) can easily break.
Plain compression rings (1) are engaged at joint.
Press plain compression rings (1) apart upwards and downwards and removed towards front.
Important!
Removal on engine:
Set engine to ignition TDC at cylinder No. 1.
Removed cylinder head:
When using special tool 11 9 000, it will be necessary to remove the aluminium profile insert.
Installing camshaft bearing strip:
Pre-install special tool 11 4 462 on cylinder 2.
Insert special tool 11 4 463 in screw connection of cylinder head cover.
Important!
Special tool 11 4 463 is a special screw.
Press down roller rocker arms (3) on 2nd cylinder with spindle nut (2) of special tool 11 4 462.
Installation:
Before installing exhaust camshaft, make sure roller rocker arm is correctly seated HVCA element and valve.
Refer to Removing and installing roller rocker arms.
Position lower bearing strip (1) with exhaust camshaft (2) on roller rocker arms.
Align exhaust camshaft (2).
Cylinders 2 and 4 are at overlap.
Cams (3) on 1st cylinder point upwards at an angle.
Part number (4) on mounting flats points upwards.
Join exhaust camshaft to lower and upper bearing strips (1) with torque wrench (2) from inside outwards to 8 Nm.
Release all screws of bearing strip (1) from outside inwards by 90°.
Installation:
Lower and upper bearing strips must be aligned to each other at ground surfaces (1 and 2).
Bring thrust piece and legs of special tools 11 4 461 into contact at milled surfaces.
Note:
Schematic depiction of special tool 11 4 461 at lower bearing strip (1) and upper bearing strip (2).
Pre-tension all special tools 11 4 461 with special tool 11 4 350 only.
Important!
Tighten screw (3) on thrust piece to 2 Nm (risk of damage).
Position special tool 11 4 461 over screw connection of bearing strips.
Make sure that legs come into exact contact on ground surfaces, lower bearing strip (1) and upper bearing strip (2).
Initially tighten screw of special tool 11 4 461 to ground surfaces of lower bearing strip (1) and upper bearing strip (2).
Important!
Tighten screws on thrust piece to 2 Nm (risk of damage).
Important!
Set special tool 11 4 350 to 2 Nm.
Pre-tension all special tools 11 4 461 with special tool 11 4 350 only.
Mount special tools 11 4 461 with screw (1) to inside of cylinder head.
On cylinder no. 2 mount special tool 11 4 461 with screw (1) facing outwards.
Position special tools 11 4 461 so that screw connections (2) of bearing strip are easily accessible.
Tighten lower and upper bearing strips with special tool 00 9 120.
Tightening torque: 11 31 1AZ.
Important!
Remove special tool 11 4 461 only when camshaft screw connection is completed.
Assemble engine.
