Camshaft, Lifters and Push Rods: Service and Repair
Valvetrain Assembly Overview
CAUTION!
Risk of damaging valves and piston heads after working on valvetrain.
• The motor must not be started for about 30 minutes after installing camshafts because the hydraulic equalization elements must seat themselves.
• To ensure valves do not strike pistons when starting, carefully rotate engine at least 2 full revolutions.
• Cylinder heads with cracks between the valve seats, or between the valve seat and the spark plug threads, can continue to be used without reducing the service life, as long as the cracks have a width of max. 0.3 mm, or only the first 4 threads of the spark plug threads are cracked.
• The illustration shows the cylinder bank 2 cylinder head (left).
1 Sealing Plug
• Install with sealant; sealant
2 Cylinder Head
• Check valve guides, refer to => [ Valve Guides, Checking ] Testing and Inspection
3 Valve Stem Seal
• Replacing with the cylinder head installed, refer to => [ Valve Stem Seals with Cylinder Head Installed, Replacing ] Valve Stem Seals with Cylinder Head Installed, Replacing
• Replacing with the cylinder head removed, refer to => [ Valve Stem Seals with Cylinder Hear Removed, Replacing ] Valve Stem Seals with Cylinder Hear Removed, Replacing
4 Valve Spring
5 Hydraulic Adjusting Elements
• Checking, refer to => [ Hydraulic Adjusting Elements, Checking ] Testing and Inspection
• Mark the installation position with paint for reinstallation
• Lubricate the running surfaces before installing
6 Valve Spring Plate
7 Valve Retainers
8 Roller Rocker Lever
• Different versions for the intake and exhaust side, do not interchange them
• Check roller for easy movement
• Lubricate the running surfaces before installing
• Clip to the hydraulic adjusting element - 5 - with the clip - 9 -
9 Securing Clip
• Different versions for the intake and exhaust side, do not interchange them
• Check for secure seat
10 Intake Camshaft
• With 3 camshaft sliders
• Do not disassemble
• Measuring axial play, refer to => [ Camshaft, Measuring Axial Play ] Camshaft, Measuring Axial Play
• Removing and installing, refer to => [ Camshafts ] Service and Repair
• Radial clearance, measuring, refer to => [ Camshaft, Measuring Radial Play ] Camshaft, Measuring Radial Play
• Run-out: max. 0.04 mm
11 Bolt
• Replace
12 Camshaft Adjuster Actuator
13 Bolt
• 5 Nm
14 O-ring
• Replace
15 Bearing Bracket
• With integrated camshaft bearings
• Removing and installing, refer to => [ Camshafts ] Service and Repair
16 Compression Ring
17 Compression Ring
18 Exhaust Camshaft
• Measuring axial play, refer to => [ Camshaft, Measuring Axial Play ] Camshaft, Measuring Axial Play
• Removing and installing, refer to => [ Camshafts ] Service and Repair
• Radial clearance, measuring, refer to => [ Camshaft, Measuring Radial Play ] Camshaft, Measuring Radial Play
• Run-out: max. 0.04 mm
19 Oil Strainer
20 Intake Valve
• Do not reface, only lapping is permitted
• Mark installed position for re-installation
• Valve dimensions, refer to => [ Valve Dimensions ] Specifications
• Check valve guides, refer to => [ Valve Guides, Checking ] Testing and Inspection
21 Exhaust Valve
• Do not reface, only lapping is permitted
• Mark installed position for re-installation
• Valve dimensions, refer to => [ Valve Dimensions ] Specifications
• Check valve guides, refer to => [ Valve Guides, Checking ] Testing and Inspection
Camshaft Guide Frame Tightening Specifications and Sequence
• The illustration shows the guide frame for the left cylinder head.
- Tighten the bolts in 3 stages in the sequence - 1 to 21 -:
- Install bolts by hand as far as the stop.
• The guide frame must be in contact with the entire contact surface of the cylinder head.
- Tighten to 8 Nm.
- Tighten an additional 90°.
Installed Position of Valve Spring
• The tight spring coils - arrow - face toward the cylinder head.