Before starting work, pay attention to the following recommendations:
When replacing the rocker arms, it is advisable to also replace the camshaft.
Mark all rocker arms before disassembling.
When replacing, you can only install rocker arms designed for engines of this series.
Before disassembling the cylinder head, do the following:
- Unscrew the temperature and other sensors.
- Remove the valve rocker arms by turning the camshaft so that the nose of the corresponding cam is positioned vertically upward.
Fig. 20. Section of the cylinder head. The valve clearance is measured between the camshaft cam and the rocker arm.
1 - threaded support,
2 - adjusting bolt,
3 - pusher.
Using a puller, press the corresponding valves with springs down and pull them out from the side of the rocker arm (see fig. 21).
Fig. 21. Removing the levers using a valve puller.
Remove the spark plugs.
Unscrew all other parts from the cylinder head. A valve puller is required to remove the valves. When using it, the valves are removed before removing the camshaft, as shown in Fig. 22. The valve crackers are removed with pliers.
If there is no valve puller, position the cylinder head so that there is a stop under each valve to prevent the valve from moving. Then place a section of pipe of a smaller diameter than the outside diameter of the valve plate on the valve plate and use a hammer to hit the pipe to release the crackers from the groove on the valve stem; the crackers will be in the pipe. Remove the pipe and collect the crackers.
Fig. 22. Removing valve springs using a valve puller.
Remove the spring plate and valve springs. Mark the inner and outer springs. Do not use springs with different color markings.
Using a puller or pliers, remove the oil deflector caps.
Remove the valves from the guide bushings and place cardboard tags with the serial number on the valves. Fig. 23 shows the valve mechanism parts.
Fig. 23. Valve mechanism.
1 - pusher,
2 - crackers,
3 - spring plate,
4 - outer spring,
5 - internal spring,
6 - valve rotation mechanism,
7 - oil deflector cap,
8 - mounting ring,
9 - inlet valve guide bushing,
10 - exhaust valve guide bushing,
11 - inlet valve,
12 - exhaust valve,
13 - rocker arm.
Unscrew all camshaft bearing supports and remove the shaft.
Material created based on the website [MERCEDESMAN.ru]
The camshafts have five bearing journals. Oil for lubricating the bearings and camshaft cams comes through a channel with a diameter of 10 mm from the rear bearing support.