Place the cylinder head on stand 6025/1 (models «518», «520») or on stand 7003/1 (models «525», «526»).
Remove the fuel pump, take out a pusher.
Remove the central oil supply pipe to the rocker shafts.
Remove the camshaft by proceeding as follows:
- Set the rocker arms of the intake and exhaust valves to the position of maximum clearance between the adjusting eccentric of the rocker arm and the end of the valve stem. Otherwise, the valve stems may bend;
- install pressure frame 6025/1 (models «518», «520») or 6025/1 (model «520i») or 7001/1 (models «525», «528»);
- remove the camshaft mounting flange (models «518», «520») or locking bolts 4 and 5 (see photo) (models «525», «528»);
- Remove the camshaft from the cylinder head bearings.
Remove the pressure frame.
Slide the rocker arms with support washers along the axes of the rocker arms and remove the retaining rings.
On car models «518», «520» Remove the rocker shafts using drift 6012.
On car models «525», «528» unscrew the plugs of the holes of the rocker arm axles and remove the front axles with the help of an inertial puller 7004, having previously removed the fastening studs. After crushing the locking plate, remove the rear axles of the rocker arms.
Remove the rocker axles carefully. Remove the spring, support washer, rocker arms, set washer, etc. from each axle (see photo) and put them in order.
Install the pressure frame on the cylinder head, compress the valve springs and free the valves from crackers. Remove the springs with plates, remove the valves and put them in order. Remove the valve stem seals from the valve guides. If necessary, use a universal spring compressor to compress the valve springs.