Removing
1. Remove the cylinder head cover (see Section Removal and installation of a cover of a casing of a camshaft).
2. Using a bar wrench, remove the two cylinder head bolts used to secure the left and right rocker shaft bearings to the cylinder head.
3. In several steps (1/2 turn per approach) evenly loosen the rocker arm axle bolts, releasing the latter from the force exerted by the valve springs. Remove the bolts, noting the original location of the oil deflector, and remove the rocker shaft assembly from the cylinder head.
4. If necessary, remove the components from the axle after removing the retaining ring.
5. Stack the components to be removed in the order in which they are installed on the axle.
Status check
Check axle surfaces (rocker arms and bearings) for signs of wear, scratches and nicks. Worn axle and/or rocker arms must be replaced.
Installation
1. Proceeding in the reverse order to the dismantling order, put on the rocker shaft the components removed from it (in the right order). Fix the assembly with a retaining ring, making sure that the latter fits correctly in its groove. Make sure that the rocker arms rotate freely on the axle.
2. Lower the assembly to its regular place in the cylinder head. Follow the correct engagement of the adjusting screws of the rocker arms in the ends of the rods of the corresponding pushers.
3. Screw in the fixing bolts (do not forget to install the oil deflector plate on the right support) and in several steps evenly tighten them with the required force.
4. Install the two cylinder head bolts used to attach the rocker shaft bearings and tighten them in three steps.
5. Adjust valve clearances (see chapter Current service).
6. Replace the cylinder head cover (see Section Removal and installation of a cover of a casing of a camshaft).