It should be noted that simultaneously with the replacement of the camshaft, it is necessary to replace the valve rocker arms. If the inspection reveals an increased clearance in the camshaft bearings, it is possible to grind the journals of the shaft to a repair size. In this case, two repair sizes of the journals of the shaft are provided.
Before disassembling the cylinder head, do the following:
Remove temperature and other sensors from the cylinder head.
Loosen the fastener and remove the intake and exhaust manifolds.
Remove the valve rocker arms as described below.
Remove the spark plugs.
Unscrew the remaining parts from the cylinder head.
Remove the camshaft housing by unscrewing the mounting bolts and removing the housing together with the camshafts.
Pull the camshafts back out of the housing. Removal and installation of the camshaft housing and camshafts can be done without removing the engine from the vehicle. This work is described in section 3.11.
To remove the valves, you need a puller similar to the puller for an eight-cylinder engine shown in Fig. 22. The valve crackers are removed using pliers.
If there is no valve puller, place the cylinder head on the workbench with the split surface facing down 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 assemble the crackers.
Remove the spring plate and valve springs.
Using a screwdriver or pliers, carefully remove the valve stem seals from the valve guides.
Remove the valves from the guides and place cardboard tags on them indicating the serial number.
Remove the key from the camshaft and remove the spacer ring.