Valve: Service and Repair

Removal Of The Valve Gear

This method presupposes that the cylinder head has been removed.

IMPORTANT: The cylindrical surfaces surrounding the valve springs are sliding surfaces for the tappets. These surfaces must not be scored. Therefore, protect the tappet guides with protective collars 83 93 746.





1. Remove the camshaft bearing caps. It is important to finish with the bearing cap on the tappets that are under load. Lift out the camshafts.
2. Remove the tappets and keep them in the Valve stand 83 93 787.





3. Fit protective collars 83 93 746
4. Use Valve spring compressor 83 93 761 and Valve spring depressor 83 93 779 to remove the valve cones.





5. Lift out the valve discs and valve springs. Lift out the washer with guide seals with the 83 94 157 pliers for removing valve guide seats
6. Remove the valves. Keep them in Valve stand 83 93 787.

Fitting The Valve Gear

IMPORTANT: Defective valve stem seals must be replaced. The sealing surfaces and bearings must be lubricated with oil before the valves are fitted. Make sure that the cylinder head rests on blocks to prevent damage to the valves (bent valve stems) when the camshafts are turned.





1. Fit the washer with valve stem seal using Pliers for removing valve guide seal 83 94 157.
2. Fit the valves and springs.





3. Use valve spring compressor 83 93 761 and valve spring depressor 83 93 779 and refit the valve cones.
4. Place valve clearance gauge 83 93 753 across two of the camshaft bearing seats with the depth gauge against the end of the valve stem.
5. Check that the maximum depth of 20.5 mm reaches down to the end of the valve stem (valve clearance gauge does not bottom in the bearing seat closest to the depth gauge), refer to Checking Valve Clearances.
6. Then check that the minimum gauge depth of 19.5 mm does not reach down to the end of the valve stem. The correct valve clearance is between the minimum and maximum gauge depths. If the clearance is less than the minimum, the valve stem must be shortened, and if it is greater than the maximum the valve seat must be reground.





7. Remove the protective sleeves and fit the valve tappets.
8. Fit the camshafts and bearing caps, starting where the cams point downwards and press on the tappets. Bearing caps marked 1-5 for the inlet side, 6-10 for the exhaust side.
Tightening torque 15 Nm (11 ft. lbs.).

IMPORTANT: The black bolts have an oilway and should be fitted on the spark plug side.

9. Line up the marks on the camshafts with their timing marks.