Overhaul

NOTE: This procedure is with cylinder head removed and mounted in holder 83 95 055, or equivalent.





REMOVAL
1. Remove the big-end bearing caps by loosening the bolts in steps of-1/2 to 1 turn. It is important to finish removal of the bearing cap where the tappets are under load and lift out the camshaft. Note the markings.

NOTE: The cylindrical surfaces round the valve springs constitute sealing surfaces for the tappets. These surfaces must not be scratched. The camshafts must come evenly from the bearing seats.

2. Remove the tappets and place them in valve stand 83 93 787, so that they do not become mixed.
3. Install the protective sleeves 83 95 022, or equivalent.
4. Use the valve spring compressor 83 93 761 and anvil 83 93 779, or equivalents and remove the collets.
5. Lift out the spring cap and valve spring. Do not forget the washers.
6. Remove the valves and place them in valve stand 83 93 787, or equivalent so they do not become mixed.





INSTALLATION
1. Install the valves, the washers and the valve springs.

CAUTION: Make sure that the cylinder head is supported so that the valves are not bent when the camshafts are tightened down.

2. Install the spring caps and the collets using valve spring compressor 83 93 761 and anvil 83 93 779, or equivalents.
3. Remove the protective sleeves and fit the valve tappets.
4. Thinly apply (10) 74 96 268, or equivalent to the front bearing cap contact surfaces against the cylinder head. Install the camshafts and the bearing caps, starting where the tappets are pointing downwards and compressing the depressors. The camshafts are marked as follows:
^ Intake: Blue or Orange paint and the letter "G".
^ Exhaust: Green paint and the letter "A"

Cylinders 1-3-5
The locating pins on the camshafts should point towards the internal bolts for the big-end bearing caps. Tighten cap bolts to 8 Nm (6 ft. lbs.).

Cylinders 2-4-6
The locating pin for the intake camshaft should be in line (downwards) with the internal bolt for the camshaft bearing cap, see illustration. The locating pin for the exhaust camshaft should be in line with the edge of the camshaft sensor (upwards), see illustration. Tighten cap bolts to 8 Nm (6 ft. lbs.).

NOTE: Tighten the bolts gradually-1/2 to 1 turn. The markings on the camshaft bearing caps and the cylinder head must match. The caps marked L1 - L8 are for the cylinder head for cylinders 1,3,5 and R1 - R8 are for cylinders 2,4,6. The camshaft bearing seats in each cylinder head are numbered 1 - 8.