Overhaul
DISASSEMBLY1. Remove the camshaft bearing caps and lift out the camshafts.
2. Remove the cam followers, placing them in order in stand 83 93 787, or equivalent to ensure that they are refitted in their original positions.
3. Remove the valves, placing them in order in stand 83 93 787, or equivalent to ensure that they are refitted in their original positions.
CAUTION: The tappet guides around the valve springs constitute the sealing surfaces for the cam followers and must therefore not be scratched or scored. Install protective sleeves 83 93 746, or equivalent in the guides to protect them. For removal of the valves, use valve spring compressor 83 93 761, or equivalent with anvil 83 93 779, or equivalent.
4. Remove the protective sleeves by applying a suitable lever underneath the lip on the sleeve.
NOTE: Prior to assembly, lubricate all the parts and replace any defective valve-stem seals.
ASSEMBLY
1. Install the valves and springs, with the protective sleeves in place in the tappet guides.
2. Check the valve clearance.
3. Install the cam followers.
CAUTION: Support the cylinder head on blocks to prevent damage to the valves when the camshafts are tightened down.
4. Install the camshafts and bearing caps. The bearing caps marked 1 - 5 go on the inlet side, and those marked 6 - 10 on the exhaust side. Tighten the bolts to 15 Nm (11 ft. lbs.).
5. Line up the marks on the camshafts with their respective timing marks.