Camshaft: Service and Repair
REMOVE1. Remove the camshaft covers.
Breather Cover:
2. Remove the nuts securing the breather housing to the front of the cylinder head and withdraw the housing.
Timing Notch Down:
3. Rotate crankshaft until the timing notches in the camshafts are facing the head.
4. Knock down the tabs and remove the upper two camshaft sprocket retaining bolts.
Camshaft Gear Bolts:
5. Slacken the adjuster locknut on the idler sprocket shaft.
Camshaft Timing Tool:
6. Rotate the engine until the valve timing tool can be fitted to the slot in the camshaft.
7. Remove the remaining camshaft bolts.
Fig. 5 Loosening idler sprocket locknut.:
8. Use service tool JD2B turned in a clockwise direction to slacken the camshaft chain.
CAUTION: Do not rotate the engine or camshafts with the camshafts disconnected.
9. Slide the sprocket up the support bracket.
10. Progressively slacken the camshaft bearing cap nuts, starting with the center cap and working outwards.
11. Lift off the bearing caps. The bearing caps must be refitted to their original location. Note the mating marks on each bearing cap and cylinder head.
NOTE: If the same bearing shells are being reused, note their location to ensure that they are fitted in the original position.
12. Lift the camshaft from the cylinder head.
REFIT
1. Fit the camshaft bearing shells.
2. Fit the camshaft in the bearings so that the keyway in the front flange is uppermost.
3. Fit the bearing caps to their respective positions and fit spring washers and nuts.
4. Tighten down the bearing caps evenly, commencing with the center cap.
5. Tighten the nuts to correct torque.
6. Align camshaft using timing tool C3993.
7. Fit the camshaft sprocket to the camshaft and ensure that the holes line up.
8. Fit two upper bolts.
NOTE: If all the preceding instructions have been followed, valve timing will be correct.
9. Rotate the engine and fit remaining bolts to the camshaft sprocket.
10. Turn up lock tabs.
11. Using tool JD2B, tension the top timing chain until slight flexibility remains in the chain on both outer sides of the camshaft sprockets. The chain MUST NOT be dead tight.
12. Check valve clearance. Adjust as needed.
13. Securely tighten the locknut.
14. Replace the camshaft covers and breather housing.