Camshaft: Service and Repair

CAMSHAFT

REMOVE OR DISCONNECT
1. Cam cover.
2. Secure cam sprocket to timing chain by installing tie-wraps through cam sprocket holes. Use four tie-wraps per sprocket.

IMPORTANT: Sprocket/chain relationship must be maintained throughout this procedure or camshaft timing will be lost and require further engine disassembly to retime.

Fig. 14 Drive Chain Tension:

3. Working behind the sprockets, install cam chain holder J 38815 so that it is positioned between chain tensioner and chain guide. Apply tension to tool by tightening tension adjusting screw.
4. Both cam sprocket bolts.

IMPORTANT: Note the relative location of the cam drive pins at the end of camshafts.

5. Work sprockets off cams using play in chain.
6. Alternately loosen cam bearing cap screws a few turns at a time until all valve spring pressure has been released. Remove bolts and caps.
7. Remove camshaft.

Measuring Camshaft Lobe:

INSPECT
^ Whenever removing a camshaft from an engine with a suspect faulty camshaft operation, the camshaft lobes should be visually checked and measured as shown.
^ Excessive wear, scoring or flaking of the lifter will usually denote camshaft lobe wear.
^ Excessive camshaft lobe wear is evidenced by grooves, scoring or flaking.
^ Bearing journals should not be scored or burned.
^ Camshafts should be replaced if any of these conditions exist.

INSTALL OR CONNECT
1. Apply camshaft prelube, part number 1052365, to the face of each cam lobe.
2. Camshaft.
3. Position cam bearing caps to cylinder head.

Cam Bearing Cap Location:

IMPORTANT:
^ Each cap is identified for position and direction.
^ Arrow points towards front of engine.
^ E indicates a cap for the exhaust cam.
^ I indicates a cap for the intake cam.
^ Position 1 is toward the front of the engine.

4. Loosely install cam bearing cap bolts.
5. Alternately tighten each bearing cap bolt a few turns at a time against valve spring pressure until all bolts are snug. Tighten bolts to 12 Nm (106 lbs. in.).

Rotating Camshaft:

6. Using hex cast into camshaft rotate cams until drive pins are in position to engage cam sprockets over cams and install retaining bolts.
7. Work cam sprockets over cams and install retaining bolts. Tighten sprocket bolts to 120 Nm (90 lbs. ft.).
8. Remove chain holder J 38815.
9. Remove tie-wraps from cam sprockets.
10. Cam cover.