Camshaft Gear/Sprocket: Service and Repair

1. On models equipped with airbags, disarm airbag system as outlined under Technician Safety Information.
2. On models less airbags, disconnect battery ground cable.
3. Drain oil and coolant from engine.
4. Disconnect throttle cable from throttle body, if equipped.
5. Disconnect accelerator cable from throttle body.
6. Remove front exhaust pipe.
7. Remove alternator.
8. Remove V-bank cover.
9. Remove ISC or IAC valve.
10. Remove throttle body and EGR pipe.
11. Remove EGR valve and vacuum modulator.
12. Remove vacuum pipe.
13. Remove distributor.
14. Remove emission control valve set, then disconnect lefthand wire harness electrical connectors.
15. Remove cylinder head rear plate, then water outlet.
16. Disconnect brake booster vacuum hose, power steering air hose, PCV hose, and EGR water bypass hose.
17. Disconnect cold start injector connector.
18. Remove air intake chamber.
19. Remove fuel delivery pipes and injectors.
20. Remove No. 1 cooler, then disconnect and remove righthand engine wire harness.
21. Remove water bypass outlet.
22. Remove intake manifold.
23. Remove righthand rear exhaust manifold.
24. Remove lefthand exhaust manifold.
25. Remove oil dipstick assembly and spark plugs.
26. Remove timing belt, camshaft timing pulleys (sprockets) and No. 2 idler pulley (sprocket). Refer to Timing Belt.
27. Remove No. 3 timing belt cover.
28. Remove cylinder head covers.
29. Remove camshafts, as follows: Since the thrust clearance of the camshafts is small, the camshaft must be held level while it is being removed.
a. Remove exhaust camshaft from righthand cylinder head. Align the timing marks (two pointed marks) on the camshaft drive and driven gears by turning the camshaft with a wrench.
b. Secure the exhaust camshaft sub-gear to the driven using an attaching bolt.

Fig. 1 RH Cylinder Head Exhaust Camshaft Bearing Cap Bolt Loosening Sequence:

c. Uniformly loosen and remove the eight bearing cap bolts in several passes, in sequence shown Fig. 1. Remove the four bearing caps and exhaust camshaft assembly.

Fig. 2 RH Cylinder Head Intake Camshaft Bearing Cap Bolt Loosening Sequence:

d. Remove the intake camshaft from the righthand cylinder head. Uniformly loosen then remove the ten bearing cap bolts in several passes, in sequence shown in Fig. 2. Remove the five bearing caps, oil seal and intake camshaft.
e. Remove exhaust camshaft from lefthand cylinder head. Align the timing marks (one pointed mark) on the camshaft drive and driven gears by turning the camshaft.
f. Secure the exhaust camshaft sub-gear to the driven gear using an attaching bolt.

Fig. 3 LH Cylinder Head Exhaust Camshaft Bearing Cap Bolt Loosening Sequence:

g. Uniformly loosen and remove the eight bearing cap attaching bolts in several passes, in sequence shown in Fig. 3. Remove the four bearing caps and exhaust camshaft.

Fig. 4 LH Cylinder Head Intake Camshaft Bearing Cap Bolt Loosening Sequence:

h. Remove the intake camshaft from the lefthand cylinder head by uniformly loosening the ten bearing cap attaching bolts in several passes, in sequence shown in Fig. 4. Remove the five bearing caps, oil seal and intake camshaft assembly. Arrange the bearing caps in correct order.
30. Remove power steering pump bracket.
31. Remove lefthand engine hanger.
32. Remove cylinder head assemblies as follows:
a. Using a suitable tool, remove the two 8 mm recessed cylinder head bolts.

Fig. 5 Cylinder Head Bolt Loosening Sequence:

b. Uniformly loosen and remove the cylinder head attaching bolts in several passes, in sequence shown in Fig. 5.
c. Lift the cylinder head(s) from the dowels on the cylinder block and place the cylinder head on a suitable workbench. If the cylinder head is difficult to remove, use a suitable screwdriver to pry off. Do not damage cylinder head to engine block mating surface.
33. Reverse procedure to install cylinder head assemblies, noting the following:

Fig. 6 Cylinder Head Gasket Identification:

a. Place cylinder head(s) onto block. Place a new cylinder head gasket in position on block as shown in Fig. 6.

Fig. 7 Cylinder Head Bolt Tightening Sequence:

b. Install the 12 sided cylinder head attaching bolts. Apply a light coat of clean engine oil onto bolt threads and under the bolt heads. Torque bolts in sequence shown in Fig. 7, in several passes to 25 ft. lb. Put a dab of paint or scribe a mark on front of bolt head. Tighten bolts in correct sequence an additional 90°. Tighten bolts another 90° in sequence. If any of the bolts break or deform, Service and Repair bolts. If any of the attaching bolts does not meet specification, Service and Repair the bolt.
c. Install the two recessed head bolts and torque to 13 ft. lb.
34. During installation of camshaft assemblies, proceed as follows:

Fig. 15 Intake Cam Installation:

a. Install the intake camshaft onto the righthand cylinder head. Apply suitable grease to the thrust portion of the camshaft. Place the intake camshaft at approximately a 90° angle of the timing mark (the two pointed marks on the cylinder head), Fig. 8. Apply seal packing (part No. 08826-00080 or equivalent) to the No. 1 bearing cap.

Fig. 9 Bearing Caps To RH Cylinder Head Intake Camshaft Installation:

Fig. 10 RH Cylinder Head Intake Camshaft Bearing Cap Bolt Tightening Sequence:

b. Install the five bearing caps in their proper locations as shown in Fig. 9. Apply a light coat of clean engine oil onto the bolt threads and under the bolt heads. Install and uniformly tighten the ten bearing cap bolts in several passes, in sequence shown in Fig. 10. Torque bolts to 12 ft. lb.

Fig. 11 Camshaft Drive & Driven Gears Timing Mark Alignment:

Fig. 12 Bearing Caps To RH Cylinder Head Exhaust Camshaft Installation:

Fig. 13 RH Cylinder Head Exhaust Camshaft Bearing Cap Bolt Tightening Sequence:

c. Install the exhaust camshaft onto the righthand cylinder head. Apply suitable grease to the thrust portion of the camshaft. Align the timing marks (two pointed marks) of the camshaft drive and driven gears as shown in Fig. 11. Place the intake camshaft onto the cylinder head. Install the four bearing caps in their proper locations as shown in Fig. 12. Apply a light coat of clean engine oil onto the bolt threads and under the bolt heads. Install and uniformly tighten the eight bearing cap bolts in several passes, in sequence shown in Fig. 13. Torque bolts to 12 ft. lb. and remove service bolt (B).

Fig. 14 Placing LH Cylinder Head Intake Camshaft At 90 Degrees Of Timing Mark:

Fig. 15 LH Cylinder Head Intake Camshaft Bearing Cap Locations:

Fig. 16 LH Cylinder Head Intake Camshaft Bearing Cap Bolt Tightening Sequence:

d. Install intake camshaft onto lefthand cylinder head. Apply suitable grease onto the thrust portion of the camshaft. Place the intake camshaft at a 90° angle of the timing mark (one pointed mark) on the cylinder head as shown in Fig. 14. Apply seal packing (No. 08826-00080 or equivalent) to the No. 1 bearing cap. Install the five bearing caps in their proper locations as shown in Fig. 15. Apply a light coat of clean engine oil on the bolt threads and under the bolt heads. Install and uniformly tighten the ten bearing cap bolts in several passes, in sequence shown in Fig. 16. Torque bolts to 12 ft. lb.

Fig. 17 Camshaft Drive & Driven Gear Timing Mark Alignment:

Fig. 18 LH Cylinder Head Exhaust Camshaft Bearing Cap Locations:

Fig. 19 LH Cylinder Head Exhaust Camshaft Bearing Cap Bolt Tightening Sequence:

e. Install the exhaust camshaft onto the lefthand cylinder head. Apply suitable grease to the thrust portion of the camshaft. Align the timing marks (one pointed mark) of the camshaft drive and driven gears as shown in Fig. 17. Place the intake camshaft onto the cylinder head. Install the four bearing caps in their proper locations as shown in Fig. 18. Apply a light coat of clean engine oil to the bolt threads and under the bolt heads. Install and uniformly tighten the eight bearing cap bolts in several passes, in sequence shown in Fig. 19. Torque bolts to 12 ft. lb. and remove service bolt (B).

35. Rearm airbag system as outlined under Technician Safety Information.