Camshaft Oil Seal: Service and Repair

Fig. 10 Checking auto lash adjuster:

Oil leak or seepage at rear cam plugs may be caused by defective or missing cam plug. This condition may be found on engines built prior to date codes of 7-5-93. Inspect at rear right-hand side of engine on each cylinder head for evidence of oil leaks or seepage. If found, replace plugs, using a light coat of RTV sealer or equivalent.

Before removing rocker arms and camshafts, check auto adjusters for freeplay. Insert a piece of wire through bleed hole in rocker arm and carefully push adjuster check ball down, while pushing down on check ball, move rocker arm up and down to check for freeplay. If there is no play replace adjuster.

Fig. 3 Intake manifold tightening sequence:

1. Remove intake manifold.
2. Remove valve covers.

Fig. 11 Installing auto lash adjuster retainers:

3. Install auto lash adjuster retainers M0998443 or equivalent, as shown.
4. Remove distributor housing attaching bolts, then distributor housing and O-ring.
5. When removing camshaft bearing caps do not remove bolts from bearing caps. Remove rocker arm, rocker shafts and bearing cap as an assembly.
6. Remove camshafts, oil seals and end seals.
7. Lubricate camshaft journals and cams with engine oil, then install camshafts on cylinder head.

Fig. 12 Camshaft bearing caps installation:

8. Align camshaft bearing caps with arrows (depending on cylinder bank) as shown.

Fig. 13 Identifying bearing caps:

9. Identify number 1 bearing cap as shown, then install rocker shafts into bearing cap 1 with end notches positioned as shown and machined portion of rocker shaft is facing down.
10. Install rocker arms, bearing caps and springs onto rocker arm shafts.
11. Temporarily install number 4 bearing cap bolts to retain assembly.
12. Apply a suitable sealant at bearing cap ends as shown.
13. Install rocker arm shaft assembly. Ensure arrow on bearing cap and arrow mark on cylinder head are pointing in same direction.
14. Torque bearing caps as follows:
a. Numbers 3, 2, 1, then 4 to 85 inch lbs.
b. In same sequence mentioned above, torque bearing cap bolts to 180 inch lbs.
15. Install distributor housing and tighten bolts to specifications.

Camshaft Oil Seal:

16. Lubricate camshaft oil seals lip with engine oil, then using camshaft oil seal installer tool No. MD998713 or equivalent, install camshaft oil seals.

Camshaft End Seal:

17. Using oil seal installer tool No. MB998306 or equivalent, install end seals.