Rocker Shafts

Rocker Shafts

Rocker shafts - remove







1. LH rocker shaft only: Remove screw securing dipstick tube to rocker cover.







2. Remove 4 Allen screws securing rocker cover to cylinder head.

NOTE: Note fitted position of 2 long screws. Later engines - multi-hex bolts are used.

3. Remove rocker cover.
4. Remove and discard gasket from rocker cover.
5. Mark each rocker shaft in relation to original cylinder head.

CAUTION: Incorrect fitment of rocker shafts will lead to an oil feed restriction.







6. Progressively slacken and remove 4 bolts securing rocker shaft assembly to cylinder head.
7. Remove rocker shaft assembly.
8. Remove pushrods and store in fitted order.
9. Repeat above procedures for remaining rocker shaft.

Rocker shafts - dismantling







1. Remove and discard split pin from one end of rocker shaft.
2. Remove plain washer, wave washer, rocker arms, brackets and springs.

Inspecting components
1. Thoroughly clean components.
2. Inspect each component for wear, in particular rocker arms and shafts. Discard weak or broken springs.
3. Inspect push rod seats in rocker arms.
4. Check push rods for straightness and inspect ball ends for damage, replace as necessary.

Rocker shafts - assembling







1. Assemble rocker shafts with identification groove at one o'clock position with push rod end of rocker arm to the right.

CAUTION: If rocker shafts are incorrectly assembled and fitted to engine, oil supply to rocker arms will be restricted.







2. Fit new split pin to one end of rocker shaft.
3. Fit plain washer and wave washer.
4. Lubricate rocker arm bushes with clean engine oil.
5. Early type rocker arms are angled, and must be fitted with the valve end of the rocker arms angled away from each other as illustrated.
6. On later type rocker arms the valve end is offset and must be fitted as illustrated.

NOTE: Early and late rocker arms are interchangeable provided the complete set is changed.

7. Assemble rocker arms, brackets and springs to rocker shaft.
8. Compress springs, fit wave washer, plain washer and secure with new split pin.

Rocker shafts - refit
1. Lubricate push rods with engine oil.
2. Fit push rods in removed order.







3. Fit each rocker shaft assembly, ensuring identification groove is uppermost and towards front of engine on RH side and towards rear of engine on LH side.

CAUTION: Incorrect fitment will result in an oil feed restriction.

4. Fit bolts and tighten to 38 Nm (28 ft. lbs.).
5. Clean gasket surface in rocker cover using Bostik cleaner 6001 or equivalent, and allow to dry.
6. Apply a thin coating of Bostik 1775 or equivalent impact adhesive to mating surfaces of rocker cover and gasket.
7. Allow adhesive to cure, then fit gasket to rocker cover.

CAUTION: Gasket fits one way round only, & it must be fitted accurately as subsequent movement will destroy bonding. Allow cover to stand for 30 minutes before fitting.

8. Fit rocker cover to cylinder head, fit Allen screws/multi-hex bolts and tighten by diagonal selection to:
Stage 1 - 4 Nm (3 ft. lbs.)
Stage 2 - 8 Nm (6 ft. lbs.)
Stage 3 - Re-torque to 8 Nm (6 ft. lbs.)

CAUTION: The 2 short screws/bolts must be fitted on side of cover nearest centre of engine.

9. LH rocker shaft only: Align dipstick tube to rocker cover, fit and tighten screw.