Removal and Replacement

Rocker Shafts

Rocker Shafts - Remove







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







2. Remove 4 bolts securing rocker cover to cylinder head.

NOTE: Mark position of 2 longer bolts.

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.

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 pushrod seats in rocker arms.
4. Check pushrods 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: Incorrect assembly of rocker shafts will lead to an oil feed restriction.







2. Fit new split pin to one end of rocker shaft.
3. Fit plain washer and wave washer.
4. Lubricate rocker arm bushes with engine oil.
5. Fit rocker arms with offsets as illustrated.
6. Assemble rocker arms, brackets and springs to rocker shaft.
7. Compress springs, fit wave washer, plain washer and secure with new split pin.

Rocker shafts - refit
1. Lubricate pushrods with engine oil.
2. Fit pushrods 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 of rocker shafts will lead to an oil feed restriction.

4. Fit bolts and starting at centre brackets, tighten to 38 Nm (28 ft. lbs.).
5. Clean gasket surface in rocker cover.

NOTE: Gaskets fitted to early engines were manufactured from cork whilst those fitted to later engines are manufactured from rubber. The later type gaskets should be fitted as replacements to all engines. Cork gaskets were retained by an adhesive whereas rubber gaskets do not need an adhesive. If cork gaskets were originally fitted, remove all traces of adhesive using Bostik Cleaner 6001 or equivalent.

6. Fit new gasket, dry to rocker cover.
7. Fit rocker cover to cylinder head, fit bolts and tighten in diagonal sequence 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 bolts must be fitted on side of cover nearest centre of engine.

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