Removal
1 Remove the camshaft sprocket as described in Section 5. Remove the rear cover plate behind the sprocket.

2 Remove the camshaft cover. For ease of access, remove the distributor cap and HT leads, air cleaner assembly and brake servo vacuum hose.

3 Remove the distributor as described in Chapter 5B.

4 Carefully ease the oil supply pipe out from the top of the camshaft bearing caps, and remove it. Note the O-ring seals fitted to each of the pipe unions on later models.

5 Where fitted undo the bolt and remove the camshaft thrust plate (see illustrations).

7.5a Removing the camshaft thrust plate bolt . . .

7.5b . . . followed by the thrust plate

6 The camshaft bearing caps should be numbered 1 to 5, number 1 being at the transmission end of the engine. If not, make identification marks on the caps, using white paint or a suitable marker pen. Also mark each cap in some way to indicate its correct fitted orientation. This will avoid the possibility of installing the caps the wrong way around on refitting.

7 Evenly and progressively slacken the camshaft bearing cap retaining nuts by one turn at a time. This will relieve the valve spring pressure on the bearing caps gradually and evenly. Once the pressure has been relieved, the nuts can be fully unscrewed and removed (see illustration).

7.7 Progressively unscrew the camshaft bearing cap nuts . . .

8 Note the correct fitted orientation of the bearing caps, then remove them from the cylinder head (see illustration).

7.8 . . . and remove the caps

9 Lift the camshaft away from the cylinder head, and slide the oil seal off the camshaft end (see illustration).

7.9 Lift the camshaft from the cylinder head

10 Obtain eight small, clean plastic containers, and number them 1 to 8; alternatively, divide a larger container into eight compartments. Using a rubber sucker, withdraw each follower in turn, and place it in its respective container. Do not interchange the cam followers, or the rate of wear will be much-increased. If necessary, also remove the shim from the top of the valve stem, and store it with its respective follower. Note that the shim may stick to the inside of the follower as it is withdrawn. If this happens, take care not to allow it to drop out as the follower is removed.

Inspection
11 Examine the camshaft bearing surfaces and cam lobes for signs of wear ridges and scoring. Renew the camshaft if any of these conditions are apparent. Examine the condition of the bearing surfaces, both on the camshaft journals and in the cylinder head/bearing caps. If the head bearing surfaces are worn excessively, the cylinder head will need to be renewed.

12 Examine the cam follower bearing surfaces which contact the camshaft lobes for wear ridges and scoring. Renew any follower on which these conditions are apparent. If a follower bearing surface is badly scored, also examine the corresponding lobe on the camshaft for wear, as it is likely that both will be worn. Renew worn components as necessary.

Refitting
13 Where removed, refit each shim to the top of its original valve stem. Do not interchange the shims, as this will upset the valve clearances (see Section 2).

14 Liberally oil the cylinder head cam follower bores and the followers. Carefully refit the followers to the cylinder head, ensuring that each follower is refitted to its original bore. Some care will be required to enter the followers squarely into their bores.

15 Liberally oil the camshaft bearings and lobes, then refit the camshaft to the cylinder head. Temporarily refit the sprocket to the end of the shaft, and position it so that the sprocket timing hole is aligned with the corresponding cut-out in the cylinder head.

Also ensure that the crankshaft is still locked in the timing position (see Section 4).

16 Ensure that the bearing cap and head mating surfaces are completely clean, unmarked, and free from oil. Refit all the caps, using the identification marks noted on removal to ensure that each is installed correctly and in its original location.

17 Evenly and progressively tighten the camshaft bearing cap nuts by one turn at a time until the caps touch the cylinder head.

Then go round again and tighten all the nuts to the specified torque setting. Work only as described, to impose the pressure of the valve springs gradually and evenly on the bearing caps.

18 Where applicable, refit the camshaft thrust plate and secure with its retaining bolt.

19 Examine the oil supply pipe union O-rings (where fitted) for signs of damage or deterioration, and renew as necessary. Apply a smear of clean engine oil to the O-rings.

Ease the pipe into position in the top of the bearing caps, taking great care not to displace the O-rings.

20 Refit the distributor as described in Chapter 5B.

21 Fit a new camshaft oil seal, using the information given in Section 6, then refit the sprocket rear cover plate. Align the cover plate using a 10 mm dowel or drill bit then secure with the retaining bolt (see illustration).

7.21 Align the camshaft sprocket cover plate using a dowel or twist drill

22 Refit the camshaft sprocket as described in Section 5.

23 Check the valve clearances as described in Section 2.

24 Refit the camshaft cover, HT leads and distributor cap, air cleaner, and brake servo vacuum hose.

25 Reconnect the battery negative terminal.