Note: Use a new timing belt when installing.
Removal
1. Remove the timing belt and associated camshaft sprockets as described in Chapter 4.
2. If the exhaust camshaft needs to be removed, unscrew the two mounting bolts and remove the distributor from the end of the cylinder head, following the Section 5, if necessary.
3. Check that the camshaft bearing caps are marked, if not, make your own marks on the caps and the top of the cylinder head using a center punch. Before removing, note the orientation of the bearing caps, as they must be installed in exactly the same position as before removal (see illustration).
4. Loosen the nuts of the corresponding camshaft bearing nuts by half a turn, then further loosen all the nuts by another half a turn, and so on (this is necessary to slowly reduce the tension of the valve springs). Note that the exhaust camshaft rear bearing cap, which also supports the distributor, is secured with four nuts (see illustration).
5. Remove the nuts and caps, then carefully lift the camshaft from the cylinder head.
6. Repeat the procedure with the remaining camshaft if necessary.
Inspection
7. Removing the camshaft (or camshafts), inspect the working surfaces of the bearings in the cylinder head and covers for signs of wear or pitting. If such damage is detected, the cylinder head and all covers must be replaced as a complete set, since there is no way to regrind them, and the covers cannot be replaced separately.
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8. There should be no marks or scratches on the journals or cam contour surface of the camshaft; if such damage is found, replace the camshaft.
9. It is recommended to always replace the front oil seal after removing the camshaft.
Installation
10. Generously coat the contact surfaces of the valve lifters and camshafts with molybdenum paste.
11. Coat the mating surfaces of the front and rear covers with sealant, install the covers in their places as noted before removal.
12. Gradually tighten the camshaft bearing cap nuts by half a turn with the tightening force specified Specifications. Note that when installing the exhaust camshaft, tighten the two smaller rear bearing cap retaining nuts first, then the main cap nuts. Also note that the two smaller nuts are tightened to a lower torque than the main nuts.
13. Rotate the camshaft until the camshaft sprocket alignment mark is in the upper position, then lubricate the sealing lips of the front camshaft oil seal. Install the oil seal using a pipe or socket with a diameter slightly smaller than the camshaft sprocket bolt washer. Thread the bolt and washer into the end of the camshaft to press the oil seal into place.
14. Repeat the procedure with the remaining camshaft.
15. Install the distributor as described in Section 5. Install a new timing belt and camshaft sprockets, then adjust the drive belt tension as described in Chapter 4 or 5.
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