1. To facilitate access to the timing belt, remove the air filter nm. "Removal and installation the air filter housing and intake noise muffler").
2. Remove the upper timing cover (see "Replacing the timing belt and its tension roller").
3. Inspect the condition of the timing belt. Replace the belt if you find the following during inspection:
- traces of oil on any surface of the belt;
- traces of wear on the toothed surface, cracks, cuts, folds and separation of the fabric from the rubber;
- cracks, folds, depressions or bulges on the outer surface of the belt;
- fraying or delamination on the end surfaces of the belt.
Warning: A belt with traces of motor oil on any of its surfaces must be replaced, as oil quickly destroys rubber. The reason for oil getting on the belt (usually due to a breach in the seals of the crankshaft and camshaft) must be eliminated immediately.
4. Check the belt tension. If the belt is tensioned correctly, the timing marks on the tension roller and its bracket will match. If necessary, adjust the belt tension (see "Replacing the timing belt and its tension roller").
5. Install the parts in the reverse order of removal.
(The text of the article was obtained from the website «CHEVYMAN.RU»)