Replace the belt if, upon inspection, you find:
- traces of oil on any surface of the belt;
- signs of wear of the toothed surface, cracks, undercuts, folds and delamination 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 engine oil on any surface must be changed without fail, as the oil quickly destroys the rubber. Cause of oil on the belt (usually this is a violation of the tightness of the seals of the crankshaft and camshafts) must be eliminated immediately.
Note: Carry out work on a viewing ditch, overpass or, if possible, on a lift.
1. Open the hood.
2. Remove the accessory drive belt (see «Checking the tension and replacing the drive belt of the auxiliary units of the F18D engine»).
3. Remove the right engine mudguard (see «Removal and installation of engine mudguards»).
4. Remove the right forward wheel.
5. Turn out two bolts 2 (pic. 5.31) and remove the upper front timing belt cover.
Pic. 5.31. Removing the upper front timing belt cover: 1 - upper front cover of the gas distribution mechanism drive; 2 - mounting bolts
6. Set the piston of the 1st cylinder to the TDC position of the compression stroke (see «Setting the piston of the first cylinder of the F18D engine to the TDC position of the compression stroke»).
7. Fix the position of the camshaft pulleys with a special tool.
Helpful Hint: In the absence of a special tool for fixing the position of the camshaft pulleys, you can use the W38 bolt with two washers and a nut.
8. Turn out a bolt of fastening and remove a pulley of a cranked shaft.
9. Turn out three bolts 2 fastenings of the bottom forward cover 1 (pic. 5.32) timing belt and remove the cover.
Pic. 5.32. Removing the lower front timing belt cover: 1 - lower front cover of the gas distribution mechanism; 2 - mounting bolts
10. Securely support the engine. Turn out five bolts and turn away one nut of fastening of the right support of the engine and remove a support (see «Replacing the suspension bearings of the power unit»).
11. Remove the middle front cover of the timing belt, overcoming the resistance of its clips.
12. Loosen the bolt securing the tension roller 2 (pic. 5.33). Insert the hexagon wrench into the hexagonal hole of the tension roller and, turning the key 1 clockwise, loosen the belt tension.
Pic. 5.33. Loosening the timing belt tension: 1 - hex key; 2 - tension roller
13. Remove the belt from the crankshaft pulley, from the tension and intermediate rollers and camshaft pulleys.
Warning: After removing the timing belt, do not turn the camshafts and crankshafts, as the pistons can damage the valves.
14. For replacement of a tension roller turn out a bolt of its fastening to the block of cylinders and remove a roller.
Note: If you disassemble the timing gear only to replace the tension roller, the drive belt can not be removed.
15. Install the tension roller in the reverse order of removal.
16. Check the coincidence of the alignment marks of the crankshaft and camshaft (see «Setting the piston of the first cylinder of the F18D engine to the TDC position of the compression stroke»).
17. Put on a belt on a gear pulley of a cranked shaft.
18. Take the tension roller clockwise until it stops and install a new drive belt, sequentially putting the belt on the camshaft pulleys, tension and intermediate rollers.
19. Turn the crankshaft three full turns and make sure that the belt is in the correct position in the pulley grooves.
20. Check up coincidence of adjusting marks of camshafts and a cranked shaft.
21. Install the parts in the reverse order of removal.