Timing Belt: Service and Repair

Fig. 22 Camshaft sprocket alignment.:

Fig. 23 Timing belt installation.:

Removal

1. Remove accessory drive belts and timing belt cover.
2. Rotate crankshaft until No. 1 cylinder is at TDC of compression stroke, ensure camshaft is positioned as shown in Fig. 22, then insert TDC lock pin Mot. 861 or equivalent through opening in side of block, Fig. 23, and ensure tool engages slot in crankshaft. If there is no reference mark on camshaft sprocket rear cover plate, scribe a matching mark in line with timing mark on sprocket.
3. Loosen timing belt tensioner, then remove timing belt. Do not rotate crankshaft or camshaft with timing belt removed.




Installation

1. Ensure TDC tool Mot. 861 is properly seated in and align camshaft sprocket timing mark with mark on rear cover plate, Fig. 22.




2. Position timing belt over crankshaft sprocket (1) first, then intermediate shaft sprocket (2), and then camshaft sprocket (3), Fig. 23.
3. Position timing belt arrow (A), indicating direction of rotation between intermediate shaft sprocket and idler pulley, Fig. 23.
4. Align timing belt marks with timing mark on camshaft sprocket (B) and crankshaft sprocket (B), Fig. 23. Intermediate shaft sprocket does not have a timing mark.
5. Adjust initial belt tension as follows:
a. On 4-105/1721cc engines, loosen tensioner pulley locknut, then turn tensioner pulley nut counterclockwise until timing belt is taut. Hold tensioner pulley nut from turning and tighten the locknut.
b. On 4-120/1965cc engines, pry tensioner inward toward belt until belt is taut, then tighten tensioner pulley locknut.
6. Remove TDC tool Mot. 861 from crankcase, then rotate crankshaft clockwise, 2 complete revolutions, then reinstall TDC tool Mot. 861 through crankcase into crankshaft.




7. Ensure camshaft sprocket timing mark is aligned with mark on rear cover plate, Fig. 22.




8. There should be 66 timing belt teeth (cogs) between camshaft sprocket timing mark (C) and crankshaft sprocket timing mark (B), Fig. 23.
9. Remove TDC tool Mot. 861 and install plug in cylinder block.
10. Check timing belt tension as follows:
a. Check timing belt deflection between intermediate shaft sprocket and idler pulley.
b. With belt cold, deflection should be 7.5 mm (0.295 inch). With belt hot deflection should be 5.5 mm (0.216 inch).
c. If deflection is excessive, loosen tensioner pulley locknut, then turn tensioner pulley nut counterclockwise to increase tension or counterclockwise to decrease tension.
d. While holding tensioner pulley locknut with suitable wrench, torque tensioner pulley locknut to 30 ft.lbs. Tensioner pulley locknut must be torqued to 30 ft.lbs. to prevent loosening of timing belt, which may cause engine damage.
11. Install timing belt cover and drive belts.