Timing Belt: Adjustments

Fig. 13 Aligning injection pump sprocket & camshaft sprocket timing marks:

Fig. 14 Loosening top & bottom belt tensioner bolts:

Fig. 15 Aligning pointer on timing cover with second tooth from alignment mark on camshaft sprocket:

Fig. 16 Checking belt deflection:

INJECTION PUMP/CAMSHAFT
1. Remove timing belt upper cover as described previously.
2. Rotate engine until No. 1 piston is at TDC of compression stroke.
3. Check that crankshaft pulley, injection pump sprocket and camshaft sprocket are aligned properly with their timing marks, Fig. 13.
4. Loosen top belt tensioner bolt 1 to 2 turns, then loosen bottom bolt 1 complete turn, Fig. 14. This allows the tensioner spring to automatically adjust the timing belt tensioner.
5. Rotate crankshaft clockwise so alignment pointer on timing cover aligns with the second tooth from alignment mark on camshaft sprocket, Fig. 15. Rotate crankshaft smoothly by the specified amount (two camshaft sprocket teeth). Failure to do so will result in an incorrect belt tension and possible engine damage.
6. Tighten top belt tensioner bolt to 16---21 ft. lbs., then tighten bottom bolt also to 16---21 ft. lbs. Tighten the top bolt first. Tightening the bottom bolt first can cause tensioner to rotate and over-tension the timing belt.
7. Rotate crankshaft counterclockwise until timing marks are aligned, Fig. 16. Push belt downward halfway between injection pump sprocket and camshaft sprocket, then check deflection. If belt is properly tensioned, belt should deflect .16---.20 inches.

Fig. 17 Top belt tensioner bolt access cover:

Fig. 18 Adjusting silent shaft belt tensioner:

Fig. 19 Installing access cover:

SILENT SHAFT
1. Rotate crankshaft until No. 1 piston is at TDC of compression stroke.
2. Remove access cover for top belt tensioner bolt by inserting a suitable screwdriver in slot shown in Fig. 17 and prying outward.
3. Loosen top belt tensioner mounting bolt 1 complete turn. Then loosen bottom bolt 1 to 2 turns, Fig. 18. This allows tensioner spring to automatically adjust belt tension.
4. Tighten bottom tensioner bolt to 16---21 ft. lbs., then tighten top bolt to 15---19 ft. lbs. Tighten the bottom bolt first. Tightening the top bolt first can cause the tensioner to rotate and over-tighten the timing belt.
5. Install access cover for top tensioner bolt by sliding downward along the two guide lines embossed on the front lower cover, Fig. 19.