Timing Belt: Service and Repair

Fig. 38 Timing pulley housing covers:

1. Remove radiator, drive belts, fan, crankshaft pulley, cover retaining bolts and covers, Fig. 38.
2. Remove injection pump timing pulley flange bolts, then remove flange.

Fig. 18 Removing tension spring:

3. Remove tension spring, Fig. 18. Do not use excessive force.

Fig. 19 Removing tension pulley nut:

4. Remove tension pulley nut, Fig. 19, then remove tension pulley and tension center.
5. Remove timing belt. Do not twist or kink belt or allow it to come in contact with water, dirt, oil or other foreign material. Do not attempt to readjust a used belt which has become loose through service.

Fig. 20 Crankshaft pulley, injection pump pulley and camshaft pulley timing marks:

6. Before installing belt, make sure that marks on crank pulley, injection pump timing pulley and cam shaft timing pulley are aligned as shown in Fig. 20. Install belt around the crankshaft pulley camshaft timing pulley and then the injection pump timing pulley. Use care to avoid damaging belt during installation.

Fig. 21 Installing tension center and tension pulley:

7. Install tension center and tension pulley, making sure that end of tension center is properly contacting the two pins on timing housing, Fig. 21. Adjust tension pulley to remove slack from belt.

Fig. 18 Removing tension spring:

8. Hand tighten nut so that tension pulley is free to slide, then install tension spring, Fig. 18, and torque pulley nut to 22-36 ft. lbs. (3-5 kg-m).

Fig. 22 Positioning crankshaft to set injection pump:

9. Turn crankshaft 2 turns in normal direction of rotation to allow belt to seat then turn crankshaft an additional 1/4 turn beyond TDC to set the injection pump, Fig. 22. Do not turn crankshaft in reverse direction of rotation.
10. Completely loosen pulley nut to allow pulley to take up slack in belt, then torque nut to 78-95 ft. lbs. (10.8-13.2 kg-m).

Fig. 23 Injection pump flange & camshaft timing pulley alignment marks:

11. Install flange on injection pump pulley. The hole in the outer circumference of flange should be aligned with triangular shaped timing mark on camshaft pulley, Fig. 23.

Fig. 4 Static timing gauge, J-28827, installed:

12. Turn crankshaft 2 turns in normal direction of rotation until No. 1 piston is at TDC compression stroke. Triangular shaped timing mark on camshaft timing pulley should be aligned with hole in flange, Fig . 25.
13. Using tension gauge J-26486 or equivalent, check timing belt tension between injection pump pulley and crankshaft pulley. Tension should be 33-55 lbs. (15-25 kg).
14. Make sure that rocker arm shaft assembly bolts are torqued to specifications.

Fig. 7 TDC timing mark:

15. Bring No. 1 piston to top dead center compression stroke by turning crankshaft until timing mark on pulley aligns with pointer, Fig. 7
16. Adjust the intake valve of Nos. 1 and 2 cylinders and exhaust valve of Nos. 1 and 3 cylinders to specifications.
17. Rotate engine one complete revolution to bring No. 4 piston to top dead center compression stroke.
18. Adjust the intake valve of Nos. 3 and 4 cylinders and exhaust valve of Nos. 2 and 4 cylinders to specifications.
19. Reverse removal procedure to install remaining parts.