Model 28-2, Model 28-IFS & 35 IFS

1. Install ring gear to differential case using new bolts, then torque bolts alternately and evenly to specifications.
2. Place differential case into position in carrier (differential case bearings should still be installed).

Fig. 4 Total Differential Case Endplay Check:

3. Force differential case away from drive pinion gear, until it is completely seated against cross bore face of carrier. Position a dial indicator so indicator tip rests on a ring gear bolt head, Fig. 4. Zero dial indicator.
4. Force ring gear against pinion gear. Rock ring gear slightly to ensure gear teeth are in contact, then force ring gear away from pinion gear, ensuring dial indicator returns to zero. Repeat this procedure until dial indicator reading is the same. This reading should be recorded as measurement ``B'' and reveals amount of shims necessary between differential case and differential bearing on ring gear side.
5. On model 28-IFS, assemble shim pack for ring gear side to measurement ``B'' minus (-) .006 inch for backlash.
6. Subtract measurement ``B'' from measurement ``A'' obtained in step 3 under ``Total Differential Case Endplay'' as previously described to obtain measurement ``C.'' Measurement ``C'' equals amount of shims required between differential case and bearing on side opposite of ring gear.
7. Assemble shim pack for side opposite of ring gear to measurement ``C'' plus (+) .003 inch for additional preload.
8. On model 28-2, assemble shim pack for ring gear side to measurement ``B'' minus (-) .005 inch for backlash.
9. Subtract measurement ``B'' from measurement ``A'' obtained in step 3 under ``Total Differential Case Endplay'' as previously described to obtain measurement ``C.'' Measurement ``C'' equals amount of shims required between differential case and bearing on side opposite of ring gear.
10. Assemble shim pack for side opposite of ring gear to measurement ``C'' plus (+) .010 inch for additional preload.
11. On model 35-IFS, assemble shim pack for ring gear side to measurement ``B'' minus (-) .008 inch for backlash.
12. Subtract measurement ``B'' from measurement ``A'' obtained in step 3 under ``Total Differential Case Endplay'' as previously described to obtain measurement ``C.'' Measurement ``C'' equals amount of shims required between differential case and bearing on side opposite of ring gear.
13. Assemble shim pack for side opposite of ring gear to measurement ``C'' plus (+) .002 inch for additional preload.
14. On all models, Remove differential case from carrier, then the bearings from case.
15. Place required amount of shims on hub of ring gear side of differential case, then install bearing and drive bearing onto hub using a suitable differential side bearing replacer.
16. Place required amount of shims on hub of differential case opposite of ring gear side, then install bearing. Place a suitable step plate on ring gear side bearing to protect bearing, then drive bearing opposite of ring gear side onto hub using differential side bearing replacer.
17. Install differential bearing cups onto bearings.
18. Mount spreader tool 4000-E and Spreader Adapter tool No. T80T-4000-B or equivalents onto carrier assembly.
19. Position a dial indicator onto carrier, then spread housing. Do not spread housing more than .010 inch on model 28-IFS and 35-IFS or .015 inch on model 28-2.
20. Install differential case into carrier. If necessary, use a rawhide or plastic hammer to seat case in carrier bore. With partial and non-hunting/partial ring gear and pinion sets, align marks on ring gear and drive pinion, if applicable. Use care not to nick teeth of ring gear or pinion.
21. Remove spreader and dial indicator.
22. Install bearing caps and bolts, ensuring letters or numbers stamped on caps correspond in both position and direction with letters or numbers stamped into carrier, then torque bolts to specifications.

Fig. 14 Ring Gear And Pinion Backlash Check:

23. Install dial indicator on case, Fig. 14.
24. Check ring gear and pinion backlash at three equally spaced points on ring gear. Back lash tolerance is .005-.008 inch and cannot vary more than .003 inch between the three points.
25. If backlash is high, ring gear must be moved closer to pinion by increasing thickness of shims on ring gear side and decreasing shims on opposite side by an equal amount.
26. If backlash is low, ring gear must be moved away from pinion by decreasing thickness of shims on ring gear side and increasing shims on opposite side by an equal amount.
27. On model 28-IFS and 35-IFS, install right hand slip yoke and stub shaft.
28. Apply a continuous bead of RTV silicone sealant 1/8-1/4 inch high and 1/4-1/2 inch wide on mating surfaces of carrier mounting face support arm, then mount carrier assembly to left hand axle arm, using two guide pins. Install mounting bolts and torque to specifications. Torque one bolt and then torque bolt directly opposite it. Torque remaining bolts in either a clockwise or counterclockwise pattern.
29. On model 28-2, install axle shafts.
30. Apply a continuous bead RTV silicone sealant 1/8-1/4 inch high and 1/4-1/2 inch wide on cover plate, then install cover plate and mounting bolts and torque to specifications. Cover must be installed on carrier within five minutes after applying sealant.
31. On all models, allow sealant one hour cure time prior to filling carrier with proper amount of specified lubricant.