Disassembly/Assembly

Eye protection must be worn when removing or installing snap rings on this unit or serious injury may result. If during the disassembly or assembly procedure on this unit, snap rings have to be removed or installed, ensure to stop at that point and wear safety goggles.
1. Remove torque tube attaching bolts, then carefully slide torque tube from rear axle.
2. Position torque tube assembly on a suitable workbench, then remove two mounting bracket bolts.
3. Remove input shaft assembly from torque tube and place into a soft jaw vise. Using a suitable puller, remove adapter sleeve (which is press fitted) from input shaft.
4. Place torque tube assembly into a suitable vise, then remove and discard oil seal from torque tube.
5. Using a suitable a suitable tool, install a new oil seal with beveled edge facing toward torque tube. Lubricate oil seal lip with suitable grease, then remove torque tube from vise.
6. Eye protection must be worn to perform the following procedure step. Place yoke end of input shaft into a suitable vise, then remove and discard snap ring.
7. Install input shaft into a suitable press with yoke end facing downward. Install a suitable bearing removal tool and remove bearing and mounting bracket. If mounting bracket is bent or damaged, if should be replace during assembly.
8. Eye protection must be worn to perform the following procedure step. Position input shaft into a suitable press with yoke end facing upward, then install mounting bracket. Install a new bearing. Ensure bearing is completely seated against input shaft shoulder and snap ring groove is clear of bearing. Install new snap ring. Ensure snap ring is completely seated in groove. Assemble press fit adapter sleeve onto input shaft. Carefully pound adapter sleeve onto shaft with a suitable hammer until snap ring in adapter sleeve bottoms out against input shaft. Avoid damaging the seal surface on the adapter sleeve. Carefully slide input shaft and adapter sleeve into torque tube. Ensure snap ring is completely seated in groove.
9. Torque two mounting bracket attaching bolts to 45-50 ft. lbs.
10. Remove eight bolts attaching cover plate to rear axle assembly. Remove cover plate and drain lubricant into a suitable container.
11. Eye protection must be worn to perform the following procedure step. Remove inner yoke snap rings using suitable pliers. Remove inner yoke shafts.
12. Remove righthand inner yoke shaft bearing and seal.
13. Remove lefthand yoke shaft seal.
14. Wipe bearing bore clean. Install new righthand inner yoke shaft bearing with name side facing outboard.
15. Install new righthand and lefthand inner yoke shaft oil seals. Grease lip seal with suitable lubricant.
16. Remove and discard rubber mounting bushing assemblies.
17. Soap new rubber bushing assemblies and mounting holes in rear axle housing. Install new rubber bushing assemblies.
18. Remove four bolts attaching bearing retaining cap and remove bearing cap.
19. Remove and discard bearing retaining cap O-ring.
20. Remove differential case assembly from housing.
21. Place differential assembly into a suitable vise. Remove righthand and lefthand differential bearing cones from differential case. Tag bearings and shims to identify from which side they were removed. Shims are available in thicknesses of .003, .005, .010 and .030 inch. If shims are bent or damaged, replace them with new ones of the same thickness during assembly.
22. With differential case assembly in a vise, remove ring gear attaching bolts.
23. Remove differential case assembly from vise. Tap ring gear on alternate sides using a suitable hammer and drift, then remove ring gear from differential case.
24. Place short inner yoke shaft in a suitable vise, locating it on yoke end. Install differential assembly onto yoke shaft. Remove differential pinion shaft roll pin using a suitable hammer and drift.
25. Remove differential pinion shaft using a suitable hammer and drift.
26. Remove differential assembly from yoke shaft, and place onto a suitable workbench with short end of differential case down. Install tool No. D80L-630-1 or equivalent into side gear.
27. Install tool No. T87P-4205-A or equivalent into differential case.
28. Install short inner yoke shaft into a suitable vise, locating it on the yoke end. Install differential assembly onto yoke shaft. Tighten forcing screw of tool installed in step 27, until pinion gears become loose.
29. Using a suitable feeler gauge, push pinion gear thrust washers from between pinion gears and differential case. Remove thrust washers.
30. Insert tool No. T87P-4205-B or equivalent into pinion shaft bore and turn case to ``walk'' pinion gears out of differential case windows. Remove pinions.
31. Remove differential assembly from yoke shaft.

Fig. 8 Clutch Pack & Side Gear Assembly:

32. Remove tool, clutch packs and side gears, Fig. 8. Inspect all components for wear or damage, replace components, if necessary.
33. Lubricate clutch plates and discs with lubricant C8AZ-19B546-A or equivalent. Assemble lefthand clutch pack and side gear assembly. Install clutch pack and side gear into differential case. Ensure clutch pack retainers are aligned in the differential case.
34. Turn differential case over and assemble righthand clutch pack and side gear assembly. Install righthand side gear and clutch pack into differential case and hold in position. Ensure clutch pack retainers are aligned in the differential case.
35. Install tool No. D80L-630-1 or equivalent into lefthand side gear. Install forcing screw of tool, through differential case and install tool No. T87P-4205-A or equivalent. Position case on inner yoke shaft. Lightly tighten forcing screw.
36. Install differential assembly over yoke shaft.
37. Position pinion gears into windows of differential case so that they mesh with side gear teeth. Hold pinion gears in position. Ensure pinion gears are 180° apart so they will correctly align with pinion shaft bore.
38. Insert tool No. T87P-4205-B or equivalent into pinion shaft bore and turn differential case. This will cause pinion gears to engage side gears and ``walk'' into differential case. Rotate differential case until pinion mating shaft holes are aligned exactly with holes in pinion gears. It may be necessary to tighten or loosen the forcing screw of tool. Allow pinion and side gears to rotate.
39. Tighten forcing screw of tool, until side gears become loose. Lubricate and install differential pinion thrust washers. Ensure thrust washers align exactly with holes and remove tools.
40. Install differential pinion shaft from roll pin hole side of case. Ensure to align pin hole in shaft with roll pin hole in case.
41. Install roll pin.
42. Remove and discard pinion to adapter O-ring seal.
43. Remove pinion nut using suitable tools. Tap pinion using a suitable hammer to remove it from housing. Save bearing preload spacer and preload shim. Remove outer pinion bearing cone.
44. Remove inner pinion bearing cone.

Fig. 9 Inner & Outer Cone Assembly:

45. Remove inner and outer pinion bearing cups, Fig. 9.
46. Remove ring gear side differential bearing cup.
47. Place differential bearing cap in a suitable vise. Remove bearing cap differential bearing cup.
48. Wipe clean pinion and differential bearing bores. Install inner and outer pinion bearing cups.
49. Install tools Nos. T76P-4020-A11, T80T-4020-F43, T76P-4020-A14 and T87P-4020-A or equivalents into inner pinion bearing bore of carrier.
50. Place gauge bar part of tool kit No. T87P-4020-A or equivalent into bearing bore.
51. Install bearing attaching cap with O-ring from gauge bar tool part of tool kit T87P-4020-A or equivalent in cap bore. Tighten retaining screws slightly.
52. Select the thickest feeler gauge or shim(s) that will enter between the pinion gauge block tool and gauge bar. The feeler gauge fit should be a slight drag type feeling. Ensure the feeler gauge or shim(s) is free of dirt to prevent an incorrect reading.
53. After the correct feeler gauge reading is obtained, check the reading. This is the thickness of shim(s) required providing that upon inspection of the service gear, there are no markings. If the service pinion gear is marked with a plus (+) reading this amount must be subtracted from the thickness dimension obtained in step 52.
54. If the service pinion gear is marked with a minus (-) reading, this amount must be added to the thickness dimension obtained in step 52.
55. For example, if a pinion is etched +3, it will require a selected shim .003 inch thinner than a pinion etched zero (0). If a pinion is etched +5, it will require a selected shim .005 inch thicker than a pinion marked zero (0).
56. Assemble selected shim and inner pinion bearing cone to pinion. Place in a suitable press, tools Nos. T62F-4621-A and T75L-1165-B or equivalents. Install bearing.
57. Install pinion bearing preload spacer, preload shims from disassembly and a new O-ring onto pinion.
58. Assemble pinion into carrier. Install outer pinion bearing cone and pinion nut. Tighten pinion nut using tools Nos. T87P-4850-A and T87P-4850-B or equivalents to 180-210 ft. lbs. Do not stake pinion nut at this time.
59. Using a suitable inch pound torque wrench and socket T87P-4850-A or equivalent, measure pinion rotational torque, it should be 15-35 inch lbs., with new bearings.
60. Install gauge bar tool No. PS85-167-1-1A or equivalent. Install dummy pinion gauge block tool No. PS85-167-1-3 or equivalent, between button on pinion and gauge bar tool.
61. Insert feeler gauge or shims between gauge bar and dummy pinion gauge block until a slight drag is felt.
62. The reading should be .020 inch, added, to the drive pinion etching, which could be plus (+) or minus (-) with a tolerance (plus or minus) of .002 inch.
63. For example, a drive pinion with a `` - 2'' etching would have a .018 inch distance and a tolerance of .020 inch, would require .016-.020 inch amount of shims.
64. If the distance must be increased, remove shims from beneath the inner pinion bearing cone. If the distance must be decreased, add shims beneath the inner pinion bearing cone.
65. Install dummy bearings T87P-4222-A or equivalent, onto differential case trunnions.
66. Install differential case assembly into carrier without ring gear. Assemble bearing retaining cap and tighten attaching screws snug. Install dial indicator and adapter tool No. T75L-4201-A or equivalent, onto carrier and locate tip of indicator on machined surface of differential case. Force case assembly as far as it will go in one direction and zero dial indicator.
67. Force case assembly as far as it will go in the opposite direction and obtain total case movement within carrier. Repeat these steps until consistent readings are obtained. Record indicator reading. This amount, in shims, will be used in final assembly to establish differential bearing preload and backlash. Remove differential case assembly.
68. Ensure flange face of case assembly is free of nicks or burrs. Install ring gear to differential case and insert attaching bolts. Torque bolts alternately to 28-32 ft. lbs.
69. With dummy bearings installed on case, place differential assembly into carrier. Install bearing retaining cap and ``snug up'' attaching screws. Place dial indicator and adapter onto machined surface of case or ring gear. Force case assembly as far as it will go in one direction. Zero (0) dial indicator.
70. Force case assembly as far as it will go in opposite direction. Repeat these steps until consistent readings are obtained. Ensure indicator returns to zero. Record this measurement.
71. Remove dial indicator and differential case assembly. Remove dummy bearings from case trunnions.
72. Subtract .010 inch from reading obtained and assemble this amount in shims onto ring gear side of differential case.
73. Install differential bearing cone using suitable tools. Ensure bearing is completely seated. Assemble shims equal to difference obtained by subtracting measurement obtained from total measurement plus an additional .005 inch onto opposite trunnion of case. Install opposite differential bearing cone.
74. For example, a total .098 inch case movement minus .058 inch movement with ring and pinion gears installed, gives a balance of .040 inch. Shim stacks for this example would be ring gear side .058 inch minus .010 inch gives .048 inch. Pinion side .040 inch plus .005 inch gives .045 inch.
75. Install ring gear side differential bearing cup into carrier.
76. Install bearing retaining cap differential bearing cup.
77. Install differential assembly into carrier. Install a new bearing retaining cap O-ring. Install bearing retaining cap. Torque four attaching bolts to 20-26 ft. lbs.
78. Install dial indicator and measure ring gear backlash in three equally spaced points. Backlash should be between .005-.008 inch. Using a suitable inch pound torque wrench, measure total pinion rotational torque. Total turning effort with differential case assembly installed (with new bearings) should be 4-7 inch lbs., greater than turning effort of pinion only. If backlash is excessive, it can be corrected by changing differential bearing shims from pinion side to ring gear side, moving ring gear closer to the pinion. If backlash is less than specified, it can be corrected by changing differential bearing shims from ring gear side to pinion side, moving the ring gear away from pinion. Turning effort to rotate pinion is corrected by adding shims to differential bearing shim stack. When both backlash and total turning effort are within specification, continue with assembly.
79. Use a white marking compound to obtain a gear tooth contact pattern. Contact pattern should be within primary area of ring gear tooth surface, avoiding any narrow or hard contact with outer perimeter of tooth (top to bottom, toe to heel). Pattern inspection should be on drive side of tooth. If an incorrect pattern error is detected, with a backlash of .005-.008 inch, adjust drive pinion gear shim stack. Increasing shim stack thickness of pinion gear should move contact pattern on drive side of ring gear toward toe of tooth. Reducing shims stack thickness should move contact pattern on drive side of ring gear tooth toward heel of tooth.
80. When the gear tooth contact pattern is acceptable, carefully stake pinion nut at keyway groove in pinion shaft. Eye protection must be worn for the following step.
81. Install yoke and snap rings.
82. Apply a bead of silicone gasket and sealant, to plate of carrier face. Install plate cover and attaching bolts. Torque attaching bolts to 7-12 ft. lbs.
83. Apply a bead of silicone gasket sealant to torque tube. Install torque tube assembly to rear axle. Install attaching bolts. Torque four attaching bolts to 40-50 ft. lbs.
84. Fill axle assembly with suitable lubricant (20.5 ounces) and friction modifier (1.5 ounces).