RPO M59

Rear Axle-Assemble

^ Tools Required
- J6133-01 Bearing Race Installer
- J8092 Driver Handle
- J8614-01 Flange Holder
- J37758 Pinion Outer Race Installer
- J37759 Pinion Inner Bearing Race Installer
- J35138 Side Gear Thrust Play Tool
- J38890 Differential Torque Check Tool
- J8001 Dial Indicator Set

Installation Procedure





1. Install the following in the right differential case:
^ Right side gear and washers
^ Differential pinion gears (2) and washers (1)
^ Cross shafts
^ Pinion cross shaft joint





2. Measure the right differential side gear (1) end play using the J8001.
3. Insert fingers through the bottom openings of the right differential case (2) half and move the right differential side gear (1) up and down while observing the J8001. The right differential side gear end play should measure 12 - 37 mm (0.005 - 0.014 inch).
4. Replace the selective shim with the appropriate size to obtain correct end play, if the right differential side gear end play is too high or low.





5. Install the cross shaft roll pins into the right differential case (4) half. The roll pin ends should be flush with the right differential case surface.





6. Install the left differential side gear (1) and washers (2) into the right differential case.

Notice: Refer to Fastener Notice in Service Precautions.





7. Install the ring gear to the differential case half. Secure with 10 bolts (1)
^ Tighten the ring gear bolts to 90 Nm (65 ft. lbs.).





8. Secure the 8 bolts (1) to join both differential case halves.
^ Tighten the bolts to 41 Nm (130 ft. lbs.).
9. Measure the left differential side gear end play using the J8001 the J35138.





10. Insert the J35138 in through the left axle shaft differential case (1) bore.
11. Adjust the J35138 until the J35138 has a firm grasp on the left differential side gear.
12. Move the J35138 up and down while observing the J8001. The left differential side gear end play should measure 12 - 37 mm (0.005 - 0.014 inch).
13. Replace the selective shim with the appropriate size to obtain the correct end play if the left differential side end play is too high or low.





14. Install the side gear preload to the left differential case (1) using the J38890.
15. Insert the J38890 into either side bearing with a torque wrench.
16. Measure the side bearing preload.
The maximum side gear preload 2.4 Nm (21 inch lbs.).

Important: After the correct end play and preload has been obtained, remove the ring gear bolts and apply GM P/N 12345493, or the equivalent, to the threaded portion of each ring gear bolt and install into the differential case assembly.

17. Inspect the side and differential pinion gears for foreign material or damage if the preload exceeds the specification.
^ Tighten the ring gear bolts to 90 Nm (65 ft. lbs.).





18. Install the right differential side bearing (1) on the right side of the differential case assembly (2) using the J37758 with the J8092.
19. Place the differential case assembly on a hydraulic press using the J8107-4 for support.
20. Place the right side bearing on the right differential case with the taper side up using the J37759 with the J8092.
21. Slowly press the right differential side bearing onto the right differential case.





22. Install the left differential case, (2) to the left side of the differential case assembly using the J37758 with the J8092 and the J8107-4.
23. Place the differential case assembly on a hydraulic press with the J8107-4 for support and to protect the right differential side bearing (1).
24. Place the left differential side bearing on the left differential case with the taper side up using the J37758 with the J8092.
25. Slowly press the left differential side bearing onto the left differential case.
26. Install the inner pinion bearing race using the J37759 and the J8092.





27. Place the differential carrier (1) on a hydraulic, press.
28. Position the inner pinion bearing race over its bore.
29. Use the J37759 inner with the J8092 to slowly press the inner pinion bearing race evenly into the differential carrier.





30. Install the outer pinion bearing race (1) using the J37758 with the J8092.
31. Place the differential carrier (2) on a hydraulic press.
32. Position the outer pinion bearing race over its bore.
33. Press the outer pinion bearing race slowly and evenly into the differential carrier using the J37758 with the J8092.





34. Install a pinion selective shim (2) onto the pinion gear shaft.
35. Install the pinion bearing (1) onto the pinion gear shaft. Use the J6133-01.
36. Place the pinion gear (3) on a hydraulic press.
37. Install the inner pinion bearing on the pinion gear shift shaft with the tapered side facing away from the pinion gear.
38. Place the J6133-01.





39. Install a new collapsible spacer (4) onto the pinion gear shaft with the short shank toward the pinion gear.
40. Install the outer pinion bearing (3) and the pinion gear (5) into the differential carrier (2).





41. Install a new pinion oil seal into the differential carrier using the J25273-
42. Apply wheel bearing lubricant GM P/N 1051344, or equivalent, to the new pinion oil seal lip.

Important: Do not overtighten the pinion flange nut when adjusting the bearing preload. Tighten the pinion flange nut gradually while taking frequent pinion bearing preload measurements with a torque wrench. If overtightening exists the collapsible spacer will crush requiring a new collapsible spacer before pinion bearing preload can be properly adjusted.

43. Adjust the pinion bearing preload using the J8614-01.
^ Tighten the nut gradually in increments of 5 Nm (44 inch lbs.).
44. Between each increments of tightening, remove the J8614-01.





45. Measure the bearing preload using a torque wrench and a 27 mm socket (2).
46. The pinion gear should require 1.2 Nm (11 inch lbs.) in order to rotate.
47. If the pinion bearing preload is less than specified, repeat the adjustment procedure until proper pinion bearing preload has been attained.
48. Install the pinion flange nut.
49. Install the side bearing races onto the differential side bearings.
50. Install the differential assembly into the differential carrier.





51. Install both side bearing adjusters (2) on the side bearing races.
52. Install both side bearing caps onto differential carrier, secure with the four side bearing Gap bolts.
^ Tighten differential side bearing cap bolts to 15 Nm (11 ft. lbs.).