GM Service Manual Online
For 1990-2009 cars only

Tools Required

   • 
  • DT-48723 Pinion Head Bearing Cup Installer.
  •    • 
  • DT-48725 Pinion Tail Bearing Cup Installer.
  •    • 
  • DT-48722 Left Axle Seal Installer.
  •    • 
  • DT-48721 Right Axle Seal Installer.
  •    • 
  • DT-48727 Pinion Seal Installer.
  •    • 
  • DT-48728 Differential Bearing Installer.
  •    • 
  • DT-48806 Pinion Bearing Measurement Spacer.
  •    • 
  • DT-48807 Pinion Head Bearing Installer.

    1. Object Number: 1958928  Size: SH

      Important: Use DT-48806 otherwise bearing height cannot be measured correctly.

    2. Measure the thickness of DT-48806 (1) using a depth gauge (2).(e.g - 3.67mm).
    3. Record the thickness of the DT-48806 (1).

    4. Object Number: 1958930  Size: SH

      Important: Rotate the pinion head bearing (2) to settle for correct measurement.

    5. Measure the thickness of the DT-48806 (1) and the pinion head bearing (2) with the depth gauge (3) (e.g - 33.925mm).
    6. Record the thickness of the DT-48806 (1) and pinion head bearing (2).
    7. Subtract the thickness of DT-48806 (1) 3.67mm from the total thickness of the pinion bearing measurement spacer (1) and the pinion bearing (2) 33.925mm to determine the pinion head bearing (2) thickness.
    8. Example - The pinion head bearing (2) thickness is 33.925mm - 3.67mm = 30.255mm

    9. Object Number: 1958931  Size: SH
    10. Record the serial number (1), set number (3) and size (4) which are stamped into the pinion gear (2).
    11. Example:
    12. • Serial Number A0200008 (1)
      • Pinion Size 106.475mm (4)
      • Set Number 260125 (3)

      Object Number: 1958933  Size: SH
    13. Check that the serial number (1) and set number (3) which are stamped into the ring gear (2) match those of the pinion set in step 7.
    14. Example:
    15. • Serial Number A0200008 (1)
      • Set Number 260125 (3)

      Object Number: 1958934  Size: SH

      Important: The identification number (1, 3, and 4) is stamped into the differential housing (2).

    16. Identify the differential housing.
    17. • Manufacturing date (1).
      • Item number (4).
      • Size equals 138 plus the number on the housing. Example - 138.180mm (3).
    18. Record the differential housing size. Example - 138.180mm
    19. Determine the thickness of the pinion shim.
    20. • Add the pinion plus the bearing Example - 106.475mm + 30.255mm = 136.730mm.
      • Subtract the pinion plus the head bearing from the housing size, also subtract the correction factor. The correction factor is .05mm. Example 138.180 - 136.730 - 0.05 = 1.40mm thickness shim required.
    21. Position the correct shim onto the pinion head.

    22. Object Number: 1958936  Size: SH

      Important: Use DT-48807 (3) to aid in pinion bearing (2) installation.

      Important: Position the pinion gear (1) onto an aluminium plate in suitable press (4) before pressing the pinion head bearing (2) to prevent damage to the pinion (1).

    23. Position the NEW pinion head bearing (2) onto the pinion gear (1).
    24. Important: Use a suitable press (4) to install the NEW differential pinion head bearing (2).

    25. Press the NEW pinion head bearing (2) onto the pinion gear using DT-48807 (3).
    26. Clean the ring gear and the contact area of the differential.
    27. Caution: Refer to Safety Glasses Caution in the Preface section.


      Object Number: 1958925  Size: SH

      Important: To make fitting easier cool the bearing cups (2).

    28. Position the NEW head bearing cup (1) into the differential housing (2).

    29. Object Number: 1958926  Size: SH
    30. Press the NEW head bearing cup in with DT-48723 (1) and rotate until it fits tightly in the front differential housing (2).
    31. Use a feeler gauge to make sure the NEW head bearing cup is seated correctly.

    32. Object Number: 1958980  Size: SH

      Important: To make fitting easier cool the bearing cup (2).

    33. Position the NEW tail bearing cup (2) to the differential housing (3).
    34. Press the NEW tail bearing cup in with DT-48725 (1) and rotate until it fits tightly in the front differential housing (2).
    35. Use a feeler gauge to make sure the NEW tail bearing cup is seated correctly.

    36. Object Number: 1958937  Size: SH

      Important: Warm the ring gear (1) evenly using a hotplate until it fits over the differential (2).

    37. Position the ring gear (1) to the differential (2).
    38. Important: Do not fully tighten the NEW ring gear to differential retaining bolts at this stage.

      Important: The ring gear has to cool before the ring gear to differential retaining bolts can be tightened.

    39. Install two NEW ring gear to differential retaining bolts.
    40. Notice: Refer to Fastener Notice in the Preface section.


      Object Number: 1958911  Size: SH

      Important: The ring gear has to cool before the ring gear to differential retaining bolts (1) can be tightened.

      Important: Tighten the ring gear to differential retaining bolts (1) working diagonally.

    41. Install the remaining NEW ring gear to differential retaining bolts (1).
    42. Tighten
      Tighten the bolts to 125 N-m (96  lb  ft).


      Object Number: 1958939  Size: SH

      Important: Use a suitable press (4) to install the right differential bearing (1).

    43. Press the right differential bearing (1) to the differential (3) with DT-48728 (2).
    44. Important: Use a suitable press (4) to install the left differential bearing.

    45. Rotate and press the left bearing to the differential with DT-48728 (2).

    46. Object Number: 1958940  Size: SH

      Important: Position the differential (1) to the differential housing (2) using a suitable tool or with the aid of an assistant.

    47. Position the differential (1) to the differential housing (2).

    48. Object Number: 1958978  Size: SH
    49. Position the left shim (3) and right shim (1) to the original position in the differential housing (2).

    50. Object Number: 1958942  Size: SH

      Important: Do not fully tighten the bearing bolts (1) is stage. The differential has to be able to move freely within the differential housing to allow fitment of the circlip.

    51. Position the differential housing cover to the differential housing and retain with the 4 bearing bolts (1).
    52. Turn the differential assembly left through 90° for the differential to slide down in the housing.

    53. Object Number: 1958944  Size: SH

      Important: Align the opening of the circlip (1) with the opening on the differential housing.

    54. Install the circlip (1) to the differential (3) with circlip pliars (2).
    55. Make sure the circlip (1) is fitted correctly.

    56. Object Number: 1958945  Size: SH

      Important: Tighten the differential housing cover to differential housing retaining bolts (1) working diagonally.

    57. Install the remaining differential housing cover to differential housing retaining bolts (1).
    58. Tighten
      Tighten the housing bolts to 53 N-m (39 lb  ft).

      Tighten
      Tighten the bearing bolts to 153 N-m (112 lb  ft).


      Object Number: 1958947  Size: SH
    59. Position the backlash tool  (1, 4) to the differential assembly (3).
    60. Secure the backlash tool (1) to the differential assembly (3) by adjusting the spreading nut (4).
    61. Mount the turning torque gauge (2) to the backlash tool  (1).
    62. Rotate the turning torque gauge (2) clockwise and record reading.
    63. Important: This figure is for NEW bearings only.

    64. Turning torque should be between 2.0 to 3.3 Nm (27 lb  in).
    65. If the measured turning torque is outside the tolerance:
    66. • Remove the rear differential housing.
      • If turning torque is too high or too low, fit a thinner or thicker shim respectively.
      • Repeat from steps 5-11 from the disassembly procedure then from step 27 onwards in the assembly procedure.
      • Check turning torque. Repeat until the turning torque is correct.
    67. Remove differential assembly. Repeat steps 5 through 11 from the disassembly procedure.

    68. Object Number: 1958948  Size: SH
    69. Position the pinion (4) on DT-48728 (3) in a suitable press (2).
    70. Important: The differential housing (1) must not rest on the press (2). Use a suitable supporting tool (3) to elevate pinion (4).

    71. Position the differential housing (1) over the pinion gear (4).

    72. Object Number: 1958949  Size: SH
    73. Position a NEW collapsible spacer (1) to the differential (2).

    74. Object Number: 1958951  Size: SH
    75. Position the pinion tail bearing (1) to the differential housing (2).

    76. Object Number: 1958952  Size: SH

      Important: Take care to only press the tail bearing until it rests on the collapsible spacer so that it is not damaged.

    77. Use a suitable press (2) and DT-48723 (1) to press the tail bearing until it rests against the collapsible spacer.
    78. Remove the supporting tool so that the differential housing rests on the table.

    79. Object Number: 1958954  Size: SH
    80. Lubricate the NEW pinion flange seal (1) with correct grease. Refer to Adhesives, Fluids, Lubricants, and Sealers .
    81. Important: Use DT-48727 to install the seals to correct depth.

    82. Install the pinion flange seal (1) to the differential housing (4) with DT-48727 (2) in a suitable press (3).
    83. Mount the differential housing (4) on a suitable holding device.

    84. Object Number: 1958955  Size: SH
    85. Position the pinion flange (2) to the differential (3).
    86. Lubricate the contact surface of the prevailing torque pinion flange retaining nut (1) with correct grease. Refer to Adhesives, Fluids, Lubricants, and Sealers .
    87. Apply correct loctite to the thread of the NEW prevailing torque pinion flange retaining nut (1).
    88. Important: Do not fully tighten the NEW prevailing torque pinion flange retaining nut at this stage. Overtightening will require disassembly and fitment of a new collapsible spacer and possibly bearings.

    89. Install the NEW prevailing torque pinion flange retaining nut (1) to the differential (3).

    90. Object Number: 1958956  Size: SH
    91. Install the universal pulley holder (3) to the pinion flange (1).
    92. Tighten the prevailing torque pinion flange retaining nut (2) carefully until it has no play.
    93. Remove the universal pulley holder from the pinion flange (1).
    94. Turn the differential assembly through 90°.

    95. Object Number: 1958958  Size: SH
    96. Position the turning torque gauge (1) to the prevailing torque pinion flange nut.
    97. Turn the turning torque gauge (1) in a clockwise direction and record reading.
    98. Important: This torque figure is for NEW bearings only.

    99. Turning torque should be between 2.2 and 2.7 Nm (20-25  lb  in).
    100. If the turning torque is below specified tolerance, tighten the prevailing torque pinion flange retaining nut in small steps and check turning torque until specified turning torque is reached.
    101. If the turning torque is above specified tolerance disassemble, fit new collapsible spacer and repeat until correct specification is achieved.

    102. Object Number: 1958959  Size: SH
    103. Position a dial gauge (2) to measure the concentric running on centering while turning the pinion (1).
    104. If the measured value is above .1mm remove the pinion flange and re-install at a different angle. Repeat steps 52-66 in the assembly procedure. Make sure the turning torque is .1-.2 N-m higher than recorded in step 63 but not higher than 2.7 N-m.

    105. Object Number: 1958960  Size: SH
    106. Position the backlash tool (2) to the differential assembly.
    107. Important: The location of the dial gauge on the backlash tool (2) arm corresponds to the edge of the ring gear (210mm)

    108. Position the dial gauge (1) to the backlash tool (2).
    109. Use a suitable tool to move the backlash tool (2) within the backlash and record the reading.
    110. Backlash must be between .07 and .18 mm.
    111. If the backlash is not between the specified tolerance, it must be adjusted with differential shims otherwise turning torque set during steps 38-43 will be changed.
    112. If a .05 mm thinner shim is used on the right a .05 mm thicker shim has to be added to the left.
    113. Remove the rear differential housing. Refer to steps 5 and 6 in the disassembly procedure.

    114. Object Number: 1958981  Size: SH
    115. Clean the mating faces of the differential housings (2).
    116. Important: Apply a 1mm liquid seal bead (1) to the differential housing. Use the graphic as a template.

    117. Apply a 1mm liquid seal bead (loctite 5910).(1) to the mating face of the differential housing. Refer to Adhesives, Fluids, Lubricants, and Sealers .
    118. Install the differential housing cover to the differential housing. Refer to steps 26 through 33.

    119. Object Number: 1958961  Size: SH

      Important: The left and right rear axle shaft seals are different sizes so there are 2 different size installers. Make sure that the correct seal installer is used for the correct seal.

      Important: Fill the space between the dust lip and the seal lip with the correct grease.

    120. Install the left and right rear axle shaft seals (1) using DT-48722 and DT-48721 (2).

    121. Object Number: 1958962  Size: SH
    122. Install two rear axle flanges or two sealing plugs (1) to seal the differential (3).
    123. Important: Set the air pressure regulator to .4 bar before connecting.

    124. Remove the oil drain plug and install the air pressure regulator (2).
    125. Connect the air supply to the regulator (2) and pressurise the differential (3) to .4 bar.
    126. Disconnect the air supply from the regulator (2).
    127. The pressure should not decrease from .4 bar within 3 minutes. If the pressure decreases, locate and repair leakage.
    128. Install the differential (3) to the vehicle. Refer to Differential Replacement .
    129. Fill the differential fluid. Refer to the filling procedure in Differential Oil Replacement .