LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 45 (Rear Drive Axle) >> Repair Instructions >> Differential Carrier Bearing Preload Adjustment (9.5 Inch Axle) >> Wedge Method

Wedge Method

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

Special Tools 

J - 22779  Side Bearing Shim/Backlash Gauge

CAUTION:

Do not re-use the old pinion nut. Stake the NEW pinion nut after the final rotating torque is achieved. If the pinion nut is not staked after the final rotating torque is achieved, the nut may lose retention causing loss of vehicle propulsion.

NOTE:
  • Ensure that the side bearing surfaces in the axle housing are clean and free of burrs. If the original bearings are to be reused, the original bearing cups must also be used.
  • The drive pinion bearing preload must be within specifications before the differential side bearing preload adjustment can be performed.
  • The differential side bearings must be initially preloaded in order to determine the backlash of the gear set. After the backlash is set, the final bearing preload is set.
    • In order to maintain the original backlash, adjust the differential case side bearing preload by changing the thickness of the left and the right side shim packs equally.
    • Measure the service shims and the spacers one at a time. Add the measurements together in order to obtain the total thickness of the left or the right side shim pack.
    • Do not use or reuse the original cast iron production shims. Use service shims and spacers instead.
    WARNING:

    To prevent personal injury and/or component damage, support the differential case when removing the case from the axle housing. If the case is not supported, the differential case could fall and cause personal injury or damage to the differential case.

  1. Remove the differential assembly, if necessary.
  2. Using an inch-pound torque wrench, measure the rotating torque of the drive pinion bearing. should be 1.7 - 3.4 N.m (15 - 30 lb in) for new bearings and 1.1 - 2.3 N.m (10 - 20 lb in) for used bearings.
  3. If the rotating torque of the drive pinion is less than: 1.7 N.m (15 lb in) for new bearings or 1.1 N.m (10 lb in) for used bearings, tighten the pinion in small increments until the specified rotating torque is obtained.
  4. If the rotating torque of the drive pinion is greater than 3.4 N.m (30 lb in) for new bearings or 2.3 N.m (20 lb in) for used bearings, replace the collapsible spacer. Refer to Differential Drive Pinion Gear Bearing Replacement (10.5 Inch Axle) , or Differential Drive Pinion Gear Bearing Replacement (9.5 Inch Axle) .
  5. GM4886706

    Use a hammer and punch to stake two sides of the drive pinion nut lip to the corresponding grooves (1) in the drive pinion gear.

  6. Install the differential assembly, if necessary.
  7. Support the differential assembly in order to prevent the differential assembly from falling out of the axle housing.
    8. NOTE:

    DO NOT force the ring gear into contact with the drive pinion.

  8. Slide the differential case assembly towards the right side axle housing until the ring gear contacts the drive pinion. This is the ZERO backlash point.
  9. Install the differential assembly with the differential side bearings and differential side bearing cups into the axle housing.
  10. Insert one 4.318 mm (0.170 in) thick service spacer into the left side of the axle housing.
  11. Side the differential assembly towards the service spacer in order to hold the spacer in place.
  12. Install the J - 22779  gauge between the right side differential side bearing cup and the axle housing.
    13. NOTE:

    Over-tightening of the J - 22779  gauge may spread the housing and result in incorrect shim selection.

  13. Tighten the knob on the J - 25588  installer until there is moderate drag when the J - 22779  gauge is moved.
  14. Remove the J - 22779  gauge.
  15. Remove the service spacer.
    16. NOTE:

    Record the measurement.

  16. Using a micrometer, measure the thickness of the service spacer.
    17. NOTE:

    Record the measurement.

  17. Using a micrometer, measure the thickness of the J - 22779  gauge in 3 locations. Calculate the average of the 3 measurements.
  18. Add the thickness of the service spacer, measured in step 11 to the average thickness of the J - 22779  gauge, measured in step 12. The resulting value is the total service shim thickness without preload for the axle.
  19. Insert one BENT 1.016 mm (0.040 in) service shim between the right side differential side bearing cup and the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
  20. Install the J 22779  gauge into the left side of the axle housing. The J 22779  gauge must be installed between the service spacer and the differential side bearing cup.
  21. While rotating the ring gear back and forth, tighten the knob on the J - 22779  gauge until there is approximately 0.025 - 0.051 mm (0.001 - 0.002 in) of backlash between the ring gear and the drive pinion.
  22. Once the correct amount of backlash is obtained, remove the J - 22779  gauge.
  23. Remove the differential assembly with the differential side bearings and the differential side bearing cups.
  24. Remove the BENT service shim.
  25. Using a micrometer, measure the thickness of the J - 22779  gauge in 3 locations. Calculate the average of the 3 measurements. This value is the left side service shim thickness without preload.
  26. In order to determine the right side service shim thickness, subtract the service shim thickness for the left side of the axle, calculated in step 17, from the total service shim thickness, calculated in step 13. This value is the service shim thickness for the right side of the axle without preload.
  27. In order to preload of the differential side bearings and set the backlash to approximately 0.127 - 0.223 mm (0.005 - 0.009 in), take the value determined in step 21 and add 0.203 mm (0.008 in) service shim thickness to this amount.
  28. Assemble the left side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of service shims equaling the thickness determined in step 24. Measure the service spacer and the service shims separately. Add the measurements together in order to determine the total shim pack thickness.
  29. Assemble the right side shim pack using one 4.318 mm (0.170 in) service spacer and the appropriate amount of service shims equaling the thickness determined in step 26. Measure the service spacer and the service shims separately. Add the measurements together in order to determine the total shim pack thickness.
  30. Install the differential assembly with the differential side bearings and the differential side bearing cups.
  31. Install the left side service spacer and service shim into the axle housing. The service shim must be installed between the service spacer and the differential side bearing cup.
  32. Install the right side service spacer between the axle housing and the differential side bearing cup.
  33. Install the right side service spacer into the axle housing using a brass drift or rod. The service shim must then be installed between the service spacer and the differential side bearing cup.
    34. CAUTION:

    Refer to Fastener Caution .

  34. Install the differential bearing caps and the bolts and tighten to:
    1. First pass at 60 N.m (44 lb ft).
    2. Final pass an additional 30 degrees
  35. Rotate the pinion several times to ensure the drive pinion and differential side bearings have seated.
    36. NOTE:

    Record the measurement.

  36. Using an inch pound torque wrench, measure the rotating torque of the drive pinion and differential side bearings which should be 0.57 - 1.13 N.m (5 - 10 lb in) greater than the rotating torque of the drive pinion measured earlier.
  37. Calculate the differential side bearing preload by subtracting the drive pinion preload, measured in step 2, from the drive pinion and differential case bearing preload, measured in step 31. Multiply the value obtained by the axle ratio. The differential side bearing preload should be 1.7 - 4.0 N.m (15 - 35 lb in).
  38. If the differential side bearing preload is not within specifications, add or subtract shim thickness equally from each shim pack as necessary in order to increase/decrease the side bearing preload.
  39. Once the differential side bearing preload is correct, measure the backlash and adjust, if necessary. Refer to Backlash Adjustment (9.5 Inch Axle) , or Backlash Adjustment (10.5 Inch Axle) .
  40. Once the differential side bearing preload and backlash is correct, perform a gear tooth contact pattern check in order to ensure proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern Inspection .
scientia non olet · About LEMON Manuals