GM S10/S15/Sonoma Pick-Ups 1982-1993 Repair Manual

Axle Housing



See Figures 1, 2 and 3

  1. Raise and support the rear of the vehicle safely using jackstands under the frame. Position a floor jack or a second set of jackstands to support the rear axle housing. If a floor jack is being used, take care when removing the U-bolts to keep the axle from suddenly dislodging.
  3. Remove the rear wheels and drums for clearance and to remove some weight from the axle housing.
  5. Matchmark and remove the rear driveshaft from the pinion flange. Either remove the shaft completely from the vehicle or support it aside from the undercarriage using safety wire, but DO NOT allow the shaft to hang from the slip joint.
  7. Remove the shock absorber-to-axle housing retainers, then swing the shock absorbers away from the axle housing.
  9. Disconnect the brake lines from the axle housing clips and the backing plates (wheel cylinders).

When disconnecting the brake lines from the wheel cylinders, immediately plug or cap the lines to prevent system contamination or excessive fluid loss.

  1. If applicable on late model vehicles, disengage the speed sensor connectors at the junction block.
  3. If necessary, disconnect the parking brake cable(s).
  5. Disconnect the axle housing-to-spring U-bolt nuts, washers. U-bolts and the anchor plates.

Click image to see an enlarged view

Fig. Fig. 1: View of the rear axle and leaf spring assembly from under the vehicle

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Fig. Fig. 2: Exploded view of the rear axle mounting

  1. Remove the vent hose from the top of the axle housing.
  3. Remove the axle with the help of an assistant by moving it to clear the leaf spring, or if desired, the leaf springs can be disconnected from the frame at the rear end to lower the axle down and back, but first refer to the leaf spring procedures for information regarding spring installation and removal.

To install:

Click image to see an enlarged view

Fig. Fig. 3: Exploded view of a common rear axle assembly

  1. With the help of an assistant, carefully position the rear axle into the vehicle.
  3. Connect the vent hose to the axle housing.
  5. Be sure the housing is properly positioned on the leaf spring, then loosely install the U-bolts, anchor plates, washers and nuts.
  7. Tighten the U-bolt nuts in a cross pattern to 18 ft. lbs. (25 Nm) to made sure everything is evenly seated. Then torque the nuts in steps to to 41 ft. lbs. (55 Nm), then to 85 ft. lbs. (115 Nm).
  9. Remove the caps from the brakes lines then connect the lines and secure them to the axle housing.
  11. If removed, connect the parking brake cable(s).
  13. If applicable, engage the speed sensor connectors to the junction block.
  15. Align and install the driveshaft assembly. Refer to the procedure earlier in this section for details.
  17. Install the shock absorbers to the lower mounts, then tighten the mount nuts.
  19. Install the brake drums and the tire/wheel assemblies.
  21. Properly refill the brake master cylinder and bleed the hydraulic brake system.
  23. Check the fluid level in the rear axle assembly and add, as necessary. Make sure the vehicle is level when checking and adding fluid.
  25. Remove the jackstands and carefully lower the truck.