GM Service Manual Online
For 1990-2009 cars only

Important: Under no circumstances should the axle housing be straightened in order to correct an alignment problem. Replace the axle assembly if faulty.

If the alignment machine or the rear tire wear indicates that the axle housing may be misaligned or damaged, the alignment can be checked using the following procedure:

  1. Check the vehicle alignment on an alignment machine.
  2. Compensate for the rear wheel runout the same as checking the front wheel toe-in.
  3. Check the camber reading which should be 0.03 degrees negative to 0.05 degrees positive.
  4. Check the amount of the toe-out which should be 0-0.05 degrees or 0-1.58 mm (0-1/16 in).
  5. • If it is necessary to back the vehicle onto an alignment machine in order to measure the alignment, the actual toe-out will be read on the scale as toe-in. If the toe-out is checked with a tram gauge, disregard this step.
    • If a tram is used for checking the toe-out, still perform Steps 1 and 2 in order to check camber.

The rear wheels cannot be aligned by conventional means. The axle housing and the springs, if damaged, must be replaced.

The frame, under most circumstances, may be straightened. The necessary straightening operations may be done using the frame straightening equipment or by relocating the spring to the axle without removing the axle housing from the vehicle. This procedure will allow the checks during the straightening operation in order to determine when the axle/spring assembly is within the correct limits.

If the frame and the springs are within specification, the rear axle assembly must be replaced.