GM Service Manual Online
For 1990-2009 cars only

Replace any wheels that are bent or dented, or have excessive lateral or radial runout. Wheels with runout greater than specified may cause objectionable vibrations.


    Object Number: 979  Size: SH
  1. Use a straight edge 203-229 mm (8-9 in) long. Place the straight edge on the wheel inboard mounting surface. Try to rock the straight edge up and down within the mounting surface.
  2. Repeat this procedure on at least 3-4 different positions on the inboard mounting surface.
  3. • If you can rock the straight edge, the mounting surface is bent and you must replace the wheel.
    • Inspect the mounting wheel/nut holes for damage caused from over-torquing the wheel/nuts. Inspect for collapsed wheel/nut bosses. Inspect for cracked wheel bosses.

    Notice: The use of non-GM original equipment wheels may cause:

       • Damage to the wheel bearing, the wheel fasteners and the wheel
       • Tire damage caused by the modified clearance to the adjacent vehicle components
       • Adverse vehicle steering stability caused by the modified scrub radius
       • Damage to the vehicle caused by the modified ground clearance
       • Speedometer and odometer inaccuracy

    Important: 

       • Replacement wheels must be equivalent to the original equipment wheels in the following ways:
          - The load capacity
          - The wheel diameter
          - The rim width
          - The wheel offset
          - The mounting configuration
       • A wheel of the incorrect size or type may affect the following conditions:
          - Wheel and hub-bearing life
          - Brake cooling
          - Speedometer/odometer calibration
          - Vehicle ground clearance
          - Tire clearance to the body and the chassis

  4. Replace the wheel if the wheel is bent.
  5. Replace the wheel if the wheel/nut boss area is cracked.

To identify aluminum wheels the code, the part number, and the manufacturer identification cast into the back side of the wheel.