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 straightedge up and down within the mounting surface.

  2. Object Number: 980  Size: SH
  3. Repeat this procedure on at least 3-4 different positions on the inboard mounting surface.
  4. • The outer ring of the mounting surface normally is raised above everything inside the mounting surface.
    • The mounting surface will be raised above the outer ring if the wheel mounting surface has been bent on a tire changer.
    • If you can rock the straight edge, the mounting surface is bent and you must replace the wheel.

    Object Number: 981  Size: SH
  5. 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.
  6. The use of non-factory wheels may cause:
  7. • 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
    • Damaged 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

  8. Replace the wheel if the wheel is bent.
  9. Replace the wheel if the wheel/nut boss area is cracked.

Identify steel wheels with a 2 or 3-letter code stamped into the rim near the valve stem. Aluminum wheels have the code, the part number, and the manufacturer identification cast into the back side of the wheel.