GM Service Manual Online
For 1990-2009 cars only

Caution: Do Not use flat mount wheels on dual ring type wheel applications. The use of flat mount wheels on a dual ring application may cause the wheel to loosen and could cause loss of vehicle control resulting in personal injury.

The 2003 model year may come equipped with 2 different style wheels.


Object Number: 964646  Size: SH
    • A Flat Mount Wheel has a flat mounting area located on the inboard side of the wheel. The Flat Mount wheel is design to improve brake corner performance. The aluminum wheels are the Flat Mount Wheel design. The flat mount wheels cannot be used to back service vehicles built with dual ring mount wheels. The aluminum wheel identification number is cast into the inboard side of the wheel.

Object Number: 964640  Size: SH
    • A Dual Ring Mount Wheel has a dual ring mounting area located on the inboard side of the wheel. The steel wheels are the Dual Ring design. The steel wheel identification number is stamped into the wheel near the valve stem.

Replace the wheel if any of the following conditions exist:

    • The wheel exhibits excessive runout
    • The wheel has elongated bolt holes
    • The wheel is severely corroded
    • The wheel is severely rusted
    • The wheel is cracked
    • The wheel is bent

Important: Air leaks caused by porosity on aluminum wheels are repairable. Refer to Aluminum Wheel Porosity Repair in Tires and Wheels.

Caution: If you are replacing the wheel(s), the wheel stud(s), the wheel nut(s) or the wheel bolt(s), install only new GM original equipment parts. Installation of used parts or non-GM original equipment parts may cause the wheel to loosen, loss of tire air pressure, poor vehicle handling and loss of vehicle control resulting in personal injury.

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