GM Service Manual Online
For 1990-2009 cars only

Inspect for the following conditions:

    â€¢ Inspect for misaligned wheels.
    â€¢ Inspect for excessive toe or camber.
    â€¢ Inspect for broken springs.
    â€¢ Inspect for sagging springs.
    â€¢ Inspect for mispositioned springs.
    â€¢ Inspect for incorrect tire balance.
    â€¢ Inspect for wear or damage to the strut.
    â€¢ Inspect for wear or damage to the shock absorbers.
    â€¢ Inspect for signs of vehicle abuse.
    â€¢ Inspect for uneven or excessive loading of the vehicle.
    â€¢ Inspect for incorrect tire pressure.
    â€¢ Inspect for properly rotated tires.

The original equipment tires have built-in tread wear indicators to show when tires need replacement. These indicators appear as 12.7 mm (1/2 in) wide bands when the tire tread depth becomes 1.6 mm (1/16 in). When the indicators appear in 2 or more grooves at three locations, tire replacement is recommended.

The following conditions may cause irregular and premature tire wear:

    â€¢ Incorrect inflation pressures
    â€¢ Lack of tire rotation
    â€¢ Driving habits
    â€¢ Wheel alignment

Rotate the tires if the following conditions are noted:

    â€¢ When the front tire wear is different from the rear tire wear.
    â€¢ When uneven wear exists across the tread of any tire.
    â€¢ When the left front and the right front tire wear is unequal.
    â€¢ When the left rear and right rear tire wear is unequal.

Check wheel alignment if the following conditions are noted:

    â€¢ When the left and the right front tire wear is unequal.
    â€¢ When the rear is uneven across the tread of any front tire.
    â€¢ When the front tire treads have a scuffed appearance with feather edges on one side of tread ribs or blocks.