For 1990-2009 cars

# TIRE WARRANTIES IRREGULAR/PREMATURE WEAR

ALL MODELS

As in the past, tires continue to be warranted by the tire manufacturer against defects in material or workmanship. Details of this limited warranty may be found in each tire company warranty booklet, which is part of the glove box material. The GM Warranty and Owner Assistance booklet also now states that the GM Dealer will assist the customer in obtaining a tire adjustment, if necessary.

Tire conditions caused by vehicle defects are warranted by General Motor. This statement is now included in the GM Warranty and Owner Assistance booklet. This applies during the basic coverage period, which is 12 months/12,000 miles, and should be applied to all past and current models. Examples of tire conditions that fall within GM's responsibility may include tire damage during vehicle assembly, tire damage due to tire-to-vehicle interference, and irregular/premature tire wear. Tire wear due to abusive driving is not covered by warranty.

Irregular/premature tire wear is aggravated by excessive toe-in (or toe-out). Excessive camber can also be a contributor, as can operating conditions, such as city driving with a lot of cornering. Irregular tire wear usually occurs on non-drive axles, such as the front wheel positions of rear drive vehicles. An early indication may be an increase in tire noise. In most cases, modified "X" tire rotation, which is a scheduled maintenance at 7500 miles, will equalize tire wear (see Fig. 1). Some amount of wear is expected and should be considered normal. Only when the crow grooves in the tread disappear within 12,000 miles should the tires be replaced under warranty (see Fig. 2). Even when these grooves disappear, however, the tire is normally only half worn in this area. Whenever tires are replaced for this reason, alignment should be checked and reset to specification, if necessary. If tires are needed for any of the above conditions, they should be purchased from your local tire outlet. If tires are not readily available, each tire manufacturer has a toll-free assistance line for car and truck dealers. These numbers have been previously provided in Dealer Management Bulletin 88-1-12. The tire invoice amount should be entered as a net item on the warranty claim. Labor code E0420, replace wheel and/or tire, should be used.

In Figure 1, the rotation pattern eventually gets each tire on all four positions. It gets those tires on the non-drive axel, which are most prone to irregular wear, to turn in the opposite direction. This will equalize wear the quickest, and tire noise related to tread wear will actually become quieter after a few thousand miles.

Evaluating Tire Wear - Typical All-Season Tire. (Figure 2)

Tire should be replaced only if these grooves are no longer visible within first 12,000 miles.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.