Factors such as maintenance, temperatures, driving speeds, vehicle loading, and road conditions affect the wear rate of the tires.

Treadwear indicators are one way to tell when it is time for new tires. Treadwear indicators appear when the tires have only 1.6mm (1/16 in) or less of tread remaining. See Tire Inspection and Tire Rotation.
The rubber in tires ages over time. This also applies to the spare tire, if the vehicle has one, even if it is never used. Multiple factors including temperatures, loading conditions, and inflation pressure maintenance affect how fast aging takes place. GM recommends that tires, including the spare if equipped, be replaced after six years, regardless of tread wear. The tire manufacturer date is the last four digits of the DOT Tire Identification Number (TIN) which is molded into one side of the tire sidewall. The first two digits represent the week (01–52) and the last two digits, the year. For example, the third week of the year 2010 would have a four-digit DOT date of 0310.
Vehicle Storage
Tires age when stored normally mounted on a parked vehicle. Park a vehicle that will be stored for at least a month in a cool, dry, clean area away from direct sunlight to slow aging. This area should be free of grease, gasoline, or other substances that can deteriorate rubber.
Parking for an extended period can cause flat spots on the tires that may result in vibrations while driving. When storing a vehicle for at least a month, remove the tires or raise the vehicle to reduce the weight from the tires.
Tire Rotation
Buying New TiresRear Side Door Window Replacement (Sedan)
Rear Side Door Window Replacement
Callout
Component Name
Warning: Refer to Glass and Sheet Metal Handling Warning.
Preliminary Procedures
Remove the rear side door trim panel. Refer to Rear Side Door Trim
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Brake Drum Refinishing
Special Tools
CH-41013 Rotor Resurfacing Kit
CH-42450-A Wheel Hub Resurfacing Kit
For equivalent regional tools, refer to Special Tools.
Warning: Refer to Brake Dust Warning.
The brake drums do not require refinishing as part of routine brake system
service. Do not refinis ...
Hub/Axle Flange and Wheel Stud Runout Inspection
Special Tools
GE-8001 Dial Indicator Set , or equivalent
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
Mark the location of the wheels to the wheel studs and mark the specific
vehicle position on each tire and wheel ?ELF, LR, RF, RR.
Remove the tire and w ...