1998 GMC Safari Owner's Manual - Page 307

Don't include the compact spare tire in your tire rotation. After the tires have been rotated, adjust front and the on rear inflation pressures as shown the Certificatiomire label. Make certain that all wheel nuts are properly tightened.See "Wheel Nut Torque" in the Index. When It's Time for New Tires One way to tell when it's time for new tires is to check the treadwear indicators, which will appear when your tires have only 1/16 inch(1.6 mm) or less of tread remaining. / L \ CAUTION: Rust or dirton awheel, or on the parts to which it is fastened, canmake wheel nuts become loose after a time. The wheel could come off and cause an accident. Whenyou change a wheel, remove any rust or dirt from places where thewheel attaches to the vehicle. In anemergency, you can use a cloth or a paper towel to dothis; but be sure touse a scraper orwire brush later,if you need to, to get all the rust or off. (See dirt "Changing a Flat Tire" in theIndex.) of You need a new tire if any the following statements are true: You can see the indicators at three or more places around the tire. You can see cord or fabric showing through the tire's rubber. The tread or sidewallis cracked, cut or snagged deep enough to show cord or fabric. The tire has a bump, bulge or split. The tire has a puncture, or other dam-age that cut can't be repaired well because the size or location of of the damage. 6-45