1996 Pontiac Trans Sport Owner's Manual - Page 295

After the tires have been rotated, adjust the front and rear inflation pressures as shownon the Certificatioflire 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 or less of tread remaining. mm> on which Rust or dirt a wheel, or on the parts to it is fastened, can make wheel nuts become loose after a time. The wheel could comeoff and cause a wheel, remove an accident. When you change any rust or dirt from places wherewheel the attaches to the vehicle. In anemergency, you can be use a cloth or a paper towel to do this; but sure to use a scraper orwire brush later,if you need to, to get the rust or off. (See all dirt "Changing a Flat Tire" in the Index.) You need a new tire if any of 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 sidewall is cracked, cut snagged deep or enough to show cord or fabric. The tire has a bump, bulge or split. The tire has a puncture, cut or other damage that can't be repaired well because of the size or location of the damage. 6-39