2003 Chevrolet Express Van Owner's Manual - Page 306

FRT FRT If your vehicle has dual rear wheels, always use one of the correct rotation patterns shown here when rotating your tires. When you install dual wheels, be sure that vent holes in the inner and outer wheels on each side are lined up. After the tires have been rotated, adjust the front and rear inflation pressures as shown on the Certificationrrire label. Make certain that all wheel nuts are properly tightened. See "Wheel Nut Torque" under Capacities and Specifications on page 5- 101. I lQ If your vehicle has single rear wheels, always use one of the correct rotation patterns shown here when rotating your tires. Rust or dirt on awheel, or on the parts to which it is fastened, can make wheel nuts become loose after a time.The wheel could come off and cause an accident. When you change a wheel, remove any rust or dirt from places where the wheel attaches to the vehicle. In an emergency, you can use a cloth or a paper towel to do this; but be sure to use a scraper or wire brush later, if you need to, to get all the rust or dirtoff. See "Changing a Flat Tire" in the Index. 5-63