2004 Chevrolet Express Van Owner's Manual - Page 319

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 Certification/Tire label of the Tire and Loading Information label. See Loading Your Vehicle on page 4-31. Make certain that all wheel nuts are properly tightened. See "Wheel Nut Torque" under Capacities and Specifications on page 5-106. If your vehicle has single rear wheels, always use one of the correct rotation patterns shown here when rotating your vehicle's tires. {CAUTION: Rust or dirt on a wheel, 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 dirt off. See "Changing a Flat Tire" in the Index. If your vehicle has dual rear wheels, always use one of the correct rotation patterns shown here when rotating your tires. 5-69