Chevrolet 2004 Express Van Owner's Manual page 319

If your vehicle has single rear wheels, always use one
of the correct rotation patterns shown here when rotating
your vehicle's tires.
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
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.
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.
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