GMC 2006 Sierra 1500 Pickup Owner's Manual page 494

If your vehicle has dual rear wheels and the tread
design for your front tires is the same as your rear tires,
always use one of the correct rotation patterns shown
here when rotating your tires.
5-82
The dual tires are rotated as a pair, and the inside rear
tires become the outside rear tires.
When you install dual wheels, be sure the 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 Tire and
Loading Information label. See Loading Your Vehicle on
page 4-48.
If your vehicle has dual
rear wheels and the tread
design for the front
tires is different from the
dual rear tires, always use
the correct rotation
pattern shown here when
rotating your tires.