Ford F series Owner's Manual page 287

Tire Rotation
Because your vehicle's front and rear tires
perform different jobs, they often wear
differently. To make sure your tires wear evenly
and last longer, rotate them as indicated in the
following diagram.
For tire rotation intervals, see the Maintenance
Schedule. If you notice that the tires wear
unevenly, have them checked.
NOTE: Do not rotate the dual rear tires.
Tire rotation pattern
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