FORD 2012 F-550 v.2 - Manual (Page 224)

WARNING: Stay out of the trajectory (1) as indicated in the
illustration.
TIRE CARE
Inspecting your tires and wheel valve stems
Periodically inspect the tire treads for uneven or excessive wear and
remove objects such as stones, nails or glass that may be wedged in the
tread grooves. Check the tire and valve stems for holes, cracks, or cuts
that may permit air leakage and repair or replace the tire and replace
the valve stem. Inspect the tire sidewalls for cracking, cuts, bruises and
other signs of damage or excessive wear. If internal damage to the tire is
suspected, have the tire demounted and inspected in case it needs to be
repaired or replaced. For your safety, tires that are damaged or show
signs of excessive wear should not be used because they are more likely
to blow out or fail.
Improper or inadequate vehicle maintenance can cause tires to wear
abnormally. Inspect all your tires, including the spare, frequently, and
replace them if one or more of the following conditions exist:
Tires, Wheels and Loading
224
2012 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)