Ford F-650 2015 Owner's Manual page 250

Even wear: A sign that the tire is being properly used and maintained.
Erosion wear: Also called rolling wear, channel or river wear, erosion
wear occurs more often on free-rolling tires. This is an indication of
using the tire in a slow wearing operation. What happens is that the belt
plies are held very rigid and the tread is not allowed to distort as it
passes through the contact area. Wear only occurs at the edge of the
tread. No corrective action required. If erosion gets to be one–sixteenth
inch (2 millimeters) or more, you can rotate the tire to a drive axle.
Chamfer or shoulder wear: With tires inflated properly, this is a
normal tendency of most radial tire designs. If both inside and outside
shoulders are wearing evenly around the tire, no further action is
required. Over-inflation is not effective in correcting this effect.
Irregular Wear: If irregular wear is present, check the axle alignment,
tire pressure, wheel balancing, shock and suspension component
condition, and wheel bearing end play.
This condition not only shortens tire life, but also adversely affects the
handling of your vehicle, which is dangerous.
Rotating tires from one wheel position to another is an often-used way to
even out many types of irregular wear or to avoid it altogether. Some of
the more effective tire rotation programs are:
• You can rotate steer tires that have developed some type of irregular
wear pattern to drive axles if using rib tires on all wheel positions.
Applying steer tires to a drive position often cleans them. You can
move them back to the steer axles or run out to re-tread stage on the
rear axle.
• Another rotation possibility for fleets with rib tires in all wheel
positions is to break in the new steer tires in the drive axle positions,
then move them to steer axles. This wears away tread rubber
relatively quickly in the early life of a tire when it is most likely to
develop an unusual wear pattern.
• You can place drive axle tires on the other end of the same axle to
reverse the direction of rotation. This is often helpful if a heel and
toe or alternate lug wear pattern has developed.
You can help minimize irregular wear by:
• Using the right inflation pressure for the load being carried.
• Maintaining proper front wheel alignment, especially toe-in, to
specifications.
• Maintaining proper tire and wheel balance.
• Maintaining shock absorbers and suspension components.
Use of Tire Chains
See the chain manufacturer's recommendation for correct tire chain
usage, installation and removal.
2015 F-650/750 (f67)
Owners Guide gf, 2nd Printing, April 2014
USA (fus)
Wheels and Tires 249