{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 needed, to get all
the rust or dirt off. See Changing a Flat Tire on
page 5-82.
When It Is Time for New Tires
One way to tell when it’s
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of
tread remaining.
Some commercial truck
tires may not have
treadwear indicators.
You need a new tire if any of the following statements
are true:
• You can see the indicators at three or more places
around the tire.
• You can see cord or fabric showing through the
tire’s rubber.
• The tread or sidewall is cracked, cut or snagged
deep enough to show cord or fabric.
• The tire has a bump, bulge or split.
• The tire has a puncture, cut or other damage that
can’t be repaired well because of the size or
location of the damage.
5-75