GMC 2009 Sierra - Manual (Page 385)

{ CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after 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 5-81.
Make sure the spare tire is stored securely.
Push, pull, and then try to rotate or turn the tire.
If it moves, tighten the cable. See Storing a Flat
or Spare Tire and Tools on page 5-94.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions,
influence when you need new tires.
One way to tell when it
is time for new tires is
to check the treadwear
indicators, which 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 new tires 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 cannot be repaired well because of the
size or location of the damage.
5-73