GMC 2004 Sierra - Manual (Page 505)

5. Remove all the wheel
nuts and take off the
flat tire.
6. Remove any rust or dirt
from the wheel bolts,
mounting surfaces
and spare wheel.
{ CAUTION:
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the 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
the 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 you need to, to get
all the rust or dirt off.
{ CAUTION:
Never use oil or grease on studs or nuts. If you
do, the nuts might come loose. Your wheel
could fall off, causing a serious accident.
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