GMC 2001 Sierra 1500 Pickup Owner's Manual page 334

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.
5-28
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.
6. After mounting the
spare, replace the wheel
nuts with the rounded
end of the nuts toward
the wheel. Tighten each
wheel nut by hand using
the wheel wrench until
the wheel is held against
the hub.