GMC YUKON XL 2003 Manual page 434

Rust or dirt on
L,"
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.
I
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, put the wheel
nuts back on 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.
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