Cadillac 2005 CTS Owner's Manual page 363

{
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.
9. Remove any rust or
dirt from the wheel
bolts, mounting
surfaces and spare
wheel.
{
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.
10. Place the compact
spare tire on the
wheel-mounting
surface.
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