Cadillac 2009 DTS Owner's 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 changing a wheel, remove any
rust or dirt from places where the wheel attaches
to the vehicle. In an emergency, 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 5-74.
11. Place the spare tire on the wheel-mounting surface.
CAUTION:
{
Never use oil or grease on bolts or nuts because
the nuts might come loose. The vehicle's wheel
could fall off, causing a crash.
12. Put the wheel nuts back
on with the rounded
end of the nuts toward
the wheel. Tighten each
nut by hand until the
wheel is held against
the hub.
5-81