GMC Yukon 2007 Owner's Manual page 546

2. If it is visible, first try to tighten the cable by
turning the wheel wrench clockwise until you
hear two clicks or feel it skip twice. You
cannot overtighten the cable.
3. Loosen the cable by turning the wheel wrench
counterclockwise three or four turns.
4. Repeat this procedure at least two times. If
the spare tire lowers to the ground, continue
with Step 5 of Removing the Spare Tire
and Tools on page 535.
5. If the spare tire does not lower, turn the wheel
wrench counterclockwise until approximately
6 inches (15 cm) of cable is exposed.
6. Stand the wheel blocks on their shortest ends,
with the backs facing each other.
546
7. Place the bottom
edge of the jack (A)
on the wheel
blocks (B),
separating them so
that the jack is
balanced securely.