GMC Sierra 2008 Owner's Manual page 502

3. Attach the wheel wrench (H) and extensions (I)
together, as shown.
5. Raise the tire part way upward. Make sure the
retainer is seated in the wheel opening.
5-110
4. Insert the hoist end (F)
through the hole (G)
in the rear bumper and
onto the hoist shaft.
Do not use the
chiseled end of the
wheel wrench.
6. Raise the tire fully against the underside of the
vehicle by turning the wheel wrench clockwise
until you hear two clicks or feel it skip twice.
You cannot overtighten the cable.
7. Make sure the tire is stored securely. Push, pull (A),
and then try to turn (B) the tire. If the tire moves,
use the wheel wrench to tighten the cable.
8. Reinstall the spare tire lock, if the vehicle has one.