GMC 2005 Sierra 1500 Pickup Owner's Manual page 500

To release the spare tire from the secondary latch, do
the following:
1. Check under the vehicle to see if the cable
end is visible.
If the cable is not visible proceed to Step 6.
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 wrench
counterclockwise three or four turns.
5-106
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 5-93.
5. Turn the 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.
7. Place the bottom edge
of the jack (A) on the
wheel blocks (B),
separating them so that
the jack is balanced
securely.