GMC 2006 Yukon XL Owner's Manual page 454

2. Assemble the wheel wrench (H) and the two jack
handle extensions (I) as shown.
Be sure the hoist end of the extension connects to
the hoist shaft (E). The ribbed square end of the
extension is used to lower the spare tire.
5-80
3. Insert the spare tire
end (open end) (F)
of the extension
through the hole (G)
in the rear bumper.
4. Turn the wheel wrench (H) counterclockwise to
lower the spare tire to the ground. Continue to
turn the wheel wrench until the spare tire can be
pulled out from under the vehicle.
If the spare tire does not lower to the ground, the
secondary latch is engaged causing the tire not to
lower. See Secondary Latch System on page 5-88.
5. Use the wheel wrench
hook that allows you
to pull the hoist
cable towards you
to assist in reaching
the spare tire.