GMC Yukon XL Denali Owner's Manual page 384

10-68 Vehicle Care
4. Assemble the two jack handle
extensions (D) and wheel
wrench (E) as shown.
5. Insert the open end of the
extension (J) through the hole in
the rear bumper (I) (hoist shaft
access hole).
Be sure the hoist end (J) of the
extension (D) connects to the
hoist shaft (B). The ribbed
square end of the extension is
used to lower the spare tire.
6. Turn the wheel wrench (E)
counterclockwise to lower the
spare tire (H) 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 10 77 for more
information.