GMC 2004 Savana - Manual (Page 325)

When the tire has been lowered, pull the tire toward you
so you can reach the tire retainer and pull it up
through the wheel opening.
If you have a vehicle which was completed from a cab
and chassis, refer to the information from the body
supplier/installer.
The spare tire is a full-size tire, like the other tires on
your vehicle.
Notice: If you drive away before the spare tire or
secondary latch system cable has been reinstalled,
you could damage your vehicle. Always reinstall
this cable before driving your vehicle.
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