GMC 1994 Yukon Owner's Manual page 234

Start with the jack, the
jack handle and the
ratchet.
If the flat tire is on the
rear of the vehicle,
you'll need the jack
handle extensions
a1 so.
Attach the jack handle
(and jack handle
extensions, if needed)
to the jack.
UP Marking DOWN Marking
The ratchet has an UP and a DOWN marking.
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