GMC 1998 Safari Owner's Manual page 253

Getting under a vehicle when it is jacked up is
dangerous. If the vehicle slips off the jack, you
could be badly injured or killed. Never get under
a vehicle when it is supported only by a jack.
Raising your vehicle with the jack improperly
positioned can damage the vehicle and even
make the vehicle fall. To help avoid personal
injury and vehicle damage, be sure to fit the jack
lift head into the proper location before raising
the vehicle.
U
7. Raise the vehicle by rotating the ratchet toward the
right. Make sure the UP mark faces you. Raise the
vehicle far enough off the ground so there is enough
room for the spare tire to fit.
8. Remove all the wheel nuts and take off the flat tire.
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