GMC 2010 Yukon XL Denali Owner's Manual page 477

Jacking Locations (Overall View)
A. Front Position
B. Rear Position
WARNING:
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.
WARNING:
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.
4. Position the jack under the vehicle as shown.
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