GMC 2007 Yukon XL Owner's Manual page 514

Jacking Locations (Overall View)
A. Front Position
B. Rear Position
514
CAUTION:
{
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.
CAUTION:
{
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.
3. Position the jack under the vehicle as shown.