GMC Sierra 2014 Owner's Manual page 449

3. Use the wheel wrench and turn it
counterclockwise to loosen the
wheel nuts. Do not remove the
wheel nuts yet.
Front Position 1500 Models
4. Position the jack under the
vehicle, as shown. If the flat tire
is on the front of the vehicle
(1500 models), position the jack
under the bracket attached to
the vehicle's frame, behind the
flat tire.
Vehicle Care
Front Position All Other Models
Position the jack under the
vehicle, as shown. If the flat tire
is on the front of the vehicle (all
other models), position the jack
on the frame behind the flat tire.
10-83