2010 GMC Sierra 1500 Crew Cab Owner's Manual - Page 568

Front Position - 1500 Models 3. Use the wheel wrench and turn it counterclockwise to loosen the wheel nuts. Do not remove the wheel nuts yet. Front Position - All Other Models 4. Position the jack under the vehicle as shown. If the flat tire is on the front of the vehicle (1500 Model vehicles), position the jack under the bracket attached to the vehicle's frame, behind the flat tire. If the flat tire is on the front of the vehicle (all other models), position the jack on the frame behind the flat tire. 6-108