GMC 2004 Sierra 1500 Pickup Owner's Manual page 502

2. Use the wheel wrench to loosen all the wheel nuts.
Turn the wheel wrench counterclockwise to loosen
the wheel nuts. Don't remove the wheel nuts yet.
Notice: If your vehicle has QUADRASTEER™ and
you use a jack to raise the vehicle without
positioning it correctly, you could damage the
QUADRASTEER™ system. When raising your
vehicle on a jack, avoid contact with tie rods and tie
rod boots.
5-102
Jacking Locations
A. Front Location (2-Wheel Drive 1500 Series)
B. Front Location (All Other Series)
C. Rear Location (All Series)
3. Position the jack under the vehicle as shown. If the
flat tire is on the front of the vehicle (Two-Wheel
Drive 1500 Series 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.
If the flat tire is on the rear, position the jack under
the rear axle between the spring anchor and the
shock absorber bracket.
If you have added a snow plow to the front of your
vehicle, lower the snow plow fully before raising the
vehicle.