2010 GMC Sierra 1500 Crew Cab Owner's Manual - Page 430

Four‐Wheel‐Drive Vehicles Use the following procedure to dolly tow a four-wheel-drive vehicle from the rear: 1. Attach the dolly to the tow vehicle following the dolly manufacturer's instructions. 2. Drive the rear wheels onto the dolly. 3. Firmly set the parking brake. See Parking Brake on page 3‑54. 4. Put the transmission in P (Park). 5. Secure the vehicle to the dolly following the manufacturer's instructions. 6. Use an adequate clamping device designed for towing to ensure that the front wheels are locked into the straight position. { WARNING: Shifting a four-wheel-drive vehicle's transfer case into N (Neutral) can cause the vehicle to roll even if the transmission is in P (Park). The driver or others could be injured. Make sure the parking brake is firmly set before the transfer case is shifted to N (Neutral). 7. Shift the transfer case to N (Neutral). See "Shifting into Neutral" under Four-Wheel Drive on page 3‑39 for the proper procedure to select the neutral position for the vehicle. 8. Turn the ignition to LOCK/OFF. After towing, see "Shifting Out of Neutral" under Four-Wheel Drive on page 3‑39. 5-54