2004 GMC Sierra 1500 Pickup Owner's Manual - Page 352

Dolly Towing Four-Wheel-Drive Vehicles Use the following procedure to tow your vehicle: 1. Drive the vehicle up onto the tow dolly. 2. Shift an automatic transmission to PARK (P), or a manual transmission to FIRST (1). 3. Turn the engine off, but leave the ignition on. 4. Firmly set the parking brake. 5. Securely attach the vehicle being towed to the tow dolly. {CAUTION: Shifting a four-wheel-drive vehicle's transfer case into NEUTRAL can cause your vehicle to roll even if the transmission is in Park (P) for an automatic transmission, or if your vehicle is in gear, for a manual transmission. You or others could be injured. Make sure the parking brake is firmly set before you shift the transfer case to NEUTRAL. Two-Wheel-Drive Vehicles Two-wheel-drive vehicles should not be towed with the rear wheels on the ground. Two-wheel-drive transmissions have no provisions for internal lubrication while being towed. Two-wheel-drive vehicles can be dolly towed with the front wheels on the ground provided that the wheels are straight and the steering column has been locked. 4-56