GMC Sierra 2010 Owner's Manual page 417

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 50.
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 36 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 36.
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