GMC 2010 Yukon/Yukon XL Owner's Manual page 407

Use the following procedure to dolly tow a four-wheel
drive vehicle from the front:
1. Attach the dolly to the tow vehicle following the
dolly manufacturer's instructions.
2. Drive the front wheels onto the dolly.
3. Shift the transmission to P (Park).
4. Firmly set the parking brake.
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).
5. Shift the transfer case to N (Neutral). See Shifting
into N (Neutral) under Four-Wheel Drive .
6. Secure the vehicle to the dolly following the
manufacturer's instructions.
7. Release the parking brake only after the vehicle
being towed is firmly attached to the towing
vehicle.
8. Turn the ignition to LOCK/OFF.
After towing, see Shifting Out of N (Neutral) under
Four-Wheel Drive .
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