Chevrolet 2006 Avalanche Owner's Manual page 342

Four-Wheel-Drive Vehicles
Use the following procedure to tow your vehicle:
1. Shift the transmission to PARK (P).
2. Turn the engine off, but leave the ignition on.
3. Firmly set the parking brake.
4. Securely attach the vehicle being towed to the tow
vehicle.
4-58
CAUTION:
{
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. See Parking Brake on
page 2-40.
5. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-35 for the proper
procedure to select the neutral position for your
vehicle.
6. Release the parking brake only after the vehicle
being towed is firmly attached to the towing
vehicle.
7. Turn the ignition off to lock the steering column.