We have a 2004 4x4 Suburban we tow. We have had no problems towing but our procedure to put the transfer case into neutral is a little different; put the ignition in the run position, place the parking brake on, place the transmission in neutral and press and hold the 2X and the 4XL buttons for approximately 10 seconds and the little red LED light will blink indicating the transfer case has been shifted into Neutral. Our steering column is locking so we have to leave the ignition in the run position to allow the wheels to turn when towing.