When towing an AWD vehicle with the rear wheels on the ground, the non-driven front wheels spin freely, while the driven rear wheels are forced to turn by the moving vehicle. This can cause damage to the transaxle, as it forces components of the AWD system, including differentials and transfer cases, to work against each other.
For safe towing of AWD vehicles, It's recommended to put all four wheels up on a flatbed tow truck or use a different method that ensures that the drive wheels can rotate freely.
