The actuator gear doesn't do anything as far as the car moving or not and it wont help with towing it either. Think of it as just adjusting how much power goes to the front or back not if the front is engaged or not. Its full time 4wd no matter what. The actuator doesn't "engage" anything.
The actuator on my wife's e53 has been fried for over a year now. New unit is laying on my desk waiting to be installed
She has put around 30,000 miles on it with it broke.