Hello all!! Question for you 4x4 experts: 04 XLT Explorer with 4.0 v6, 70k miles, and 44-11 transfer case (2 speed). I am looking for information on how the front axle actuates. (IE, is it a live axle or is there a disconnect such as a vacuum or electric motor setup). I understand how the Auto/4Hi/4Lo works on the tcase. But how does this interact with the front axle? I am researching a loud bang that occurs as I backup and turn the vehicle. It's almost as if I get crowhop and then something in the axle lets loose when it binds up. There are no codes or other drivability issues. This is entirely in auto 4wd mode. The system seems to work fine in 4Hi and 4Lo modes with the normal crowhop but without the bang that I described above. Please advise or let me know if there is info I left out. The driveshaft joints seem to be fine.

Thanks!! ed