I am having problems with the transfer case in my AWD for my 1999 Ford Explorer, it is cranking and slipping, what could be the cause?

Your Ford most likely is not disengaging/engaging correctly with your 4WD

AAMCO  | 09/14/2010
Auto Repair & Service Car Problems & Safety

Bruce says: Your Ford most likely is not disengaging/engaging correctly with your 4WD. The specialists at AAMCO are experienced in diagnosing problems such as this one occurring with your Ford Explorer.

Call AAMCO to at 1-(800) 462-2626 to schedule a diagnosis.
or locate an AAMCO near you, by visiting the AAMCO Locator page