Would any happen to know if a anti spin differential was put into the Sport Tracs? If so would the VIN No. indicate it? If not, best way to identify it? If Ford did have a optional limited slip would anyone know if this unit could be swapped with another ford unit? Reason for the last question I have a 98 Splash 4x4 that the stock axle went out of and put a limited slip into it from a mustang which supposedly had the same axle. It did wonders in getting around without even putting the truck into 4x4 off road.

Limited slip was an option for the Sport Trac.. What year do you have? You can identify the axle options by the VCL (vehicle certification label) in the drivers door jamb.. Where it says 'axle' there should be a 'D' code 2~4 for the limited slips/ratios.. It will/should also have the rear diff tagged with the identifier info..