Mountaineer - hard steering at lower speed turns
 

I expirience hard steering at lower speed turns, it's like a 4x4 locked
My car :mercury mountaineer AWD 2004 4.6 V8
I just got this car, change the:
Front wheel bearings
Front deferential
Oil I transfer case
Oil in rear deferential
Car works just fine straight out but when I'm steering left or right , drive or revers car is stuck I berly can move , just like 4x4 locked mode, but I don't have option to switch that in this version , it's just AWD simple
Help!!!
Marrecki_max@yahoo.com