1998 xlt 5.4 once i try to change it into 4x4 hi, lo, or 4awd it does want to move and if it does it pops very hard and in will barly move, but when i put it back into 2wd, it drives fine. So do you think it is the transfer case? Or is there a motor to replace on the transfer case or something? I nerve had a 4x4 truck/suv so thats what i am thinking, i just got it on trade. Thanks