there is your problem right there. No need for a new tcase. Your shifter linkage is probably binding from the 2" body lift. Here is what I would do. Remove the 2" body lift and replace with a 2" spacer lift on the springs. That should get your tcase shifter back where it should be.
The problem arises because part of the shifter mechanism is mounted on the body tub, and part is mounted to the tcase. So when you lift the body it misaligns the shifter linkage and causes it to bind, pop out, or not function at all.