Sounds like a binding center differential. I'm unfamiliar with the center diff on the 4EAT but I've had a binding center diff on a manual and it exhibits this exact behavior as the front and wheels want to turn at different speeds but aren't able to do so.
edit: Just read it's a transfer clutch..wonder if that's seized or a solenoid is dead.
edit: Just read it's a transfer clutch..wonder if that's seized or a solenoid is dead.
