From what you're describing. .. that would be my bet. I'd open up and take a look. I recently priced up all of the parts for replacing the clutches and I believe it was well under $100.... and reading through the instructions it looks relatively straight forward for someone with a decent mechanical aptitude...

If You haven't already done so, download the parts manual from the sticky in the technical section. There's an exploded view of the tcase and you can order the parts from mopar-wholesale (or similar website).

Next summer I might pick up a junkyard tcase and rebuild it just so I have a spare on hand.... And because I love taking tcases apart; their internals are so cool. 8)