Guess it was bound to happen. Prep shop told me that my diff was leaking. I took it apart this weekend to repair and found that the ring gear and pinion (might have my terminology wrong - the big gear and the little one that meshes into) are missing teeth with the teeth in the case. from my reading, it looks like this "happens." Any cause for it? (Wasn't running low on gear oil).
In terms of replacing them, the car has an old Mazda Comp diff that's never given me any trouble. Should I just get new ones and have a shop set it up? Or should I upgrade to a torsen?