My jeep used to have the same issues. I ignored it (i was a teenager) and ended up having my T-case basically explode.
In a related story, after my T-case was replaced I ignored my transmission leaking and kept it full of fluid and checked it regularly. One day on the freeway 5th gear decided to give up on life and grenade, perfing my transmission and leaving me a loooong way from home.
Those 2 fixes cost me about 3 grand and that was with cheap labor as I knew the owner of the shop I took it to.
Moral of the story? Take it to the dealership and explain what's going on and see if you will be covered. If not, spend the few hundred bucks to find out the actual cause of the issue and fix it. You'll save a crap-ton of cash in the long run.
(( My jeep still runs with over 220k miles on it and over the course of it's life has had these parts replaced: both axles, both driveshafts, 2x T-case, 1 Transmission, and 3 or 4 fresh installs of carpet in it, none for upgrades, all because I trashed the stockers LOL ))