As previously stated, you have a T5 problem. Weak tranny. If it were me, I would replace it with something better. Yesterday I saw a T176/D300 combo for sale for $300. Will post up the link if I can find it again. Personally, I wouldn't waste any time or money on another T5 just to have it crap out on me again. That's why I'm now running a T18.
RED Friday. Remember Everyone Deployed
45 MB, 67 Commando, 85 CJ, 08 JKU, 11 JKU