Long story here. I bought my 2007 rubi unlimited used 2 years ago. (Jan 2008) It had 38,000 k on it. I took it out to McLean did some jeepin, and noticed that the rear locker light would flash sporadicly when in use, the front locker light would stay steady. At 50,000k I took the jeep into Tower chrysler to get some warrenty work done, and asked them to look into the rear diff, at this point they asked me what oil i used in the rear diff, I used 80W90 as per the manual. They then told me they would not look at it because I used the wrong oil. They said the book was a misprint, and I should use 75 w 140 synthetic. So I went and bought some valoline oil at can tire and changed the oil, put a couple thousand kms on it and tried the locker again, no change. So I called Tower back up and left a message for the service people to call me back as I wanted to make another appointment to get it looked at. They never called me back, and as I have the gold warrenty package I was not to worried about it. So now at 98,000 k I have taken it to Varsity chrysler, as it is close to work, they tell me I need a new carrier, and if I dont supply them with reciepts for the diff servicing I have no warrenty and I have to eat the bill for the repair. I am in the midst of moving, and I packed my garage, so I am not sure if I even have reciepts to givbe them. So does anyone here have experience dealing with this sort of thing?