I have bought a Chrysler T&C 2001 AWD and have noticed as I drive that right between 40 and 45mph I feel a dull vibration in my seat. I had the dealership to look at it and they say they fixed the problem which was the rearend gears. Its been abot a year now and I feel the same thing at the same speed. Has anyone else had this experience with this type of van and what did you do that fixed it. Any help would srely be appreciated.