Hi ...I have a 2002 suburban with 198K miles. It recently has started to vibrate around 60-65mph. If I go 72-80, the vibration stops.. I am not a auto expert and don't want to get ripped off. Has anyone else encountered what might be cuasing this problem? Initially the truck all of a sudden started to vibrate regardless of speed, and they replaced the u-joints. That fixed the continuous vibration problem, but left me with the 60-65mph issue...any suggestions? thanks!