I have a 2004 Toyota Rav4. My car starts to vibrate at 40-45mph. The tires have been balanced and checked several times, but several mechanics have confirmed that this is not the problem. At this moment, it is still up on a mechanic's lift and everything on the outside underneath has been checked, the wheels and tires have been removed. The mechanics are baffled. The car vibrates on the lift when they rev it to 44MPH. Can a faulty constant velocity joint be causing this problem?