Vibration from Rear Drive Train

[JohnGarziglia]

I am getting a vibration above 70 mph from the rear drive train, which particularly manifests itself when accelerating above 60 mph. I know that it is impossible to definitively diagnose something like this from just describing it. But, I am wondering if anyone has had this symptom before, and if so what was the culprit? I am pretty sure it is not tire balance as it is much too fast a vibration to be either balance or an out-of-round tire. Rather, it has the feel of a worn U-joint, slip spline, out-of-balance drive shaft or whatever is there between the motor and the rear wheels.

Does anyone have any advice on what to look for? Is this something I need to take to a Tesla SC, or could a shop that does suspension work diagnose and repair whatever is the issue? Any advice or observations are greatly appreciated. Thanks!

 

[ML Auto]

If it changes when you accelerate and decelerate, it is probably a CV joint in one of the axles. Unless you have a ton of miles, a bad CV joint is usually due to a torn CV boot, which you can easily check. If there is no change to the vibration, try gently applying the brakes, as you could have a warped rotor or binding caliper (parking brake?). If neither one of those changes anything, then it is probably the tires. Any vibration in the rear would be tied to rotational speed, so they would all feel similar. If you definitely have a faster than wheel speed type of vibration, then it would be in the motor/gearbox area, which is not something you can easily diagnose.