OK since I've owned this caddy in July, I've had a constant problem with a vibration in which I fully expected to be a wheel balance problem. From the countless balancing (5 or 6 times all four wheels) to the new tires put on in September, this wonderful "shimmy, shake, vibration" has yet eluded me from its origin. I even went as far as to replace that right rear with a new tire AND a new wheel.

FINALLY, two weeks ago I took it to this independent alignment shop and he spun the tires on the car. The front ones did great, the left rear not enough to get upset about, but the right rear,.........HELLO! He puts his magical machine and spins the tire up past 100mph then on it's way down bingo! A wonderful HUGE vibration/shake at approx 70mph (which is right on really to my hwy experience)

Now the question is, the tire is brand new and so is the wheel but the perfectly balanced wheel still does it's familiar vibration/shake between 65 and 85 mph.

I'm beside myself here.

Any suggestions? Tips? Hints?

Any familiar scenarios?

All is appreciated, thanks. Kevin

 

However you want to do it swap known good tire/wheel to right rear and spin it up again. If vibration is gone you know it's with the wheel and tire. Go back to the seller to have them determine cause. If vibration is still there rotor or hub could be the cause, you need to check 'run out' on both. More than .003 is not good. Hub bearing also should not have any play.

 

Struts my friend, how are yours mine were bad in the rear and shaking bad at hwy speeds it caused me to blow threw tried fast I just replaced my shocks and tired then bingo problems solved... so I think yes this drastically helped but, now I can notice the faint front end vibration which I've done a lot of work on I would recommend shocks again (front), and control arms because they have new ones out with better bushings. I think you had commented before about checking the steering rack how did that turn out I've had the same thought about my deville? And another thing to check out is where the cv shaft enters the tyranny there's a seal that goes bad from a faulty bearing inside the trans that could cause the shaking and if it's the culprit you will likely have a leak coming from where the cv fits into the trans. Just thought this info might help maybe someone can figure this out.