Can I ask how many miles on your car ?
Have you checked for bent rims (wheels) or core shift in the tires front and back ?

 

162k. The short story is that the rack was replaced as a result of $3k of damage done in a parking lot in August of 2018. The tires, though I've had bad ones as you describe, are about 2 years old. The rims aside from scuffs are like new. I knew I was due for struts and had a bad right LCA. I replaced the LCA, got the struts and sway link ends but still had that shaking, like a missing wheel weight. I took it to a shop I use and they kept it for several days and couldn't find the issue. Then he calls and tells me the rack is bad. It's great now. Back to driving like a new car again.

 

OK going to ask the same question to the OP.

Can I ask how many miles on your car ?
Have you checked for bent rims (wheels) or core shift in the tires front and back ?

 

Mine started out that way which had me chasing other fixes. Those things needed to be done anyway as many suspension parts were pretty old. But the vibration got progressively worse and was beginning to be noticeable at 50mph. I would never have even guessed at the steering rack, nor would I have been able to easily diagnose it myself. It was a shop that found it.

 

The car has 113866 miles on it , and I replaced the transmission because I thought it vibrated like the torque converter was out of balance . I found a transmission fairly cheap so it wasn't a big deal .

 

But you haven't answered my question.
Have you checked for bent rims (wheels) or core shift in the tires front and back ?

 

You already wrote that your tires are replaced and they are still young. Therefore, I do not insist, but ...
A couple of years ago, I noticed that at low speeds (traffic in a "traffic jam" of 5 miles per hour), my Hippo moves with a duck walk. Not very distinct, but right / left. And at speeds from 60 to 85, the vibration increases, then disappears after crossing the speed threshold of 85.
The problem was discovered: the cord burst inside the tire body and the tread curved, swelling. My tires were old, although the tread depth is decent.

 

Yes I replaced the front and rear tires and checked the rims on a balancing machine before I replaced the tires .

 

Catman read post #1, list line #7.

7. Replaced and or balanced all tires ( pulled off tires and checked rims for being bent )

 

Well guy's I finally got the vibrating issued fixed . After I had enough and the suspension on the car is brand new now I brought the car to a local repair shop . One guy looked at it and said everything looked good but said it had a bad vibration to it , Thanks guy !
So next they brought the car to another part of the shop and used a forced tire balancer and found out that there was some high spots in the tires possibly from carbon deposits . OMG the car runs and drives like a dream now !
The positive side of this is that I learned alot about it and that possibly that my tire balancer needs to be re-calibrated , I was amazed it didn't pick it up but I guess even though a static balancer is used sometimes the problem will not be found .