Quote Originally Posted by MrJakob View Post
No weird noises. Just the rumbling. I also feel it in my seat. I wonder if the balancing issue is what is causing this other problem. When I hit a bump on the highway, going around 60 mph. The car jerks to the left and right, it vibrates from what feels like the wheels to the steering collumn. Would the off balance also cause that? I would love to be able to get that fixed. Hate going over a series of bumps feeling like I am going to fly off into another lane.
Now what you are describing (the jerking over bumps) sounds like a balljoint on its way out (starting to become loose and sloppy from wear). If the car all of a sudden seems to steer or jerk you one way or another over bumps it is likely balljoint or other suspension pieces/bushings. A worn balljoint can be very dangerous if it actually fails at speed - I would have this checked ASAP.

The constant vibration/rumbling at certain speeds still sounds like a balancing issue, so you may have two or more issues in total.