2012 Subaru, 138000 on the odometer, violent shaking and bouncing
I was driving 70 mph on the interstate in the left hand lane. The steering wheel started shaking back and forth as though a wheel was out of balance. Quickly it got much worse and was dangerously unstable; it felt as though the entire car was bouncing.
I moved to the right hand lane and that maneuver felt like I might be out of control. I started slowing and the shaking started diminishing. I exited, stopped, inspected the car and saw nothing unusual. I drove back home about 30 miles at speeds below 55 mph, and visited my tire company and mechanic; both of whom I have used for decades, there was no shaking during the return home. It was racked and inspected and driven at interstate speeds by both and the shaking never repeated. Neither found any issues.
any thoughts on what may have caused this?
Something was obviously missed when the car was checked out. Presumably tire balance, ball joints, and tie-rod ends where inspected for wear. Were suspension bushings checked? Wheel bearings? Were suspension and steering rack attachment points checked for rust?
maybe you picked up some debris on the freeway
