I have an automatic 2010 GT Stang. I just had to place lock nuts on my panhard bar due to the bolts somehow becoming loose. It would cause my back end to shake left-to-right when I would initially place my foot on the pedal and let off the pedal. Also, if I would keep my foot pressed on the pedal to try to cruise, my back end would shake vigorously. After getting the lock nuts put on, I am now begging to feel a shake when I press the gas, and let off the pedal. But very slightly. Now a new issue has popped up, as I am cruising from 45 and up in speeds when the pedal is pressed down (not flooring, but slightly pressed) my car feels as if it is shaking front to back now, and feels as if my left rear tire is skipping down the road. I turned my O/D off and it actually began to run smoother, but there was still the left-to-right shaking. I need help, and advise on what I should do. Thank you.