NHTSA Complaint #11452299 — 2006 FORD F-350

8 years ago was crossing RR tracks and vehicle started violently shaking had to slow to 10mph for it to stop. Checked found nothing wrong finished drive home. Took to Ford dealership and they said some tricks shake when tire pressure is wrong and didn't find anything wrong with vehicle. Truck did this once more and after that when I approach RR tracks I slow to 5- 10 mph to keep it from happening. Took it back to Ford 1 time and again they spoke about tire pressure but tire pressure was fine. In the last 2 weeks anytime I hit a bump the truck violently shakes I took to a mechanic shop and they said something was wrong with front end but not sure what. I called Ford and they said to bring it in. We will see what happens because this truck has done this off and on for the last 8 years, but now it does it all the time. It has been shaking so violently I wouldn't be surprised if other damages have happened from it.