Hello, I have a '94 1500 Sierra and I bought it as is from a private party. For the last month I've been having an issue with my front end. Whenever I hit a bump of any size and any speed my front end feels as if its jumping. It shakes my cab so much like I'm driving on severe washboards on pavement. I've taken it in to get looked at (by 3 different mechanics)and theye all say there's nothing wrong. I know I'm not imagining this and it also wanders badly. What can I do? Any info would be helpful