My van was driving down the highway, fine as usual, then the drive light switched on and off and then the the car stopped being propelled forward when I stepped on the gas. It just revved the engine. I pulled over to the side of the road and then I put it in park and then I put it in drive and it went again and then I hit a bump and it stopped going forward again. I finally just had myself towed to a car repair shop. Any ideas what might have happened. That morning I had gone over a speed bump very fast and bottomed out? Could this have caused the steering column to break something in the drive shift in the steering column?