I have a bad vibration above 65mph, if I stay in the groves of the road it drives fine, but if I get out of the grooves, it will shake me to pieces. I read a post about this subject, posted by Silvan, saying the same.

How do check the ride height, and how do I adjust it if it were to be wrong? I can't find a leveling valve anywhere. I've looked around both axles, and the frame rails. If it helps my truck does not have a dump valve. It's a 2004 Int 9200i that I bought used.