Well I wasn't watching where I was going and ended up off the trail a little driving over a rock pile and hitting 2 big rocks on the underside of my truck. Now the truck has a huge vibration problem but what I can't figure out is it is completely normal and silent with just someone on the drivers side but when someone sits in the passenger seat it gets loud enough of a vibration its hard to hear the person talking to you in the passengers seat. I know that I hit the back U-joint and it is worn out but it seems like something more because the back U-joint is pretty loose but the amount of the vibration and how it acts when it only has a problem when someone sits in the passenger seat I'm just not sure what it is. Any thoughts?

 

does the vibration get louder the faster you go? or maybe the higher the rpm's? Need more information about whats going on when the vibration is at its worst or most noticeable point.