2nd Gen Non-Engine/Transmission bed vibrations with gooseneck trailer

[BrandonF]

we have a 99 dodge 5spd 4x with 48k on the odo. I have a vibration and faint noise that really sounds like an exhuast vibration. We cannot fint any rub points or shiny spots on exhaust. It gets worse with the trailer on it small trailer 20ft stock empty. The vibration happens at idle speeds and it is coming from the bed area. I think it is the bed riding on the B&W plate but I cannot seem to find it. Has any one had any vibration issued like this

 

[B.G. Smith]

Have you checked the center support bearing/ also called carrier bearing by some? bg

 

[HHhuntitall]

At idle speed? Moving or sitting still? IF sitting, then try putting a jack under the rear bumper/hitch and lifting it slowly to see if the vibration goes away..... With the B&W hitch, I'm betting it's either the overload springs touching just on the rear pads or the hitch is bowing ever so slightly and allowing the bed to vibrate on top of the B&W hitch center section. That can be isolated by getting in the bed with it making the noise, and stepping on the area on each side of the hitch. It should quit at that point.