I recently purchased a Holiday Rambler Presidential TT. The tow vehicle has a goose neck hitch (disappearing ball type) installed in addition to the class IV hitch. The trailer is quite heavy. Both my wife and I noted that the ride was very stiff and rough if there is any issues with the roadway.
Last week while changing the rear shocks I noted that the goose neck ball when in the reversed position was rusty except the flat top of the ball (bottom when reversed). The ball has been hitting the rear swaybar. Once the ball was removed the ride became a lot smoother.
Thought I would throw this out for novices like me that might have similar circumstance.
DMVibbert
USA (Ret)
1997 F250HD
2007 Holiday Rambler Presidential TT