I still maintain Chugging is from the acceleration and braking of the vehicle combination, which can be reduced if your brake controller is adjusted correctly.
As for the up and down movement which is wrongly called Chugging I took a long look at the connection between my table and pin hook when hooked up, I noticed there was quite a large gap which created a space for up and down movement.
I have since added a second silicone ring which reduces and makes the up/down movement less which in turn creates for a smoother ride.
I have also, having a two piece hitch, greased a cut 1/2 hose under each mounting shaft which also reduces movement and noise.
It works for me but make sure the gap will take another ring and not cause a problem.
If the gap is ok its worth concidering and for the cost of less than $20.. And if it doesn't you have a spare ring.