Chucking is that forward/backward surging motion that you can get when towing on concrete highways. Lots of theories of causes...poured section not level, wear over time, distance between camper/truck axles, truck rear suspension, phases of the moon. Anytime that I've had it occur and was able to switch into the left lane, the chucking was gone, so I have no doubt that the biggest factor is the road surface itself. We had a 2300 mile trip to AR and back last year and only experienced chucking on a 15 mile long section of I69 in MI, north and southbound.
Based on that kind of frequency, I'm not planning on throwing much money at a fix. If I was ordering a new camper, I'd go for the optional pinbox over the std as many offer the MOR/Ryde or RotoFlex as extra. That way I'd only be paying for it as a discounted price along with the camper.
The pin boxes I mentioned (there are others) isolate the camper from the kingpin by rubber or air bag mounting and are thought to absorb that forward/backward surging. Reports that I've read say that it greatly reduces but doesn't completely eliminate chucking.
There are also air mounted 5W hitches such as Trailer Saver ( link Trailer Hitches – Air Ride Trailer Hitch & Fifth Wheel Hitch
) that isolate the truck from the hitch plate and is thought to absorb the vertical motion from bumps. I've read that the combination of the isolating pin box and isolating hitch are the cat's ***** in towing. The total cost is too rich for me.
Hope this sheds some light on the subject...