Jayco Seneca Super C JRide

Google "jayco J ride problems" you will find that Moryde does the suspension modifications to the stock ford frames before the factory builds the coach portion. I know you are probably not on the Ford chassis, but..... many of the rear suspension Hellwig helper springs are set up incorrectly for the weight of the finished coach. It seems like most are set up too soft. Not sure if that would make for the ride you are experiencing. But according to a Hellwig rep i spoke to on my 2006 jayco greyhawk 31ss, the helper spring should be no more than 2 - 1 1/2 inches from the stock ford spring pack. (mine is 4 inches, but im ok with the ride) Check your rear springs to see how far the end of the helper springs are away from the stock springs.