Our Jayco greyhawk is a 2006 chassis with a 2007 coach. It's is a 31ss and per the manufacturer weighs 14,050 lbs. ( I think a hundred of those pounds was the old tube style TV! It took 2 of us to take it out) It has Helwig helper Springs and rubber isolator pads under the coach supports. But none of the other "J Ride" upgrades. I do not feel any driveshaft vibration. While driving. But oh how I wish it had bilstein shocks, and Hellwig sway bars. The front end just needs to be "tightened up" for sure.