Kelderman has a recurring ad in MotorHome on a retrofit air suspension system for the F-53 Ford chassis. Their website claims it changes a dump truck ride to one resembling a Greyhound bus. That analogy pretty well describes the ride we get from our 99 Pinnaclechasssis. The basic parts of their system appears to be softer front leaf springs, an air bag and Monroe shocks. In an attempt to improve our ride we had Monroe's installed about five years age and Goodyear 670RV tires about two years ago. Neither imroved our ride. Anybody out there with any experience on the Kelderman system? I talked with them this AM and they seem to have a lot of experience with what their system does on an F-53 chassis.