Sumo "springs" in a Class B Sprinter van?

[BigFatGuy]

My RV is a class b in a Sprinter van. the back end of the vehicle is very prone to an oscillating sway if I, for instance, hit a moderate size speed bump at anything other than 90 degrees... or if I nick the non-ramp edge of a driveway while turning onto the street. The entire rear of the vehicle swings side-to-side for several seconds.

This doesn't really hurt handling, I can drive straight while it's swaying, but it feels damned scary, and messes up the beer bottles in my fridge.

I figure it's a symptom of the vehicle being under-loaded. When returning from my hunting trip, with the rear of the van holding about 500 lbs of meat, coolers, and ice, the RV drove like a dream. It was immune to speed bumps, the suspension felt a lot less stiff, and the RV slowly "porpoised" after hitting a bump in the road in a very comfortable and non-beer-bottle-jarring way. I've noticed similar improvements when putting some serious weight in the back of my Bronco.

I was thinking about trying Sumo Springs (basically stiff closed-cell-foam "springs"), as I can add them to all 4 corners for less than $500, and they use stock mounting locations for rubber bump-stops.

I'm thinking, though, if the issue is that the RV is over-sprung and under-loaded, will adding "helper" springs really make the issue better? or will it make the issue worse?

Anyone have any experience?

[luckylogger6]

sumo springs seem to just be an alternative to the more common air bag helpers. I think you problem is in the shocks. their job is to dampen the "bounce" of the suspension. look into RV specific shocks. Koni, Bilstine and others make specialized RV shocks to handle just what I think your describing.

[BigFatGuy]

sumo springs seem to just be an alternative to the more common air bag helpers. I think you problem is in the shocks. their job is to dampen the "bounce" of the suspension. look into RV specific shocks. Koni, Bilstine and others make specialized RV shocks to handle just what I think your describing.

I figure that to be the case... but a new set of shocks is a lot more expensive than some rubber inserts for the suspension. :-)

[gorn5150]

I have a sprinter with a class C setup. I've never experienced the sway so it could be the lack of load weight you are talking about. I've had air bags on a couple of class A motorhomes and they made a huge difference in handling and sway.

[sonofeugene]

Springs support the load and shocks control the bounce and movement of the suspension.

If the springs are sufficiently stiff to support the loads you carry, then the problem is shocks, not springs. You might also look into some rear anti sway bars.