SuperSprings SSR-106-47-1 | SumoSprings Rear for Ford E-350|E-450

I installed this on a Ford E-350 motorhome that is 26' long, has a V10 engine, a GVWR of 12,500 lbs, & a 50 gallon fresh water tank located above the rear axle (gray & black tanks located behind the rear axle).Before installing, the motorhome had serious steering wander. Even on flat roads without any crosswind I was constantly fighting the back and forth of the steering wheel while driving. I experienced fatigue sooner than normal due to constantly fighting the steering. When I drove slowly over bumps, the entire RV rocked back and forth like a cradle giving everything in the cabinets a very loud back and forth shake. I considered selling the RV.There are three sizes of Sumosprings: Blue-40 (2600 lb capacity at 50% compression), Black-47 (4600 lb capacity at 50% compression), & Yellow-54 (5400 lb capacity at 50% compression). The manufacturer does not offer weight guidelines but instead recommends the blue-40 for light & medium duty, the black-47 for light, medium, & heavy duty, and the yellow-54 for medium & heavy duty. So I didn't know if I should get the black-47 or the yellow-54. To make my decision, I unofficially designated the blue-40 for up to 10,000 lb GVWR, the black-47 for 10,000-20,000 GVWR, and the yellow-54 for 20,000-30,000 GVWR. Then I chose the black-47.I chose the SumoSprings SSR-106-47-1 (rated for 4600 lb capacity at 50% compression) and installed it on the rear suspension. SumoSpring uninstalled height: 6-3/4" SumoSpring height after installed on my motorhome: 5-5/8" (1-1/8" of compresssion with full water tank & nothing attached to rear hitch) SumoSprings raised back of RV 3/4" at rear wheelsNow there is much less rocking like a cradle when driving over bumps. There is still slight steering wander, but overall the steering wander was improved by approximately 75% just by adding the sumosprings. I did not make any other changes: I did not upgrade front or rear sway bars, shocks, steering stabilizer, etc.Considering the 50% compression would be 3-3/8", the sumosprings are about 1/3 compressed after installation with 2/3 compression available for driving conditions. I am glad I chose the black-47 & I am happy with the improvement in drivability.

A bit of a challenge to install, which would have been nearly impossible if I didn't have hydraulic levelers on the RV. Who has access to a perfectly level RV parking spot and maybe a hydraulic jack or two? Anyway, with a bit of leveling adjustments, I was able to locate one of the factory chassis holes, bore it out to 1/2", then another and finally drill the remaining holes for the brackets.I haven't extensively road tested the springs yet to see if the ride is improved or not and I'm not sure how they affect the function of the stock inflatable helper springs. I may back off some pressure on these springs to see how the coach rides under different pressures. Overall, I'm looking for a better, smoother, more stable ride. I also added heavier sway bars to enhance the ride and reduce cornering sway and maybe reduce getting pushed around by the big rigs.

Produxt may be good but it would not fit my 2017 E450 motorhome. The specific design of the motorhome would not allow for a proper installation. I am going to try Supersprings to see if they work.