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Ron Dittmer · 01-30-2021, 11:53 PM

Quote:

Originally Posted by wanderso

I added a Hellwig rear sway bar to an E350 Chinook Concourse I used to own and it made a huge difference in reducing sway. It did not make the ride any more harsh. I added Sumos to my 2008 Winnebago View sprinter chassis and it made a big difference in reducing sway. Can’t say how the sumos would help you on an E350, but they were good on the sprinter. If I needed to do it again on a Ford, I’d probably go with the sway bar just due on my prior experience.

Your signature picture shows a pre-2008 chassis. If that was your Chinook Concourse, that means you had "no" rear stabilizer bar of any kind, so adding a heavy duty rear stabilizer bar would have been a night-versus-day difference. Had you done the same, replacing your wimpy front stabilizer bar with a heavy duty version, you would have noticed an even bigger difference because the front heavy duty bar would work in unison with the rear one. So I always say when upgrading, do both front and rear to get the full benefit. Just the rear is much better than doing nothing, but upgrading both is doing it right for a multitude of safety and driver fatigue benefits.

wanderso · 01-31-2021, 12:15 AM

Correct Ron. It was my 05 Chinook and it had no rear sway bar prior to installing.

jackreno · 02-05-2021, 09:33 PM

Well I just installed the 1500 lb rated sumo springs today, had to really lift the rv up to get the axle to drop so I could fit the sumo springs, I didn't even use the 1 inch spacers that came with it no need to cause there was no more room, the sumo's by themselves came in to contact with the axle with the rv lifted, it raised my rear around a 1/2 to 3/4 inch once I removed the jack and that was good cause with the 42 gal water tank and 55 gal gas tank [full] that sit behind the axle made the rv squat a little bit.

Only went on a short drive and did notice less sway and less wobble in the back, I will be doing a highway test this weekend at higher speeds to see how it really handles, I also did not notice any ruff ride, maybe cause I went with the lightest load carrying sumo's.

What I really noticed under the rv before installing the sumo's was how the leaf springs look like is was loaded at its max cause the springs were sprung a little down ward, they sit a bit more straight now with the sumo's.

Even though the rv is 2000 lbs under the gross weight [before the 42 gals of fresh water] the back is where most of the weight sits, the fresh water tank should have been forward of the axle.

gladu2 · 02-06-2021, 01:49 AM

We had Sumo Springs installed on our 2016 E350 26ft Class C 11,500 lb GVWR, went with 5000 lb rear SSR-106-47-1 and 1000 lb front SSF-106-47 Sumo Springs.Couldn't be happier, eliminated all the sway, porpoising and roll. The RV handles more like a well behaved van now then a lumbering overloaded RV.

Ron Dittmer · 02-06-2021, 07:51 AM

In my mind, adding Sumo springs for the "sole reason" of improving handling, is addressing the problem in the wrong fashion. The right approach is investing in heavy duty front and rear stabilizer bars.

It's a different situation if your rig "also needs" extra support as jackreno stated. Sumo springs offer a do-it-yourself solution. But even still, why not add a rear leaf spring (or two) in back? If your front needs a lift, why not replace your front coil springs with higher-rated ones? I was quite surprised how easy it is to replace front coil springs. It might be easier than adding Sumo springs.

In my case, the front suspension was over-rated with too much excessive weight margin, confirmed with weigh-ins. The front end was way high and the ride was rough. I replaced the front springs with softer ones which lowered the front by 1.25", something it needed. Doing so raised the rear bumper by about the amount jackreno achieved with his Sumo springs.

Here was my front with the original over-rated coil springs. It was dang high, looking like a 4x4.

Here it is with the lower-rated front coil springs, the front lowered by 1.25" and the ride much nicer. These springs are a better match to the actual weight. This better levelled the rig and raised the rear bumper a little bit too.

I compared the spring specs of my particular E350 chassis to the E450 chassis of the same model year. They have the same Super Duty front coil springs. That got me investigating to determine if I had too much spring up front for my actual weight, and I surely did.

jackreno · 02-06-2021, 02:59 PM

Quote:

Originally Posted by gladu2

We had Sumo Springs installed on our 2016 E350 26ft Class C 11,500 lb GVWR, went with 5000 lb rear SSR-106-47-1 and 1000 lb front SSF-106-47 Sumo Springs.Couldn't be happier, eliminated all the sway, porpoising and roll. The RV handles more like a well behaved van now then a lumbering overloaded RV.

I went with the 1500 lb Sumo's on back cause I didn't want a hard ride, did the 5000 lb Sumo's in back make the ride hard, they also have a 2800 lb Sumo for the E-350.

I also wonder if I went to lite of Sumo's in back.

jackreno · 02-07-2021, 11:37 PM

Update :

I did some highway driving with the Sumo springs, the ride had very little sway and even the steering was even better, the back sits up almost a inch higher, even took some sharp turns and the RV had very little roll and so far could not feel any harsher ride.

I would say the improvement was a 4 out of 5, I might add some upgraded sway bars in the future to finish it off and new Koni shocks when the new shocks start to wear out.

I think going with the 1500 lb rate Sumo's saved me from a possible harsh ride in back, glad I went with the lower weight rating Sumo's.