Sprinter 3500 chassis upgrades

[Elkman]

I had the heavy duty versions of the SumoSprings installed on our 2021 Navion and they made the driving tolerable. Fox shocks have been on backorder for months so not an option.

I did learn that SuperSprings sells overload springs for the new Sprinter 3500 chassis. They are the SSA11 that sell for $439 and require their MTKT mounting kit that sells for $82. Add in the cost of 1-2 hours of labor although I have no problems installing them on two other vehicles and the work can be done with the wheels on the ground.

With more leaf support of the load it is a good idea to also upgrade the factory shocks although the shocks do not work as hard as there is less suspension travel with the added load capacity from the SuperSprings.

The added support will help with handling when ther is more than half the load on one side of the RV but the payload capacity is limited by the axle and wheel bearings and tires so OCCC may not be increased.

[crah]

Originally Posted by Elkman

I had the heavy duty versions of the SumoSprings installed on our 2021 Navion and they made the driving tolerable. Fox shocks have been on backorder for months so not an option.

I did learn that SuperSprings sells overload springs for the new Sprinter 3500 chassis. They are the SSA11 that sell for $439 and require their MTKT mounting kit that sells for $82. Add in the cost of 1-2 hours of labor although I have no problems installing them on two other vehicles and the work can be done with the wheels on the ground.

With more leaf support of the load it is a good idea to also upgrade the factory shocks although the shocks do not work as hard as there is less suspension travel with the added load capacity from the SuperSprings.

The added support will help with handling when ther is more than half the load on one side of the RV but the payload capacity is limited by the axle and wheel bearings and tires so OCCC may not be increased.

Are you proceeding with the overload leaf springs? I'm curious if they will help the handling. I have the heavy duty sumos which helped the handling. I also have the fox 2.5 shocks. They made no difference at all in the ride and I was a little dissapointed.

The added leaf springs sound like they would be the better fix.

[Elkman]

I will probably go ahead with the SuperSprings. Good information by RV owners in the Sprinter-source.com forums.

Shocks are more accurately called "dampeners" by the Brits. They dampen spring movement but they do not add load support. Good to know that the Fox shocks did little for your RV and they are backordered for 4-5 months at this time.

With a heavy duty pickup that had a payload rating of 2800 lbs. I added the Supersprings and increased the payload to more than 4200 lbs and with a 3700 lb camper in the bed the truck was level with no sag at the rear and the ride was stable. Without the Supersprings the truck would have been difficult to drive even with a 2800 lb load in the bed.

I installed them myself twice, once with a single leaf and then again with double leaf on each side. The second leaf was definitely needed to get the load support I needed with my truck. Installation time was less than 1 hour and the only special tool I needed was a very large C-clamp.

[Neon]

I have a 21D on order and "in theory" should be delivered in 30-days. I am trying to prepare for what I may need.

I would have assumed that the chassis should have been engineered properly for the job, but there seems to be a lot of necessary modifications being done to the sprinter chassis.

Can I get some clarification on what the following items do, and which are the most critical to upgrade.

1. SumoSprings - Front
2. SumoSprings - Rear
3. Overload Springs - Rear
4. Fox 2.5 Shocks
5. Hellwig Rear Sway Bar

[Dmarcian]

I put the Sumos on front and rear. To me they make a huge difference with sway, especially in cross winds. These rigs max out the payload capacity of the chassis, and if you are not careful, even exceed it. The sumos do make the ride a bit harsher in my view. If you travel out west you know the winds can really kick up, and the sumos will definitely help. I have heard good things about Fox shocks but have never tried them. 2020 VJ

[maasthor]

FYI Supersprings has a deal till July 5, 25% off anything. Code: JULY4TH Would love to hear how well the supersprings work. I added the heavy duty sumo's and it seems they help on highway, but may be making the ride a bit more harsh.

[Viper One]

I have Sumo springs front and rear, Hellwig rear sway bar and Fox 2.5 shocks. I also run 58 psi on all tires. I’m very pleased with ride and handling. My chassis is a 2018 Sprinter.

[Elkman]

The only way to increase the payload capacity is with the SuperSprings. I have heard that on the Sprinter 3500 they raise the rear about 2 inches which is actually a good thing as less chance of bottoming out at the back.

[71_340]

Originally Posted by Elkman

The only way to increase the payload capacity is with the SuperSprings. I have heard that on the Sprinter 3500 they raise the rear about 2 inches which is actually a good thing as less chance of bottoming out at the back.

The payload or allowable (safe) cargo weight is set by the manufacturer and printed on the yellow label. You can install all the springs you want, cargo capacity will not increase. Just imagine you cause an accident and they find out you were overweight.

Anyway, I had two Sprinter based RVs and low pay load is a given on one of those and you know that before you purchase (or should know). As far as suspension upgrades are concerned, rear Sumos make it ride very harsh. On my 2019 I installed a rear Helwig sway bar, the lightest front Sumos and rear HD Bilstein shocks (Fox were not available) and it handled pretty well and I was always maxed out on weight or about 100 pounds over.

[Sisu]

Our first trip with our new 2020 View 24D on I 40 heading west to Flagstaff was as windy as any we've experienced since. There was a tractor trailer blown off the road by strong crosswinds. My wife, who is prone to motion sickness, became nauseated similar to her experiences while boating in rough weather. After that trip I began to research solutions to control the excessing swaying. A friend sent me the following post that he had come across (unfortunately he could not remember where or the name of the author):

I have a new configuration of rear suspension on my 18NJ. Since this is a VERY long post, I'll start with the end first...

CONCLUSION: After driving more than 20,000 miles with various rear suspension upgrade combinations, I now feel that I've found the perfect configuration for my rig: Hellwig sway bar + Agile Tuned Fox 2.5 Rear Shocks (with no rear Sumos!). The motorhome drives the best it ever has! I tested it on the dirt roads in Quartzsite, in/out of driveways and gas stations, in Arizona winds on the I-10 as well as with semi-trucks passing at various speeds. The motorhome is stable, the rocking is very controlled and the ride is quieter with less vibrations (compared to with Sumos). I initially kept the blue front Sumos on to isolate my opinion to the changes in the rear — but after 400 miles, I have now removed the front Sumos too. I have driven more than 1,500 miles on what I think is now my final suspension configuration, and I think the ride is even further improved (in terms of comfort, noise and vibration without any downside in wind or in/out of driveways). I drove in very windy conditions on the I-10 freeway passing through Palm Springs, CA and I always felt in control, albeit two hands were definitely on the wheel.

Now, for those interested, here are the details...

I've driven my 18NJ during the past 15 months with the following rear suspension configurations:

* Stock suspension (1,000 miles)

* Hellwig sway bar only (5 miles)

* Hellwig + black Sumos (18,000 miles)

* Hellwig + black Sumos + 2.5 Fox Shocks (1,000 miles)

* Hellwig + yellow Sumos + 2.5 Fox Shocks (400 miles)

* Hellwig + 2.5 Fox Shocks + no Sumos in rear (400 miles)

* Hellwig + 2.5 Fox Shocks + no Sumos front/rear (1,500 miles)

From my perspective, I'm convinced that these tall, heavy rigs need some suspension tweaks before they feel stable at a range of speeds, have controlled rocking entering/existing a variety of driveways — and before I could feel comfortable with only one hand on the steering wheel at highway speeds.

Most of my driving (as indicated above) has been with the Hellwig + black Sumos on the rear. It was definitely better than stock, but I didn't know how much better it could get until I drove Brad Weinfeld's rig of the same model year (thanks again Brad!). He has the Hellwig + 2.5 Fox Shocks and no Sumos on front or rear. It was quiet and very controlled entering/exiting driveways and while driving on LA freeways.

I eventually upgraded to the 2.5 Fox Shocks, but kept the black sumos. I thought I noticed some change, but it didn't drive like Brad's rig. I thought maybe I needed more resistance, so I upgraded to the yellow rear sumos (keeping the Hellwig and 2.5 Fox Shocks in place).

Only at Quartzsite was I able to "downgrade" to the stock rear bump stops that I had originally thrown away, but Bob Swor rescued some for me from the trash (thanks again Bob!).

Immediately after leaving the campsite at Quartzsite, and driving through the wash, etc., I realized that the new configuration (Hellwig + 2.5 Fox Shocks and no rear sumos) was the feel I was hoping was possible! I drove the dirt roads from the V/N campsite to Route 95 three times (out, in, then out again) and drove the rockiest parts at various speeds each time to test the sway and overall feel.

In the second photo on this post, note the two electronic candles that I have on the back shelf above the J bed. They are just sitting there, and are not stuck, yet they didn't move an inch in the 120 miles I've driven since leaving Quartzsite which included the three trips to/from the campground, going in/out of a gas stations and store, on/off I-10, etc. In the past, the candles would have slid around and/or fallen onto the bed.

COMPRESSING THE SHOCKS BY HAND:

I tried compressing the 2.5 Fox Shocks before installing. I placed the shock vertically and put all my body weight on it. After a few seconds, by holding all of my weight, it began to compress very, very slowly, though did not accelerate with any momentum. When I let go, it took about 30 seconds to fully extend. I tried the same thing with the stock shock (after it was removed), and it was almost a joke how easily you could compress it with hardly trying. And, similar to the difference in thickness of the stock sway bar vs. Hellwig sway bar, the 2.5 Fox Shocks are impressively large in diameter when comparing them to the stock shocks (sorry, no photo comparison!).

FINAL THOUGHTS / MY OPINON:

I've realized that while sumos certainly help and are definitely preferred over no suspension upgrade, it's my analysis that Sumos can never do what a great shock can do. When installed at the same time as a shock upgrade, they can get in the way because they are the first line of defense, restricting the shock from doing its job. Rear Sumos seem to be a bit of a bandaid, adding suspension in a part of the chassis that wasn't originally designed to dampen the ride. Instead, they connect the axle and chassis in a place that transfers noise and vibration (while of course limiting body roll by adding constant resistance). However, since Sumos are simply resisting weight without any intelligent, dynamic dampening of an offroad-style shock absorber, it makes sense that they don't offer the body roll control of the heavy-duty, custom-tuned shock that Agile Offroad (in partnership with Fox Shocks) has designed for our rigs.

And, of most important note, Sumos don't resist on the way up like a shock does — they seem to act more like a ping-pong spring with high resistance to limit the travel, but they don't actually hold on and slowly release like a high-end shock. Needless to say, I'm a huge fan of my new, smoother, more stable and quieter ride!

INSTALLATION INFO:

It's relatively easy — I did it myself. The difficulty level is similar to upgrading the sway bar, which isn't hard. You don't need to lift the rig since the shocks are not weight bearing, but you will need a jack to compress the shock once you have the top bolt holding the shock in position. For a video of how to do it, check out the link below. Please note: the video features a 2500 chassis and a different version of the Fox Shock with different torque settings, but the process is identical.

Hellwig Sway Bar: https://amzn.to/2HBSPep

2.5 Fox Shocks: https://bit.ly/2RQcMVt

Install video: https://youtu.be/grVpPIJ8zZY?t=146

18NJ

I ordered a Hellwig Sway bar but on measuring its diameter vs the OEM (only 0.1" difference) and because of the much lighter mounting bracket of the Hellwig, I decided against installing it. I understand that as of 2019 the OEM sway bar is beefier than prior models. I was able to get the 2.5 FOX shocks and had them installed at a local shop. The ride in our MH is much improved with this one improvement. We have driven 7,000 miles since, often on I- 10 and I-40 in significant crosswinds with no excessive sway and no issues around 18 wheelers. I have no plans to make any other changes.

[creativepart]

I found the original Blog post that has this quoted post.

https://www.viewnavion.com/mods/suspension

One thing to keep in mind... Sprinter chassis do change every few years. And a 2017 18ft Navion may not be the same as a 2020 24ft View.

When discussing suspension mods/additions/changes it's important to realize that what works for one user on one RV may not be the same as what works for you on your RV.

Heaven knows, I've made my share of suspension changes - about $4,000 worth. But even with those I'm not entirely satisfied with the results and don't feel qualified to advise other RVers about what works and what doesn't. I can only detail what I've done and what I think the results have been.

[RJ2]

Did all the tricks , drove like a dream compared to stock. Got 50 k on it then decided all that stuff does not do a thing for the to much weight for a 3500 sprinter. AS FAR AS THE BRAKE DUST FOULING THE ABS SENSORS CONSTANTLY. We’ll known unfixable
Mercedes issue , to much weight for the axles hubs and brakes . Brake metal dust gets attracted to the Abs sensor magnets , one wheel the tranny shifting goes out with the cruise control. I ignored the error lights trying to get to Tampa from Atlanta, and found out the default outcome is it will start shifting from 1st to fifth. And the brakes default to going completely out /useless , coast to stop playbook.
Let me know if anyone can find a Mercedes rep that will argue anything I have written is disputable. They like selling there sprinter chassis , and put
In *free ABS SENSOR for the life of the truck.
Love the ride, just thought I would share a quirk that bothers me .

* Free. …not exactly when your in Montana 500 miles from a Mercedes
Dealer.

[Elkman]

The 2020 motorhomes were attached to the 2019 Sprinter chassis which had a number of upgrades from the prior generation of Sprinters. The OCCC is only available if you drive to a dealer and they happen to have the model you want on their lot. Otherwise it is hidden from customers and not on any documents one can obtain from Winnebago prior to the purchase. This is very different than what one encounters with a travel trailer where the dry and maximum capacity is on every bit of sales and product data sheets.

I put SuperSprings on a pickup with a factory payload capacity of 2800 lbs and later drove it thousands of miles with a 4,000 lb camper load. It took some digging to find the AAM axle rating for the ones used by General Motors but the rest of the load calculations only required a single weighting at a local Cat scale. I also added the Big Wig sway bar and it did nothing for the handling with a heavy load in the bed but greatly improved the ride when the bed was empty and reduced wheel hop considerably.

I put the heavy duty SumoSprings front and rear and also put the Hellwig anti-sway bar on our 2020 Sprinter chassis with a 2021 Navion installed. I did not expect much of a gain with the Hellwig for the 2020 chassis but as I was going to be driving the RV 600 miles back to our house I did it in case it might help. Lots of sway with the heavy duty SumoSprings installed and enough play with wind gusts to activate the Mercedes "keep awake" alert continually.

My top priorities for any vehicle is that I can make an emergency maneuver safely and that I can brake in time to avoid a collision. The ride is not important for a motorhome or a truck. If I want a comfy highway vehicle I would be driving our Chevy Traverse. If a soft ride is important then better to be looking at a Class B motorhome or a travel trailer that can be towed with a 1500 Class pickup truck.

[rprochnow]

There is an OCCC label on the front door frames on our 21D's 2019 Sprinter chassis.

Views and Navions are basically large bricks with wheels. They aren't very aerodynamic - and are relatively top heavy - so they are going to be more susceptible to high winds - especially crosswinds. Adding upgrades won't change the aerodynamics.

While we are able to maintain 80 MPH with our View, that's only under ideal conditions - and we often have to reduce speed due to the wind - especially if we get a crosswind warning from the MBUX system.

I've checked with Lichtsinn and with our Sprinter service about doing upgrades and they've both recommended against the upgrades - in their opinion they wouldn't provide much value above what comes with the newer Sprinter chassis.

[Elkman]

Why would anyone think that a person at an RV dealership would have any expertise on an RV suspension? It is unfortunate but people will say not to do something when they should say that they have no experience and cannot provide advice. They are also understandably reluctant to talk about how overloaded the motorhomes are that they are selling.

The Winnebago personnel that I spoke with at several dealerships could not tell me the OCCC and would say that they would get back to me. Known of them knew anything about the new for 2019 Sprinter 3500 chassis and cab and what was changed. And none of them had first hand experience with adding any suspension upgrades on a motorhome they owned or had ever driven on a trip.

The sway aspect occurs when more than 50% of the load is on one side of the chassis which is already maxed out 100% even on flat ground and no wind. At a certain point the chassis will bottom out and their are rubber pads on the suspension for this reason. All the SumoSprings do is replace the stock pad with a taller one.

Unfortunately the Sprinter chassis is not really able to handle the weight of a class C motorhome. Can you imagine a truck with a GVWR of 11,000 lbs that off the lot weighed 10,000 lbs so after you added passengers you could put at most a large dog in the bed of the truck?

That is basically what you get with a Class C motorhome mounted on a 3500 class chassis. What is needed is a 4500 class chassis as with the Chevy ones used by Coachmen which adds 9,000 lbs to the GVWR as compared to the Sprinter 3500.

[Neon]

I am hearing that the new Sprinter chassis (2019+ I think) has a more robust sway bar from the manufacturer? Has anyone confirmed this, and how does it compare to a Hellwig sway bar? Is a Hellwig something still worth considering to be installed in a 2021-2022 View?

[crah]

Yes the new VS30 chassis has more robust sway bars than than the previous generation. The Hellwig is still thicker but a very small margin (3/16 inch) so it may not make any difference. On the previous generation chassis, the sway bar was much thinner than the hellwig sway bar, so owners have relayed it makes quite a bit of difference on the previous generation.

[crah]

In my opinion, the new sprinter chassis handles terrible in stock suspension form. It does handle fine if there is no wind or passing vehicles or any turns of any sorts which is almost impossible not to have. This is my 3rd motorhome so I at least have something to compare to. Hands down the worst handling of the 3. Once I added the front and rear Sumo springs (huge improvement), it was better but still have room for improvement. In stock form, I thought I made a huge mistake in my purchase. If the sumo springs didn't improve the handling, 8 would have sold it.

My neighbor has a 2017 View. She had never heard of suspension mods to make improvements and lived with if for all these years. What you don't know, you don't know.

[Neon]

So Sumo Springs and/or SuperSprings? I am trying to narrow down my options and have the parts ready for when my unit is delivered.

Sound like Fox 2.5 shocks will take a lifetime to get if I order them now.

[crah]

Originally Posted by Neon

So Sumo Springs and/or SuperSprings? I am trying to narrow down my options and have the parts ready for when my unit is delivered.

Sound like Fox 2.5 shocks will take a lifetime to get if I order them now.

The company Super Springs makes the Sumo Springs (high density cellular urethane). They feel like a thick compressible rubber to me and I am satisfied with the money spent. They also make a Superspring (similar to a added leaf to the existing factory springs). I have not tried these and am contemplating. I don't know of any others that have tried it yet.

I have the fox 2.5 shocks from Agile Offroad. They made no noticeable difference to me. I do have an extra set of Fox 2.0 shocks (supposedly they are the same as the Fox 2.5 shocks) but valved to the maximum. I never put them in.

You may want to just wait until you take delivery and test the stock suspension. Seems there are some others satisfied with the stock suspension.