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SumoSprings Solo Custom Helper Springs - Rear Axle

SumoSprings Solo Custom Helper Springs - Rear Axle

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2,800-lb Capacity. Upgrade your vehicle's rear suspension with these maintenance-free helper springs. Sturdy microcellular urethane springs cushion bumps and help support a heavy load to level your ride and minimize sway. No-drill installation. Lowest Prices for the best vehicle suspension from SuperSprings Intl. SumoSprings Solo Custom Helper Springs - Rear Axle part number SSR-121-54 can be ordered online at or call 1-800-940-8924 for expert service.
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SuperSprings Intl Vehicle Suspension

  • Jounce-Style Springs
  • Rear Axle Suspension Enhancement
  • SuperSprings Intl
  • Standard Duty

2,800-lb Capacity. Upgrade your vehicle's rear suspension with these maintenance-free helper springs. Sturdy microcellular urethane springs cushion bumps and help support a heavy load to level your ride and minimize sway. No-drill installation.


  • Helper springs upgrade your vehicle's rear suspension for improved driver control and comfort
    • Keep your vehicle level when you're towing or hauling a heavy load
    • Help to absorb bumps and shocks
    • Minimize sway
  • Progressive load control - springs compress according to the weight of your cargo
    • Lighter loads - springs compress easily at first for soft engagement and a less bumpy ride
    • Heavier loads - springs compress by as much as 80 percent for support
  • Springs work independently from each other to compensate for off-center loads and reduce body roll during sharp turns
  • Durable, high-density microcellular urethane
    • Works in temperatures from -25 F to 200 F
    • Resists damage caused by oils, road salts, and UV rays
  • Minimal lateral expansion - springs compress vertically instead of to the sides so they aren't easily damaged when operating in tight spaces
  • Maintenance-free - no tubing to run or air pressure to monitor like with air springs
  • Simple, no-drill installation
  • 2 Jounce-style springs included
  • Made in the USA


  • Weight capacity (at 50-percent compression): 2,800 lbs
    • SumoSprings will not increase your vehicle's weight-carrying capacity
  • Limited lifetime warranty
  • 30-Day satisfaction guarantee

Rear Suspension Support

Towing or hauling a heavy load can cause rear sag as your factory suspension compresses under the weight of the load. This means that the rear axle is trying to support not only the extra load but also the weight of your vehicle. And because there is less weight on your front axle, your front tires make less contact with the road, which causes problems with traction, steering, and braking. SumoSprings upgrade your vehicle's factory suspension to level your vehicle, improve driving performance, and keep your ride comfortable.

Installed spring when it is not compressed

SumoSprings provide progressive load control - the more you load them, the stiffer they become. With a lighter load, the springs will compress easily for soft engagement and a less bumpy ride. The closed-cell urethane material allows for smooth contact between the springs and your vehicle. And the springs act like a shock absorber to dampen road vibration.

Installed spring when it is compressed

The springs can also compress by as much as 80 percent to support a heavy rear load and to help your factory suspension bear up under the load. This evens out the weight, which levels your vehicle and ensures that your front tires are making better contact with the road. A level ride means that you have improved driving control, ensures safe headlight aim, and helps to minimize sway. The springs also support your factory suspension, which helps prevent sagging and reduces bottoming out.

The springs work independently from one another to support each side of your vehicle. This action helps to reduce body roll when you make a sharp turn. This also helps compensate for an off-center load.

Durable, Custom-Fit Springs

These microcellular urethane springs are tough. They resist abrasion, oil, salt, and UV rays that can more quickly wear out other springs, and they perform well in temperatures ranging from -25 F to 200 F (-33 C to 93 C).

SumoSprings compress vertically with minimum expansion to the sides, so they won't be damaged by nearby mechanical parts and they fit safely into tighter spots. And unlike air springs, SumoSprings require no maintenance or adjustment.

The helper springs are custom designed to fit your vehicle, and they install easily - no drilling required.

SSR-121-54 SuperSprings Sumo Springs Solo Rear Vehicle Suspension Kit for Vans

Item # SSR-121-54

Installation Details SSR-121-54 Installation instructions

This Product Fits The Following Vehicles

Customer Reviews

SumoSprings Solo Custom Helper Springs - Rear Axle - SSR-121-54

Average Customer Rating:  4.7 out of 5 stars   (1374 Customer Reviews)

2,800-lb Capacity. Upgrade your vehicle's rear suspension with these maintenance-free helper springs. Sturdy microcellular urethane springs cushion bumps and help support a heavy load to level your ride and minimize sway. No-drill installation.

Ford Transit Connect

These sumo springs did the job. I'm an electrician and our vans are heavly loaded when set up. I put them on a Ford 250 transit van to bring it back up to stock height after the van was loades with shelving, ladder racks, tools, and parts. The ride is great and the install was very easy. I would buy them again.


Significant improvement in the handling in windy and rough road conditions. Increased height of back of my 2017 Fuse 23A by 1 to 1 1/2 inch.
I added the springs to help with the addition of another a/c on top at rear of my unit.
Very pleased and installation was straight forward and relatively easy. Took about 1 hour to complete.

The increased handling and height gain are helpful on all the road conditions I have encountered. The ride is a little more stiff than the original factory suspension but the improvement of handling and reduction of sway is worth the small increase in the stiffer ride. Would recommend for all Winnebago Fuse owners
Gary - 06/30/2021

2021 Ford Transit T350

Easy order. Quick delivery. Easy instal lation.


Better ride for my transit250 high roof extended van

2017 Ford Transit T350

Easy install, great performance, no maintenance. What could be better.

2016 Ford Transit T350

These work out very well. The customer was happy. Not hard to install was a plus.




Review from a similar SumoSprings Solo in Vehicle Suspension

I would have give it a 5star but the bolts are 1/4” I think it should be at least minimum of 3/8” or1/2” bolts to hold the sumo springs. I like them toed the camper handles very well. Wishi got these a long time ago worth getting. With out camper can tell that it’s there but rides ok. I wanted the same ride it not quite. I ask what the how high they are said 5” with bracket but it’s actually 6” with bracket see picture. I would recommend getting the sumo springs ssr-610-47.

They are working great in my 12 tundra still would recommend them. I tow 8000lbs camper handles great at times I probably wished I got the next step up but might be to hard when not towing. Will see next time I need to get some for next truck. Wish they have measurements to know how high they are from the lighter ones to the heavier ones.
Luc - 04/18/2022

by: 01/31/2021

Review from a similar SumoSprings Solo in Vehicle Suspension

2015 Frontier Crew cab Desert Runner (purchased the yellow Sumo Springs). Easiest install ever! 18mm deep socket and long breaker bar for breaking nuts loose. Removed factory bumpstop, install sumo bracket and retighten U bolts to 58 foot pounds. After installing both brackets, lifted back of truck up 4 inches to install sumo spring with blue lock tight on bracket bolt, tighten sumo spring onto bracket and lowered truck off the jack. Overall it raised the back of my truck bed 1 inch. Ride is stiffer with no bed roll in the turns. Loaded my 24 foot travel trailer with load leveler- equalizer bars and gained 3 inches (less “squat”.) Truck is level now vs nose high (without the sumo springs). Definitely an upgrade that was needed in 2015 when I first bought the truck!!!

Yellow for the super heavy load and daily driving I have the black middle weight springs. Easy swap out when I need the yellow Heavy Duty.
Mike M - 02/01/2022


Review from a similar SumoSprings Solo in Vehicle Suspension

I just finished installing the Sumo Springs to my 2020 Ram 3500. The install was super easy. Instruction were easy to follow and the whole thing took less time than I thought. I won’t know how they perform until I pull the 5er out of storage this spring, but I am ready. My only question and the reason for 4 stars instead of 5 was I thought they would sit closer to the axle than they did, may 2” from axle and I would have liked may 1” maybe I could have used another spacer and longer flat head screw to bring it closer but we will see when I put the weight on the truck. I included picks if someone wants to give me their opinion. So far I am really happy with them.

Fantastic, the Sumo’s are working as promised. Helps with sag, smooths out the ride and provides support from sway. I couldn’t be more happy. This year we will be adding Sumo’s to the 5er to help in the back, super excited about this upgrade.
Brian - 01/31/2022


Review from a similar SumoSprings Solo in Vehicle Suspension

Very straight forward installation. Simple. very noticeable difference under load. Towing with the gooseneck also an improvement, looking forward to the longer road trip test. So far pleased with the product and results

after a year i could buy them again. great performance and no issues.
Richard J - 06/04/2022


Review from a similar SumoSprings Solo in Vehicle Suspension

Parts arrived on schedule. At first I thought that the parts did not fit my truck, so I called customer service and they immediately started to send me a return label and refund. It turned out that I was wrong, and the parts did fit. I called them back cancelled the refund action.
Great friendly service!
I also found that the price I paid was much cheaper than [online store]. I highly recommend etrailer!

The springs still work as they should. They are nice because they dont seem to affect the ride quality when the camper is not on the truck. Very happy with my purchase.
David B - 05/31/2022


Review from a similar SumoSprings Solo in Vehicle Suspension

We pull an off-road teardrop camper with our 2013 Toyota Tacoma and were looking for a little help with the rear end sag when we have that hitched plus putting some weight in the back of the truck (firewood, water, etc). Our Tacoma is lifted (2.5") but the lift kept the stock springs with an added Deaver leaf to help with the notoriously soft Toyota springs. However, with the shell and ~300 pounds of weight in the back, it still sagged, especially with another 250 lbs of tongue weight from the trailer. The Sumos have eliminated that sag, even with bigger loads in the bed, eliminated body roll (also notoriously bad with Tacomas) and didn't destroy the ride for day to day driving. There might be a slight bit more stiffness when hitting speed bumps, but definitely not bad at all. If anything, I would say it IMPROVED the ride and handling.

The springs themselves were simple to install, less than half an hour start to finish. Some reviews have said they were bumping the frame after installing but we had about 1/2" gap on both sides. The only "specialty" tool would be a torque wrench capable of 90 lbs to get it to spec.

We considered Firestone air bags but after talking with the reps at e-trailer, we decided on these and couldn't be happier. Reasonably priced (half the price of air bags), no maintenance, great customer service...can't argue with anything at all.

One year and working better than I imagined it would. Carrying loads in my Tacoma is no longer an exercise in fear and my shocks are way happier happier with a little help!
Barry - 08/07/2021


Review from a similar SumoSprings Solo in Vehicle Suspension

I have always used airbags in the past and this is my 1st time using SumoSprings and I can say I will never go back to airbags! I run a heavy load on a 21’ 4Runner pulling a Teardrop with two motorcycles on stock suspension


Review from a similar SumoSprings Solo in Vehicle Suspension

I am happy doing bussines with Etrailer, I ordered the wrong Super springs for my Ram Promaster 2500 by mistake, called them up spoke to miss Paula and she was able to find and ship the correct one fot my Vehicle within a couple of days. She even send me a Return lable so I can return the other one back to the company. I look forward to continue doing bussines with this company.


Review from a similar SumoSprings Solo in Vehicle Suspension

2007 Workhorse W22 chassis, easy install, slight KJ knuckle busting on drivers side, but patience works.

Most Excellent, great ride
Bryan - 12/30/2021


Review from a similar SumoSprings Solo in Vehicle Suspension

When installing the springs I discovered that one of the mounting plates (1 out of 4) had 2 of the holes missed drilled and was unable to install. I had to send back to etrailer.

Sorry to hear about this defect. I see in your account that the manufacturer has provided you with a new mounting plate.
-- Etrailer Expert Sierra K - 10/18/2021


Review from a similar SumoSprings Solo in Vehicle Suspension

Instructions were adequate. installer has to contribute to the outcome with bolt cleaning, match marking axle saddle and finding out "u" bolt torque value.
I think the mount should be radiused where the "u" bolt contacts it as opposed to the square edge. Was unnecessary to jack up truck to get clearance to screw on spring, I put a wood between frame and leaf and raised the box 1/2" with a wedge.
I got the ride height I was looking for, the blue springs are very close to offsetting trailer tounge weight allowing for a bit of takeup with my Andersen hitch.
Barely noticeable change in unloaded rear end stiffness.


Review from a similar SumoSprings Solo in Vehicle Suspension

We installed the SumoSprings SSR-612-40and replace the OEM shocks with the Rancho RS9000 XL on a 2016 Nissan Frontier. When pulling a trailer (KZ Sportsmen Classic 160QB)the back of the truck sag only 1 1/4".I have used Sumosprings in the past and with great results.


Review from a similar SumoSprings Solo in Vehicle Suspension

Senior citizen Installed in 30 mins on a 2022 f250 that hauls a 5th wheel. If I can do it must be an easy install. Use only one 1/2” spacer. Will test out in the coming weeks.


Review from a similar SumoSprings Solo in Vehicle Suspension

Couldn’t have been a simpler install! Total time was less than 15 minutes which included digging the floor jack out, blocking the tires and cleanup. Makes a heck of a difference in keeping the nose of the truck up when towing trailer or hauling 16 golf cart batteries.

Still awesome. A year later, have hauled up to 16 golf cart batteries with no issues due to the weight. A real help in getting the work done without the fear of bottoming out.
EV T - 08/19/2021


Review from a similar SumoSprings Solo in Vehicle Suspension

This is one of the best upgrades ever. The sumo springs were like adding pillows to the back. Took out the bad body roll and rear shock chatter from the factory junk rancheros. On my Sierra 1500 2017 z71. Easiest install and upgrade spent on this truck.


Review from a similar SumoSprings Solo in Vehicle Suspension

Haven’t got to pull trailer yet, that’s why I bought them, but compared to the old ones, uh there’s no comparison, looking forward to pulling my trailer without worrying about how trailer is towing and not swaying


Review from a similar SumoSprings Solo in Vehicle Suspension

I have an ARE Overland camper shell on my 2019 Toyota Tacoma. Installed these to help with the over all ride especially over hard bumps. Sounded like I was hitting the bump stops hard. Installed and ride did improve for the back. Also less body roll. P.s. George J is the best! Always on it when it comes to getting parts out!.

Show More Reviews

Ask the Experts about this SuperSprings Intl Vehicle Suspension

  • Suspension Help for a 2017 Ford Transit 350 Cutaway Cargo Van
    There are springs available that will enhance the suspension of your 2017 Ford Transit 350 Cutaway, though there are no rear sway bars that will fit. The helper springs that will fit your 2017 Transit Cutaway are the SumoSprings Solo Custom Helper Springs # SSR-121-54 and # SumoSprings Solo Custom Helper Springs SSR-121-47. Each of these helper springs absorb shocks, reduce sway and keep your van level even when making sharp turns. They install without drilling and will not require any...
    view full answer...
  • Sumo Springs Solo Helper Spring Recommended for Coachmen Beyond Class B Motorhome
    You're on the right track in my opinion. I'd eliminate the Sumo Springs Solo # SSR-121-54 from consideration because that'd be more support than you'd actually need and would tend to provide a harsher ride than what your looking for. The SumoSpirings # SSR-121-40 offers 1000 lbs of additional support and the # SSR-121-47 would give 1500 lbs of additional support. The # SSR-121-47 would provide the best compromise between the needed support without making your motorhome ride like a buckboard,...
    view full answer...
  • Does SumoSprings Solo Spring Kit # SSR-121-54 Fit 2020 Ford T350 Transit
    Yes the SumoSprings Solo Springs part # SSR-121-54 are a confirmed fit for your 2020 Ford Transit T350 with a high roof.
    view full answer...
  • Will SumoSprings Solo Custom Helper Springs SSR-121-54 Fit A 2020 Ford Transit T250 AWD?
    I reached out to SuperSprings and the SumoSprings Solo Custom Helper Springs - Rear Axle # SSR-121-54 you were looking at is confirmed to fit your 2020 Ford Transit T250 AWD and is a great option for adding 2800lbs of load leveling support to your rear suspension. I included a video review for you to take a look at.
    view full answer...
  • Is There a Gap with SumoSprings Solo Custom Helper Springs On 2016 Ford Transit T350 Chassis
    I reached out to my contact at SuperSprings about the SumoSprings Solo Custom Helper Springs part # SSR-121-54 for a 2016 Ford Transit T350 chassis and they stated that the gap between the spring and contact point can vary by application as this spring can be used on both standard models and cutaways. The gap should be less when used on a motorhome but there are too many factors to say exactly what that will be. They stated a lot of these small Sprinter van chassis don't pre-load the spring...
    view full answer...
  • Mounting Bolt Sizes Used With SumoSprings Solo Helper Springs on 2017 Ford Transit T350
    The SumoSprings Solo Custom Helper Springs # SSR-121-54 will include 2 sets of M10-1.5 bolts for mounting in place of the factory bump stop. The lengths are going to be 55mm and 80mm to account for the different height spacers that you may need.
    view full answer...
  • Should SuperSprings or Air Lift be Used on a 2017 Thor Motor Coach Gemini Motorhome
    The air springs are great products but are more for hauling trailers or equipment. Since you have a model C motorhome I highly recommend going with the SumoSprings Solo Custom Helper Springs # SSR-121-54. The SumoSprings have a weight capacity of 2,800 lbs and will not only work to help control sway and squatting, but they are also maintenance free so after you install them you don't ever have to think about them again. Please note that any suspension enhancement system will not increase...
    view full answer...
  • SumoSprings for RV on 2016 Ford Transit 350 Chassis
    For your RV built on a Ford Transit 350 chassis I highly recommend the SumoSprings Solo Custom Helper Springs # SSR-121-54. These springs will compress to help the squatting you are experiencing in your motorhome. Any suspension enhancement you get is going to impact how your RV drives, but it will be an improvement. The SumoSprings # SSR-121-54 keep you level and work independently so there will be less sway and body roll as you turn. They are simple to install and do not require drilling,...
    view full answer...
  • Rear Helper Springs for a 2016 Ford Transit T250 Cutaway with KUV Utility Body
    The chassis on your 2016 Ford Transit T250 cutaway is the same as the cargo van models so you can use SuperSprings # SSA11. But what I recommend that will work just as well and that costs less is the SumoSprings # SSR-121-54. They will help keep the van level, absorb road shock, and reduce sway or body roll.
    view full answer...
  • Suspension Enhancement Recommendation for Ford Transit T350 RV Orion RV
    The perfect suspension kit you'd want is the SumoSprings part # SSR-121-54 which is a confirmed fit for the Cutaway chassis models of the 2017 Ford Transit T350 like what the RVs are built on. These are also very popular in the RV industry to help prevent sag and improve ride quality.
    view full answer...
  • Recommended Suspension Enhancement For 2016 Thor Gemini 23TR
    I do have a suspension enhancement option for you but the Firestone Ride-Rite Air Helper Springs part # F2603 are designed for the Ford Transit Cargo Van. There are currently not any air bags available for the 2016 Thor Gemini 23TR on Transit Chassis but I recommend to use the SumoSprings part # SSR-121-54. According to our installers, the SumoSprings progressive spring design is much better at combating sway and supporting the load on a motor home compared to air bags. The progressive...
    view full answer...
  • Can SumoSprings SSR-121-54 Be Installed W/ Firestone F2603 On 2017 Winnebago Fuse Motorhome?
    You can install both the SumoSprings Solo Custom Helper Springs - Rear Axle # SSR-121-54 and the Firestone Ride-Rite Air Helper Springs - Double Convoluted - Rear Axle # F2603 on your 2017 Winnebago Fuse motorhome, but it really comes down to what you are planning on towing/carrying as having both would be a bit of overkill. If you are not planning on towing with your motorhome using just the # SSR-121-54 would be my recommendation as they do not require any maintenance while still providing...
    view full answer...
  • Which Jounce Bumper Replacement Helper Spring for 2021 Ford Transit T250 Camper Conversion
    If your 2021 Ford Transit T250 is a high roof model, the Timbren # TFRTR350 you'd looked at would be a fit. This being said, the Timbren # TFRTR350 which provide a combined 5600 lb capacity would provide a pretty harsh ride, which I'm not certain you'd be happy with. Instead, I'd recommend the SumoSprings # SSR-121-54 which bolt to the frame above the rear axle, replacing the factory bump stops. The SumoSprings have a combined 2800 lb rated capacity, and are constructed of a more pliable...
    view full answer...
  • Recommended Rear Suspension Enhancement for a 2020 Ford Transit T350 with Dual Rear Wheels
    I have a few different suggestions and it all depends on what style of 2020 Ford Transit T350 you have. If your T350 is a cargo van then the best suspension enhancement available is the Firestone Ride-Rite Air Helper Spring Kit # F2603 because you can manually adjust how much help your rear suspension is getting at any given point in time. To help you monitor and control the amount of psi in the air springs I also recommend installing the Air Command Compressor System # F2610. This not...
    view full answer...
  • Recommendation to Help Reduce Rear Sway on a 2017 Okanagan Tribute with Ford T350 Chassis
    For your 2017 Okanagan Tribute, on a 2016 Ford T350 chassis, the only kind of rear stabilizer available is the Blue Ox TigerTrak Rear-Axle Stabilizer # TT2603. This is a great option that will help to reduce the sway that you are experiencing but I also recommend adding some suspension enhancement as well. The SumoSprings Solo Custom Helper Springs # SSR-121-54 are the best option in this case for a few reasons. First of all they perform really well and we have received great feedback...
    view full answer...
  • Recommended Air Helper Springs For A 2020 Ford Transit T250 With 6 Inch Lift
    When installing Air Helper Springs on your 2020 Ford Transit T250 with a 6 inch lift I recommend The Air Lift LoadLifter 5000 Ultimate Air Helper Springs with Internal Jounce Bumpers - Rear Axle # AL88213. The Sumo Spring option # SSR-121-54 will not work because there is not way to get it to work with the 6 inch lift. The Airlift # AL88213 has a 2-ply, fabric-reinforced rubber air spring which is very durable. The load-leveling capacity is up to 5,000 pounds, and the adjustable air pressure...
    view full answer...
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Info for this part was:

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