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  1. Trailer Leaf Spring Suspension
  2. SuperSprings Intl
  3. Leaf Spring Enhancement System
  4. Boat Trailer
  5. Camper
  6. Car Hauler
  7. Snowmobile Trailer
  8. Utility Trailer
SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Overslung

SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Overslung

Item # TSS-107-40
Our Price: $267.99
You Save: $24.19
Trailer Leaf Spring Suspension
Shipping Weight: 6 lbs
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Improves suspension, handling and safety. Progressive spring rate. Provides additional support as needed so you always have a smooth, comfortable ride. Great Prices for the best trailer leaf spring suspension from SuperSprings Intl. SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Overslung part number TSS-107-40 can be ordered online at or call 1-800-940-8924 for expert service.
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SuperSprings Intl Trailer Leaf Spring Suspension - TSS-107-40

  • Leaf Spring Enhancement System
  • Boat Trailer
  • Camper
  • Car Hauler
  • Snowmobile Trailer
  • Utility Trailer
  • 3000 lbs
  • 4000 lbs
  • 5000 lbs
  • Single Axle
  • Jounce Springs
  • SuperSprings Intl

Improves suspension, handling and safety. Progressive spring rate. Provides additional support as needed so you always have a smooth, comfortable ride.


  • Improves suspension, handling and safety
  • Provides additional support as needed so you always have a smooth, comfortable ride
  • Allows the leaf spring ample movement while cushioning light loads
  • Becomes more rigid as more weight is added
    • Increases stability, providing great performance while hauling heavy loads
    • Raises trailer ride height
  • Works independently side-to-side
    • Helps compensate for off-center loads
    • Reduces body roll when swerving and turning corners
    • Works to eliminate trailer sway
  • Acts as shock absorbers, taking the brunt of bumps and rough roads
    • Reduces load on leaf spring assembly
    • Extends the life of your trailer's suspension
  • Designed to work with a suspension system that is in good working order
  • 2 Jounce-style springs, line relocation bracket, mounting brackets and hardware are included
    • Maintenance-free - no tubing to run or air pressure to monitor like with air springs
    • Simple, no-drill installation
  • Made in the USA


  • Application: 3,000-lb to 5,000-lb single, overslung axle - springs sit over axle
    • For tandem axle applications, use 2 kits
  • Capacity: 500 lbs at 50 percent compression
    • Do not exceed the trailer's weight-carrying capacity
  • Spring dimensions: 5" tall x 4" diameter
    • Compresses up to 70 percent of original height with full memory rebound
  • Required clearance between top of spring plate and bottom of trailer frame: 5-5/16" - 6-1/2"
  • Limited lifetime warranty
  • 30-Day satisfaction guarantee

Note: Does not work with spring plates wider than 4-1/4".

TSS-107-40 SumoSprings 3K-5K Trailer Helper Springs w/Bracket-Overslung

Replaces SuperSprings TSS-104-40

Installation Details TSS-107-40 Installation instructions

Customer Satisfaction Score:

Customer Reviews

SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Overslung - TSS-107-40

Average Customer Rating:  4.8 out of 5 stars   (78 Customer Reviews)

Improves suspension, handling and safety. Progressive spring rate. Provides additional support as needed so you always have a smooth, comfortable ride.


I made some brackets to bolt to the frame. Now I have 100% contact with the Sumo Springs. The are working extremely well!


My only complaint is that even with adding the two provided spacers, I was still a quarter inch short of touching the top rail. It is supposed to be set with a slight pushing down from the top rail. It went on easily and I am sure it will still work whenever there are significant bumps in the road.


Help a lot with the bounce from the leaf springs



Working great


For the money I believe its the best thing you can do to improve the ride of your trailer. Lessons the shock of the bad roads (like I-95 in south carolina) on the leaf springs and hangers.


Easy install. It took me approximately 3 hours for the entire project. That's cleaning a few things up also. I did not notice much difference in "body roll". Honestly,, I never had much before. Now, anytime going over rougher roads, railroad tracks, etc.... That was a big difference. It took a lot of that movement out. I hardly knew the trailer was going over it. I installed these on a 5th wheel.


Easy Installation. I'm expecting them to act as shock-absorbers, and I haven't experienced any adverse handling issues, so I guess they're working. I haven't noticed any difference in handling, so I guess that's OK. I hoped for additional capacity, too, and that's hard to measure. Sorry this isn't more definitive, but I'm satisfied that they are helping.


Fantastic upgrade for the cheap factory suspension!


These were very easy to installed and have done a great job smoothing out the ride of the camper. It has made a big difference in how the camper tows and has calmed it down with crosswinds and when big trucks pass by. We did not have the clearance to install a shock kit and the tech at etrailer highly recommended these, I am glad he did. So far I am very happy with this product.



These are still going strong after a year of abuse from these horrible roads. I still feel that they have done a lot to smooth out the ride of the trailer.


When I decided to replace the RV trailer leaf springs I decided to update the suspension by adding Sumo Springs as well. The installation was simple and quick. Between and Sumo Springs websites all the information is available for the do it your-selfer. Thanks for shipping to Canada. I will continue to support your company.


Kit came with more than I needed but I can see where some trailers might have used different hardware and all scenarios were included in kit. I went with these to help eliminate my tires rubbing against bottom of trailer floor on rough roads "California" and give an overall smoother ride hopefully extending the lifespan of our trailer. I also Installed Dexter EZ Flex at the same time.


These helped the tow quality of my boat trailer immensely. The trailer feels so much smoother on big bumps on the highway and the gear in the boat moves around a lot less than before. Super easy to install as well.


Was easy to install I removed the wheels which made it easy to access the u bolt flange that they mount to I moved the propane line further away from the area, took about an hour to complete install which included greasing the spring mounts.


Installation was very straightforward and they made a significant difference in pulling.



Springs are still getting the job done~!


Simple call to identify part number needed, Fast delivery, Clear instructions, Extremely easy install.

Greg S.


Great spring support solution to resolve bounce and sway! Perfect addition to our 2019 Riverstone 5th Wheel


One year in already? Wow time flies! These sumo springs have been a GREAT addition to our 32' travel trailer. Easy to install and they've been perfect ever since. I definitely recommend these!



Still so glad we got these ... Things stay put in the trailer, no matter how bumpy the roads get!


I had always taken the clover leaf ramps on freeways slow while towing my trailer from fear of tipping. It's stupid, but I feel much better going traffic speed on the ramps now with these springs installed on the trailer. I also feel more comfortable towing with side winds. I don't have a lot of experience towing in high winds, but the few trips I have done with moderate winds felt safe.


Was having a control issue with my camper, corresponded with Gregory and he knew what I needed to fix the problem, these mad hauling my camper enjoyable and not a white knuckle experience.


The only reason I can't give a 5 star is that we haven't taken the trailer out yet to test the sumo's.
From the install point of view, they were great! easy to follow instructions and assembly.

My only suggestion comes from my own mistake. Maybe consider adding an additional line to your step 1. "Ensure the landing gear / jacks / stabilizers are retracted before taking measurements". I had measured and installed two sumo's before I realized the gears were still down which, obviously, messed up my measurements. Thus I had to take off the sumo's, hook up the 5th wheel, raise the jacks, then restart the process. Went smooth after that. My daughter installed one with no problem. Thanks.



I believe they are working as advertised. They smooth out the bumps felt inside the trailer. I also installed sumos on our pickup. They make a HUGE difference when pulling our 5th wheel. Very satisfied.


After installing the trailer specific sumo springs the trailer is more stable when towing. I would recommend this easy upgrade to your towable RV.


Installed with EZ-flex equalizer kit. Easy to install when the suspension is lowered. Make sure to measure the gap between the springs and frame before you take off the wheels. Seems like good quality and does improve the ride.


This was probally the single best improvement we did to our 2018 Coleman Light trailer. The have helped reduce the ping pong effect, reduced trailer sway when being passed by semis on the road and made the trailer easier to pull in general.


Excellent product and great service


Great add on to our travel trailer suspension to assist in the ride of our leaf spring suspension. We also have MORryde 3000, HD shackle wet bolts , and X-factor crossmembers on our trailer as well. All of the above makes for a great towing experience as we tow our rig between 10 and 15k miles a year from upstate NY to the Rockies as well as traveling the Adirondack mountains and New England with plans for Alaska after COVID. Another great add are the Goodyear Endurance tires on our trailers....fantastic tires! We have a tpms for our trailer tires and I check tire temperature every 2 to 4 hours of travel
With an infrared thermometer.... safe travels!


Short of installing independent suspension or adding shock absorbers (did this on my 2014 radiance, DIY project, lots of upside down drilling) this is the upgrade for you. Installation and directions are straight forward and only took me about an hour to install. Due to the COVID, we were only able to take four trips since we purchased our 2020 Grand Design 303RLS and these helper springs have made a WORLD of difference. The side to side motion is less and the ride is MUCH smoother. Also changed out our fifth king pin which helped with the chucking. Highly recommend these helper springs and as a bonus, dealing with etrailer is a great experience and they are always there to help and support. Customer service is Top Notch.


Easy install needed to get more spacers due to distance from spring to frame happy with results

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