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  1. Trailer Leaf Spring Suspension
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  3. Leaf Spring Enhancement System
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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
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Our Price: $224.99
Trailer Leaf Spring Suspension
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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. Lowest 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 800-298-1624 for expert service.
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  • Reviews (45)
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SuperSprings Intl Trailer Leaf Spring Suspension - TSS-107-40

  • Leaf Spring Enhancement System
  • Springs
  • 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 80 percent of original height with full memory rebound
  • Limited lifetime warranty
  • 30-Day satisfaction guarantee

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 Reviews

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

Average Customer Rating:  4.7 out of 5 stars   (45 Customer Reviews)

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

- TSS-107-40

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

Springs are still getting the job done~!
Tom - 02/28/2022

- TSS-107-40

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.
Tom - 04/14/2022

- TSS-107-40

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.
Dale - 07/25/2020

- TSS-107-40

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

Great spring support solution to resolve bounce and sway! Perfect addition to our 2019 Riverstone 5th Wheel
Greg S - 02/27/2021

- TSS-107-40

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.

- TSS-107-40

They were easy to install and definitely made our 5th wheel handle better. I would have gave them a 5 start but I stumbled into the perfect 5th wheel for me and traded my old one off, so I don't have any long term information.

- TSS-107-40

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!

- tss-107-40

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.

- TSS-107-40

Trailer is more stable with the sumo springs, easy to install great product.

- TSS-107-40

Received the SumoSprings a day early. The installation on 5th wheel was quick and easy with the provided instructions and Etrailer video. Called to ask if it was ok to use one spacer on rear axle and 2 on front to get correct loading on SumoSprings on both axles and tech said no problem. Can't wait to try it out! I'm confident it will help the highway bounce.

- TSS-107-40

Although product was on back order etrailer kept me well informed on order progress which was appreciated. Seems to be a great product,untested at this time. Very easy installation ,hoping for the best.

Have had a great experience with sumospings on 31ft 5th wheel,8500 miles, smoother ride and less internal movement of objects.
Terry - 02/21/2021

- TSS-107-40

No room for the Lippert shock kit (outboard side) so I went with the Sumo Springs. Easy install. The way the kit hugs the frame, there has to be improvement in the rocking from side to side.

- TSS-107-40

Wow, these things make the trailer so much smoother! Great service from Etrailer, as Always!

- TSS-107-40

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.

- TSS-107-40

these went on so quickly. We took the trailer for a short drive around town and it felt like driving a new car. Increased stability. Hands down this add on is the cats pajamas. Thumbs up,thanks you much.

- TSS-107-40

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!

- TSS-107-40

Tammie I want to thank you for the personnel attention you gave to my order. The springs came faster then I expected. I just got off the phone with a good friend of mine that just received his Sumosprings from etrailer yesterday. We are both long time customers of etrailer and are extremely happy with your products and service. I always tell fellow RV'ers. about your company and hopefully they will buy from you. The company is lucky to have a dedicated and considerate salesperson like you on their staff. Will start the install today. Thanks again.

- TSS-107-40

etrailer has delivered again. Great company for your RV parts. Looking forward to next trip to see how Suspension Upgrade works, but took trailer for short 10 mile test pull, & so far I think I'm going to be impressed.

- TSS-107-40

Fast delivery, simple and quick install. Have not taken 5th wheel out to test. Will follow up later.

- TSS-107-40

easy install works great very well label and instructions. fast shipping

- TSS-107-40

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.

- TSS-107-40

Best addition ever to my trailer wish I had had them 2 sets of springs ago

- TSS-107-40

I received exactly what was promised in a well packaged box with all the small parts separately packaged. Installation of the SumoSprings was easy and straight forward though I did need additional spacers that etrailer had available. The most time consuming and difficult part of installing the SumoSprings was moving the gas line, which parts came with the kit to help with, that ran on the trailer frame where the SumoSpring makes contact. Definitely recommend.

- TSS-107-40

These springs, combined with the Dexter EZ Flex equalizer system, and heavy duty shackles, made a huge difference in the amount of trailer bounce I experienced in towing a 34' travel trailer. The entire rig is much more stable and under control. Towing went from scary to mildly pleasant.

- TSS-107-40

Just installed 2 sets. The included spacers definitely helped address the variable spacing between the 4 axle points and the frame. Had to relocate both gas line (for which brackets were included) and a grey water line (no brackets included). I only give 4 starts for now because the replacement clamps for the gas line do not come with the correct hardware to attach to accompanying bracket. The clamps holes are way too big for the screw that is included. I had to use the old clamps, which is fine. Also, only got one drop of thread lock out of the included tube - too viscous / dried up otherwise. I'll test the ride this weekend.

Show More Reviews

Ask the Experts about this SuperSprings Intl Trailer Leaf Spring Suspension

  • Troubleshooting SumoSprings Compressed 1/2 to 2/3s After installation
    I spoke with my contact at SuperSprings to find out if this would present any issues for you. Although the amount of compression you are describing with the # TSS-107-40 installed is not ideal, they assured me that the system would still work as intended and would not cause a problem. With the amount of compression you are describing, you may need to replace your leaf springs. If you provide me with the measured distance from center eye to center eye as well as the capacity of your axle...
    view full answer...
  • Which SumoSprings Suspension Kit Fits 2021 Winnebago 2401 RG
    I looked up the axle capacities of your 2021 Winnebago 2401 RG and based on that the SumoSprings part # TSS-107-40 that you referenced would be correct. Your trailer would have 3,500 lb axles and this fits axles between 3,000-5,000 lb.
    view full answer...
  • How Wide can the Bracket on a SumoSpring TSS-107-40 Adjust to?
    I had the bracket SumoSprings Trailer Helper Spring # TSS-107-40 measured, and it will go from 4 1/2 inches at the widest and 3 3/4 at it most narrow positioning. Not knowing how wide the plate is for your MORryde shock kit is, you will need to measure to make sure this will fit or not.
    view full answer...
  • Recommended Preload for SumoSprings TSS-107-40 Trailer Helper Springs
    The folks at SuperSprings tell me that ideally, you'd see about 1/4 inch of pre-load between the # TSS-107-40 spring and the underside of the trailer frame, but they tell even if there's no preload, the SumoSprings would still provide benefit. You can even trim the spring if you need to, but SumoSprings cautions that doing so will void the warranty.
    view full answer...
  • Can SumoSprings # TSS 107-40 be Used with Shock Kit Installed on Trailer
    The SumoSprings Kit part # TSS-107-40 would work just fine on a trailer with shocks like what you have. The shocks will still provide the dampening to make it feel less bouncy and harsh whereas the SumoSprings would just give you more support which reduce the bouncing. If you are getting sway though I would recommend you try moving the weight of any cargo in the trailer as far forward as you can and also make sure you are using a ball mount that allows the trailer to sit level as well.
    view full answer...
  • Correct SumoSprings for Keystone Passport Elite Travel Trailer 4,400 Lb Axles
    The correct SumoSprings Trailer Helper Springs for overslung axles (axle under leaf springs) is part # TSS-107-40. The springs will be pre-loaded upon installation therefore the space you have between the frame is spring loaded will be less than the height of the spring and bracket. This won't be an issue.
    view full answer...
  • Is The SumoSprings Trailer Helper Springs TSS-107-40 A Set Or An Individual Spring?
    The SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Overslung # TSS-107-40 you were looking at comes with both the right and left hand springs and all of the hardware needed to get them installed on your trailer. Keep in mind the # TSS-107-40 is designed for 3000lb - 5000lb axles that have overslung springs meaning the springs are on top of the axle. I included a video of the # TSS-107-40 for you to take a look at.
    view full answer...
  • Will SumoSprings 7k Trailer Axle Kit TSS-107-40 Fit 2016 Grand Design 350M Toy Hauler
    Yes the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket # TSS-107-40 will work on your tandem 7k axles. Since this is a single axle kit you'd need a quantity of two of the # TSS-107-40.
    view full answer...
  • Is It Okay To Have 1/8th Inch Load After Installing The Sumo Trailer Springs?
    When installing the Sumo Trailer Springs # TSS-107-40, is very important as the Trailer SumoSprings provide the maximum level of vibration reduction and damping with the 1/4”-1/2” preload. That being said, the measurement is extremely close and after talking to SumoSprings it will indeed be okay. Be sure to share some pictures of the process/finished product on our website!
    view full answer...
  • Recommended SumoSprings Trailer Helper Springs for 2021 Grand Design Reflection 5th Wheel
    SuperSprings recommends the # TSS-107-40, which is designed for 3000-5000 lb capacity axles. Once installed, the springs would sit so the top is 6-1/2 inches above the top of the spring pack. Two 1/2 inch thick spacers are included, so if one spacer was added, it would sit 7 inches above the spring pack and 7-1/2 inches if both spacers are used. Ideally, you'd want to see about 1/2 inch of preload. To determine if the # TSS-107-40 would work, with the trailer on the ground as you'd typically...
    view full answer...
  • How to Determine What Trailer Helper Springs TSS-107-40 Will Fit
    I can help you to determine if the SumoSprings Trailer Helper Springs # TSS-107-40 will fit your trailer, though there isn't a list or anything similar with fits; it is a universal type of fit. In order to determine if this will work for your 2011 trailer there is some necessary information you need to have, which is simply the weight rating of your axles and to know if they are overslung - which means the leaf springs will be on top of the axle beam as opposed to under. If your boat trailer...
    view full answer...
  • Fit of SumoSprings TSS-107-40 On Dexter Axle Leaf Spring U-Bolt Plates
    I forwarded your photo to the folks at Sumo Springs, and was told that as long as the spring mounts so its level and doesn't rock back and forth, you'll be just fine. From what's shown in your photo, everything looks like it's nice and level and stable. The engineering Manager at Super Springs assures me that their brackets are designed to work with several different styles of spring plates, including the ones with the ribs on them like what what's on your trailer. If you click the provided...
    view full answer...
    Image 1 for
  • Sumo Springs Versus Shocks for Toy Hauler
    Because they are maintenance free, less expensive and easier to install than shocks, I'd definitely recommend going with the SumoSpring option. They'll work with your existing leaf spring suspension to help dampen the suspension, but will also reduce sway and body roll during turns. For a tandem axle application, you'll need two sets of the # TSS-107-40 which are compatible with 3000-5000 lb capacity axles. As a bonus, the SumoSprings are also especially effective against porpoising, the...
    view full answer...
  • SumoSprings Helper Springs on a 5th Wheel with Under-Spring 7k Tandem Axle
    I'm happy to inform you that the SumoSprings Trailer Helper Springs, part # TSS-107-40, will work for your setup. They are designed to sit over the axle and can handle axles between 3K and 5K. I've linked to a video review of these springs for you to look at. Keep in mind that since you have a tandem axle, you will need 2 kits. You can check the product page for this kit's current price.
    view full answer...
  • Using SumoSprings Trailer Helper Springs In Place of Shock Kit on Trailer
    The SumoSprings Trailer Helper Springs # TSS-107-40 are a great alternate solution to the Lippert Shock Kit that you mentioned when you don't have the needed tire to frame clearance. The jounce-style urethane springs will essentially act as shock absorbers to take a lot of the jolt out of bumps and rough roads and will definitely work to prolong the life of your suspension. Because they won't be constantly engaged like traditional shocks they aren't going to have quite the same effect with...
    view full answer...
  • Will SumoSprings Kit # TSS-107-40 Fit Trailer with Overslung Axles
    Yes, since you are moving your axle setup to be an overslung setup the correct SumoSpring kit you need is the part # TSS-107-40 as long as your axles are between 3k and 5k.
    view full answer...
  • Can SumoSprings Trailer Helper Springs be Cut to Fit Trailer Correctly
    You definitely can cut the SumoSprings Trailer Helper Springs # TSS-107-40 to fit your application if you don't have enough room. We have confirmed this with SuperSprings on multiple occasions. You might also want to make sure that you haven't overloaded your trailer and that your leaf springs are in good shape. Unless you put larger tires on your Keystone Cougar 26RBS than what came as stock you shouldn't be having the tires bump up against the underbelly material unless you are flying...
    view full answer...
    Image 1 for
  • Will SumoSprings Trailer Helper Springs Work with Slipper Springs
    Yes, the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket # TSS-107-40 will work with both slipper and double eye leaf spring styles. Double eye springs are just more popular than slipper springs which is why all of the photos and videos you're currently seeing about this kit show it on double eye springs.
    view full answer...
  • How Much Room Is Needed To Install SumoSprings On A Trailer
    I measured the SumoSprings Trailer Helper Springs # TSS-107-40 and it will be either 6-3/4" with both spacers, 6-1/4" with one spacer, or 5-3/4" with no spacer when measured from the top of the U-Bolt plate to the top of the spring once put together and installed. So you do have some adjustability if needed. It will also accommodate a U-Bolt plate that is up to 5 inches wide. The SumoSprings # TSS-107-40 are made from patented micro-cellular urethane, so there will be no air in them. These...
    view full answer...
  • How Many Of The SumoSprings TSS-107-40 Trailer Helpers Are Needed For A Tandem Axle Trailer
    The SumoSprings Trailer Helper Springs w/ Line Relocation Bracket # TSS-107-40 will cover one axle. If you have a tandem axle and want to get both of them supplemented, you will need to get two sets. They currently are not offered as combined sets for tandem or triple axles.
    view full answer...
  • Will SumoSprings Trailer Helper Springs TSS-107-40 Work with Overslung Axle
    The SumoSprings Trailer Helper Springs w/ Line Relocation Bracket # TSS-107-40 was designed for overslung axles like yours and would work great with the 7-1/2 inches of clearance you have now.
    view full answer...
  • On Part # TSS-107-40 What Is The Minimum Dimension Between Frame and Top Of Spring Plate
    The # TSS-107-40 will not work on spring plates wider than 4.25 inches. The total height with the spacers is 6.75 inches, and without the spacers is 5.75 inches. I have attached a review video link below.
    view full answer...
  • Will the SumoSprings # TSS-107-40 Correct a 2-Inch Tall Ride Height Difference on the Front End?
    Since the height of the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 5K - Overslung # TSS-107-40 depends on the amount of compression sustained, it is difficult to 100% confirm whether the springs can correct a ride height difference to the height you need. However, with that being said, at maximum 80% compression, the spring height is 1 inch tall. With that measurement, it will be close to what you need given that you do the spring rests somewhere...
    view full answer...
  • SumoSprings Trailer Helper Springs Recommendation for OverSlung Trailer Axle
    Drop axles don't drop the distance between the trailer frame and axle as basically the drop is after the suspension and between the spindle. So the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket # TSS-106-40 would install just fine on a drop axle. But sounds like you have an overslung axle based on the distance between your leaf spring and trailer frame. So for that you'd instead want the part # TSS-107-40.
    view full answer...

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Info for this part was:

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Expert Research:
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Employee Kathleen M
Installed by:
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Employee Chris R
Video Edited:
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Updated by:
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