1. Trailer Leaf Spring Suspension
  2. SuperSprings
  3. Leaf Spring Enhancement System
  4. Springs
  5. 3000 lbs - 8000 lbs
  6. Single Axle
SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 8K - Overslung

SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 8K - Overslung

Item # TSS-107-40
lowest price pledge
Our Price: $214.99
Trailer Leaf Spring Suspension
This item qualifies for Free Shipping
Shipping Weight: 6 lbs
In Stock
SuperSprings Springs - TSS-107-40
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

Customer Photos

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. SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 8K - Overslung part number TSS-107-40 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
  • All Info
  • Reviews (16)
  • Q & A (34)
  • Photos
  • Why etrailer?

SuperSprings Trailer Leaf Spring Suspension - TSS-107-40

  • Leaf Spring Enhancement System
  • Springs
  • 3000 lbs - 8000 lbs
  • Single Axle
  • SuperSprings
  • Jounce Springs

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
  • Progressive spring rate
    • 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
  • Application: 3,000-lb to 8,000-lb single, overslung axle - springs sit over axle
    • For tandem axle applications, use 2 kits
    • 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
  • 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
  • Patented micro-cellular urethane construction
  • Limited Lifetime warranty
  • 30-Day satisfaction guarantee
  • Made in the USA

  • TSS-107-40 SumoSprings 3K-8K 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 8K - Overslung - TSS-107-40

    Average Customer Rating:  4.5 out of 5 stars   (16 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

    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. 674897

    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

    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. 681092

    - TSS-107-40

    Easy install needed to get more spacers due to distance from spring to frame happy with results 903241

    - 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. 902103

    - TSS-107-40

    Excellent product, very well designed and made, easy to install, no negatives. 895328

    - TSS-107-40

    These are wonderful, this is the SECOND set. Already have them on one axel of my TT. Also I found while just sitting, no up and down bouncing when people are walking around. My trailer has 4 corner scissor jacks plus I put one on center each side. Should have saved my money on the center jacks. Personally I would recommend these. 893933

    - 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. 872049

    - TSS-107-40

    A bit underwhelmed at how small and squishy these are, just out if the box. Will be interesting to see if there's any benefit for my 14k pound fifth wheel. Sumo factory guy was of little help answering technical questions. etrailer did well for me, shipping promptly to Alaska. I'll update as possible later. 830177

    - 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 etrailer.com and Sumo Springs websites all the information is available for the do it your-selfer. Thanks etrailer.com for shipping to Canada. I will continue to support your company. 817278

    - TSS-107-40

    Quick shipping and all contents where in the package, Packed well no damage, will post pictures after installation 786261

    - TSS-107-40

    Great product great people and good pri ces 764876

    - TSS-107-40

    Simple call to identify part number needed, Fast delivery, Clear instructions, Extremely easy install. 759251

    - 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. 756773

    - 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. 736952

    - TSS-107-40

    Anyone with a fifth wheel trailer that is at or near it's GVWR should really consider adding these to their springs. 641706

    - TSS-107-40

    Perhaps this product would work well on a lighter trailer. My trailer has 7K axles and product did not help at all. 601010

    Replaced with new 8k springs
    Ken - 01/29/2020


    Ask the Experts about this SuperSprings Trailer Leaf Spring Suspension

    • SumoSprings for KZ Sportsmen Dual Axle Travel Trailer
      The SumoSprings Trailer Helper Springs # TSS-107-40 are designed for single axle trailer applications, so for your tandem axle travel trailer, you'll just need two of these kits. These SumoSprings will fit your 2016 KZ Sportmen travel trailer as long as each of the axles is rated between 3,000 lbs and 8,000 lbs and they are overslung, where the springs sit on top of the axle. If your springs sit below the axle, which is the more common setup, you'll want to use two of part # TSS-106-40,...
      view full answer...
    • Will the SumoSprings Trailer Helper Springs Fit a 2020 Keystone Cougar?
      The SumoSprings Trailer Helper Springs part # TSS-107-40 are compatible with practically any trailer that has a 3K to 8K overslung axle or in other words the leaf springs are mounted on top of the axle. If you have an underslung axle in which the leaf springs are mounted below the axle then you need the SumoSprings Trailer Helper Springs part # TSS-106-40 which is also designed for 3K to 8K capacity axles. I spoke with SuperSprings and they informed me that there isn't a minimum space...
      view full answer...
    • Is There a Spacer for the SumoSprings Trailer Helper Springs for Over Slung Axles
      There are not any spacers specifically for the SumoSprings Trailer Helper Springs part # TSS-107-40 aside from the two included with the kit but you could use the Timbren 1" Spacer part # A25723-90AH00 just keep in mind you'd need a longer bolt.
      view full answer...
    • Can the Leaf Springs Be Upgraded On a Lippert 3,500 Lb Axle
      It is possible to upgrade the leaf springs on a trailer to a higher rated set but I do not recommend this as it can create a rough ride. The better option would be to install the SumoSprings Trailer Helper Springs part # TSS-107-40 for overslung or part # TSS-106-40 for underslung axles. These will offer both additional support without decreasing the ride quality. If you would still like for me to recommend a set of upgraded leaf springs, I'd need to know the unloaded length from eye to eye.
      view full answer...
    • Compatibility of SumoSprings TSS-107-40 with Trailer U-Bolt Plate
      The SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 8K - Overslung # TSS-107-40 has brackets that are designed to fit up to 3 inch wide brackets according to my contact at SuperSprings. This fits the traditional trailer leaf spring widths of 1-3/4 inch, 2 inch, and 2-1/2 Inch but will not fit the large 3 inch slipper springs because the with of the U-bolt Plate will be too large. I am not sure what plate you are describing at there isn't a U-bolt...
      view full answer...
    • How to Determine What SumoSprings Leaf Spring Enhancement Will Work
      In order to determine the correct SumoSprings Leaf Spring Enhancement System for your trailer, you need to need the weight capacity of the axles and if you have an overslung or underslung axle (which I'll explain). Based on your 2017 Montana's weight, both available kits have the right capacity, so all you need to do is find out if your Montanta has an overslung (springs sit over axle) or underslung axle (springs sit under axle). All this means is the position of the leaf springs...
      view full answer...
    • Can SumoSprings Trailer Helper Springs be Used on Slipper Spring Setups
      Yes, the SumoSprings Trailer Helper Springs part # TSS-107-40 that you referenced can be used with slipper springs and since you have 3,500 lb axles it would be exactly what you'd need as well.
      view full answer...
    • What Helper Springs do I need for my 2,000 lb. Trailer Axle
      The width of the clamp on portion of the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket part # TSS-107-40 is likely not to fit the thinner upper plate on the lighter 2,000 lb. axle. These helper springs are designed for 3K to 8K axles. Instead, go with the Timbren Trailer Suspension Enhancement System Light-Duty Trailers 1,000 lbs part # TTRA1702 these will attach to the frame instead of the springs and have you in good shape. Check out the video I've linked for you.
      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...
    • Picking Out Suspension Enhancement for 2018 Cargo Trailer that is 10 Feet Long
      We might have a suspension enhancement kit that could fit your trailer axles, but I would need to know the capacity of your axles. The kit you referenced most likely would be rated too high since it's for 3,000 to 8,000 lb axles. For lighter axles we have the part # TTRA1702 which was intended for 1,000 lb axles. If this would not work let me know what axle capacity you have and I'll see what we have that would work best.
      view full answer...
    • Will SumoSprings Trailer Helper Springs Work for 7,000 lb Axle
      I'm not quite sure what you are referring to by "the black ones" but I can tell you that the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket - Single Axle - 3K to 8K - Overslung # TSS-107-40 should be great for you. The reason I say "should" is because you mentioned that you have an RV with a GVWR of 14,000 lbs, so I am assuming you have a tandem axle trailer with axles that are rated for 7,000 lbs (or in that range). The SumoSprings are rated for axles between 3,000 lbs...
      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...
    • 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...
    • SumoSprings for Jayco Jay Flight SLX-7 183RB Baja & How to Determine Solar Power Needed
      Based on my research, your 2020 Jayco Jay Flight SLX-7 183RB Baja has a single 3,500 lb axle which is overslung - meaning the leaf springs sit over the axle. Knowing that, the correct SumoSprings for your trailer are the SumoSprings Trailer Helper Springs # TSS-107-40. These will do a great job of helping stabilize your trailer and reduce the amount of body roll that can occur. I have added links to the instructions as well as video reviews for you to check out as well of the SumoSprings...
      view full answer...
    • Will SumoSprings Trailer Helper Springs fit Fifth Wheel Trailer with 4,400 lb Axles
      The SumoSprings Trailer Helper Springs w/ Line Relocation Bracket # TSS-107-40 will work with 4,400 lb axles. It will fit your trailer so long as the axle is an overslung axle, which means the leaf spring will be over the axle. If you take a look at the accompanying cut out of the linked installation manual you can see how the springs will mount and what your axle needs to look like for the helper springs to work. When installed the SumoSprings # TSS-107-40 will be a good addition...
      view full answer...
    • How Much Preload Should SumoSprings kit for Trailer Suspension Have When Installed
      One inch of preload is too much for the install of the SumoSprings kit part # TSS-107-40 that you referenced. You want between 1/4 and 1/2 inch of preload otherwise you'll have a harsher ride quality. If you have spacers installed you would need to remove them so that the preload lowers. This process is outlined in the attached install instructions link.
      view full answer...
    • Suspension Upgrade For 2007 Keystone Everest 344J
      There are suspension upgrades available for the 2007 Keystone Everest 344J but they are not designed to raise your carrying capacity of the fifth wheel trailer. The carrying capacity of your trailer is set by the manufacturer and cannot be changed. Suspension enhancement is designed to support the existing suspension on the trailer to prevent sagging, improve ride quality, and prolong the life of your suspension components. The carrying capacity I was able to find on line for the Keystone...
      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 8k.
      view full answer...
    • Which SumoSprings Trailer Helper Spring Kit Fits 2019 Jayco HT 25.5REOK
      The SumoSprings Trailer Helper Springs # TSS-107-40 is the correct fit for your 2019 Jayco HT 25.5REOK based on the axle capacity, axle configuration and also works well with the MorRyde CRE 300 kit you have. This will give you additional support when towing that will improve ride quality and handling!
      view full answer...
    • 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 3000-8000 lb capacity axles. As a bonus, the SumoSprings are also especially effective against porpoising,...
      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 8K. 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...
    • How to Determine Correct Replacement Springs for a 2019 Keystone Fuzion 424 Toy Hauler with 7K Axles
      I was able to find that your 2019 Keystone Fuzion 424 Toy Hauler has 7K axles and while we do have leaf springs for 7K axles, you'll need to take some measurements of your leaf springs to ensure that you get leaf springs that are the correct length for your application. Height can be a factor as well unless you are swapping out all of your leaf springs on all of your axles. If you are referring to suspension enhancement we have that too. Unfortunately we don't have a way to look up exactly...
      view full answer...
    • Could Timbren Axle Less Kit Be Installed on Truck Bed Trailer Frame
      The Timbren Silent Ride # TSR7KS02 that you referenced was intended for attaching to a trailer frame, but could also attach to a truck frame too assuming it's a standard boxed frame. I attached a picture that shows how it typically bolts to a frame and shows relevant dimensions that you should check out and compare. You really don't want to install suspension enhancement like the # TSS-107-40 you referenced on suspension that is showing signs or being worn out like yours. These kits...
      view full answer...
    • Timbren vs. Sumo Spring Jounce Bumpers Trailer Upgrade Recommendation
      Both the Timbren Trailer Suspension Enhancement System part # TTRA15252 and the SumoSprings Trailer Helper Springs part # TSS-107-40 are great upgrade to make to your trailer. Since you are on the higher side the Timbren's will be more in line with your loads but requires welding to install. The Sumos are slightly lighter but are bolt on. Clearly there are give and takes. I would go with the Sumos so I could bolt them on. Given the up to 8K support and you using two kits then you...
      view full answer...
    • Can Lippert Shock Kit Be Used on Trailer with Less Than 4 of Clearance Between Tire and I-Beam
      I reached out to my contact at Lippert and he said unfortunately if you don't have at least 4 inches of clearance between the I-beam flange and inside of the tire the Shock Kit # LC281281 cannot be used. There is not a solution that would allow this system to work properly. For an alternate solution to provide additional suspension support for a smoother ride on the trailer I recommend the SumoSprings Trailer Helper Springs # TSS-107-40. These springs will act as shock absorbers to...
      view full answer...
    • Sumo Springs Recommendation for 2018 Ford F-250 SuperDuty when Bumper Towing Reflection 312BHTS
      When it comes to adding some extra support to improve your towing experience I love the SumoSprings because they're easy to install and they provide you with progressive load support that doesn't effect the unloaded ride quality on your vehicle. With that said, the TSS-107-40 (for trailers) and CSS-1168F (for coil springs) are not the parts you're looking for. Because of the 800-1200-lbs tongue weight of your trailer, I recommend using the SumoSprings # SSF-111-47 (front) and # SSR-127-47...
      view full answer...
    • What Causes Trailer Leaf Springs To Break Continuously
      Yes, leaf springs must be replaced in pairs which is why one side left go and then the other shortly after. In regards to the stent you get on a full set of leaf springs, there are really a ton of variables present here so it is hard to predict. However, if you are a full-timer then odds are your trailer is going to be subjected to harder conditions and most likely more weight than the average trailer therefore your suspension components will wear faster. I have attached our leaf spring...
      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...

    Do you have a question about this Trailer Leaf Spring Suspension?

    • Why etrailer.com?

      At etrailer.com we guarantee:
    • Highest quality trailer leaf spring suspension for the best price.

      Our Lowest Price Pledge ensures you will never overpay for the parts you need.
    • Real product know-how.

      We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
    • Most detailed, accurate trailer leaf spring suspension information available.

      Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
    • Installations, made easy.

      We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
    • Fast shipping.

      Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
    • Personalized service for life.

      We provide one-on-one, personalized service from the ordering process through the life of your product.
    • Trusted since 1946.

      We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
    • Returns Policy

      Need to return an item? No problem. Please read our Returns Policy for more information.

    Info for this part was:

    Expert Research:
    Mike L
    Expert Research:
    Jameson C
    Installed by:
    Kathleen M
    Video Edited:
    Chris R
    Updated by:
    Sarah W
    Updated by:
    Noah M
    Edited by:
    Daron K
    Written by:
    Jessie B

    At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.

    Product Experts Available Now!
    Call 800-298-8924