Blue SumoSprings

SumoSprings Bump Stop Replacements for 5th Gen 4Runner

Brenda Ely SumoSprings Leave a Comment

Original post by Brenan Greene of Trail4runner


SumoSprings are a line of bump stops designed and manufactured by SuperSprings International. They are offered for the Toyota, 4Runner, Tacoma, Tundra, along with many other makes and models. SuperSprings International has offered load-carrying enhancement suspension parts for many different trucks, and SUVs since 1996.

With a platform such as the 4Runner, we have many different options when it comes to building out these rigs. Whether you want to build a badass rock crawler, a full-blown overland build, or just to enhance to ride quality of your daily driver, SuperSprings International has an option for you – and that’s what makes them truly unique.


Blue SumoSpring installed on 5th Gen 4Runner

Well, let’s first introduce the company…

Who is SuperSprings International? 

SuperSprings International is the company. SuperSprings International has been designing and manufacturing American-made suspension products since 1996. Their product line includes many types of suspension load-carrying enhancements for trucks, SUVs, trailers, jeeps, RVs, and everything in between.

What are SumoSprings? 

SumoSprings is a product line that SuperSprings International offers. SumoSprings are the first load-assisted airless airbags on the market. This doesn’t necessarily mean that SumoSprings’ sole purpose is for towing though. In fact, the Blue and Black SumoSprings are designed to replace the factory bump stops providing a better, smoother ride all around, for both on-road and off-road applications. They are maintenance-free, do not leak air, and do not require airlines or compressors. They enhance the load-carrying/towing ability and most importantly for the 4Runner, they reduce and stabilize sway. Overall, they will improve driver control and ride comfort when daily driving, off-road driving, and even rock crawling.

There are two different density options to choose from; Blue and Black. The blue SumoSprings are made of a softer density material, while the black is made of more firm density material.

The blue SumoSprings takes less weight to compress which results in a softer unloaded and loaded ride. The black SumoSprings have a higher density, meaning there’s more material packed into the same size SumoSpring, which in turn necessitates more applied weight to compress it. This is what gives the black version a higher load rating, but also what creates a stiffer unloaded ride. In most cases, the blue version will apply to most 4Runner drivers on the road.

Blue SumoSprings

  • 1400 (lb) Capacity at 50% Compression

Black SumoSprings

  • 1800 (lb) Capacity at 50% Compression

Features & Specs:

  • Maintenance-free
  • Designed, made, and supported in the U.S.A.
  • Enhances load capacity
  • Reduces and stabilizes sway
  • Improves handling
  • Improves overall ride comfort
  • Compress up to 80% of original height with full memory rebound
  • One-piece unit attached on one side used as a replacement/upgrade to factory bump stops
  • Progressive spring rate with superior damping properties
  • Made from patented micro-cellular urethane
  • Guaranteed not to leak or rupture

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Blue SumoSpring installed on 5th Gen 4Runner

As I mentioned before, these bump stops have a progressive spring rate that adjusts automatically. This means that the patented micro-cellular urethane is continually adapting to how much load is upon it at any given time. This alone is a huge benefit when it comes to offroad applications because you will have more control of your up travel.

If you plan on off-roading your 4Runner, then you should invest in aftermarket bump stops. The bump stops by SumoSprings are a perfect alternative to stock bump stops as they provide the protection you need from harsh bottom-outs all while providing enhanced ride comfort.

Even the mild to rough terrain getting to the actual trailhead is going to be much more enjoyable with a set of these.

SumoSprings have shock damping properties which means the ride quality off-road is going to be a night and day difference.


Blue SumoSprings installed on 4Runner

On-road driving with the SumoSprings is just as enjoyable as off-road driving. The highly durable closed cell microcellular polyurethane material provides a plush ride over bumps and rough roads while providing complete control of the vehicle. When you hit something like a speed bump, the SumoSprings will help soak up the bump, but when you’re doing a lot of cornering, the SumoSprings will help provide rigidity.

If you are going with an overland build, then consider getting some SumpSprings bump stop replacements plus SumoSprings coil reinforcements. These inserts are installed into the middle of the coil spring and have a similar purpose as airbags. They will stiffen your suspension, which keeps the 4Runner from handling like a boat when it’s loaded down.


Blue SumoSprings installed on 4Runner

If you plan on towing frequently, some kind of spring reinforcement is needed. The reason for this is the 4Runner was not designed to support a ton of weight. Airbags, or in this case airless airbags, are designed to support the weight while towing, which in turn gives you more control. This is a must-have for those long trips while pulling a camper or even short trips towing your boat to the lake.

While towing, these bump stops act as airbags but without the air. This will not only provide a much more enjoyable ride, but your rear-end will no longer sag. If you are looking at towing, you may want to consider the black SumoSprings bump stops. The bump stops we received are the blue SumoSprings. The black SumoSprings are designed to support more weight.

There are many guys who have installed airbags for towing but unlike airbags, SumoSprings are guaranteed to not pop or lose air. If you’ve ever owned airbags, you also know how sketchy it can be working on them. Not to mention, the amount of time an install takes.

If you are looking to increase the stability of your 4Runner while towing heavier applications, you may want to consider getting the Coil SumoSprings as we mentioned above. These won’t support the weight of a trailer, but they will prevent harsh bottom-outs, body roll, nose dive, and more.


Coil SumoSprings

Features of the Coils

  • Sold as a pair (left and right)
  • Maintenance-free
  • Fits both front and rear coil springs
  • Coil SumoSprings simply slide between the turns of coil springs
  • Enhance front suspension when fitting snow plow, winch, or bumper
  • Enhance rear suspension when adding tow hitch
  • Reduces side-to-side body roll and front end dip
  • Produced from SumoSprings closed micro-cellular urethane
  • progressive spring rate with superior damping properties
  • Coil capacity increased by 15% to 30%
  • Typical installation completed in less than 30 minutes
  • Never load any vehicle beyond the manufacturer’s GVWR

The Coil SumoSprings slip right into your factory or aftermarket coils (both front and rear). The purpose of these is to help prevent sagging when your 4Runner is loaded down or nose dive in the front when braking. This is the middle ground for someone looking to do a little bit of towing or a great addition to running a set of blue/black SumoSprings.


Tools to install SumoSprings laid out on the ground

The install for the SumoSprings is very straightforward. I took the tire off on one side just to get better pictures, but on the other side (passenger side) I left the tire on and it wasn’t any more difficult. If you choose not to take the tires off then the only tool you’ll need is a 13mm gear wrench.

Tools and Materials

  • 13mm Gear Wrench
  • New Hardware (provided)
  • Blue Locktite (provided)
  • Breaker Bar (optional)
  • Impact (optional)



Removing factory bump stop from 4Runner

After you have parked the vehicle on a hard, level surface and engaged the emergency brake, place blocks in front and behind the wheels to prevent rolling. Observe all safety precautions and wear safety glasses.

Raise the rear of the vehicle allowing the axle to hang freely and rest the frame on the safety jack stands rated for the weight of the vehicle. Removal of the rear wheels is optional. Starting on the driver’s side, unscrew the two bolts and remove the factory bump stop from the underside of the frame.


Bracket of SumoSpring bolted on

Attach the mounting bracket to the top of the SumoSprings using the supplied M8 hex bolt and washer after applying a drop of blue thread locker to the threads of the bolt. Use the center of the three holes on the top part of the bracket.


Blue SumoSpring installed on 4Runner

Attach the assembly to the underside of the frame using the supplied M8 hex bolts and washers after applying a drop of blue thread locker to the threads of the bolts. Be sure to position the bracket so that the SumoSprings is offset 1/2″ outboard (toward the wheel). Don’t tighten down the bracket all the way just yet.


Blue SumoSpring lined up with axle of 4Runner

There are slotted holes in the bracket for the bump stops which allow you to move the bracket left or right in order to center the bump stop on the axle. Keep in mind that when the axle flexes, it also rotates forward a little bit with the factory 4-link.

As you can tell in the picture, the previous bump stop was a bit too far forward. With the axle level, place the new bump stop a little bit in front of it and tighten down the hardware. When the axle comes up in this position, it will be centered with the new bump stop.


White 4Runner parked

If the rear wheels were removed, you can now reinstall them. (Torque wheel nuts to manufacturers spec). Clean up all your tools and call it a day.

Before you take it for a spin, ensure emergency brake cables are not touching the SumoSprings. Secure any cables out of the way with zip ties or by re-routing. Ensure all A/Clines, brake cables, and frame are clear of contact or interference.


White 4Runner off-roading

Overall, we are extremely impressed with the quality of these SumoSprings. We replaced our Timbren bump stops (a very reputable company) with a set of these Blue SumoSprings on the rear of the white 4Runner.

The bump stops feel great both on and off the road. I noticed a smoother contact while wheeling around the rocks over the Timbrens. When wheeling with the Timbrens, you can literally feel the bumpstop hit the axle – it’s better than stock but the Blue SumoSprings are much smoother.

These really have stabilized our sway, improved the overall driver control, ride comfort, and will enhance load carrying ability if we tow anything.

The thing that stood out to us about SumoSprings is the fact that they have three options available for the 4Runner. No matter what route you go with your 4Runner build, SumoSprings has an option for you.

Use our application guide to see what we have for your vehicle.

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