Blue Front SumoSprings for 4Runner


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Original post by Eric Keller of Trail4runner


If you’ve been around Trail4Runner for a while, you’ve probably seen Brenan’s intro article of the SumoSprings by SuperSprings International. In that article, he showed you their awesome new rear bump stops and coil spacers.

Fast forward a few months, and now SuperSprings has released a bump stop for the front of our Toyotas to compliment their rear bump stops.

This post will obviously focus on the 4Runner, but SuperSprings has released front bump stops for Tacomas and Tundras too!


Installed front SumoSpring on 4Runner

For those who missed the last article on the rear bump stops, let’s take a minute and re-introduce SuperSprings International and their SumoSprings line of bump stops.

Who is SuperSprings International?

Since 1996, SuperSprings International has been designing and manufacturing suspension components for cars, trucks, SUV’s, trailers, and RVs, right here in the USA. They have a product to fit almost any vehicle and any type of application from towing your toy hauler to carving up canyon roads in your sports car to offroading in our Toyotas.

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.

How do they help? 

This, in turn, provides 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.

As of this writing, there is only one density option to choose from for the front; the blue. The blue SumoSprings are made of a softer density material, while the black is made of more firm density material that you will find as an option for the rears.

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


Parts included in Front SumoSprings kit

The installation of these could not be simpler and requires only one fairly basic tool. The kit comes with everything you need to install these in your garage/driveway. This install should take you ~30-45 minutes from opening the box to taking a test drive.

Note: The nuts and washers in the kit are not needed for our application. You can toss them in your random hardware bucket cause you never know when you’ll need hardware of this size (I’m not the only one who has a random bolts bucket am I?).

What’s In The Box?

  • SumoSprings Front Bump Stops
  • Nyloc Nuts (not used in our application)
  • Washers (not used in our application)
  • Tube of Blue Thread Locker
  • Installation Instructions

Tools Required

  • 15″ Channel Lock Pliers (or another suitably large set of pliers or wrench)

Start by positioning wheels

After making sure your vehicle is in park with the emergency brake engaged, turn the front wheels to full lock. Depending on which side you are working on, turn your steering to full lock in the opposite direction (i.e. if you’re working on the driver’s side then turn the wheel all the way to the right/passenger side). The goal here is to give yourself enough room to easily access the bump stop with your adjustable wrench/pliers.

There is no need to jack your vehicle up here as long as you are lifted. I am lifted 3″ in the front and had no issue installing these bump stops while the vehicle was on the ground.


Removing the factory front bump stop from 4Runner

Using your large channel lock pliers or a pipe wrench, grasp the hex portion of your stock bump stop and remove it.

The bump stop is threaded into its mount under a decent amount of torque, so be prepared to put some effort into it. Once it starts turning, it will be easier to remove and can be spun by hand after a turn or two (at least for me on the west coast). Remove the factory bump stop and toss it in the trash because it’s time for an upgrade.

Prep the SumoSpring for Install

In your kit, you’ll find a small tube of blue Thread Locker. Snip a small portion of the tip of the nozzle off and applied a small dab of Thread Locker to the threads of one of the bump stops. It is important here to only apply thread locker to one bump stop at a time so you don’t risk the thread locker setting up before you’re ready to install.


Start the install by threading the SumoSrings bump stop in by hand until it is tight.

Take your large channel locks and do your final tightening. Tighten down the bump stop hand tight, and then give it an extra force of hand tight until the blue material on top of the bump stop starts to shred off. There is no torque spec here, but I went until I felt the metal base snug up on the frame and then gave it a bit more until I felt it was good and tight.

Repeat Steps

The steps to install the bump stops are the same for both driver and passenger sides. The only difference is the direction you need to turn the wheels to gain more access to the bump stops. Just remember you need to turn the wheels in the opposite direction of the side you are working on (turn the wheels to driver lock if you are working on the passenger side).


Factory 4Runner front bump stop compared to Blue SumoSprings
Factory bump stop (left) compared to upgraded blue SumoSpring (right)

I have been driving on these bump stops for a few weeks now on many types of terrain and driving scenarios and I have to say, I am impressed!

The two areas I noticed immediate improvement is in body roll and at full bump. The sway is much more limited/controllable and at full compression, hitting the limit is far less harsh. I believe this comes down to the progressive spring rate and length of these bump stops.

When cornering, the 4Runner rolls but it is predictable and slightly less than what I previously had with the stock bumps. This is great for on-road scenarios such as high-speed cornering as well as off-road scenarios both for cornering and off-camber situations.

Where these bump stops really shine is at full compression or high-speed G-outs. Long gone are the days of going to full bump and feeling the abrupt stop of hard rubber on metal. The SumoSprings really control and soften the hit of going to full bump. On G-out situations from large dips in the road or the occasional large hole in the trail at speed, the vehicle doesn’t hit you hard in the seat anymore. In these situations, you can feel the bump stop slow the travel to a stop over the last 5-10% of suspension travel instead of just an immediate abrupt stop at full articulation.

I know there are several options for front bump stops available for our 4Runners, but I would highly recommend this bump stop to anyone!

Whether you have stock bumps or a different brand, the SumoSprings are just way smoother and add a lot to your driving experience.


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

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