Sumo Springs

camjr · October 22, 2021

Hello all. 2021 3.0L Duramax X31 Elevation owner. I am about to take ownership of a travel trailer and will be using a WD hitch (roughly 6500 pounds of trailer with a 700 tongue weight). Both well within the ratings, but I'll need to be wary of the truck's payload capacity. I will eventually replace the spongy Rancho shocks with Bilsteins when they wear out, but was looking for something to assist with squat and stability when towing. I ordered the blue Sumo Springs after researching Timbrens and other options. Ordered Monday direct from the manufacturer and received them two days later. They only took about 30-45 minutes to install them this morning, and much of that was chocking the fronts, jacking it up, and placing jack stands. Huge improvement in the unloaded stability and ride of the truck when going over bumps and on corners - not near as much bounce, and not harsh at all. Anyone else running the Sumo Springs?

DustSierra · October 22, 2021

My pops is. They will definitely stiff up the rear end. But unless you are pulling a Trailer north of 8-10k on a regular basis, I think most people would think they degrade the ride quality. Same reason you aren't going to see a bunch of people running serious off-road suspensions on their daily driver as they lessen articulation, but provide a much stiffer ride.

Most people prefer that Cadillac ride. But they are certainly a viable option for anyone towing heavy, frequently. As you mentioned, Timbrens are also a popular option.

camjr · October 22, 2021

1 hour ago, DustSierra said:

My pops is. They will definitely stiff up the rear end. But unless you are pulling a Trailer north of 8-10k on a regular basis, I think most people would think they degrade the ride quality. Same reason you aren't going to see a bunch of people running serious off-road suspensions on their daily driver as they lessen articulation, but provide a much stiffer ride.

Most people prefer that Cadillac ride. But they are certainly a viable option for anyone towing heavy, frequently. As you mentioned, Timbrens are also a popular option.

Not harsh at all when unloaded because I opted to:

1. Not use the optional 1" spacer that would place the Sumo Spring in direct contact with the axle, thereby only engaging it when there is a lot of movement in the axle.

2. I opted for the mid-level "blue" product rather than the much firmer "black" option.

Edited October 22, 2021 by camjr

Anacortes Army Guy · October 22, 2021

2 hours ago, camjr said:

Not harsh at all when unloaded because I opted to:

1. Not use the optional 1" spacer that would place the Sumo Spring in direct contact with the axle, thereby only engaging it when there is a lot of movement in the axle.

2. I opted for the mid-level "blue" product rather than the much firmer "black" option.

And the blue is much prettier as well. I opted to go with the Timbren SES part, which, like the Sumo product without the spacer, should only make itself known when loaded down and the suspension is compressed, or so I hope. My intent is to reduce squat when towing my small trailer, which currently is not severe, but noticeable. And since I plan on moving up to a slightly larger trailer, I figured something like the Sumo or Timbren would be beneficial.

DustSierra · October 23, 2021

22 hours ago, camjr said:

Not harsh at all when unloaded because I opted to:

1. Not use the optional 1" spacer that would place the Sumo Spring in direct contact with the axle, thereby only engaging it when there is a lot of movement in the axle.

2. I opted for the mid-level "blue" product rather than the much firmer "black" option.

They take load off of the leaf spring. There's no two ways around it. Anything that is going to cause your suspension not to sag when under load is going to stiffen the suspension except for true airbags.

FWIW I don't care to argue, but look at this forum as a compilation of information for other T1 Owners and future owners. Just trying to put the right information out there.

camjr · October 23, 2021

38 minutes ago, DustSierra said:

They take load off of the leaf spring. There's no two ways around it. Anything that is going to cause your suspension not to sag when under load is going to stiffen the suspension except for true airbags.

FWIW I don't care to argue, but look at this forum as a compilation of information for other T1 Owners and future owners. Just trying to put the right information out there.

Agree completely. I think the best way to explain the ride after installing the Sumo Springs is it rides like I have about 750 pounds in the bed of the truck - it's not floating and bouncing. Feels good to me :thumbs: .

Flatblack83 · October 24, 2021

I put the black sumo springs on my 19 2 years ago. They work perfect for what I need. I have them tho with a spacer but I have a 2 inch rear lift. I have these set about 1/2-3/4 from the axle. Normal driving they don't touch. When I haul a ton in the bed it goes down about 1-1.5 inches. Towing they work perfect, I hauled 3-6k on my car trailer. The pic it looks close to the axle but it's because the pics so dark.

Edited October 24, 2021 by Flatblack83

mrtizzom · October 27, 2021

I have the blue sumos and bilstein's on the rear. The bilstein's def improved the ride by themselves. We have a travel trailer close to the same weight as the OP and I notice a difference when pulling the trailer for sure. The sumos help with the slight bounce we had...no noticeable difference in ride quality when unloaded(maybe on some super harsh bumps...thanks MI roads). Of course a properly setup WDH hitch also helps with the bounce. Overall...very happy with our setup.