Adding “mods”, or modifications, to your rig is what one does to make it yours, add flair and impact functionality! We have done a ton of mods and will do more but nothing has been as impactful as adding Sumo Springs to both the truck and the 399TH! 7,500 miles of Sumo Springs so far and here is my take!
Our Setup:
2019 Ram 3500 DR Diesel … originally with no airbags, then added AirLift 5000XL airbags and removed them to add Sumo Springs 7,500 miles ago on the 399TH and 40,000 miles ago on the Dodge Ram 3500 DRW..
2020 Grand Design Momentum 399TH … we ordered this unit and took possession of it before GD started offering independent suspension and disc brakes. UVW = 15,900, GRVW = 20,000 and hitch weight = 3,400. We do not haul toys because our garage has been modified to be our office on the road. We do have a Reese GooseBox 2.0 20k installed.
So, we took possession of the rig in December 0f 2020 with no mods to the suspension and the truck stock as well with the only unusual addition to the normal rig was the addition of the Reese GooseBox prior to leaving the dealer.
Overall towing performance out of the box was ok. The truck did squat a bit more than we were comfortable with but nothing out of the ordinary that needed correction.
We added the AirLift 5000XL bags about 90 days in not as a necessity but more of a luxury particularly because of our plans for a lot of long haul mileage ahead. The expectation was to eliminate the squat, which it did, as well as help with the ride, which it did to a small extent. I was never unhappy with our investment in the AirLift bags.
With the truck squared away I was on the hunt for something to help with the suspension on our “JoyHauler”. I wasn’t planning on adding independent suspension because I wasn’t planning on being near a MORryde installer in the near future.
This mod began with my good friend, and Director of Service at United RV, Jim Vititow’s love for Sumo’s and Adam Weisner’s, Chief Commercial Officer Sumo Springs International, interest in seeing how they would perform on a big 3 axle rig like a toy hauler. So, in July of 2020 we had them installed. Because we were stationary in the DFW area for a month they only got a 25 mile workout from the dealer to our home base. That said, in those 25 miles I was taken back by how smooth the rig rode in freeway conditions. To complete the package we pulled the AirLift bags and added Sumo’s to the Ram 3500 as well.
If you want the short story … the performance of the truck, the 399TH and the overall rig together is outstanding! I could not be any happier!
More Specifically:
The Truck – with the AirLift bags I definitely saw improved performance when not hauling. It made the ride smoother than it was without bags but the ride was still what I would call hard. Hit a small bump you still felt it (not as much) and it felt hard. Hit a big bump and you still felt it (not as much) and it would take 5 or 6 bounces to recover. Hit the kind of humps you run into on the road and the same, some help but still 5 or 6 bounces to recover.
The Truck with Sumo Springs – hit a small bump and instead of a hard feeling the best way I can describe it is it seems to round out the bump. No Jarring or hard feeling. The same thing happens when it’s a big bump but where the Sumo Springs really show up is that the truck recovers in just to or three bounces. Same happens with the humps … much quicker recovery!
The Toy Hauler – when you hit something with the truck, small, medium or big you know you are about to feel it with the trailer. With the Sumo Springs you feel nothing with the small or medium hits and, as with the truck, the big ones feel as if they have been rounded off.
Where you will see the biggest difference is inside your rig. We no longer have any damage, even incidental, inside of our rig even when we have experienced bad roads, as we have on this long of a trip through 8 states so far. This thrills my wife to no end. Plus, I know that there is a lot less damage being done to the entirety of my rig … frame, body, suspension and everything else because the rolling earthquake has been minimized.
The entire rig, truck and toy hauler – I would be remiss if I didn’t mention the impact the quicker recovery of the truck has on the entire set up. Instead of the 5 to 6 bounces/shocks the truck experiences it only has a couple and then is back to ground zero. That means the shockwaves the truck transmits to the rig are limited as well.
All of the above means less wear and tear, less maintenance and a much more enjoyable ride!
I trust this has been helpful! Feel free to ask me any questions you would like … I am always glad to answer!
Thanks Jim Vititow and Charles Lansdon at United RV and thanks Adam Weisner with Sumo Springs International! You guys are the best …
Joyhauling With Team Jacobus 
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