SumoSprings: Front Bumpstops replacements from Thuren

[bamnq6]

Hello all-

Over the weekend I started to replace my OEM from Rubber Bumpstops with SumoSprings from Thuren. During my last desert roaming adventure I whacked the front bumps hard rolling down a two track at about 20. It seemed prudent to me to go from the hard rubber to the progressive urethane bumpstock for more control and forgiveness at the upper extreme of travel.

Install of the Driver side spring went well enough, there's roughly 1.5" from the SumoSpring to the coil spring.



I got into the passenger side and noticed that the SumoSpring would end up VERY close to the passenger coil spring. Like 1/8" close. Too close for my comfort. I think that 1/8" gap isn't enought to keep the coil spring from contacting the SumoSprings top plate. The axle definitely moves around during articulation, particularly with the rubber bushes in the OEM Trackbar.



Ive reached out to Thuren and SumoSprings tech support. They're stating the parts look like all the rest of the part on the shelves and that these clearances are normal, particularly with the bow in the OEM Springs.

Thoughts? Anyone else out there running SumoSprings on the front? Should I just give up, return to the OEM rubber bumps?

Thanks-

 

[flan]

One way to find out!

 

[Rockcrawlindude]

Are you lifted? If so, how much? You mentioned oem trackbar

Also, the black sumo springs are rock hard. I have them in the rear

 

[bamnq6]

Suspension is all factory Power Wagon parts at this time-

 

[jetrinka]

They seem much longer than the stock bump stops? Wouldn’t they limit travel of the front axle during articulation? I can understand the molar jarring hitting the bump stops would bring but it also means they’re doing they’re job

 

[Poolmonkey]

I have them, haven’t noticed anything except cushier whoops

 

[Poolmonkey]

They seem much longer than the stock bump stops? Wouldn’t they limit travel of the front axle during articulation? I can understand the molar jarring hitting the bump stops would bring but it also means they’re doing they’re job

Like the boogie bumps, the truck has no problem smashing them. It’s a much nicer smashing than the factory bumps. I hung wheels a few times last month and the opposite was thoroughly stuffed.
I have considered cutting off the bottom “bubble”, but all good so far.

 

[Power247]

I have the softer blue sumo springs on the front of my truck and yes the passenger is closer to the coil spring than the driver side. So far it hasn't rubbed or caused any other issue, but I'm not off-roading like you are either.

Sent from my SM-T860 using Tapatalk

 

[H3LZSN1P3R]

As the suspention compresses the trac bar pushes the axle and springs to the right and away from that bump stop so you have nothing to worry about

 

[bamnq6]

Thanks for all the details! Hopefully the rain knocks off this evening and I can get back under there and wrap up the install.

Good notes H3LZSN1P3R, I wasn't accounting for the arc of axle travel in my fears of contact

Your assistance is appreciated!!

 

[el_barto]

I have the blue ones up front, it’s close ish to the coil but doesn’t seem excessively close.

Truck still flexes fine. It’s much softer than the stock bumps so it’s progressive you don’t even feel it engage

 

[jetrinka]

I guess I don’t know much about these bump stops but curious as to the benefit of them? Especially on a PW?

 

[el_barto]

I guess I don’t know much about these bump stops but curious as to the benefit of them? Especially on a PW?

Progressive vs harsh bottom out.

Bottoming out on the stock hard rubber bump stops (which happens fairly often offroad) is kinder to the truck and less shocking/butt clenching feel for the passengers

 

[jetrinka]

Progressive vs harsh bottom out.

Bottoming out on the stock hard rubber bump stops (which happens fairly often offroad) is kinder to the truck and less shocking/butt clenching feel for the passengers

Gotcha. So they’re soft enough they really don’t even affect travel?

 

[el_barto]

Gotcha. So they’re soft enough they really don’t even affect travel?

Yeah, they are soft like a running shoe midsole, Vs the stock bump stops are a super hard rubber

Still flexes fine…See image above

 

[Rockcrawlindude]

Gotcha. So they’re soft enough they really don’t even affect travel?

Yeah, they are soft like a running shoe midsole, Vs the stock bump stops are a super hard rubber

Still flexes fine…See image above

I wish I got the blue ones for the rear of my truck.

The black ones are too stiff for daily driving but they’re really good for towing so it’s a trade off I roll with.

 

[whitexc]

E Trailer chic is saying I should get the yellow 2800# Sumos. Thinking they will be a bit harsh on the daily, which the truck isn't but I do need to not be driving a stagecoach again. That was the 2002 24v! I think the black ones may suit us with the new 5er.

Sorry, I searched quick and thought this was RCs thread about the Sumos on the rear of his truck.

 

[AH64ID]

Got the black ones for upfront to pair with my new Thuren sway-bar.

I was tempted to get the blue ones, but didn’t want the blue color.

I’m rarely under 5200lbs FAW, so I don’t think the added stiffness will be an issue.

Looking forward to getting them both installed.

 

[el_barto]

Got the black ones for upfront to pair with my new Thuren sway-bar.

I was tempted to get the blue ones, but didn’t want the blue color.

I’m rarely under 5200lbs FAW, so I don’t think the added stiffness will be an issue.

Looking forward to getting them both installed.

Picking a part based on the color when you can’t even see it without crawling under the truck is pretty silly. Also my blue ones faded(?) to black after a year

That said, sounds like the difference between the blue and black up front isn’t that big of a deal

 

[AH64ID]

Picking a part based on the color when you can’t even see it without crawling under the truck is pretty silly. Also my blue ones faded(?) to black after a year

That said, sounds like the difference between the blue and black up front isn’t that big of a deal

Agree, but in reality the 1200lb springs are better rated for my CTD… so just having fun with it.