Hydraulic bumpstop install and impressions

[ArmyRN]

23 JLU XR Willys 2.0T. Original BFG 35" tires. Clayton 2.5" springs rear, factory XR springs up front with a TF 1/2" spacer (so 2" lift total up front). Fox 2.0 IFP shocks for a 2 - 3" lift. That gave me 1.75" of space before the front bumpstop made contact. I wanted more (the XR bumpstops are about 1.375 to 1.5" longer than non XR Jeeps).

Iron Rock Offroad (IRO) sells a 2" hydraulic bumpstop kit. Fairly easy install (gotta cut factory bumpstop tubes, so no going back). There's an install video in the link. Pretty straightforward install.

https://www.ironrockoffroad.com/product/trail-tamer-20-hydro-bump-kit.html

IRO also sells a tool to tighten the rings on the assembly. I'd recommend purchasing it if you decide to purchase this bumpstop.

So I took one for the team today. I hope this helps other XR owners.

Installed it today. Essentially drop axle, pull springs, cut tube, install hydraulic bumpstops, put back together.

After install, now I have 3" clearance before making bumpstop contact, plus add the 2" for the hydraulic bumpstop compression.

All good right? Kinda.

I put a tire on, connected the shock, no spring, swaybar still disconnected, track bar connected, and cycled the suspension (only did driver's side, passenger side was left hanging). Tire (factory BFG 315.70.17) was tucked in and made contact with fenderwell with 1" left to go of bumpstop compression, and shock was getting close to full compression. In real life would I ever get it this twisted? Probably not, but technically I guess it is possible based on my suspension cycling. And yes, in the picture below the bumpstop is making contact and has compressed about an inch.

Then I put it all back together. I ordered a 1.25" front bumpstop extension to address this (should be here next week) so I'll drive it easy till then. I don't really fourwheel this Jeep. I debated a 1" bumpstop extension, but thought an additional .25" would add a small margin of safety.

https://www.extremeterrain.com/clay...ont-bump-stops-125-inch-tall-cor-1409101.html

So when I put in the bumpstop extension, I'll kinda be back where I started (about 1.75" before bumpstop makes contact), but after that I'll have another 2" of progressive compression with the hydraulic bumpstop. Not huge, but double from what I had before adding the hydraulic bumps.

Someday I'll get a winch and bumper, and will get rid of the front factory XR springs and spacer, and put in Clayton 2.5" Overland springs up front. We'll see if the added weight up front but taller stiffer springs cancel each other height wise (and corresponding bumpstop space).

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That extra two inches of compression is way better that the harsh thud--at least that's what I experienced. Nice write-up.

 

[ArmyRN]

That extra two inches of compression is way better that the harsh thud--at least that's what I experienced. Nice write-up.

Thanks. That's what I'm hoping for - less sudden thud.

 

[EbyCreek]

I see Teraflex has some composite bump stops. I wonder if they would be softer than the nitrogen filled bump stops?
https://teraflex.com/jl-jt-jk-2-stroke-speedbump-bump-stop-kit-front-2-5-3-5-lift.html

 

[Prot]

That’s one thing Jeep really got half assed on with the XR package. I often read about people bottoming out just going over a speed bump in a parking lot.

Hopefully the next generation Wrangler has a better implementation of a 35” tire package.

 

[Membrain]

Nice option, I have the FOX version of those pending installation for the front and rear.

 

[ASSFROW]

Would you not need a 3 inch extension? Don't you want it bumped at full compression?

 

[Odyssey USA]

Maybe it’s the angle the pic was taken from but at that compression, would the bump stop hit the bottom ID of the spring?

My novice mind would tend to think the bump stop piston starting position wouldn’t count. Just need to know where the hard stop needs to be considering the tire/fender clearance. No suspension guru here so I really don’t know but I’m curious about how to measure correctly and how to anticipate issues.

 

[ArmyRN]

Would you not need a 3 inch extension? Don't you want it bumped at full compression?

Not sure I understand the question.

As it sits now (no spacer) I can go 3 inches before making contact. But once the bumpstop hits and compresses an inch, the tire is hitting the inside of the fenderwell (this is with the opposite tire drooped). And it looked like if it did go the additional inch, my shock will be fully compressed, possibly before the full second inch of bumpstop compression.

Add the 1.25" spacer, and now I've got 1.75 " before the bumpstop hits, but I can go the full two inches with the bumpstop (bumped at full compression), and the tires will (or should be) close to the fenderwell but not touching, and the shock should not be fully compressed.

I'm thinking this is about as good as you can get based on what Jeep gave us to work with. My next set of tires will be MT BB AT 315-70-17 (same size as I've got now) but I suspect they will be a little truer to size (read taller) than my factory BFGs.

 

[ASSFROW]

Not sure I understand the question.

As it sits now (no spacer) I can go 3 inches before making contact. But once the bumpstop hits and compresses an inch, the tire is hitting the inside of the fenderwell (this is with the opposite tire drooped). And it looked like if it did go the additional inch, my shock will be fully compressed, possibly before the full second inch of bumpstop compression.

Add the 1.25" spacer, and now I've got 1.75 " before the bumpstop hits, but I can go the full two inches with the bumpstop (bumped at full compression), and the tires will (or should be) close to the fenderwell but not touching, and the shock should not be fully compressed.

I'm thinking this is about as good as you can get based on what Jeep gave us to work with. My next set of tires will be MT BB AT 315-70-17 (same size as I've got now) but I suspect they will be a little truer to size (read taller) than my factory BFGs.

Ok, I think the picture is fooling my eyes. In the pic of it stuffed without the spring, it looks like there is another inch to go before it hits the bump pad. But it is actually fully stuffed and the bump is compressed all but an inch, so what you said in the original post makes sense.

 

[ArmyRN]

Maybe it’s the angle the pic was taken from but at that compression, would the bump stop hit the bottom ID of the spring?

My novice mind would tend to think the bump stop piston starting position wouldn’t count. Just need to know where the hard stop needs to be considering the tire/fender clearance. No suspension guru here so I really don’t know but I’m curious about how to measure correctly and how to anticipate issues.

Picture the driver's side tire up as far as it can go, and the passenger tire dropped as low it can go. Worst case scenario. With the swaybar connected (no disconnect) and the fact I don't wheel this Jeep, I don't know if I'd ever get it this twisted. But plan for the worst.

Putting in a spacer I'm accounting for tire/fender clearance.

And yes, the picture does show it hitting the outer edge of the axle pad. That's with the axle totally twisted, worst case scenario. In real life I don't think it'll get that twisted. I'm thinking more pot holes, dips, etc. More straight up and down.

 

[ASSFROW]

Picture the driver's side tire up as far as it can go, and the passenger tire dropped as low it can go. Worst case scenario. With the swaybar connected and the fact I don't wheel this Jeep, I don't know if I'd ever get it this twisted. But plan for the worst.

Putting in a spacer I'm accounting for tire/fender clearance.

And yes, the picture does show it hitting the outer edge of the axle pad. That's with the axle totally twisted, worst case scenario. In real life I don't think it'll get that twisted. I'm thinking more pot holes, dips, etc.

Yeah, I understand. I wasn't seeing it right in the pic. It does look like it might rub the spring, but meh. Please let us know how they feel, sound, last. I am very interested. Thanks for the info and being the guinea pig.

 

[ArmyRN]

Yeah, I understand. I wasn't seeing it right in the pic. It does look like it might rub the spring, but meh. Please let us know how they feel, sound, last. I am very interested. Thanks for the info and being the guinea pig.

Will do.

This particular hydraulic bumpstop comes with two different sets of tips. Hard plastic or rubber (I went with the rubber). The rubber may have at best a mm of compression, but mainly they're supposed to be quieter when making contact vs. the hard plastic.

In my normal driving I don't think I'll be hitting the bumpstops much. However, I'm taking the Jeep and trailer to Canada and Alaska this summer. Including the Alaska Highway and the Dalton Highway up to Prudhoe Bay. That's where the front suspension will get a workout (and the justification for this bumpstop project).

 

[ArmyRN]

Closing the loop here. Today I installed the 1.25" bumpstop spacers. Pretty easy when you remove the wheels and tires.

Look at the picture. What's limiting my uptravel is my shocks (Fox 2.0 IFP for 2 to 3 inch lift). I've got basically 4" of uptravel. The hydraulic bumpstops should absorb the last two inches.

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