JL frame twist

sourdough

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Read this on the Northridge 4x4 website.....
"Jeep had a brilliant idea to make the JL frame rails out of a new harder material, but trail testing has exposed a major flaw: thinner walls but stronger material twists! Early in 2018's Easter Jeep Safari exposed major flexing and twisting in rigs coming back off their day's runs."
it's and excerpt from here...https://www.rockhard4x4.com/product_p/rh-90509.htm
In this youtube link, frame twist is again mentioned.... This and the frame weld issues that are well reported has got me a little worried. I just ordered a '19 Rubicon.
https://jalopnik.com/new-jeep-wrangler-frame-welds-are-failing-and-now-fca-i-1829551649





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Jeeper Fever

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Ignore Jalopnik, it's part of the Gawker, Gizmodo, Kotaku, Jezebel etc. media circus. Nothing but trolling and crud.

The factory optimizes for lightweight and low cost, which is good unless it is overdone. Sure, Tower International screwed up the frames, but that is mostly in the past now, there are not many new reports of serious problems. Just read up on the frame weld problem threads, inspect your frame at the trackbar, look over the welds and make sure they are mediocre rather than bad, as they will never be great looking.

I think I am still in D status, hence still posting on random threads and pressing refresh on the forums 50 times a day.

See you around!

<refresh>
 

Sean K.

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Read this on the Northridge 4x4 website.....
"Jeep had a brilliant idea to make the JL frame rails out of a new harder material, but trail testing has exposed a major flaw: thinner walls but stronger material twists! Early in 2018's Easter Jeep Safari exposed major flexing and twisting in rigs coming back off their day's runs."
it's and excerpt from here...https://www.rockhard4x4.com/product_p/rh-90509.htm
This and the frame weld issues that are well reported has got me a little worried. I just ordered a '19 Rubicon.
https://jalopnik.com/new-jeep-wrangler-frame-welds-are-failing-and-now-fca-i-1829551649

The quote and your link to Rockhard's skid is a marketing pitch. They are effectively claiming that adding the skid plate will make the frame rails more rigid. I personally haven't seen this "major flexing and twisting"....as this is a body on frame vehicle, it would be apparent when flexed up as bumpers would be rubbing the paint off the body, doors and the rear hatch would misalign and the core support would float/bind when twisted up. And yes, I am aware that some folks with the steel rear bumper have complained of it flexing into the body and rubbing the paint....but my understanding that it was due to the bumper being flimsy enough that when hit by a ledge or rock that it was being pushed into the body....not from merely flexing the suspension out.

Granted,I've removed both bumpers on my wife's JLUR and the front is now part of the frame (as the rear likely will be) but I've had the doors/hatch open when twisted up (to get pics and the like) and haven't noticed any frame twist issues.

JmoS69I.jpg


While I'd agree that theoretically adding a belly skid will increase rigidity, I'm not convinced it's at all necessary on the JL.
 

Sean K.

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You could be right! You might want to take up your position with their marketing department. I read them saying their braces and belly pan tied the frame rails together and made the difference. Could be true, don't know my JL is still not even made. I was thinking a belly pan was more for protection rather than rigidity.
It's definitely more for protection....however, they are playing on people's fears of "frame twist" to nudge a buyer towards a decision to purchase the skid as a "fix" for an alleged problem that may not be all that legitimate.
 

WXman

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I'm not sure why a rock crawler would be upset about frame twist. It's been documented in many videos and reviews that Toyota gets the suspension articulation out of the Tacoma the way that they do by using a rear frame section that can twist more than the competitors. The result is that a Tacoma keeps a tire on the ground far more often than a Ranger/Colorado while on the trails. That's a good thing for safety. We're not dealing with 1-ton pickups here, so we don't need ultra-rigid frames. If the JL frame is twisting some, that doesn't bother me at all.
 

Sean K.

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I'm not sure why a rock crawler would be upset about frame twist. It's been documented in many videos and reviews that Toyota gets the suspension articulation out of the Tacoma the way that they do by using a rear frame section that can twist more than the competitors. The result is that a Tacoma keeps a tire on the ground far more often than a Ranger/Colorado while on the trails. That's a good thing for safety. We're not dealing with 1-ton pickups here, so we don't need ultra-rigid frames. If the JL frame is twisting some, that doesn't bother me at all.
Having owned and built first & second gen Hiluxes and Tacomas/3rd gen 4Runners....frame twist is not a good thing. In the crawling community, Toyota guys (like myself) spend a lot of time adding 3/16" or 1/4" plates to the frames on the newer gens (the older ones didn't need it) to reinforce them due to cracking issues. In short, your suspension should be doing the vast majority of the flexing. Short of a full tube frame, you're going to get some chassis flex (well, even in a tube frame actually)...but it should be as minimized as feasible.
 

offcamber

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The quote and your link to Rockhard's skid is a marketing pitch. They are effectively claiming that adding the skid plate will make the frame rails more rigid. I personally haven't seen this "major flexing and twisting"....as this is a body on frame vehicle, it would be apparent when flexed up as bumpers would be rubbing the paint off the body, doors and the rear hatch would misalign and the core support would float/bind when twisted up. And yes, I am aware that some folks with the steel rear bumper have complained of it flexing into the body and rubbing the paint....but my understanding that it was due to the bumper being flimsy enough that when hit by a ledge or rock that it was being pushed into the body....not from merely flexing the suspension out.

Granted,I've removed both bumpers on my wife's JLUR and the front is now part of the frame (as the rear likely will be) but I've had the doors/hatch open when twisted up (to get pics and the like) and haven't noticed any frame twist issues.

JmoS69I.jpg


While I'd agree that theoretically adding a belly skid will increase rigidity, I'm not convinced it's at all necessary on the JL.
IT is due to the frame flexing. There isn't a mark on my bumper. I haven't hit anything with it but it's rubbed on my body and made gouges in the paint on both sides.
 

Sean K.

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IT is due to the frame flexing. There isn't a mark on my bumper. I haven't hit anything with it but it's rubbed on my body and made gouges in the paint on both sides.
I stand corrected then. :)

That said, if it's flexing that badly at the rear with a crossmember the size and shape that Jeep put back there....then adding a belly skid isn't likely to stop the flex at the rear of the vehicle.

I was already considering dumping the rear exhaust, cutting out that rear x-member and building something one could actually tow with (really so I could build the rear bumper the way I wanted)....sounds like I might as well if the rear frame flex is that bad.

Thanks for the correction.
 

Blu bi Kong

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My steel DV8 rear bumper rides with an even 1/4" gap along rear and up around the corners. Super flexing, crazy rock crawling, twisted opposite directions going up thru ditches....and have hit the bottom corners!
Bumper has not hit body yet.
 

GRAK

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IT is due to the frame flexing. There isn't a mark on my bumper. I haven't hit anything with it but it's rubbed on my body and made gouges in the paint on both sides.
How bad are the marks? Mine is doing it too, never hit anything. Hard washboard roads I can hear and feel it hitting. What are you going to do?
 

Tech Tim

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Anytime you have a ladder style frame like the JL (and all Jeeps before it), you will have frame twist to some degree. Although newer metallurgy and frame design can help mitigate that a lot, a ladder frame will have twist.

Adding extra crossmembers and skids can help stiffen the frame, BUT the main reason to add those items is to protect all the vulnerable things under your JL, like your oil pan, transmission, T-case, fuel tank etc.
 

offcamber

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How bad are the marks? Mine is doing it too, never hit anything. Hard washboard roads I can hear and feel it hitting. What are you going to do?
Right now I think I could cover them up with touch up paint but they get worse every time I wheel. I'm going to replace the bumper at some point in the spring. Luckily my Jeep is black so it's fairly easy to hide it, but if it was a lighter color, I'd be pissed.
 

GRAK

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Right now I think I could cover them up with touch up paint but they get worse every time I wheel. I'm going to replace the bumper at some point in the spring. Luckily my Jeep is black so it's fairly easy to hide it, but if it was a lighter color, I'd be pissed.
Okay. Same, bumper replace. Yes mine’s yellow and I’m pissed lol
 

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