Made in USA
Orem, Utah
Lifetime Guarantee
Unconditional
10 Colors
In-house powder coat
Ships in 3 Days
From our UT facility
Fully Adjustable
0-6" of lift
3 X-Series Options
Only Core 4x4
Why Builders Choose Core 4x4
The only aftermarket suspension brand with an X-Series product system
vs. MetalCloak
One price point, no tier options. Core 4x4 Crawl matches their performance at a better price with a better warranty.
Their “lifetime” language refers to their service model. Actual parts warranty: 1 year. Ours: lifetime.
vs. Teraflex
Skip a grease interval? Warranty voided. Core 4x4 Cruise requires zero maintenance — and our warranty covers everything.
Skip a maintenance interval? Their warranty voids. Ours doesn’t.
vs. Clayton / Budget
Cheaper arms exist. But adjustable, American-made, 10 colors, lifetime guarantee, and an upgrade path? Only Core 4x4.
Clayton warrants their Johnny Joints for 90 days. We cover ours for life.
JKS Greasable Heavy Duty Boomerang Rear Shackles for XJ Cherokees and MJ Comanches have been a staple of the off-roading and desert racing world for decades! Boomerang shackles, due to their unique shape, allow the leaf spring eye to travel dramatically farther up and around the back of the vehicle in extreme articulation conditions, resulting in full compression and extension of the leaf springs. No matter the type of off-roading you are doing, your XJ or MJ's stock shackles and bushings are surely not up to the task. These heavy duty shackles from JKS an extremely strong, fabricated steel design that are up to the task of off-roading or desert racing. Dura-Thane bushings are greasable thru the zerk fitting on the shackle to provide long life and quiet operation.
| Brand | JKS |
Select your lift size in Step 1 — the kit ships with the correct geometry for that height. If you’re running a non-standard setup, call us before ordering and we’ll confirm compatibility.
Death wobble is a geometry problem, not just worn parts. Cruise Series corrects caster angle and eliminates the flex points that let shimmy start. Replacing one part at a time delays the fix — this replaces the geometry.
Yes, if you’ve done a lift kit before. Full-day project. Watch the complete JT install walkthrough on our YouTube channel — most owners wrap it in a day. Any off-road shop can run it if you’d rather have it done.
Any non-wear component fails — we replace it. No mileage cap. No maintenance intervals to track. No fine print about voiding if you miss a service. Lifetime means lifetime.
Teraflex’s lifetime warranty voids if you miss a maintenance interval. MetalCloak’s actual parts warranty is 12 months — their “lifetime” language refers to their service program. No conditions here.
See It Installed
Install videos and build guides on our YouTube channel.
Watch more installs on YouTube
Reviews from Google
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132 reviews
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Ajay Paynter
Mar 4, 2026
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Great company, who worked with me on shipping parts to arrive in time for a show. When I explained my concern they went above and beyond to make it happen. Quality of the parts is top notch.
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Ryan Colligan
Mar 4, 2026
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I have nothing but good things to say about Core 4x4. I have the crawler series on my JKU and we take it all over the place. These parts handle everything we throw at them.
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Marcus Torres
Jan 15, 2026
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Best control arms I have installed on any of my builds. After running every major manufacturer, Core 4x4 is on par or better than all the high-end companies at a fraction of the cost. Lifetime warranty is the cherry on top.
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Sebastian
Oct 24, 2025
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Great products they sell, got a crawl series long arm kit for my xj and it has held up quite nice, they are beefy, and for what ever reason they fail it has a great warranty with a customer service to match, when someone asks what control arm kit to buy I always recommend core 4x4
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Korosunagi
Jul 26, 2025
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I broke a grease fitting off in my end link. I thought I was going to have to buy a new one. Reached out to Core 4x4 and wham! bam! They fixed it and sent it back with 2 day shipping. Got it a day early even. If they couldn't fix it they were going to send me a new one. Now that's customer service! They are now a permanent part of my garage.
Thank you Core 4x4!
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Andrew LaFave
May 27, 2025
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I am really please with this company. Great product, i had an issue with a couple of the jonnhy joint bushings, they explained what had caused it and how to fix it. Within hrs of receiving my inquiry, i had heard back with the required info I needed. A couple hrs later problem was fixed and ready for the trail again. They care about heir product and their customers. Thanks crew, you rock
TM
Tony Moller
Aug 25, 2025
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Awesome parts! Support the older Jeeps! Great customer service.
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Brantly Musgrave
Jan 22, 2026
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First and foremost would like to say that Core4x4s customer service is top notch and they definitely stand behind their warranty on products! Highly recommend using them for any of your off road needs! It’s rare to find a company now a days that backs their products and they do!
Had a few issues with mounts and control arms and they handled it without hesitation! Thank you!
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Nick
Sep 24, 2025
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I have a 2016 RAM 1500 Crew Cab and I replaced the rear upper and lower control arms also the pan hard track bar and also the sway bar and links for the rear with all I had the articulating bushings. The vehicle now has no body role. They are absolutely incredible if you get the control arms you gotta get the CORE 4 x 4sway bar end links don’t don’t try and be cheap and get Moog or something else you got to get articulating bushings get the core 4 x 4 ones they are the best. My truck drives now through the canyons like a BMW. I have Fox high-performance shocks on there as well with all the CORE 4 x 4 suspension parts and they are amazing. Well worth the money I would highly recommend anybody thinking about CORE 4 x 4 go with CORE 4X4 and if you can go with their articulating bushings, they’re unbelievable drives better now than my Escalades. Well planted no body role and smooth on the Highway unbelievable the difference they all made!!
THANKS AGAIN CORE 4x4!!!!
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Ma TheMeatLoaf
Mar 23, 2024
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Their website estimated 2 days to get my parts but actually took 11. No communication to let me know what’s going on. Parts were missing. Some days they answer questions, some they don’t. Didn’t let me know I’d have to alter stock bolts to fit their parts.
All around just seems like they don’t care.
