Made in USA
Orem, Utah
Lifetime Guarantee
Unconditional
10 Colors
In-house powder coat
Fully Adjustable
0-6" of lift
3 X-Series Options
Only Core 4x4
RockJock's Front Axle Housing Johnny Joint Kit for JL Wrangler, JL Unlimited and JT Gladiator vehicles replaces the front differential housing upper control arm bushings with Johnny Joint rod ends from RockJock to get maximum articulation out of your suspension! This kit includes a Johnny Joint inserts that replace the rubber bushings on the axle housing, greasable bolts, installation tool and complete instructions.
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Gladiator | 2020 - Present | |
| Jeep | Wrangler | 2018 - Present |
| Vehicle | Jeep Gladiator JT (20–Present) or Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
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DSI
Jul 26, 2025
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Great products with excellent customer service after the sale
K
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!
PB
Peter Busack
May 27, 2025
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Purchased a set of Trailing arms for my Ram 1500, quality is first class. I bought the ones with the Jonny Joints for more articulation and it appears from the construction I should get a lifetime of use, Zerk fittings are an added plus. Would defiantly recommend, and the the service team answered all of my questions.
JT
jacob trice
Apr 27, 2025
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Core 4x4 has outstanding products at a fair price and unmatched customer service. When you call Korby, it's like talking with a friend. Very cool and helpul!
I ordered some custom control arms, but from the wrong product line and they were super cool about returning them and upgrading to a better "Crawl" series. Only charged the difference between the two products. They paid all the return shipping and sent the uprgaded arms super quick. It was only a couple days. Awesome!!
I couldn't be happier with the transaction👍🏼
Also, these control arms are stout and take a beating. I run heck out my Jeep in the rocks and desert. No problems whatsoever.
Thanks Core 4x4, ya'll are welcome at my campfire anytime!
Jake T.
Pleasant Hill, Or.
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Zion
Sep 24, 2025
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Every product I have received from them has been nothing short of fantastic. Korby in Customer service went above and beyond to help me fix my own mistake. I cannot reccomend them enough.
BC
Brad C
Mar 24, 2021
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Outstanding experience! I asked Core to build me a set of custom control arms that were larger/heavier than they normally build. They gladly accepted the challenge and turned out an expertly crafted and super strong product ahead of schedule. Fit and finish are excellent. Spence and Cameron were a pleasure to work with every step of the way. And all of this for a very reasonable price. I highly recommend these guys!
RH
R and H H
Oct 24, 2025
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Top notch company. Mechanic lost bolts that clamp upper control arms. Korby sent out spare bolts no charge. Best customer service I’ve come across in a long time. Only suspension brand I’ll ever use.
AP
Ajay Paynter
Mar 9, 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 of possibly not getting the control arms in time. Quality is amazing on the part, affordable price for what you get, and the powdercoat is top notch, not a single issue with this product, would buy again.
RH
Rex Hodges
Jun 26, 2025
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After ordering an upper and lower adjustable control arm kit manufactured by CORE 4X4 from a jeep parts distributor who's intials are E.T., they came with 3 of the threaded ends missing. After over 2 months of phone calls and emails to this E.T. company nothing was resolved. I finally decided to call CORE 4X4 myself and tell them my dilemma. I spoke with a very personable and professional gentleman named Korby, who is one of CORE 4X4's representatives, after a brief discussion of what I went thru he simply asked me for a picture and some measurements and the items I was missing and asked if I could cover ONLY the cost of shipping and I had my missing parts in exactly 1 weeks time. This company not only builds all it's parts in the U.S.A., they stand behind their products with great customer service and life time warranty. My experience with this company and their Rep Korby was fantastic. I would definitely recommend CORE 4X4 to anyone who needs parts for any 4x4 projects. You just can't beat their quality and service.
Rex Hodges
Valparaiso, Indiana
AM
Adam M
Sep 24, 2025
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First time buying from Korby @ Core 4x4 and it’s being nothing short of a great experience. I bought the non adjustable Trail kit for my 5th Gen Ram 1500 with a 2” lift. The welds look great, nice powder coat finish and quality bushing. Had some trouble fitting the grease nipples due to the powder coating but a thread tap would fix that. They fit easily and perform great. I felt the improvement straight away. No more wheel hop on hard acceleration which was my main reason for the purchase.
I was missing some smaller bushings needed for the 5th Gen and Korby’s custom service was on point, with responsive emails and mailing out the missing parts straight away. Very happy with their products and customer service. Highly recommended company👌🏽
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Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |