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, single joint) for JL Wrangler, JL Unlimited and JT Gladiator vehicles replaces either front differential housing upper control arm bushing with a Johnny Joint rod end to get maximum articulation out of your suspension! This is a single joint only, see RJ-301000-101 for a complete kit. Finish is zinc plating.
| 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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Tony Moller
Aug 25, 2025
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Awesome parts! Support the older Jeeps! Great customer service.
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mark hinz
Mar 2, 2026
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Went above and beyond to get the parts we needed to complete our customers build for Moab Easter safari cant thank you enough for all your hard work and efforts
Thank you and look forward to working with you in the near future
EL
Eric Labrum
May 27, 2025
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Best customer service I have ever experienced. They are my go to source do to quality and service
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niceguyr1
Mar 24, 2023
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I purchased upper and lower adjustable arms for my WJ and lowers were missing the spacers. I didn't know until 3 months later when I was installing them. With absolutely zero hassles they quickly sent me the missing spacers. Fantastic product and service! Huge thank you guys for the awesome service and parts!!! Customer service is quickly becoming a lost commodity and you guys gave me hope that it's still alive and well, you just have to buy from the right people... Thanks again for going above and beyond! 👍👍
MP
matthew patterson
May 27, 2025
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Ive used core products for my last two jeeps and now my ram. They’re parts are the absolute best quality youll find ANYWHERE. Top quality products and A+ custom service keeps the as my go Roger for any suspension needs.
TG
Travis Grimm
Mar 23, 2024
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To start off if you're looking to upgrade your control arms definitely hit this company up. Great product, easy install of the product, with three different tiers everything is priced pretty good, I'm a sticker guy and they sent a sticker for each arm each track bar and also three extra ones so the extra are on the Jeep the advertise them for sure. If you're reading this review I highly recommend you to check their website out.
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
CD
Christopher Dami
Jun 26, 2025
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2022 I ordered a 2023 Jeep Wrangler Rubicon in High Velocity yellow. Without any hesitation I knew I was going with Core 4x4’s 16pc Camp series suspension, powder coated in yellow. Compliments were a given from any and everyone that looked under my jeep. So beefy, I may have left some yellow paint on the rocks from Maine to Florida, but no bends or breaks. Customer service has been perfect each and every time I have needed something. Their warranty is top notch! Their communication is also wonderful. Might upgrade to the Crawl Series control arms where the Johnny joints are on both sides. Great all around company and a great team to troubleshoot your issue and come to a conclusion. Nothing bad to say about this company. Just love this suspension.
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Sal Giordano
Sep 24, 2025
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I want to take the time to share my experience with Core 4x4.
I have a 2004 Jeep Wrangler and was looking to upgrade some suspension parts. I went with Core 4x4 upper & lower adjustable control arms and a front adjustable track bar. Everything arrived quickly, and right out of the box I was impressed with the quality and craftsmanship.
I had a few questions during installation (measurements and torque specs), and I spoke with Korby on a couple of occasions. Not only did he send me detailed instructions, but he also shared an installation video specific to the part and vehicle I was working on, something you don’t get from many companies.
The control arms fit perfectly, look great, and perform exactly as I hoped. I did run into an issue with the front track bar touching the front diff. When I reached out, Korby had me send pictures and then immediately offered two solutions: his bar guy could make a different bend and send it out to me, or I could get a full refund. His response honestly blew me away. As much as I wanted to run the Core 4x4 track bar, I chose the refund. Korby sent me a prepaid shipping label right away, no hassle.
My experience with Core 4x4 has been excellent. Korby was extremely understanding, communicative, and helpful every step of the way. The parts I received were high quality, and the customer service was second to none.
I would absolutely recommend Core 4x4 10 out of 10 times and will be using them again. Just a great American company with awesome people who truly care about their customers.
Thank you Korby, and thank you Core 4x4!
JH
Joe Hu
Sep 24, 2025
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Amazing! I put all my new control arms and it drives a lot smoother and looks great!!!
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Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |