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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Jaime Overmyer
Nov 23, 2025
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Korby was extremely helpful in helping me find the right part for my truck. He was kind, knowledgeable, and patient while I asked a million questions. He also went out of his way to find the right shipping option for me since it’s tricky where I live. I’m looking forward to getting the parts so I can fix my truck and go adventuring again soon!
SG
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!
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DSI
Jul 26, 2025
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Great products with excellent customer service after the sale
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Ben
Mar 24, 2021
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2001 Wrangler TJ- i have purchased all front/rear upper/lower control arms. Front track bar and rear track bar. Quality is excellent and extremely durable you can tell its built to last. Bent a bolt on the front track bar and called and spoke with Spence. He immediately sent me out new hardware plus some! Product is amazing but what really separates companies apart is their service and these guys are second to none. Thank you all!
JL
John Luna
Nov 23, 2025
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Great team, and help to support my jeep and provide best stuffs
BA
bryan angell
Jun 26, 2025
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First off amazing products. I got a set of adjustable control arms for my XJ and it is so nice to be able to dial in caster and pinion angles. A quick call and I was able to purchase an adjustable track.
TM
T Mac
Mar 23, 2026
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CORE 4X4 Company produces/manufactures exceptional products. My rear upper and lower control arms and rear track bar were powder coated custom Fox “Shock Orange” for my 2024 Bronco Wildtrak. OEM looks minimal compared to the CORE 4X4 control arms. Plus they’re adjustable, serviceable and rebuildable. Shipment was very fast and packaging used custom foam wrapped around the arms and heavy duty boxes. Not even UPS could damage. Korby L. was great to work with and responded quickly with emails and product information. Great products. Great people from the State of Utah. All Made in the USA. 5 Stars!!!
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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
MR
Melanee Raynes
Mar 25, 2019
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Awesome product and service! I even got some of their swag because it looked pretty darn good. I will definitely be going back and would suggest this business to others looking for quality control arms. Buy local!
SH
Shawn Hooten
Apr 27, 2025
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Great products, shipped the next day during a big sale event. Core 4x4 gets it right and gets it done! Thank you all.
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Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |