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 Sport Edition Johnny Joint Suspension System for JL Wrangler Unlimiteds (4-door) with the EcoDiesel engine provides 3 1/2 inches of lift and allows for efficient clearance of up to 37 in. tall tires (with minor trimming, larger tires will require aftermarket fenders). This kit is comprised of only the highest end components in the areas of strength, fit, finish, function, and the engineering to back them. This kit is more than sufficient for those who want to lift their vehicle, install big tires and hit some trails on the weekend! Included in this kit are front upper and rear upper Johnny Joint adjustable control arms, set of 4 progressively wound coil springs including one front and one rear coil spring shim, front, EcoDiesel specific) and rear bump stop kits, Johnny Joint adjustable front trac bar, rear trac bar geometry relocation bracket, front and rear adjustable extended sway bar links and front brake line relocation brackets. For those who intend to do more serious 4 wheeling and rock crawling, you'll want to look at all of the upgrade parts that RockJock has to offer that can be added to this kit to get your vehicle to it's full potential. Next level offerings such as Johnny Joint lower control arms, Antirock Sway Bars and Currectlync Heavy Duty Steering are a must for serious off-roading! Shock options to suite this kit are available from all of the top suppliers.
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Wrangler | 2018 - Present |
| Vehicle | Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
DA
Dastrup Auto
Mar 25, 2019
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I have bought a bunch of sets of arms, track bars and even had custom work done by Core 4x4. Just yesterday, Spence and Cam delivered an awesome cross member they designed and built for me! All of their products have been exceptional! I have personally seen their progression with design changes/updates. They truly take pride in their work and products. Quality control is second to none! They’ve also helped me diagnose issues with different jeeps I’ve had, as well as Dodge/Rams. These guys know their stuff! Really! I trust them whole heartedly and absolutely love their products/quality of work! I’ve referred many people, and will always continue to do so. Keep up the good work Core4x4!
RR
Ryan Rogers
Aug 25, 2025
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I purchased a set of the Cruiser Series control arms for my Jeep Jk based on postive reviews from different Jeep Facebook pages. Ordered and 2 days later realized they had the very same exact arms on sale in the overstock section. Called them up and they refunded me the savings from my original purchase. Amazing, honest service. Can't wait to get them installed. Keep up the good work guys.
TW
Travis Walker
Sep 24, 2025
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I have nothing but great things to say about this company and their customer service. If you like American made products backed by warranty and amazing customer support, this is the company for you. I have a Lexus GX470 and love their rear control arms.
JM
Jay Miller
Jul 26, 2025
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I purchased a upper and lower set of control arms from core 4x4 they came early then expected and seem to be very nice quality I ran into a complication installing them and emailed them my question I was expecting to get the response maybe the next day because it was after hours I got a response in about a few minutes which allowed me to finish the project that day I super appreciate that, the products are good strong lifetime warranty and their customer service is top notch
JA
Jonathan Aguilera
Jan 22, 2026
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Great experience with Core 4x4! I purchased some suspension parts for my dad's 98 Jeep TJ. The products they make are super durable and look even better in person. Attention to detail and overall superior quality. The staff at Core 4x4 is super helpful also, Korby has been great. Updating me on the status of my order and sending me tracking numbers as well. Thank you all at Core 4x4, keep up the amazing work!
GC
Grant Chaisson
Jun 26, 2025
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These guys are awesome!! They have helped me build multiple jeeps from zjs to mjs and now with my lj build they all ways impress.
There products are the best on the market in my eyes. The best part about it all is it's all made right here in american and shipped anywhere in the world 🌎 .
Don't think twice when your looking for control arm or lift kits for your vehicle if these guys sell it BUY IT!!!
DN
Devan Nelson
Mar 25, 2019
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Had a great experience with Core 4x4, I desperately needed a custom track bar and found out just a couple days before Easter Jeep Safari. Spence was a huge help and made it happen with plenty of time to spare. Their parts are top notch!
EC
Eric Cox
Jul 26, 2025
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Prompt, professional, and courteous service! Quality parts and broad assortment of products to suite your 4x4 needs:)
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!
MM
MIKE (Mike the Mechanic)
Jul 26, 2025
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Amazing company and customer service!!!! I messed up on my order and the fixed it immediately. Would definitely recommend them. Can't wait to hit the trails with their product.
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Specifications
| Vehicle | Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |