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 narrow forged Johnny Joints for fabricators and suspension system builders offer up to 40 degrees of unrestricted movement in any direction as compared to 22 degrees on a common heim joint! Johnny Joint rod ends offer cushioning that a heim joint cannot provide via high-density urethane bushings that encase the inner ball. The heat treated center balls are cross-drilled for thru-bolt lubrication and the joint internals are retained with 2 heavy duty, heat treated side washers and a snap ring. This specific joint features a narrow 2 1/2 in. diameter joint body, fitted with a zerk fitting for greasing, 2.3 in. of 7/8 in.-14 right hand threads on the shank, and a 2.440 in. mounting width ball with a .515 thru bolt hole. Finished in gold zinc plating.
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
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.
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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.
ZA
Zen Asher
Mar 23, 2025
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The quality and durability of the arms are the best. They are super heavy duty. And lifetime warranty is crazy
BW
Brian Wadsworth
Jun 26, 2025
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Amazing product! Shipping was quick, packaging was great and support was outstanding!!
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.
DR
David Rogers
Aug 25, 2025
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Ive had the front adjustable control arm kit in bright green for my 1996 ZJ.
Ive had the kit for about a year now and i have to say, im extremely impressed, over 1000 miles off-road and roughly 20,000 miles on the highway. These control arm kits for any vehicle built by core 4x4 are well worth the money, just be aware thereight be some minor scatches or chips from shipping ( but who should care about that if you're beating the crap out of em' they way they were built and designed for)
LS
Leonard Smith
Jan 22, 2026
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I don’t write reviews often, but Core 4x4 absolutely earned this one.
I recently ordered leaf spring mounts and realized after the fact that I messed up my order. Totally my mistake. Instead of giving me the runaround or pointing at a return policy, Core 4x4 emailed me back and forth, worked through exactly what I was doing with my build, and made sure I ended up with the correct parts.
That kind of customer service is rare these days — especially in the off-road world where a lot of companies stop caring once the order is placed.
The parts themselves are exactly what you hope for: solid, well-made, confidence-inspiring hardware that looks like it belongs under a vehicle that actually gets used. You can tell these are designed by people who understand suspension geometry and real-world abuse, not just CAD screenshots.
Mistakes happen — especially on custom or modified builds — and Core 4x4 handled mine like pros. Fast responses, clear communication, and a genuine effort to help me get it right.
If you’re on the fence: don’t be. Core 4x4 is the kind of company you want backing your build — the kind that treats customers like fellow enthusiasts, not order numbers.
BB
Brayden Brockey
Mar 23, 2024
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Got a set of upper control arms for my xj, really impressed with the quality
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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!
MT
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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Specifications
| Brand | RockJock |