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 style weld-on 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. The 2 1/2 in. narrow style outer shell is weldable CNC machined DOM tubing that is fitted with a zerk fitting for greasing. This specific joint's 74mm mounting width ball with a 16mm thru bolt hole is designed to fit the frame side of the 2021 and up Bronco's rear control arms.
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
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.
GH
Gary Haag
Aug 25, 2025
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Ordered a set of Core 4x4 control arms for my 2006 Jeep TJ. These are some heavy duty quality control arms. Can't wait to get them installed. Great customer service too!
N
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! 👍👍
KK
Kevin Kinard
Oct 24, 2025
★
★
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Great product, excellent customer service. I mistakingly ordered a track bar for the wrong year model and Korby helped me out by sending me the correct part that I needed no questions asked. I highly recommend.
GM
George Mar
Sep 24, 2025
★
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Great company. Highly satisfied with Core 4x4 customer service. Had some bushings fall apart around 600 miles from home. Called and spoke with Korby Linscomb on Thursday, late in the afternoon. He was able to get my bushings sent across country overnight at a very reasonable rate. Had me up and running by Friday evening with enough time to enjoy the Great Smoky Mountain Jeep Invasion. Thanks Guys!
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
PM
Paul Melancon
Aug 25, 2025
★
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Ordered a control arm and track bar kit for my WJ from Core 4x4 on Monday 7/28 and received it today, Friday 8/1. Im not a state or two away, im in CT aka the other side of the country. Communication is phenominal, emails were responded too in an hour or less. Parts arrived well packed, not damaged, and are great quality for my needs. There arent many companies left that service customers as well as Core 4x4 and i wont hesitate to check them out again if i need something else. Well done!
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!
LM
Logan Matejek
May 27, 2025
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★
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The parts are a massive improvement over factory. I accidentally ordered the wrong endlinks and they helped me figure out the correct size and sent me new ones.
Definitely an awesome store
C
caleb
Mar 24, 2022
★
★
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★
Absolutely a great company. Ordered rear lower control arms with hardware but when i got it the hardware wasn't there but they sent it out right away and got a free t-shirt! Highly recommend.
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Specifications
| Brand | RockJock |