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 weld-on Johnny Joints for fabricators and suspension system builders offer 30 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 outer shell is weldable .180 in. wall machined DOM tubing that is fitted with a zerk fitting for greasing. This specific joint's 70mm mounting width ball with a 16mm thru bolt hole is designed to fit the axle 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
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Ryan Colligan
Mar 4, 2026
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I have nothing but good things to say about Core 4x4. I have the crawler series on my JKU and we take it all over the place. These parts handle everything we throw at them.
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
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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William Turton
Nov 23, 2025
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Finally a company with a great product and customer service to match. I changed my order last minute from short arms to long arms. The lift is extremely well built. Korbey was awesome! Highly
recommend Core 4x4
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Danny
Oct 24, 2025
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Outstanding customer service to match the high quality parts. This is the go-to company.
RM
R2d2 Movi78
Feb 21, 2026
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I’m extremely impressed with Core 4x4. The quality of their parts is outstanding — everything feels solid, well‑built, and engineered with real attention to detail. Shipping was fast and everything arrived perfectly packaged. Their customer service is just as good as their products: responsive, helpful, and genuinely committed to making sure you get exactly what you need.
Overall, a top‑tier experience. I’ll definitely be buying from them again. Specially thank you Mr. Linscomb from Core 4x4. Arturo M.
OK
oleg k
Nov 23, 2025
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I recently ordered a set of control arms from Core 4x4, and the entire experience was absolutely top-notch from start to finish. The ordering process was smooth, the parts arrived quickly, and the control arms themselves are extremely high quality—solid construction, great finish, and clearly built to last.
I also want to give a special shout-out to Korby, the guy I spoke with during the process. His customer service was amazing. He went above and beyond to make sure I got exactly what I needed, answered all my questions, and made the whole experience stress-free. You don’t see service like that very often these days.
If you’re looking for high-quality suspension components backed by truly exceptional customer service, I highly recommend Core 4x4. I’ll definitely be buying from them again.
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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! 👍👍
JT
Jay Taylor
May 27, 2025
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Had a worn out set of rear upper control arms on my TJ. These were old rubicon express long arms. can’t buy replacements and no one makes a direct fit replacement.
Talked with Korby at core off road sent some measurements and photos and a week later new arms showed up. Packaging was perfect fit was perfect.
Would highly recommend giving these guys a call.
CL
Colten Lockwood
Mar 25, 2019
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Recieved warrenty exchanges for my control arms last night couldnt be happier!!! Lets talk about the arms tho! Great quality arms in multiple styles and colors!!! I purchased the teir 3 short arns for my 98 xj. I can say that they setoff nicely so my 35 inch tires do not rub! As long as you can get a photo or video of broken hardware core will take care of you. The body of the arm is bulletproof. However make sure to maintain and grease the joints regularly as with any greaseable joint and they shouldkast forever. I had a few problems arise a year after purchase and after some troubleshooting spence was able to help get me the correct parts to get back on the road. I recommend this setup to any and all jeepers looking to get away from the stock arm setup. Alltogether i am Very happy with the performace of my control arms!!!! Mechanic and bodyman of 12 years and my first choice for quality control arms!!
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Specifications
| Brand | RockJock |
