RockJock's narrow forged Johnny Joints for fabricators and suspension system builders offer 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 bushing that encases 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 is a 2 in. diameter, fitted with a zerk fitting for greasing, 2 1/4 in. of 3/4 in.-16 left hand threads on the shank, and a 1.600 in. mounting width ball with a .625 in. thru bolt hole. Finished in gold zinc plating.
| Brand | RockJock |
See It Installed
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Ajay Paynter
Mar 4, 2026
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Great company, who worked with me on shipping parts to arrive in time for a show. When I explained my concern they went above and beyond to make it happen. Quality of the parts is top notch.
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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.
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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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Paul
Mar 24, 2023
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I've been having trouble with the track bar (on my 2nd gen Dodge) since I installed the 3rd gen Synergy adapter bracket and a 3rd gen stock bar.. oddly, they call it a '3rd gen bracket' and the stock 3rd gen bar doesn't quite fit, making contact with the bracket. I had attempted to clearance the bracket but it was still making contact and I could feel it over large bumps.
I reached out to a lot of companies, but Core 4x4 offered to make a custom bar for the application with adjustability and dual Johnny joints. The first pass on it didn't work but they sent me out another passenger side end that made it fit incredibly well.
This was all done solely over email/descriptions/pictures/measurements.
Bar is super high quality and heavy duty, made in the US by a family owned company and carries a lifetime warranty. The customer service was responsive and superb, and the price was a lot less than I expected.
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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)
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Mark DiGrappa
Apr 27, 2025
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First off: Korby, the gentleman that helped me decide on which kit to go with is EASILY the nicest, and most patient person I’ve dealt with, when ordering parts for this build. Second: the quality of the product is INSANE! These parts are so nicely fabricated, then powder coated for extra longevity, and they even offer an aluminum upgrade in some cases (which I went with, to save weight). Having said all of this, the most impressive thing was the lead time. These parts are build to order, and I literally ordered my suspension one week ago, today! Yes, they built, powder coated, packaged, shipped my suspension components (RAM 1500 Track rear trailing arm full set in 7075 aluminum, and front upper control arms), AND they arrived, all within a week! Granted, that I’m only one state away, but WOW!!! One week?! Amazing! So, in sort: excellent products, which arrived excellently packaged (no damage, an boxes not over-stuffed with heavy suspension parts; three boxes total, as opposed to one super heavy one…my back thanks you), super quickly, and customer service that ANY business would be envious of….so, if you’re in the market, absolutely go with Core 4X4!
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Jason Mitchell
Dec 8, 2025
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Installed the full kit on my XJ. Ride quality is night and day better than what I had before. The articulation on the trail is insane. These guys know what they are doing. Already recommended Core 4x4 to everyone in my club.
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Gil Valk
Sep 24, 2025
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Excellent service, Prompt responses when needing technical assistance, Amazing looking parts that fit excellently. I would recommend them to anyone looking for suspension components. Also very well packaged when we received the shipment, which means no damage from shipping company!! We went with the Crawl Series double adjustable kit and it definitely looks killer on our build!!!
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Adam
Oct 24, 2025
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I couldn't have been more excited for the initial unboxing of these new Core 4x4 UCA's!
They appear to be so well built and just a true quality product.
Installation was a breeze and the initial testing with the forklift appears to have given me some additional flex with less binding on the rest of the components now that the geometry is back properly aligned.
Time will tell how they hold up on my near future off-road adventures but I don't have any doubt that they are up to the task!
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Canon TeSelle
Jun 26, 2025
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Great Experience. I wanted to make changes to my order and Korby was more than willing to work with me to get everything corrected. Hope to deal with these guys again in the future.