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 3 in. diameter joint body, fitted with a zerk fitting for greasing, 3.67 in. of 1 1/2 in.-12 right hand threads on the shank, and a 3.250 in. mounting width ball with a .750 thru bolt hole. Finished in gold zinc plating.
| Brand | RockJock |
See It Installed
Install videos and build guides on our YouTube channel.
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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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Justin
Mar 24, 2021
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Small business, family owned, made in the USA, lifetime warranty. Purchased Tier 3 control arms and rear track bar for a 2006 Jeep LJ. Simple website and easy to contact over phone and email. I had some technical questions and they were happy to answer them. They allow local pickup and were built to order same week. The order was wrapped and ready when I walked in and even gave a tour of the shop. They abrasive blast all raw materials to achieve a better surface profile for powdercoat to adhere and create a smooth, durable finish. I also noticed several CNC machines and a robotic welder they use for all their parts. A small outfit with a robotic welder? Their concern for quality is obvious and it shows in the parts they make. Very impressed. Happy to do business with these guys.
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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!
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Mike T
Nov 23, 2025
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Korby and the rest of the team at Core 4x4 know there stuff and answered my question in a timely manner. They even were able to quick ship a re-build kit for me so I could get my truck back on the road- Thanks!
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John Cutler
Oct 24, 2025
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In September 2025, we visited CORE 4x4 in Orem, Utah. CORE 4x4 makes control arms and other similar parts that stiffen the suspension of an off-road 4x4 vehicles, so that the off-road vehicles can travel on more rugged terrain. CORE 4x4 used to share this building with another business, and since this other business has moved elsewhere, CORE 4x4 will continue to expand and grow their business. Good for CORE 4x4 to be a growing company and to expand into the vacant part of the building.
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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! 👍👍
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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!!!