RockJock's forged 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. This specific joint is designed to fit the frame side of the 2021 and up Bronco's rear control arms and feature a 2 1/2 in. diameter joint body, fitted with a zerk fitting for greasing, 2.3 in. of 1 1/4 in.-12 right hand threads on the shank, and a 3.150 in. mounting width ball with a .718 in. thru hole. Finished in gold zinc plating.RockJock's forged 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. This specific joint is designed to fit the frame side of the 2021 and up Bronco's rear control arms and feature a 2 1/2 in. diameter joint body, fitted with a zerk fitting for greasing, 2.3 in. of 1 1/4 in.-12 right hand threads on the shank, and a 3.150 in. mounting width ball with a .718 in. thru hole. Finished in gold zinc plating.
| Brand | RockJock |
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132 reviews
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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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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
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Aaron Lake
Apr 27, 2025
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Korby was a great help with getting me a set of leaf springs for my Cherokee. Great customer service and an awesome product all made in the USA. Proud to support and rock their parts on my vehicle. 👍 …
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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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Melanee Raynes
Mar 25, 2019
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Awesome product and service! I even got some of their swag because it looked pretty darn good. I will definitely be going back and would suggest this business to others looking for quality control arms. Buy local!
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Matthew Handy
Sep 24, 2025
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Ran into an issue with a part that I ordered. Got ahold of them explained to them the issue I was having and they jumped in and got the issue fixed. Hands down the best customer service I have ever dealt with. The parts are hands down amazing. Highly recommend.
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Cade Leith
Mar 23, 2024
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Have full upper/lower CA set on both front and rear axles on a 96 ZJ. These are the rubber bushing sets not joint sets. I have beat the hell out it in the Nevada desert for 2 years and has been great. I don’t go fast but I do articulate suspension a lot. Super solid and haven’t any issues. Just inspected the entire set recently due to some banging under it. Turns out the banging is lower rear shock bushings. Inspected each CA along the way nothing. Aside from dirt and obviously winter roads and what not still in excellent condition, bushings are solid like the day they were installed. I’ll add that I’m about tapped on a short arm at 4.25(less with settle) so the front CA’s get beat on just from that, still they’re like new. Paint is great condition, this set is red. I would definitely buy again. Another plus for me, Utah isn’t local necessarily, but it’s nice to support businesses closer to me.
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Korosunagi
Jul 26, 2025
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I broke a grease fitting off in my end link. I thought I was going to have to buy a new one. Reached out to Core 4x4 and wham! bam! They fixed it and sent it back with 2 day shipping. Got it a day early even. If they couldn't fix it they were going to send me a new one. Now that's customer service! They are now a permanent part of my garage.
Thank you Core 4x4!