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 a 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 1/2 in. diameter, fitted with a zerk fitting for greasing, 2 1/4 in. of 1 1/4 in.-12 right hand threads on the shank, and a 2.625 in. mounting width ball with a .562 in. thru bolt hole. Finished in gold zinc plating.
| Brand | RockJock |
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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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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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Paul Griffin
Feb 21, 2026
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Great long arm kit with everything else I needed as well! They worked with me to ensure that I was getting an upgraded components kit just like I wanted. Fast shipping with some of the best packaging that I have ever seen. Nothing was scratched or missing and this kit is even more impressive than the videos or website can show. Powder coating looks great with no issues.
I would highly recommend CORE 4x4 to anyone looking for a great quality kit.
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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.
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Victor Keele
Sep 24, 2025
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Great customer service. I got my front upper and lower control arms and hardware on Friday afternoon. It didn’t come with instructions so I called Core 4X4 and they immediately e mailed me the instructions. Also, the kit I got had the spacers missing so I called. It was late Friday by thus time but they took care of the issue first thing Monday morning and I got the spacers on Tuesday. Great company.
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Bailey Smith
Mar 23, 2025
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Core 4x4 excels with precision and service and keeps nothing else higher in mind. Everyone I've met at the company is very honest and down to earth, 10/10 would recommend.
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David
Nov 23, 2025
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First of I just want to say Great customer service korby Has helped me from the start and has not let me down! Reached out to him again today and he was able to warranty some parts out for me.
As far as the quality of the parts.. excellent! The build quality is great. I can definitely tell a
Difference from the cheap oem rear control arms to these and the pan hard bar.
Color, From what I can tell it’s super durable been through a few mud holes on top of the daily road grime and after a quick wipe they still pop!
Overall I recommend. Customer service is everything for me and it’s definitely there at Core 4x4.
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Logan Matejek
May 27, 2025
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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