All pre-2007 Jeeps use 10mm as factory bolt size. For front and rear upper control arms.
JK, JL, and JT all use 12mm as factory bolt size. For front upper control arms only.
| Bolt Diameter | Select or 10mm or 12mm |
See It Installed
Install videos and build guides on our YouTube channel.
Watch more installs on YouTubeReviews from Google
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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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Matt
Mar 23, 2024
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The best products on the market. 95% of my xj is core 4x4 products
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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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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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Erica Grissom
May 27, 2025
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First off, I wish I knew about them sooner. The customer service is top tier. The response time is about 30 min no waiting 1-3 days to get a response. The parts are heavy-duty and look amazing. The packaging is perfect, I can't wait to hit some trails. Thanks Core4x4
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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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Aaron
Mar 23, 2024
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I have recently come to know Core 4x4 when I purchased a Jeep XJ and was looking for a place that had dedicated XJ suspension and components. Here is what makes them different than most other shops. All of their components are top shelf quality and they back it up if you break any of it. I was able to see their shop when I picked up an order locally and was impressed with their attention to detail and how they assemble and powder coat each part. I had an issue with a shackle and needed the threaded shaft to be shorter. I called in and talked to Kaden and he told me to come by and they would shorten it for me. When I got there, Kaden and Spencer (the owner) met me and talked about options and proceeded to make the right adjustments to fit my XJ. Told me if anything changes in the future and I need additional length, they would take care of me. So what really sets them apart from others is their Customer Service. Try calling in to any other Jeep suspension or part shop and see how they treat you. Been there - done that.
Will continue to do business with Core and their team. Getting that kind of service for just a shackle has me thinking I may need to replace my JT components with Core's. Thanks Guys for being helpful good humans!
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Tim Reigies
Mar 25, 2018
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Received the track bar I ordered, product looks extremely strong, thx core 4x4