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.
MT
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.
CM
Cameron Masters
Mar 24, 2023
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Absolutely incredible family owned business. I asked to pick up my order since I’m local and they came in on a weekend to accommodate. Had to make some adjustments to parts and took the time to make sure it was perfect. Parts are incredible quality. If you have a Jeep, do not hesitate to support this local business.
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Robert C
May 27, 2025
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Fantastic products! Outstanding performance!! Absolutely the best customer service!! You will not be disappointed!
DT
Dean Tk421
Feb 21, 2026
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I purchased the Jeep WJ control arms Camp series over a year ago. Very pleased and impressed. Easy installation and solid build. Bracket broke for rear upper control arm, they redesigned it to be more robust and sent me a new one with hardware, honoring their guarantee!
RP
Robin Poole
Jul 26, 2025
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I had several questions before my purchase and Korby helped me with the correct parts to order and recommendations. Outstanding customer service and product knowledge! Can't wait to install them!
RM
R2d2 Movi78
Feb 21, 2026
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I’m extremely impressed with Core 4x4. The quality of their parts is outstanding — everything feels solid, well‑built, and engineered with real attention to detail. Shipping was fast and everything arrived perfectly packaged. Their customer service is just as good as their products: responsive, helpful, and genuinely committed to making sure you get exactly what you need.
Overall, a top‑tier experience. I’ll definitely be buying from them again. Specially thank you Mr. Linscomb from Core 4x4. Arturo M.
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Morgan Griffith
Mar 25, 2018
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I met a couple of the Core 4x4 guys at the Salt Lake Offroad Expo and decided to try them out after noticing one of my control arm bushings was disintegrated. I called to discuss parts on Thursday and I was leaving for a trip on Saturday. These guys built my control arms and had them ready to be picked up Friday, 24 hours later. The parts seem to be great quality and they charged me nothing extra to have them painted. These guys were extremely helpful and without them my trip probably would have been cancelled. looking forward to testing out the arms on my next trip to Moab.
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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