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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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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Mark DiGrappa
Apr 27, 2025
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First off: Korby, the gentleman that helped me decide on which kit to go with is EASILY the nicest, and most patient person I’ve dealt with, when ordering parts for this build. Second: the quality of the product is INSANE! These parts are so nicely fabricated, then powder coated for extra longevity, and they even offer an aluminum upgrade in some cases (which I went with, to save weight). Having said all of this, the most impressive thing was the lead time. These parts are build to order, and I literally ordered my suspension one week ago, today! Yes, they built, powder coated, packaged, shipped my suspension components (RAM 1500 Track rear trailing arm full set in 7075 aluminum, and front upper control arms), AND they arrived, all within a week! Granted, that I’m only one state away, but WOW!!! One week?! Amazing! So, in sort: excellent products, which arrived excellently packaged (no damage, an boxes not over-stuffed with heavy suspension parts; three boxes total, as opposed to one super heavy one…my back thanks you), super quickly, and customer service that ANY business would be envious of….so, if you’re in the market, absolutely go with Core 4X4!
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Travis Walker
Sep 24, 2025
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I have nothing but great things to say about this company and their customer service. If you like American made products backed by warranty and amazing customer support, this is the company for you. I have a Lexus GX470 and love their rear control arms.
JI
Jerome Segura III
Jun 26, 2025
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I bought the 16pc Cruise Series Adjustable Control Arm, Track Bar, Steering, End Link Kit to replace a worn budget 4" lift on my used JKU. These are top quality parts; very solid. Customer service is unsurpassed. They even matched prices on my order placed before the tax day sale. I made an error in ordering a drag link flip kit; they were quick to help me fix this too. There's peace of mind knowing these components are made in the USA. Thank you. 👍👍
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George Mar
Sep 24, 2025
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Great company. Highly satisfied with Core 4x4 customer service. Had some bushings fall apart around 600 miles from home. Called and spoke with Korby Linscomb on Thursday, late in the afternoon. He was able to get my bushings sent across country overnight at a very reasonable rate. Had me up and running by Friday evening with enough time to enjoy the Great Smoky Mountain Jeep Invasion. Thanks Guys!
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Andrew LaFave
May 27, 2025
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I am really please with this company. Great product, i had an issue with a couple of the jonnhy joint bushings, they explained what had caused it and how to fix it. Within hrs of receiving my inquiry, i had heard back with the required info I needed. A couple hrs later problem was fixed and ready for the trail again. They care about heir product and their customers. Thanks crew, you rock
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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!