RockJock's Front Axle Housing Johnny Joint Kit for TJ Wrangler, LJ Unlimited, XJ Cherokee, MJ Comanche and ZJ Grand Cherokee vehicles replaces the front differential housing upper control arm bushings Johnny Joint rod ends to get maximum articulation out of your suspension! This kit includes a Johnny Joint insert for gear case ear and installation tool, as well as 1 in. thick flame-cut steel upright for the tube side, with the Johnny Joint already installed. This kit has you cut off the top of the stock bracket that is on the tube and install the new RockJock piece into the existing bracket base. You then weld the RockJock piece to the existing bracket base. This allows for no welding to be done on the tube, resulting in no warpage of the tube. This kit requires cutting and welding equipment for installation! Greasable hardware included. NOTE: this kit is for use on any factory Dana 30 or 44 differential only!
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Cherokee | 1984 - 2001 | |
| Jeep | Comanche | 1986 - 1992 | |
| Jeep | Wrangler | 1997 - 2006 | |
| Jeep | Wrangler | 2004 - 2006 |
| Brand | RockJock |
See It Installed
Install videos and build guides on our YouTube channel.
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Reviews 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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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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Travis Grimm
Mar 23, 2024
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To start off if you're looking to upgrade your control arms definitely hit this company up. Great product, easy install of the product, with three different tiers everything is priced pretty good, I'm a sticker guy and they sent a sticker for each arm each track bar and also three extra ones so the extra are on the Jeep the advertise them for sure. If you're reading this review I highly recommend you to check their website out.
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Eric Cox
Jul 26, 2025
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Prompt, professional, and courteous service! Quality parts and broad assortment of products to suite your 4x4 needs:)
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Cody Whitlock
Sep 24, 2025
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10/10 overall experience, shipping, customer service, and such a great product!
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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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Adam
Oct 24, 2025
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I couldn't have been more excited for the initial unboxing of these new Core 4x4 UCA's!
They appear to be so well built and just a true quality product.
Installation was a breeze and the initial testing with the forklift appears to have given me some additional flex with less binding on the rest of the components now that the geometry is back properly aligned.
Time will tell how they hold up on my near future off-road adventures but I don't have any doubt that they are up to the task!
JS
Jon Stempien
May 27, 2025
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Big thanks to Corby at core 4 x 4 outstanding customer service I like to thank them or 4 x 4 for helping me Well-made product in the United States recommend core 4 x 4 for all jeep Owners that like the four wheel
