Made in USA
Orem, Utah
Lifetime Guarantee
Unconditional
10 Colors
In-house powder coat
Fully Adjustable
0-6" of lift
3 X-Series Options
Only Core 4x4
RockJock Uni-Balls for Front Axle Housings are used in 3-link suspension applications, where the passenger’s side upper control arm has been eliminated and all of the suspension load is now being applied to the one axle housing mounting location. Our Uni-Balls press into the stock bushing holes on the casting side, driver’s side ONLY) of the front differential housing and provide a durable solution that incorporates a 5/8 in. thru-bolt hole for heavier hardware. This Uni-Ball will press into a stock JK or a stock TJ/LJ/XJ/MJ/ZJ housing, as well as aftermarket replacement differentials from companies such as Dana, UD-60s), Dynatrac, East Coast Gear, Fusion 4x4 and Currie Enterprises, cast center housings ONLY, does not apply to 9 in. / fabricated style differentials). Additionally, “most in. aftermarket differentials that are intended for installation in a JL/JT vehicle, still retain the bushing specs. of a JK bushing, making this the applicable Uni-Ball to install in an aftermarket differential, again, cast center only, not 9 in. style going into a JL/JT., for STOCK JL/JT housings, see our RJ-301002-101 Uni-Ball. The mounting width of the center pivoting assembly is 2 in., to allow it to fit into the fork on JL/JT/JK/TJ/LJ/XJ/MJ/XJ front upper control arm, however, the 5/8 in. thru-bolt hole will require drilling of the bolt hole in the control arm fork. Uni-Balls feature a sealed bearing assembly, so no greasing is required. Finish is clear zinc plating.
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Cherokee | 1984 - 2001 | |
| Jeep | Comanche | 1986 - 1992 | |
| Jeep | Gladiator | 2020 - Present | |
| Jeep | Grand Cherokee | 1993 - 1998 | |
| Jeep | Wrangler | 1997 - 2006 | |
| Jeep | Wrangler | 2004 - 2006 | |
| Jeep | Wrangler | 2007 - 2018 | |
| Jeep | Wrangler | 2018 - Present |
| Vehicle | Jeep Gladiator JT (20–Present) or Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
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!
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
CL
Colten Lockwood
Mar 25, 2019
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Recieved warrenty exchanges for my control arms last night couldnt be happier!!! Lets talk about the arms tho! Great quality arms in multiple styles and colors!!! I purchased the teir 3 short arns for my 98 xj. I can say that they setoff nicely so my 35 inch tires do not rub! As long as you can get a photo or video of broken hardware core will take care of you. The body of the arm is bulletproof. However make sure to maintain and grease the joints regularly as with any greaseable joint and they shouldkast forever. I had a few problems arise a year after purchase and after some troubleshooting spence was able to help get me the correct parts to get back on the road. I recommend this setup to any and all jeepers looking to get away from the stock arm setup. Alltogether i am Very happy with the performace of my control arms!!!! Mechanic and bodyman of 12 years and my first choice for quality control arms!!
S
Sebastian
Oct 24, 2025
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Great products they sell, got a crawl series long arm kit for my xj and it has held up quite nice, they are beefy, and for what ever reason they fail it has a great warranty with a customer service to match, when someone asks what control arm kit to buy I always recommend core 4x4
DD
Dmitriy D
May 27, 2025
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Installed rear and upper control arms and track bar on my 3rd Gen 4RUNNER to align rear axle and restore factory wheel base after 3.5" lift. Car drives better than New! Improved handling cornering and overall driving. Very solid and high quality made product. Support is outstanding. Shipping extremely fast.
Thank you so much. I wish you will have something new for my car.
LM
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
JM
Jay Miller
Jul 26, 2025
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I purchased a upper and lower set of control arms from core 4x4 they came early then expected and seem to be very nice quality I ran into a complication installing them and emailed them my question I was expecting to get the response maybe the next day because it was after hours I got a response in about a few minutes which allowed me to finish the project that day I super appreciate that, the products are good strong lifetime warranty and their customer service is top notch
BM
Brantly Musgrave
Jan 22, 2026
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First and foremost would like to say that Core4x4s customer service is top notch and they definitely stand behind their warranty on products! Highly recommend using them for any of your off road needs! It’s rare to find a company now a days that backs their products and they do!
Had a few issues with mounts and control arms and they handled it without hesitation! Thank you!
RC
Robert C
May 27, 2025
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Fantastic products! Outstanding performance!! Absolutely the best customer service!! You will not be disappointed!
CM
Craig MacIver
May 27, 2025
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Got the CAMP version of adjustable control arms and track bars for our 03 TJ with a 3” lift and 33x10.5 KO 2’s.
Super beefy bars, great fit and adjustability.
Friendly advice and support from Korby at CORE 4X4. Good follow up as well.
The ride quality is great as well as the handling. I think it all looks pretty good as well.
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Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |