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
★
★
★
★
★
132 reviews
SC
Singer Heating and Cooling
Mar 25, 2018
★
★
★
★
★
These guys are great. You can get them on the phone for support. This important and is not always the case with other custom parts builders. Their control arms are bomb proof and offer plenty of options. You can get real genuine Currie Johnny joints without paying the price for Currie arms.
DN
Devan Nelson
Mar 25, 2019
★
★
★
★
★
Had a great experience with Core 4x4, I desperately needed a custom track bar and found out just a couple days before Easter Jeep Safari. Spence was a huge help and made it happen with plenty of time to spare. Their parts are top notch!
TG
Travis Grimm
Mar 23, 2024
★
★
★
★
★
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.
JJ
Jason Jukich
Jul 26, 2025
★
★
★
★
★
Fast shipping, excellent communication, and awesome products
RR
Ryan Rogers
Aug 25, 2025
★
★
★
★
★
I purchased a set of the Cruiser Series control arms for my Jeep Jk based on postive reviews from different Jeep Facebook pages. Ordered and 2 days later realized they had the very same exact arms on sale in the overstock section. Called them up and they refunded me the savings from my original purchase. Amazing, honest service. Can't wait to get them installed. Keep up the good work guys.
RD
Reagan D'mello
Dec 23, 2025
★
★
★
★
★
Love the product. Excellent customer support 👍🏽 …
S
Sebastian
Oct 24, 2025
★
★
★
★
★
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
MP
Mirko Pompili
Mar 19, 2026
★
★
★
★
★
I want to share a truly positive experience.
I ordered a car kit consisting of two packages, but unfortunately one was lost during shipping with UPS. The situation could have become complicated... but it didn't.
The company manager was extremely helpful and professional: he personally followed up on the situation and did everything he could to resolve the issue, even sending me the package again without hesitation.
It's rare to find such attentive and reliable customer service these days.
My sincere congratulations on your professionalism and commitment: that makes all the difference.
BM
Brantly Musgrave
Jan 22, 2026
★
★
★
★
★
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!
TH
Todd Hume
Jan 22, 2026
★
★
★
★
★
Their products are great but the service is even better!! Thanks Korby.
Your Dynamic Snippet will be displayed here...
This message is displayed because youy did not provide both a filter and a template to use.
Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
