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
FS
Fernando Salazar
Aug 25, 2025
★
★
★
★
★
Great quality control arms and great customer service. Korby has been a great help at answering my questions on some issues I’ve been having with installation!
MN
Mike Nielsen
Nov 23, 2025
★
★
★
★
★
The customer service is first class. I had an issue with a track bar I installed on my F350. I don’t have any other Core 4x4 parts yet, but with the way I was treated, I know their parts are well done, because they went above and beyond to make sure I was made whole. They wouldn’t be in business if they had to take care of a lot of people like they took care of me. Will definitely be back when it’s time to build the Jeep!
JS
Jeffrey Shafer
Jan 22, 2026
★
★
★
★
★
Exceptional customer service. All my questions were asked in a timely manner and parts were replaced when an error occured. I encourage people to make purchases due to their exceptional quality products, but also because of their customer service. Will make additional purchases in the future.
MG
Morgan Griffith
Mar 25, 2018
★
★
★
★
★
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.
RM
R2d2 Movi78
Feb 21, 2026
★
★
★
★
★
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.
D
Don
Jul 26, 2025
★
★
★
★
★
Great shop, great parts and great service. You want to buy off this company and company’s like this!!!! Wish we had more companies as good as this one!! Thank you
MS
Mr. Smith
Nov 23, 2025
★
★
★
★
★
Have yet to get to try them but I bought some upper, and then later , lower control arms for my 03 rubicon. The pricing is very fair, so fair I was hesitant to even purchase. When the product came in I was happily mistaken. These are some beefy units with an incredible warranty! I’m very excited! I went with the “Camp”series as I mostly daily it.
I have trouble with the shipping at times when I ordered but Corby is quick to notice things and help communicate the solution. Looking forward to buying more parts!
JG
James Griffin
Jul 26, 2025
★
★
★
★
★
Customer service is top notch. They answered all of my questions and got me my tracking number for my packages. I just received both of them and the quality is next level. You guys are truly awesome.
TH
Todd Hume
Jan 22, 2026
★
★
★
★
★
Their products are great but the service is even better!! Thanks Korby.
AS
Anthony Snyder
Jun 26, 2025
★
★
★
★
★
Great experience and really great parts
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 |
