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
NM
Noah Myers
Mar 23, 2024
★
★
★
★
★
I contacted these guys on a Saturday through email and needed some control arms by the following weekend, Spence got back with me and told me he would make sure the order got shipped out on Monday, they got busy and wasn’t able to ship the package out so he got back with me that evening and upgraded my shipping for free and shipped out the next day, only because he told me he’d make sure I’d have them by the weekend! This company sticks to their word! The customer service from these guys are unmatched and they will have another lifetime customer here!
PB
Peter Busack
May 27, 2025
★
★
★
★
★
Purchased a set of Trailing arms for my Ram 1500, quality is first class. I bought the ones with the Jonny Joints for more articulation and it appears from the construction I should get a lifetime of use, Zerk fittings are an added plus. Would defiantly recommend, and the the service team answered all of my questions.
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.
GN
Glenn Nowosad
Jan 22, 2026
★
★
★
★
★
I just finished installing the Peak 2.0 Front Suspension system with the Core 4x4 Blue Tacoma Rear Suspension system on my 2024 TRD Offroad Premium Tacoma. The two upgraded suspension systems really made a difference in how the ride feels, whether we’re off-road or on the road. A big thank you to Korby and the team at Core 4x4 for their support and for getting the shipping sorted out so quickly!
RD
Reagan D'mello
Dec 23, 2025
★
★
★
★
★
Love the product. Excellent customer support 👍🏽 …
AH
Abbey Hiett
Mar 25, 2019
★
★
★
★
★
Company finally made things right
NP
Norb Pranger
Oct 24, 2025
★
★
★
★
★
Not sure where to start, Products or Service or Warranty.
Products: I found Core4x4 through a very respected YouTuber in the Jeeping community. I purchased an entire set of Core4x4 Control Arms three years ago and have beat the daylights out of them and they are still in great condition. Now, I purchased another Jeep, this time for my daughter and bought yet another set of Control Arms because I know that these things can take a beating and stand up to it. I plan on replacing more parts on this TJ and my JL and will continue to buy from Core4x4.
Service: This isn't some huge name conglomerate that treats you like you're just another customer. They are quick with responses and will always make things right should something be a problem. Oh and the quickness in which they ship their products is unmatched. I bought these CAs for my TJ on Thursday, I received them on Monday. Most other manufacturers will tell you weeks, they had them to me in 2 shipping days.
Warranty: Seriously, a lifetime warranty? Yes please. Nothing more to say.
I can't say enough about how great of a company this is. I've even spoken to the owner through email a few years back on some questions that I had. Support small American built businesses.
P.S. Core 4x4, feel free to make me an ambassador and send me some swag :) .
MM
MIKE (Mike the Mechanic)
Jul 26, 2025
★
★
★
★
★
Amazing company and customer service!!!! I messed up on my order and the fixed it immediately. Would definitely recommend them. Can't wait to hit the trails with their product.
LS
Leonard Smith
Jan 22, 2026
★
★
★
★
★
I don’t write reviews often, but Core 4x4 absolutely earned this one.
I recently ordered leaf spring mounts and realized after the fact that I messed up my order. Totally my mistake. Instead of giving me the runaround or pointing at a return policy, Core 4x4 emailed me back and forth, worked through exactly what I was doing with my build, and made sure I ended up with the correct parts.
That kind of customer service is rare these days — especially in the off-road world where a lot of companies stop caring once the order is placed.
The parts themselves are exactly what you hope for: solid, well-made, confidence-inspiring hardware that looks like it belongs under a vehicle that actually gets used. You can tell these are designed by people who understand suspension geometry and real-world abuse, not just CAD screenshots.
Mistakes happen — especially on custom or modified builds — and Core 4x4 handled mine like pros. Fast responses, clear communication, and a genuine effort to help me get it right.
If you’re on the fence: don’t be. Core 4x4 is the kind of company you want backing your build — the kind that treats customers like fellow enthusiasts, not order numbers.
8
89Patriot
Jan 22, 2026
★
★
★
★
★
Great company! I have used there products consistently with no complaints with quality you can see and feel. From my experience, their customer service is also amazing. Core 4x4 has no issues standing behind their already amazing products and will quickly and professionally solve issues may they arise. I will continue to be a customer.
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Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
