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Johnny Joint Uni-Ball for 3-Links. Fits JL, JT Aftermarket Diffs (only) and all JK, TJ, LJ, XJ, MJ and ZJ Stock and Aftermarket Diffs.
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173.00 173.0 USD 173.00

173.00

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Fitment guarantee Ships from Orem, UT 4–8 hr install
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https://core4x4.com/web/image/product.template/24174/image_1920?unique=de245c6

Johnny Joint Uni-Ball for 3-Links. Fits JL, JT Aftermarket Diffs (only) and all JK, TJ, LJ, XJ, MJ and ZJ Stock and Aftermarket Diffs.

Johnny Joint Uni-Ball for 3-Links. Fits JL, JT Aftermarket Diffs (only) and all JK, TJ, LJ, XJ, MJ and ZJ Stock and Aftermarket Diffs.
SKU: RJ-301001-101
Pick your vehicle to confirm fit

173.00 173.0 USD 173.00

173.00

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Lifetime warranty Made in USA

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
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Reviews of Core 4x4

See all on Google
5.0
132 reviews
5
97%
4
2%
3
0%
2
1%
1
0%
TD
Tim Davis Sep 24, 2025
Google
Customer service is amazing, responds fast and know what they are talking about. Their product looks top of the line.
LS
Leonard Smith Jan 22, 2026
Google
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.
JG
James Griffin Jul 26, 2025
Google
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.
Review photo 1
TH
Todd Hume Jan 22, 2026
Google
Their products are great but the service is even better!! Thanks Korby.
EL
Eric Labrum May 27, 2025
Google
Best customer service I have ever experienced. They are my go to source do to quality and service
AH
Abbey Hiett Mar 25, 2019
Google
Company finally made things right
ZA
Zen Asher Mar 23, 2025
Google
The quality and durability of the arms are the best. They are super heavy duty. And lifetime warranty is crazy
JW
Jonathan Word Aug 25, 2025
Google
Beefy parts made and painted well, very fair pricing for what you get, and fantastic customer service to boot. Easily my favorite place to get suspension parts.
JT
Jay Taylor May 27, 2025
Google
Had a worn out set of rear upper control arms on my TJ. These were old rubicon express long arms. can’t buy replacements and no one makes a direct fit replacement. Talked with Korby at core off road sent some measurements and photos and a week later new arms showed up. Packaging was perfect fit was perfect. Would highly recommend giving these guys a call.
JL
John Luna Nov 23, 2025
Google
Great team, and help to support my jeep and provide best stuffs

Specifications

Vehicle Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present)
Brand RockJock
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