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RockJock Pro Edition Johnny Joint Suspension System for JL Wrangler w/ 392 Hemi, 3.5 in. lift
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4,300.00 4300.0 USD 4,300.00

4,300.00

Not Available For Sale

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Fitment guarantee Ships from Orem, UT 4–8 hr install
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RockJock Pro Edition Johnny Joint Suspension System for JL Wrangler w/ 392 Hemi, 3.5 in. lift

RockJock Pro Edition Johnny Joint Suspension System for JL Wrangler w/ 392 Hemi, 3.5 in. lift
SKU: RJ-JL3921-101
Pick your vehicle to confirm fit

4,300.00 4300.0 USD 4,300.00

4,300.00

Not Available For Sale

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Alignment recommended 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's Pro Edition Johnny Joint Suspension System for JL Wrangler Unlimiteds (4-door) with the 392 Hemi engine provides 3 1/2 inches of lift and allows for efficient clearance of up to 37 in. tall tires (with minor trimming, larger tires will require aftermarket fenders). This kit is comprised of only the highest end components in the areas of strength, fit, finish, function, and the engineering to back them. This kit is designed specifically for the serious off-roader who not only wants to lift their vehicle and install big tires, but also wants to tackle the toughest trails in the country with confidence and ease.Included in this kit is the full set of 8 Johnny Joint adjustable control arms, set of 4 progressively wound coil springs including one front and one rear coil spring shim, front (392 specific) and rear bump stop kits, Johnny Joint adjustable front and rear trac bars, 392 specific rear trac bar geometry relocation bracket, front and rear adjustable extended sway bar links and front brake line relocation brackets. For the ultimate off roading package, you'll want to look at all of the upgrade parts that RockJock has to offer that can be added to this kit to finish this build off! Next level offerings such Antirock Sway Bars and Currectlync Heavy Duty Steering are a must for serious off-roading! Shock options to suite this kit are available from all of the top suppliers.

Make Model Submodel Years
Jeep Wrangler 2018 - Present

Vehicle Jeep Wrangler JL / JLU (18–Present)
Brand RockJock
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Reviews of Core 4x4

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5.0
132 reviews
5
97%
4
2%
3
0%
2
1%
1
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Colten Lockwood Mar 25, 2019
Google
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!!
TH
Todd Hume Jan 22, 2026
Google
Their products are great but the service is even better!! Thanks Korby.
D
Danny Oct 24, 2025
Google
Outstanding customer service to match the high quality parts. This is the go-to company.
EA
Eric Ahonen Mar 24, 2021
Google
Awesome control arms! My mechanic said “ your Jeep is pretty much bulletproof now.” And I just got the tier 1 arms! The people at the core 4x4 shop were really nice too. They were running behind on shipping, (which is understandable) so I decided to go pick it up because it was only an hour drive. They gave me a free $60 hardware kit for the inconvenience. Thanks core 4x4! You guys are awesome!!
NP
Norb Pranger Oct 24, 2025
Google
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 :) .
EC
Eric Cox Jul 26, 2025
Google
Prompt, professional, and courteous service! Quality parts and broad assortment of products to suite your 4x4 needs:)
MM
MIKE (Mike the Mechanic) Jul 26, 2025
Google
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.
GV
Gil Valk Sep 24, 2025
Google
Excellent service, Prompt responses when needing technical assistance, Amazing looking parts that fit excellently. I would recommend them to anyone looking for suspension components. Also very well packaged when we received the shipment, which means no damage from shipping company!! We went with the Crawl Series double adjustable kit and it definitely looks killer on our build!!!
Review photo 1 Review photo 2 Review photo 3 Review photo 4
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DSI Jul 26, 2025
Google
Great products with excellent customer service after the sale
E(
Eric Hernandez (savagefit) May 27, 2025
Google
The whole process was quick and painless. The products are top tier and when I reached out them for package update info, Korby Linscomb was very responsive, and got me the answers I needed the same day. Even when I emailed back to some additional info, he sent what I was looking for that same day. I love core 4x4 and will be giving them my business from now on.

Specifications

Vehicle Jeep Wrangler JL / JLU (18–Present)
Brand RockJock
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