Skip to Content
Shop
RockJock Pro Edition Johnny Joint Suspension System for LJ, 4 in. lift
Pick your vehicle to confirm fit

$ 4,134.95 4134.95 USD $ 4,134.95

$ 4,134.95

Not Available For Sale

See financing options →

Fitment guarantee Ships from Orem, UT 4–8 hr install
ADD TO CART →
https://dev.core4x4.com/web/image/product.template/24667/image_1920?unique=09d00f0

RockJock Pro Edition Johnny Joint Suspension System for LJ, 4 in. lift

RockJock Pro Edition Johnny Joint Suspension System for LJ, 4 in. lift
SKU: RJ-LJ0001-101
Pick your vehicle to confirm fit

$ 4,134.95 4134.95 USD $ 4,134.95

$ 4,134.95

Not Available For Sale

  • Brand

Select Color to see price and add to cart.

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 LJ Unlimiteds provides 4 inches of lift and allows for efficient clearance of up to 35 in. tall tires (when used with body and motor mount lift, 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, double adjustable uppers), set of 4 progressively wound coil springs, front and rear bump stop kits, Johnny Joint adjustable front and rear trac bars, rear trac bar geometry relocation bracket and front sway bar disconnects. 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 2004 - 2006

Brand RockJock
Google

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.
C
Chris Oct 24, 2025
★ ★ ★ ★ ★ Google
Great product for a good price. Customer service is top notch, I had an issue which was self cause and Core 4x4 helped me out even though it was my own fault. Would definitely recommend and use them again.
AP
Ajay Paynter Mar 9, 2026
★ ★ ★ ★ ★ Google
Great company, who worked with me on shipping parts, to arrive in time for a show, when I explained my concern of possibly not getting the control arms in time. Quality is amazing on the part, affordable price for what you get, and the powdercoat is top notch, not a single issue with this product, would buy again.
AL
Aaron Lake Apr 27, 2025
★ ★ ★ ★ ★ Google
Korby was a great help with getting me a set of leaf springs for my Cherokee. Great customer service and an awesome product all made in the USA. Proud to support and rock their parts on my vehicle. 👍 …
JL
John Luna Nov 23, 2025
★ ★ ★ ★ ★ Google
Great team, and help to support my jeep and provide best stuffs
RH
Rex Hodges Jun 26, 2025
★ ★ ★ ★ ★ Google
After ordering an upper and lower adjustable control arm kit manufactured by CORE 4X4 from a jeep parts distributor who's intials are E.T., they came with 3 of the threaded ends missing. After over 2 months of phone calls and emails to this E.T. company nothing was resolved. I finally decided to call CORE 4X4 myself and tell them my dilemma. I spoke with a very personable and professional gentleman named Korby, who is one of CORE 4X4's representatives, after a brief discussion of what I went thru he simply asked me for a picture and some measurements and the items I was missing and asked if I could cover ONLY the cost of shipping and I had my missing parts in exactly 1 weeks time. This company not only builds all it's parts in the U.S.A., they stand behind their products with great customer service and life time warranty. My experience with this company and their Rep Korby was fantastic. I would definitely recommend CORE 4X4 to anyone who needs parts for any 4x4 projects. You just can't beat their quality and service. Rex Hodges Valparaiso, Indiana
VK
Victor Keele Sep 24, 2025
★ ★ ★ ★ ★ Google
Great customer service. I got my front upper and lower control arms and hardware on Friday afternoon. It didn’t come with instructions so I called Core 4X4 and they immediately e mailed me the instructions. Also, the kit I got had the spacers missing so I called. It was late Friday by thus time but they took care of the issue first thing Monday morning and I got the spacers on Tuesday. Great company.
Review photo 1 Review photo 2
CL
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!!
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.
RP
Robin Poole Jul 26, 2025
★ ★ ★ ★ ★ Google
I had several questions before my purchase and Korby helped me with the correct parts to order and recommendations. Outstanding customer service and product knowledge! Can't wait to install them!

Specifications

Brand RockJock
ADD YOUR VEHICLE Find exact-fit parts
Find →
Pick your series in 30 seconds.
Find My Series →
30-second quiz
Shop by vehicle
Loading…
UNIVERSAL · FITS ANYTHING
DRIVETRAIN Choose vehicle for fit
Drivetrain Coming Soon Axles · Gearing · Driveshafts ›