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
This pair of RockJock rear coil springs will provide 3 1/2 inches of lift in JL Wrangler Unlimited applications that feature the EcoDiesel or 392 Hemi powertrains. These springs directly replace factory springs and are designed to work with RockJock Johnny Joint suspension systems or other manufacturer's lift kits and provide improved ride quality and height control. Finish is gloss black powder coat. Extensive research was done by RockJock to develop the perfect spring rate and quality of the coil springs. The results: they provide the best in comfortable ride and excellent performance off-road. If you need help choosing the correct springs for your Jeep - just call the RockJock sales staff!
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Wrangler | 2018 - Present |
| Vehicle | Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
AL
Andrew LaFave
May 27, 2025
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I am really please with this company. Great product, i had an issue with a couple of the jonnhy joint bushings, they explained what had caused it and how to fix it. Within hrs of receiving my inquiry, i had heard back with the required info I needed. A couple hrs later problem was fixed and ready for the trail again. They care about heir product and their customers. Thanks crew, you rock
PG
Paul Griffin
Feb 21, 2026
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Great long arm kit with everything else I needed as well! They worked with me to ensure that I was getting an upgraded components kit just like I wanted. Fast shipping with some of the best packaging that I have ever seen. Nothing was scratched or missing and this kit is even more impressive than the videos or website can show. Powder coating looks great with no issues.
I would highly recommend CORE 4x4 to anyone looking for a great quality kit.
JT
Jay Taylor
May 27, 2025
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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.
DR
David Rogers
Aug 25, 2025
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Ive had the front adjustable control arm kit in bright green for my 1996 ZJ.
Ive had the kit for about a year now and i have to say, im extremely impressed, over 1000 miles off-road and roughly 20,000 miles on the highway. These control arm kits for any vehicle built by core 4x4 are well worth the money, just be aware thereight be some minor scatches or chips from shipping ( but who should care about that if you're beating the crap out of em' they way they were built and designed for)
D
David
Nov 23, 2025
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First of I just want to say Great customer service korby Has helped me from the start and has not let me down! Reached out to him again today and he was able to warranty some parts out for me.
As far as the quality of the parts.. excellent! The build quality is great. I can definitely tell a
Difference from the cheap oem rear control arms to these and the pan hard bar.
Color, From what I can tell it’s super durable been through a few mud holes on top of the daily road grime and after a quick wipe they still pop!
Overall I recommend. Customer service is everything for me and it’s definitely there at Core 4x4.
DD
DANIEL DUSSAULT
Nov 23, 2025
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Very beefy items for a very reasonable price. Personally have CORE rear track bar and all upper control arms for my 04 Jeep TJ. Had a slight issue with control arm length and they went above and beyond to swap jam nuts to get me where I needed to be. Really have to appreciate a company like this.
RG
Robert Van Gorder
Apr 27, 2025
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Amazing service. Bought a track bar through Americantrucks.com and they sent it with the wrong size bushing sleeve. Korby at Core 4x4 was quick to get me the correct size and very responsive. Will definitely be using more of their stuff.
RC
Robert C
May 27, 2025
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Fantastic products! Outstanding performance!! Absolutely the best customer service!! You will not be disappointed!
MT
Marcus Torres
Jan 15, 2026
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Best control arms I have installed on any of my builds. After running every major manufacturer, Core 4x4 is on par or better than all the high-end companies at a fraction of the cost. Lifetime warranty is the cherry on top.
M
Matt
Mar 23, 2024
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The best products on the market. 95% of my xj is core 4x4 products
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Specifications
| Vehicle | Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |