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 4 inches JK Wrangler and JK Wrangler Unlimited (2 or 4-door) applications. 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 | 2007 - 2018 |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
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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.
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Cade Leith
Mar 23, 2024
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Have full upper/lower CA set on both front and rear axles on a 96 ZJ. These are the rubber bushing sets not joint sets. I have beat the hell out it in the Nevada desert for 2 years and has been great. I don’t go fast but I do articulate suspension a lot. Super solid and haven’t any issues. Just inspected the entire set recently due to some banging under it. Turns out the banging is lower rear shock bushings. Inspected each CA along the way nothing. Aside from dirt and obviously winter roads and what not still in excellent condition, bushings are solid like the day they were installed. I’ll add that I’m about tapped on a short arm at 4.25(less with settle) so the front CA’s get beat on just from that, still they’re like new. Paint is great condition, this set is red. I would definitely buy again. Another plus for me, Utah isn’t local necessarily, but it’s nice to support businesses closer to me.
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Colten Lockwood
Mar 25, 2019
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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!!
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Peter Busack
May 27, 2025
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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.
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R2d2 Movi78
Feb 21, 2026
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I’m extremely impressed with Core 4x4. The quality of their parts is outstanding — everything feels solid, well‑built, and engineered with real attention to detail. Shipping was fast and everything arrived perfectly packaged. Their customer service is just as good as their products: responsive, helpful, and genuinely committed to making sure you get exactly what you need.
Overall, a top‑tier experience. I’ll definitely be buying from them again. Specially thank you Mr. Linscomb from Core 4x4. Arturo M.
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Melody Baker
Jan 22, 2026
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I ordered a part for my 03 Jeep TJ and all I can say is wow! Korby at Core 4x4 is a total rockstar!! There was a glitch with my payment and within minutes, Korby reached out to me to get it fixed, then sent my receipt with the tracking number. I lost the number and reached out to him during the Holidays and got a rapid response with the number again. I can’t say enough about the customer service and the quality of parts. Thank you!!
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Nick
Sep 24, 2025
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I have a 2016 RAM 1500 Crew Cab and I replaced the rear upper and lower control arms also the pan hard track bar and also the sway bar and links for the rear with all I had the articulating bushings. The vehicle now has no body role. They are absolutely incredible if you get the control arms you gotta get the CORE 4 x 4sway bar end links don’t don’t try and be cheap and get Moog or something else you got to get articulating bushings get the core 4 x 4 ones they are the best. My truck drives now through the canyons like a BMW. I have Fox high-performance shocks on there as well with all the CORE 4 x 4 suspension parts and they are amazing. Well worth the money I would highly recommend anybody thinking about CORE 4 x 4 go with CORE 4X4 and if you can go with their articulating bushings, they’re unbelievable drives better now than my Escalades. Well planted no body role and smooth on the Highway unbelievable the difference they all made!!
THANKS AGAIN CORE 4x4!!!!
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Robert C
May 27, 2025
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Fantastic products! Outstanding performance!! Absolutely the best customer service!! You will not be disappointed!
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R and H H
Oct 24, 2025
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Top notch company. Mechanic lost bolts that clamp upper control arms. Korby sent out spare bolts no charge. Best customer service I’ve come across in a long time. Only suspension brand I’ll ever use.
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Adam M
Sep 24, 2025
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First time buying from Korby @ Core 4x4 and it’s being nothing short of a great experience. I bought the non adjustable Trail kit for my 5th Gen Ram 1500 with a 2” lift. The welds look great, nice powder coat finish and quality bushing. Had some trouble fitting the grease nipples due to the powder coating but a thread tap would fix that. They fit easily and perform great. I felt the improvement straight away. No more wheel hop on hard acceleration which was my main reason for the purchase.
I was missing some smaller bushings needed for the 5th Gen and Korby’s custom service was on point, with responsive emails and mailing out the missing parts straight away. Very happy with their products and customer service. Highly recommended company👌🏽
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Specifications
| Brand | RockJock |