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 a TJ Wrangler, or 3 inches of lift in an LJ Unlimited. 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 | 1997 - 2006 | |
| Jeep | Wrangler | 2004 - 2006 |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
BW
Brian Wadsworth
Jun 26, 2025
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Amazing product! Shipping was quick, packaging was great and support was outstanding!!
JT
jacob trice
Apr 27, 2025
★
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Core 4x4 has outstanding products at a fair price and unmatched customer service. When you call Korby, it's like talking with a friend. Very cool and helpul!
I ordered some custom control arms, but from the wrong product line and they were super cool about returning them and upgrading to a better "Crawl" series. Only charged the difference between the two products. They paid all the return shipping and sent the uprgaded arms super quick. It was only a couple days. Awesome!!
I couldn't be happier with the transaction👍🏼
Also, these control arms are stout and take a beating. I run heck out my Jeep in the rocks and desert. No problems whatsoever.
Thanks Core 4x4, ya'll are welcome at my campfire anytime!
Jake T.
Pleasant Hill, Or.
J
Justin
Mar 24, 2021
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Small business, family owned, made in the USA, lifetime warranty. Purchased Tier 3 control arms and rear track bar for a 2006 Jeep LJ. Simple website and easy to contact over phone and email. I had some technical questions and they were happy to answer them. They allow local pickup and were built to order same week. The order was wrapped and ready when I walked in and even gave a tour of the shop. They abrasive blast all raw materials to achieve a better surface profile for powdercoat to adhere and create a smooth, durable finish. I also noticed several CNC machines and a robotic welder they use for all their parts. A small outfit with a robotic welder? Their concern for quality is obvious and it shows in the parts they make. Very impressed. Happy to do business with these guys.
GH
Gary Haag
Aug 25, 2025
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Ordered a set of Core 4x4 control arms for my 2006 Jeep TJ. These are some heavy duty quality control arms. Can't wait to get them installed. Great customer service too!
TM
Tony Moller
Aug 25, 2025
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Awesome parts! Support the older Jeeps! Great customer service.
OJ
Oldgreg jr
Mar 23, 2025
★
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Good company, they offer well built parts and Great customer service.
I had a couple of hang ups with my control arms that I purchased, they were very easy to work with and found the solution to make them work.
MG
Morgan Griffith
Mar 25, 2018
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I met a couple of the Core 4x4 guys at the Salt Lake Offroad Expo and decided to try them out after noticing one of my control arm bushings was disintegrated. I called to discuss parts on Thursday and I was leaving for a trip on Saturday. These guys built my control arms and had them ready to be picked up Friday, 24 hours later. The parts seem to be great quality and they charged me nothing extra to have them painted. These guys were extremely helpful and without them my trip probably would have been cancelled. looking forward to testing out the arms on my next trip to Moab.
JF
jacob fezza
Mar 24, 2022
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I wanted to take a moment and give these guys a shout out, I’ve currently got, for my xj, their adjustable control arms, tier 4 adjustable track bar and adjustable leaf spring shackles. You can always count on a fair price, high quality products, and quick delivery. Keep up the great work guys, will definitely continue to shop with you
RH
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.
P
Paul
Mar 24, 2023
★
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I've been having trouble with the track bar (on my 2nd gen Dodge) since I installed the 3rd gen Synergy adapter bracket and a 3rd gen stock bar.. oddly, they call it a '3rd gen bracket' and the stock 3rd gen bar doesn't quite fit, making contact with the bracket. I had attempted to clearance the bracket but it was still making contact and I could feel it over large bumps.
I reached out to a lot of companies, but Core 4x4 offered to make a custom bar for the application with adjustability and dual Johnny joints. The first pass on it didn't work but they sent me out another passenger side end that made it fit incredibly well.
This was all done solely over email/descriptions/pictures/measurements.
Bar is super high quality and heavy duty, made in the US by a family owned company and carries a lifetime warranty. The customer service was responsive and superb, and the price was a lot less than I expected.
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Specifications
| Brand | RockJock |