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 front coil spring shim for JL Wrangler and JT Gladiator is 3/16 in. thick and mounts between the welded on coil spring axle pad and the coil spring isolator. The indexing pin in the coil spring isolator fits thru the hole in this shim to properly clock it. These shims are used to fine tune vehicle height per model, engine combination and added weight load. Shims may be stacked a maximum of 2 high. Semi-gloss black powder coat finish.
| Make | Model | Submodel | Years |
|---|---|---|---|
| Jeep | Gladiator | 2020 - Present | |
| Jeep | Wrangler | 2018 - Present |
| Vehicle | Jeep Gladiator JT (20–Present) or Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
Reviews of Core 4x4
5.0
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132 reviews
BZ
Brandon Zeiders
Dec 23, 2025
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I ordered the jeep xj long arm lift kit. Control arms showed up first they turned out amazing!! Had some issues with the powder coating on the cross member and sent korby and the team at core4x4 an email. They got right on making me another cross member and sending it out. I appreciate all the help they've given me along the way. Very fast response thru emails. Build quality seems to be pretty dang nice!! Can't wait to install it and enjoy it!
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Bailey Smith
Mar 23, 2025
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Core 4x4 excels with precision and service and keeps nothing else higher in mind. Everyone I've met at the company is very honest and down to earth, 10/10 would recommend.
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Darin Wuebbels
May 27, 2025
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Thanks for the fabulous customer service. Your products and customer service are first class. I highly recommend these guys. Excellent experience.
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Aaron
Mar 23, 2024
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I have recently come to know Core 4x4 when I purchased a Jeep XJ and was looking for a place that had dedicated XJ suspension and components. Here is what makes them different than most other shops. All of their components are top shelf quality and they back it up if you break any of it. I was able to see their shop when I picked up an order locally and was impressed with their attention to detail and how they assemble and powder coat each part. I had an issue with a shackle and needed the threaded shaft to be shorter. I called in and talked to Kaden and he told me to come by and they would shorten it for me. When I got there, Kaden and Spencer (the owner) met me and talked about options and proceeded to make the right adjustments to fit my XJ. Told me if anything changes in the future and I need additional length, they would take care of me. So what really sets them apart from others is their Customer Service. Try calling in to any other Jeep suspension or part shop and see how they treat you. Been there - done that.
Will continue to do business with Core and their team. Getting that kind of service for just a shackle has me thinking I may need to replace my JT components with Core's. Thanks Guys for being helpful good humans!
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niceguyr1
Mar 24, 2023
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I purchased upper and lower adjustable arms for my WJ and lowers were missing the spacers. I didn't know until 3 months later when I was installing them. With absolutely zero hassles they quickly sent me the missing spacers. Fantastic product and service! Huge thank you guys for the awesome service and parts!!! Customer service is quickly becoming a lost commodity and you guys gave me hope that it's still alive and well, you just have to buy from the right people... Thanks again for going above and beyond! 👍👍
RP
Robin Poole
Jul 26, 2025
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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!
AP
Ajay Paynter
Mar 9, 2026
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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.
RM
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.
EL
Eric Labrum
May 27, 2025
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Best customer service I have ever experienced. They are my go to source do to quality and service
AH
Abbey Hiett
Mar 25, 2019
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Company finally made things right
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Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |