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 1/4 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
JL
John Luna
Nov 23, 2025
★
★
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★
Great team, and help to support my jeep and provide best stuffs
RC
Ryan Colligan
Mar 4, 2026
★
★
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I have nothing but good things to say about Core 4x4. I have the crawler series on my JKU and we take it all over the place. These parts handle everything we throw at them.
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.
AH
Abbey Hiett
Mar 25, 2019
★
★
★
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Company finally made things right
RT
Ruby Timm
Apr 27, 2025
★
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Bought a new 2019 Ram 1500. Had bad rear wheel hop since new, got all four core 4x4 control arms and it fixed the issue. Thanks
BA
bryan angell
Jun 26, 2025
★
★
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First off amazing products. I got a set of adjustable control arms for my XJ and it is so nice to be able to dial in caster and pinion angles. A quick call and I was able to purchase an adjustable track.
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.
SH
Shawn Hooten
Apr 27, 2025
★
★
★
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Great products, shipped the next day during a big sale event. Core 4x4 gets it right and gets it done! Thank you all.
BB
Brayden Brockey
Mar 23, 2024
★
★
★
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Got a set of upper control arms for my xj, really impressed with the quality
MT
Mike T
Nov 23, 2025
★
★
★
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★
Korby and the rest of the team at Core 4x4 know there stuff and answered my question in a timely manner. They even were able to quick ship a re-build kit for me so I could get my truck back on the road- Thanks!
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Specifications
| Vehicle | Jeep Gladiator JT (20–Present), Jeep Wrangler JL / JLU (18–Present) |
| Brand | RockJock |
