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6pc Rear Adjustable Heavy-Duty Kit Long Arm Upgrade Kit

Jeep Wrangler JL / JLU 18+ 6pc Rear Adjustable Heavy-Duty Kit Long Arm Upgrade Kit
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1,994.95 1994.95 USD 2,099.95

2,099.95

(Save 5%)

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Order today — ships within 1–3 business days
Enter ZIP for arrival estimate change
Order by 3:00 PM MT today — we'll start tomorrow
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Lifetime warranty Fitment guarantee Ships from Orem, UT 4–8 hr install
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COLOR 12 colors — pick yours
https://dev.core4x4.com/web/image/product.template/1896/image_1920?unique=edc8f61

6pc Rear Adjustable Heavy-Duty Kit Long Arm Upgrade Kit

Jeep Wrangler JL / JLU 18+ 6pc Rear Adjustable Heavy-Duty Kit Long Arm Upgrade Kit
SKU: J-JL-R-LAK4
Pick your vehicle to confirm fit

1,994.95 1994.95 USD 2,099.95

2,099.95

(Save 5%)

COLOR 12 colors
Black Blue Charcoal Green Light Green Orange Purple Red White Yellow Raw Aluminum Custom Color - Other than what is listed above. Extra charge varies. We will reach out after order is placed.

Build Your Kit

  • Vehicle
    Confirm this matches your vehicle. Use Shop by Vehicle to filter correctly.
  • Brand
  • Color
    Powder coat color for control arms and track bars. Does not affect performance.
  • Lift Size
    Choose your current front lift height. Measure from center of wheel to fender if unsure.
  • Note to Core4x4:

Select Color to see price and add to cart.

Order today — ships within 1–3 business days
Enter ZIP for arrival estimate change
Order by 3:00 PM MT today — we'll start tomorrow
See full timeline

Alignment recommended Lifetime warranty on all non-wear items Made In USA

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

Upgrade Your Jeep’s Rear Suspension for Maximum Off-Road Capability

Take your 2018-Present Jeep Wrangler JL to the next level with the CORE 4X4 JL Rear Long Arm Kit (J-JL-R-LAK4)—a game-changing suspension upgrade designed to enhance articulation, rear axle stability, and overall ride quality. This weld-on kit completely transforms your Jeep’s rear suspension geometry, offering a longer arc of travel for smoother suspension movement, increased traction, and superior off-road handling.

Designed for serious off-roaders, this kit features heavy-duty bracketry, extended-length control arms, and industry-leading materials to ensure unparalleled durability, strength, and performance. Whether you're conquering technical rock crawls, rugged trails, or heavy towing applications, this rear long arm kit provides unmatched control and stability.

Key Features and Benefits

  • Optimized Suspension Travel Geometry – The long arm design extends control arm mounting points, providing a longer suspension arc for smoother articulation, better traction, and improved ride quality. Reduces axle steer, ensuring better performance across all terrains.
  • Ultra-Strong 7075 Aluminum Control Arms with ‘Memory’ – Constructed from 2-inch and 1.5-inch 7075 aluminum, these control arms flex upon impact and return to their original shape, ensuring proper suspension geometry and long-term reliability.
  • Precision-Welded 3/16” Steel Brackets for Maximum Durability – All frame brackets are laser-cut and precision-bent from 3/16” steel, creating an unbreakable mounting system that eliminates flex and maximizes rear-end stability.
  • Weld-On Installation for a Permanent Performance Upgrade – This kit requires cutting and welding, ensuring a permanent and incredibly strong suspension system. Professional installation is recommended for best results.

Recommended Pairing

Pair this Rear Long Arm Kit with our Front Long Arm Kit (J-JL-F-LAK4) for a complete suspension transformation and maximum off-road capability.

Two-Stage Powder Coating for Maximum Durability

All control arms undergo a two-stage powder coating process for enhanced corrosion resistance and customization. This process includes:

A zinc primer base coat to prevent rust and extend longevity.

A top coat available in 10 colors to match your Jeep’s aesthetics.

Brackets come raw steel to ensure proper welding and post-installation finishing.

Proudly Made in the USA

Designed and manufactured in Orem, UT, using only the highest quality American-sourced materials. Strict quality control, rigorous testing, and precision engineering ensure every component is built to handle the toughest off-road conditions. By choosing CORE 4X4, you’re supporting American manufacturing and getting an unmatched product that delivers lasting performance.

Final Thoughts

The CORE 4X4 JL Rear Long Arm Kit (J-JL-R-LAK4) is the ultimate rear suspension upgrade for Jeep Wrangler JL owners looking to maximize off-road performance and ride quality. With extended-length control arms, precision-engineered bracketry, and 7075 aluminum’s impact-resistant memory, this kit delivers exceptional articulation, axle stability, and durability.

Upgrade your Jeep Wrangler JL today with the CORE 4X4 Rear Long Arm Kit and experience next-level suspension performance and control—on the trail and the road!


  • Vehicle Fitment: Jeep Wrangler JL 18+ – This rear suspension upgrade enhances articulation, axle stability, and overall ride quality, providing superior off-road performance and control across all terrains, whether off-roading or towing.

  • CORE Advantage: The true long arm design optimizes suspension geometry by extending control arm mounting points, increasing the arc of travel, resulting in smoother suspension movement and improved traction across rugged trails and obstacles.

  • Adjustability: On-vehicle adjustability allows for fine-tuning of the suspension geometry, axle alignment, and pinion angle without removal, ensuring perfect axle centering and optimal ride quality for lifts ranging from 0 to 6 inches.

  • Construction: Built from ultra-strong 7075 aluminum (2” OD for lower arms, 1.5” OD for upper arms), these control arms offer a perfect blend of lightweight durability and impact resistance, ensuring consistent geometry and long-term off-road reliability.

  • Two-Stage Powder Coating: Zinc primer base and top coat available in 10 vibrant colors protect against corrosion and allow for personalized styling of your rig.

  • Warranty and Origin: Proudly manufactured in the United States, our product includes a lifetime warranty on all non-wear items, providing you with confidence and peace of mind in your purchase.

Built With

Rear Lower Control Arms Built With 2” 7075 Aluminum Forged Johnny Joints on both adjustable ends with 1.25” x 12 TPI - 2.32” long threads.

Rear Upper Control Arms Built With 1.5” 7075 Aluminum Forged Johnny Joints on both adjustable ends with 1” x 14 TPI - 3.25” long threads.

Make Model Submodel Years
Jeep Wrangler 2018 - Present

Each rebuild kit includes all necessary components to replace and restore wearable parts.

Construction & Materials

Rear Lower Control Arms Built With 2” 7075 Aluminum Forged Johnny Joints on both adjustable ends with 1.25” x 12 TPI - 2.32” long threads.

Rear Upper Control Arms Built With 1.5” 7075 Aluminum Forged Johnny Joints on both adjustable ends with 1” x 14 TPI - 3.25” long threads.

Vehicle Jeep Wrangler JL / JLU (18–Present)
Brand CORE 4X4
Color Black or Blue or Charcoal or Green or Light Green or Orange or Purple or Red or White or Yellow or Raw Aluminum or Custom Color - Other than what is listed above. Extra charge varies. We will reach out after order is placed.
Lift Size 6"+ or 4" — 6"
Placement on Vehicle Rear Upper, Rear Lower, Rear
Mounting Style Weld-On

Use the vehicle selector on our website to shop by your year, make, and model. On product pages, use the kit builder to select your color, series, lift height, and any add-on options, then add to cart. If you need help, call or email our team.

Standard orders typically ship within 1–3 business days of ordering. Custom color orders take approximately 5–10 business days. Because everything is built in-house, we can turn orders quickly even for custom specifications.

You can reach our team through the contact form on our website, or browse to the Contact Us page. Our team is available to answer pre-sale and technical questions before and after your purchase.

Google

Reviews of Core 4x4

See all on Google
5.0
132 reviews
5
97%
4
2%
3
0%
2
1%
1
0%
DS
Dana Smith Jul 26, 2025
Google
Excellent, strong, and durable products—perfect for both on-road and off-road applications. The customer service is outstanding—friendly, knowledgeable, and extremely helpful with understanding installation and ensuring I got exactly what I needed. I would definitely order again. Top-notch company with high-quality products made right here in the U.S.A.
Review photo 1 Review photo 2 Review photo 3
E(
Eric Hernandez (savagefit) May 27, 2025
Google
The whole process was quick and painless. The products are top tier and when I reached out them for package update info, Korby Linscomb was very responsive, and got me the answers I needed the same day. Even when I emailed back to some additional info, he sent what I was looking for that same day. I love core 4x4 and will be giving them my business from now on.
RH
Roger Hooks Jun 26, 2025
Google
2018 Ram 2500 Rear Control Arms and Rear track Bar been running for about a year, Great Solid Products and great one on one customer service, same day response with issue resolved! Thanks Korby!
OA
Owen Adams Sep 24, 2025
Google
These guys are awesome I messed up my address on my order somehow and they were so so helpful Korby was right there every step to a solution very communicative and respectful I will definitely be ordering parts with them in the future!
MG
Morgan Griffith Mar 25, 2018
Google
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.
DN
Devan Nelson Mar 25, 2019
Google
Had a great experience with Core 4x4, I desperately needed a custom track bar and found out just a couple days before Easter Jeep Safari. Spence was a huge help and made it happen with plenty of time to spare. Their parts are top notch!
AL
Andrew LaFave May 27, 2025
Google
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
LS
Leonard Smith Jan 22, 2026
Google
I don’t write reviews often, but Core 4x4 absolutely earned this one. I recently ordered leaf spring mounts and realized after the fact that I messed up my order. Totally my mistake. Instead of giving me the runaround or pointing at a return policy, Core 4x4 emailed me back and forth, worked through exactly what I was doing with my build, and made sure I ended up with the correct parts. That kind of customer service is rare these days — especially in the off-road world where a lot of companies stop caring once the order is placed. The parts themselves are exactly what you hope for: solid, well-made, confidence-inspiring hardware that looks like it belongs under a vehicle that actually gets used. You can tell these are designed by people who understand suspension geometry and real-world abuse, not just CAD screenshots. Mistakes happen — especially on custom or modified builds — and Core 4x4 handled mine like pros. Fast responses, clear communication, and a genuine effort to help me get it right. If you’re on the fence: don’t be. Core 4x4 is the kind of company you want backing your build — the kind that treats customers like fellow enthusiasts, not order numbers.
MT
Mike T Nov 23, 2025
Google
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!
DA
Dastrup Auto Mar 25, 2019
Google
I have bought a bunch of sets of arms, track bars and even had custom work done by Core 4x4. Just yesterday, Spence and Cam delivered an awesome cross member they designed and built for me! All of their products have been exceptional! I have personally seen their progression with design changes/updates. They truly take pride in their work and products. Quality control is second to none! They’ve also helped me diagnose issues with different jeeps I’ve had, as well as Dodge/Rams. These guys know their stuff! Really! I trust them whole heartedly and absolutely love their products/quality of work! I’ve referred many people, and will always continue to do so. Keep up the good work Core4x4!

Specifications

Color Black, Blue, Charcoal, Green, Light Green, Orange, Purple, Red, White, Yellow, Raw Aluminum, Custom Color - Other than what is listed above. Extra charge varies. We will reach out after order is placed.
Lift Size 6"+, 4" — 6"
Vehicle Jeep Wrangler JL / JLU (18–Present)
Brand CORE 4X4
Note to Core4x4: -
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