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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%
JG
James Griffin Jul 26, 2025
Google
Customer service is top notch. They answered all of my questions and got me my tracking number for my packages. I just received both of them and the quality is next level. You guys are truly awesome.
Review photo 1
JJ
JT JT Dec 23, 2025
Google
We have all shopped places where the person on the phone makes you feel like they don't have the time to talk to you the customer or answer your questions. I can tell you first hand that's not Core 4x4. They have the best customer service I have seen so far. They have taken the time to respond to all of my questions in a very prompt and professional manner, taking the time to answer each and every question I have had. Lets put it this way if Core 4x4 sells a product I am wanting for my truck I will buy it from them, I highly recommend Core 4x4.
CW
Cody Whitlock Sep 24, 2025
Google
10/10 overall experience, shipping, customer service, and such a great product!
Review photo 1
EC
Eric Cox Jul 26, 2025
Google
Prompt, professional, and courteous service! Quality parts and broad assortment of products to suite your 4x4 needs:)
RH
R and H H Oct 24, 2025
Google
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.
AL
Aaron Lake Apr 27, 2025
Google
Korby was a great help with getting me a set of leaf springs for my Cherokee. Great customer service and an awesome product all made in the USA. Proud to support and rock their parts on my vehicle. 👍 …
EL
Eric Labrum May 27, 2025
Google
Best customer service I have ever experienced. They are my go to source do to quality and service
AP
Ajay Paynter Mar 9, 2026
Google
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.
DD
Dmitriy D May 27, 2025
Google
Installed rear and upper control arms and track bar on my 3rd Gen 4RUNNER to align rear axle and restore factory wheel base after 3.5" lift. Car drives better than New! Improved handling cornering and overall driving. Very solid and high quality made product. Support is outstanding. Shipping extremely fast. Thank you so much. I wish you will have something new for my car.
Review photo 1
RP
Robin Poole Jul 26, 2025
Google
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!

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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