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Jeep Wrangler JK / JKU 07-18 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

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Order today — ships by Mon, Jun 1
Salt Lake City, UT change
Order by 3:00 PM MT today — we'll start tomorrow
See full timeline
Lifetime warranty Fitment guarantee Ships from Orem, UT 4–8 hr install
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COLOR 12 colors — pick yours
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6pc Rear Adjustable Heavy-Duty Kit Long Arm Upgrade Kit

Jeep Wrangler JK / JKU 07-18 6pc Rear Adjustable Heavy-Duty Kit Long Arm Upgrade Kit
SKU: J-JK-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 by Mon, Jun 1
Salt Lake City, UT 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 Dominance

Take your 2007-2018 Jeep Wrangler JK to the next level with the CORE 4X4 JK Rear Long Arm Kit (J-JK-R-LAK4)—a game-changing upgrade designed to enhance articulation, ride quality, axle stability, and durability. This weld-on kit completely redefines your rear suspension geometry, allowing for a longer arc of travel, resulting in smoother suspension movement, better traction, and unmatched off-road capability.

Designed for serious off-roaders, this kit features massively upgraded bracketry, extended-length control arms, and industry-leading materials for a stronger, more controlled, and more capable suspension system. Whether you're tackling extreme rock crawls, desert trails, or rugged terrain, this rear long arm kit provides unparalleled handling and durability.

Key Features and Benefits

  • Optimized Suspension Travel Geometry – The true long arm design extends control arm mounting points for a longer arc of suspension travel, resulting in a smoother ride, better flex, and superior traction across all terrains. Reduces axle steer and bump steer, improving both high-speed stability and low-speed crawling performance.
  • Ultra-Strong 7075 Aluminum Control Arms with ‘Memory’ – Rear Lower and Upper Long Arms are crafted from 2-inch and 1.5-inch 7075 aluminum, balancing lightweight performance and extreme durability. The 'memory' of 7075 aluminum allows the control arms to flex under impact and return to their original shape, preventing permanent bending or deformation. Improves suspension longevity, ensuring consistent geometry and reliability on the toughest trails.
  • Precision-Welded 3/16” Steel Brackets for Maximum Durability – All frame brackets are laser-cut and precision-bent from 3/16” steel, delivering an unbreakable mounting system that eliminates flex and provides rock-solid stability. The rear frame brackets integrate body mount relocation, eliminating interference issues while reinforcing your Jeep’s structure.
  • Weld-On Installation for a Permanent Performance Upgrade – Requires cutting and welding for installation, ensuring a permanent and incredibly strong suspension system. Professional installation is recommended for optimal results.

Recommended Pairing

For a complete long arm suspension solution, pair this Rear Long Arm Kit with our Front Long Arm Kit (J-JK-F-LAK4) to maximize axle control, stability, and articulation across all terrains.

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. After installation, they can be painted or coated as desired.

Proudly Made in the USA

At CORE 4X4, we manufacture our Long Arm Kits in Orem, UT, using only the highest quality American-sourced materials. Our commitment to strict quality control, rigorous testing, and precision engineering ensures 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 JK Rear Long Arm Kit (J-JK-R-LAK4) is the ultimate rear suspension upgrade for Jeep Wrangler JK owners looking to push their off-road performance to new heights. With extended-length control arms, precision-engineered bracketry, and 7075 aluminum’s impact-resistant memory, this kit delivers maximum articulation, axle stability, and durability.

Upgrade your Jeep Wrangler JK today with the CORE 4X4 Rear Long Arm Kit and experience next-level suspension performance and ride quality, whether on the trail or the road!

 

  • Vehicle Fitment: Jeep Wrangler JK 07-18 – This rear long arm kit enhances suspension travel, articulation, and stability, ensuring a smoother ride and more control, even on the toughest trails and rugged terrains.

  • CORE Advantage: The extended control arm design optimizes suspension geometry, creating a longer arc of travel for smoother suspension movement. This reduces axle steer and bump steer while improving traction and off-road performance.

  • Adjustability: Features on-vehicle adjustability, allowing fine-tuning of axle position and alignment. Fine-tuning ensures optimal suspension geometry for 0-6 inches of lift, while also ensuring perfect control under varying terrain and load conditions.

  • Construction: Built from 2” OD 7075 aluminum for rear lower arms and 1.5” OD for upper arms, this kit ensures maximum strength and flexibility. These arms return to their original shape after impacts, maintaining consistent suspension geometry and long-term durability.

  • 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 2007 - 2018

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 JK / JKU (07–18)
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

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5.0
132 reviews
5
97%
4
2%
3
0%
2
1%
1
0%
D
DSI Jul 26, 2025
Google
Great products with excellent customer service after the sale
MP
Mirko Pompili Mar 19, 2026
Google
I want to share a truly positive experience. I ordered a car kit consisting of two packages, but unfortunately one was lost during shipping with UPS. The situation could have become complicated... but it didn't. The company manager was extremely helpful and professional: he personally followed up on the situation and did everything he could to resolve the issue, even sending me the package again without hesitation. It's rare to find such attentive and reliable customer service these days. My sincere congratulations on your professionalism and commitment: that makes all the difference.
D
David Nov 23, 2025
Google
First of I just want to say Great customer service korby Has helped me from the start and has not let me down! Reached out to him again today and he was able to warranty some parts out for me. As far as the quality of the parts.. excellent! The build quality is great. I can definitely tell a Difference from the cheap oem rear control arms to these and the pan hard bar. Color, From what I can tell it’s super durable been through a few mud holes on top of the daily road grime and after a quick wipe they still pop! Overall I recommend. Customer service is everything for me and it’s definitely there at Core 4x4.
SH
Shawn Hooten Apr 27, 2025
Google
Great products, shipped the next day during a big sale event. Core 4x4 gets it right and gets it done! Thank you all.
MP
matthew patterson May 27, 2025
Google
Ive used core products for my last two jeeps and now my ram. They’re parts are the absolute best quality youll find ANYWHERE. Top quality products and A+ custom service keeps the as my go Roger for any suspension needs.
A
Adam Oct 24, 2025
Google
I couldn't have been more excited for the initial unboxing of these new Core 4x4 UCA's! They appear to be so well built and just a true quality product. Installation was a breeze and the initial testing with the forklift appears to have given me some additional flex with less binding on the rest of the components now that the geometry is back properly aligned. Time will tell how they hold up on my near future off-road adventures but I don't have any doubt that they are up to the task!
Review photo 1 Review photo 2 Review photo 3 Review photo 4
AM
Adam M Sep 24, 2025
Google
First time buying from Korby @ Core 4x4 and it’s being nothing short of a great experience. I bought the non adjustable Trail kit for my 5th Gen Ram 1500 with a 2” lift. The welds look great, nice powder coat finish and quality bushing. Had some trouble fitting the grease nipples due to the powder coating but a thread tap would fix that. They fit easily and perform great. I felt the improvement straight away. No more wheel hop on hard acceleration which was my main reason for the purchase. I was missing some smaller bushings needed for the 5th Gen and Korby’s custom service was on point, with responsive emails and mailing out the missing parts straight away. Very happy with their products and customer service. Highly recommended company👌🏽
Review photo 1 Review photo 2 Review photo 3 Review photo 4
CM
Cameron Masters Mar 24, 2023
Google
Absolutely incredible family owned business. I asked to pick up my order since I’m local and they came in on a weekend to accommodate. Had to make some adjustments to parts and took the time to make sure it was perfect. Parts are incredible quality. If you have a Jeep, do not hesitate to support this local business.
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
C
caleb Mar 24, 2022
Google
Absolutely a great company. Ordered rear lower control arms with hardware but when i got it the hardware wasn't there but they sent it out right away and got a free t-shirt! Highly recommend.

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 JK / JKU (07–18)
Brand CORE 4X4
Note to Core4x4: -
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