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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

1,994.95 1994.95 USD 2,099.95

2,099.95

Build Season · Save 5% — $105 off · ends Aug 28

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100% bolt-on no welding MADE IN USA · Orem, Utah Expert Support 100K+ Community
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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

Build Season · Save 5% — $105 off · ends Aug 28

More ways to pay ▾

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 Delivery date by ZIP
Order by 3:00 PM MT today — we'll start tomorrow
See full timeline
Core 4x4 Manufactured

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

Product Details

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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4.8
161 reviews
5
97%
4
2%
3
0%
2
1%
1
0%
SG
Sal Giordano Sep 24, 2025
Google
I want to take the time to share my experience with Core 4x4. I have a 2004 Jeep Wrangler and was looking to upgrade some suspension parts. I went with Core 4x4 upper & lower adjustable control arms and a front adjustable track bar. Everything arrived quickly, and right out of the box I was impressed with the quality and craftsmanship. I had a few questions during installation (measurements and torque specs), and I spoke with Korby on a couple of occasions. Not only did he send me detailed instructions, but he also shared an installation video specific to the part and vehicle I was working on, something you don’t get from many companies. The control arms fit perfectly, look great, and perform exactly as I hoped. I did run into an issue with the front track bar touching the front diff. When I reached out, Korby had me send pictures and then immediately offered two solutions: his bar guy could make a different bend and send it out to me, or I could get a full refund. His response honestly blew me away. As much as I wanted to run the Core 4x4 track bar, I chose the refund. Korby sent me a prepaid shipping label right away, no hassle. My experience with Core 4x4 has been excellent. Korby was extremely understanding, communicative, and helpful every step of the way. The parts I received were high quality, and the customer service was second to none. I would absolutely recommend Core 4x4 10 out of 10 times and will be using them again. Just a great American company with awesome people who truly care about their customers. Thank you Korby, and thank you Core 4x4!
Z
Zion Sep 24, 2025
Google
Every product I have received from them has been nothing short of fantastic. Korby in Customer service went above and beyond to help me fix my own mistake. I cannot reccomend them enough.
JA
Jonathan Aguilera Jan 22, 2026
Google
Great experience with Core 4x4! I purchased some suspension parts for my dad's 98 Jeep TJ. The products they make are super durable and look even better in person. Attention to detail and overall superior quality. The staff at Core 4x4 is super helpful also, Korby has been great. Updating me on the status of my order and sending me tracking numbers as well. Thank you all at Core 4x4, keep up the amazing work!
EG
Erica Grissom May 27, 2025
Google
First off, I wish I knew about them sooner. The customer service is top tier. The response time is about 30 min no waiting 1-3 days to get a response. The parts are heavy-duty and look amazing. The packaging is perfect, I can't wait to hit some trails. Thanks Core4x4
MS
Mr. Smith Nov 23, 2025
Google
Have yet to get to try them but I bought some upper, and then later , lower control arms for my 03 rubicon. The pricing is very fair, so fair I was hesitant to even purchase. When the product came in I was happily mistaken. These are some beefy units with an incredible warranty! I’m very excited! I went with the “Camp”series as I mostly daily it. I have trouble with the shipping at times when I ordered but Corby is quick to notice things and help communicate the solution. Looking forward to buying more parts!
Review photo 1
JC
John Cutler Oct 24, 2025
Google
In September 2025, we visited CORE 4x4 in Orem, Utah. CORE 4x4 makes control arms and other similar parts that stiffen the suspension of an off-road 4x4 vehicles, so that the off-road vehicles can travel on more rugged terrain. CORE 4x4 used to share this building with another business, and since this other business has moved elsewhere, CORE 4x4 will continue to expand and grow their business. Good for CORE 4x4 to be a growing company and to expand into the vacant part of the building.
Review photo 1 Review photo 2 Review photo 3 Review photo 4
JH
Joe Hu Sep 24, 2025
Google
Amazing! I put all my new control arms and it drives a lot smoother and looks great!!!
Review photo 1
NP
Norb Pranger Oct 24, 2025
Google
Not sure where to start, Products or Service or Warranty. Products: I found Core4x4 through a very respected YouTuber in the Jeeping community. I purchased an entire set of Core4x4 Control Arms three years ago and have beat the daylights out of them and they are still in great condition. Now, I purchased another Jeep, this time for my daughter and bought yet another set of Control Arms because I know that these things can take a beating and stand up to it. I plan on replacing more parts on this TJ and my JL and will continue to buy from Core4x4. Service: This isn't some huge name conglomerate that treats you like you're just another customer. They are quick with responses and will always make things right should something be a problem. Oh and the quickness in which they ship their products is unmatched. I bought these CAs for my TJ on Thursday, I received them on Monday. Most other manufacturers will tell you weeks, they had them to me in 2 shipping days. Warranty: Seriously, a lifetime warranty? Yes please. Nothing more to say. I can't say enough about how great of a company this is. I've even spoken to the owner through email a few years back on some questions that I had. Support small American built businesses. P.S. Core 4x4, feel free to make me an ambassador and send me some swag :) .
JW
Jonathan Word Aug 25, 2025
Google
Beefy parts made and painted well, very fair pricing for what you get, and fantastic customer service to boot. Easily my favorite place to get suspension parts.
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
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Made in Orem, UT · Lifetime warranty
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