JKS Manufacturing Adjustable J-Flex Upper Control Arms (REAR)

2018–2026 Jeep Gladiator

JKS1667

Overview:

Upgrade the rear suspension of your Jeep Gladiator JT with the JKS Manufacturing Adjustable J-Flex Upper Control Arms. Designed for both stock and lifted Gladiator models from 2018 through 2026, these control arms provide superior strength and precise adjustability to optimize rear axle positioning and pinion angle. Whether you're tackling rugged off-road trails or cruising on pavement, these arms deliver enhanced durability and smooth operation, ensuring your Gladiator performs reliably in all conditions.

Built to replace the factory upper control arms, the J-Flex arms improve articulation and suspension geometry, reducing drivetrain vibrations and improving ride quality. Their adjustable design allows for fine-tuning at a wide range of lift heights, making them an essential upgrade for Gladiator owners seeking improved handling and longevity.

Key Features:

The JKS Adjustable J-Flex Upper Control Arms combine advanced engineering with durable materials to enhance your Jeep Gladiator’s rear suspension. Key features include:

• Adjustable length design to dial in rear axle position and pinion angle for lifts from 0 to 4.5 inches
• Heavy-duty 2” OD x .250-wall DOM steel tubing for increased strength over factory arms
• Premium OE-style rubber bushings at the axle mount to absorb noise and reduce vibrations for a quieter ride
• Unique hex-shaped threaded bung at the frame mount for easy adjustment of the forged flex end
• Forged flex joint allowing up to 30 degrees of misalignment (15 degrees in either direction) for exceptional articulation
• Greaseable flex ends to extend bushing life and maintain smooth operation
• Rebuildable flex ends for long-term serviceability
• Durable gloss black powder coat finish for corrosion resistance and lasting appearance
• Backed by JKS Manufacturing’s limited lifetime warranty
• Sold in pairs for complete rear axle upgrade

Construction & Design:

JKS Manufacturing builds these adjustable J-Flex upper control arms using heavy-duty 2-inch outer diameter DOM (Drawn Over Mandrel) steel tubing with a .250-inch wall thickness. This construction offers a significant strength improvement compared to factory control arms, ensuring durability under demanding off-road conditions. The axle-side mount features OE-style rubber bushings engineered with a specific durometer to isolate noise, vibration, and harshness (NVH), providing a comfortable and quiet ride without sacrificing performance.

The frame-side mount incorporates a forged flex end with a unique hex-shaped threaded bung, enabling precise length adjustments and alignment corrections. This flex joint design accommodates up to 30 degrees of misalignment, allowing for impressive suspension articulation and reducing stress on drivetrain components. The greaseable design ensures long-lasting bushing life, and the rebuildable flex ends make maintenance straightforward and cost-effective.

Installation & Fitment:

These JKS Adjustable J-Flex Upper Control Arms are designed as direct bolt-in replacements for the rear upper control arms on Jeep Gladiator models from 2018 through 2026. They fit a wide range of trims including Rubicon, Mojave, Overland, Sport, Willys, and special editions such as the 80th Anniversary and Launch Edition. Installation requires basic hand tools and moderate mechanical skill, with no welding or frame modifications needed. The adjustable length feature allows you to fine-tune the rear axle position and pinion angle to match your specific lift height and suspension setup, ensuring optimal driveline geometry and performance.

What's Included:

• Pair of JKS Manufacturing Adjustable J-Flex Rear Upper Control Arms
• Greaseable forged flex ends with jam nuts
• Installation hardware and instructions

Ideal For:

These adjustable J-Flex upper control arms are ideal for Jeep Gladiator owners who want to improve rear suspension strength, articulation, and driveline alignment. They are perfect for enthusiasts running stock or lifted suspensions up to 4.5 inches, especially those who frequently drive off-road or require enhanced durability and ride quality. Whether you’re upgrading for trail performance, daily driving comfort, or both, these control arms provide a reliable and adjustable solution to optimize your Gladiator’s rear suspension.

JKS Manufacturing builds Jeep and off-road suspension parts—lift systems, control arms, track bars, disconnects, and supporting hardware—engineered for articulation and durability. It’s a popular choice for Wrangler and Gladiator owners looking to improve clearance, ride quality, and capability for real trail use.