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

Jeep Wrangler 07-18 3.8L/3.6L/2.0L

JKS1665

Overview:

The JKS Manufacturing Adjustable J-Flex Upper Control Arms are engineered to enhance the off-road capability and suspension reliability of your Jeep Wrangler and Grand Cherokee. Designed specifically for rear suspension applications, these control arms provide precise adjustability to optimize suspension geometry, improving handling, articulation, and tire clearance. Ideal for Jeep enthusiasts looking to upgrade their vehicle’s suspension for rugged terrain or lifted setups, these arms deliver durability and performance without compromising ride quality.

Built to withstand the demands of off-road driving, the J-Flex control arms offer a fully adjustable design that allows fine-tuning of caster and pinion angles, ensuring your Jeep maintains proper alignment and driveline angles after suspension modifications. Their rebuildable and greaseable ends extend service life, making them a smart investment for long-term use.

Key Features:

These adjustable rear upper control arms incorporate advanced engineering and robust materials to deliver superior performance and reliability:

• Fully adjustable design with forged J-Flex ends and jam nuts for precise suspension tuning
• CNC-bent from durable DOM (Drawn Over Mandrel) steel tubing for strength and consistency
• Heavy-duty 1-1/4"-12 threads combined with hex-shaped weld-in bungs for secure and easy adjustment
• Factory-style rubber bushings at the non-adjustable end for quiet, maintenance-free operation
• Rebuildable and greaseable forged ends to extend component life and maintain smooth articulation
• Powder-coated finish for corrosion resistance and long-lasting durability
• CNC-formed to ensure proper clearance for tires, frame, and axle mounts
• Sold in pairs to maintain balanced suspension performance

Construction & Design:

The JKS Adjustable J-Flex Upper Control Arms are crafted from high-strength DOM steel tubing, which offers superior resistance to bending and fatigue compared to standard tubing. The CNC bending process ensures precise shaping for optimal fitment and clearance around suspension components and tires. The forged adjustable ends are designed to handle extreme off-road stresses while allowing fine adjustments to suspension geometry.

Each arm features heavy-duty threaded sections with jam nuts that lock securely in place, preventing unwanted movement during demanding driving conditions. The factory-style rubber bushings at the fixed end reduce noise and vibration, delivering a smooth, quiet ride on and off the road. A durable powder-coated finish protects the arms from corrosion and environmental damage, ensuring they look and perform well for years.

Installation & Fitment:

Installation of the JKS Adjustable J-Flex Upper Control Arms is straightforward for experienced DIYers and professional installers alike. These arms are designed as direct replacements for factory rear upper control arms on compatible Jeep models, requiring no major modifications. The adjustability allows for fine-tuning after installation to achieve optimal suspension alignment and driveline angles, especially important when running lifted suspensions or larger tires.

Fitment includes a wide range of Jeep Wrangler models from 2007 through 2018, as well as select Jeep Grand Cherokee models from 2005 to 2010. This ensures compatibility with many popular Jeep configurations, including Rubicon, Sahara, Sport, and Unlimited variants.

What's Included:

• Pair of JKS Adjustable J-Flex Rear Upper Control Arms
• Jam nuts for secure adjustment locking
• Grease fittings installed on rebuildable forged ends
• Installation hardware not included (vehicle-specific)

Ideal For:

This product is ideal for Jeep owners who want to improve their vehicle’s off-road suspension performance, especially those with lifted or modified suspensions. It suits enthusiasts who demand precise suspension geometry adjustments to maintain driveline angles, reduce premature wear, and enhance articulation. Whether you’re tackling rocky trails, mud, or desert terrain, these control arms provide the durability and adjustability needed for serious off-road adventures.

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.