ARB Adjustable Rear Upper Control Arms – UCAJKRR

The ARB UCAJKRR adjustable rear upper control arms are a heavy-duty suspension upgrade designed for Jeep Wrangler JK and JL. They are engineered to restore and fine-tune rear axle geometry after suspension lifts, ensuring correct driveline angles, improved stability and controlled axle movement in both road and off-road conditions.

Detailed description

After lifting a vehicle, factory rear upper control arms are no longer able to maintain correct axle geometry. This can result in improper pinion angle, driveline vibrations, accelerated component wear and unstable handling. The ARB UCAJKRR control arms allow precise adjustment of rear axle positioning, enabling proper correction of pinion angle and suspension geometry.

Compared to OEM fixed-length arms, these adjustable control arms provide greater strength, adjustability and durability, making them suitable for vehicles used daily as well as those subjected to demanding off-road conditions.

Role in the suspension system

The rear upper control arms control axle rotation and driveline alignment. By allowing accurate adjustment, the ARB UCAJKRR arms help:

• Restore correct pinion angle after suspension lifts.
• Reduce driveline vibrations and stress on drivetrain components.
• Improve rear axle stability and vehicle handling.
• Maintain proper suspension geometry under load.

Construction and materials

• Manufactured from high-strength DOM steel tubing.
• Tube dimensions: 1.25" diameter with 0.188" wall thickness.
• Heavy-duty forged ends for increased structural rigidity.
• Max-C bushings with dual-durometer compound for durability and controlled articulation.
• Corrosion-resistant coating with durable powder coat finish.
• Locking adjusters to securely maintain alignment settings.

Driving performance benefits

Correcting rear axle geometry has a direct impact on vehicle behavior. With ARB adjustable control arms installed, the vehicle benefits from:

• Improved straight-line stability.
• Smoother driveline operation.
• More predictable handling on-road.
• Controlled axle movement during off-road articulation.

Key features and advantages

• Adjustable design for precise rear axle geometry correction.
• Heavy-duty construction suitable for lifted vehicles.
• Max-C bushings balancing comfort and off-road durability.
• High resistance to corrosion and environmental exposure.
• Suitable for daily driving, overlanding and off-road use.

Technical data

Compatibility – Fitment

• Jeep Wrangler JK (2007–2018) – 4-door models
• Jeep Wrangler JL (2018–2022) – 4-door models

Application / Who this product is for

The ARB UCAJKRR rear upper control arms are recommended for:

• Vehicles equipped with suspension lift kits.
• Drivers seeking proper driveline alignment after suspension modification.
• Daily-driven vehicles requiring stable and predictable handling.
• Off-road and expedition builds where durability and adjustability are essential.