UMI Performance 2039CM-R Lower Control Arms with Roto-Joints Chrome Moly

UMI Performance 2039CM-R Lower Control Arms deliver bind-free suspension performance with on-car adjustability for GM muscle cars and performance vehicles. These control arms feature UMI's proven Roto-Joint technology combined with polyurethane bushings for an optimal balance of precision handling and street-friendly ride quality.

Construction and Materials:

• Premium 4130 chrome moly steel tubing (1.250" x 0.095" wall thickness) for increased strength with reduced weight
• TIG welded 4140 chromoly tube adapters for maximum durability
• Heat-treated chromoly adjuster for on-car length adjustment
• Durable powder coat finish for corrosion resistance
• Uses OEM mounting hardware for direct fitment

Roto-Joint Technology:

• 28 degrees of total unrestricted movement for bind-free operation
• 4140 chromoly hard chrome plated spherical ball with CNC machined delrin race
• Greaseable and 100% rebuildable design for long-term serviceability
• Adjustable tension via spanner wrench as delrin race wears
• Superior articulation compared to rubber or polyurethane bushings
• Reduces wheel hop and improves traction through minimal deflection

Hybrid Bushing Configuration:

This set features polyurethane bushings on the chassis mount end and Roto-Joints on the axle end. The polyurethane bushings absorb road noise and vibration before entering the passenger compartment, while the Roto-Joints provide precision movement at the axle for optimal suspension geometry. This hybrid setup is ideal for street performance applications where both handling and comfort matter.

Adjustability Benefits:

• On-car adjustable length allows fine-tuning of rear axle position
• Move axle forward or backward to accommodate larger tires and wheels
• Essential for centering aftermarket rear end assemblies
• Prevents tire rubbing in the wheel wells
• Adjustable without removing control arms from vehicle

What's Included:

• Fully assembled lower control arms (left and right)
• Swivel Roto-Joints pre-installed
• Ready to install out of the box

All bushing ends and Roto-Joints are greaseable for low maintenance operation. The adjustable and rebuildable design ensures these control arms will provide years of reliable performance on your street cruiser or performance vehicle.