UMI Performance 4042-B Rear Lower Control Arms with Roto-Joints

The UMI Performance 4042-B rear lower control arms are engineered to eliminate wheel hop and improve traction through precision construction and advanced Roto-Joint technology. These boxed control arms are fabricated from heavy-duty 3" x 1-1/2" x 1/8" rectangular steel tubing with 0.120" wall thickness, providing exceptional strength and rigidity for high-performance street and track applications.

Roto-Joint Technology:

Each control arm features UMI's proprietary Roto-Joints on both ends for maximum performance and suspension travel. The Roto-Joint design utilizes a greaseable delrin-lined pivot ball that offers 28 degrees of total unrestricted movement, delivering bind-free operation with low friction. Unlike factory rubber or aftermarket polyurethane bushings, the delrin race absorbs shock and road noise while allowing the suspension to articulate correctly for precision handling and improved cornering performance.

Construction Features:

• CNC machined drawn-over-mandrel bushing holders for accurate tolerances and perfect fit
• MIG and TIG welded construction for superior strength and durability
• MIG welded end caps keep out road debris and contaminants
• Reinforced sway bar holes with TIG welded 0.120" wall thickness steel sleeves
• Boxed design eliminates control arm flex and bushing deflection
• Durable powder coat finish for long-lasting corrosion resistance

Installation:

Ships fully assembled and ready to install using OEM hardware. The greaseable Roto-Joints require minimal maintenance, making this an excellent street setup for cruisers or an ideal performance upgrade for autocross and road race applications. Compatible with stock or aftermarket rear sway bars.