UMI Performance 4039-B Rear Upper Control Arms with Roto-Joints

UMI Performance's 4039-B Roto-Joint adjustable rear upper control arms deliver bulletproof performance for street, strip, and pro-touring applications. These premium control arms feature UMI's proprietary spherical Roto-Joints that drastically minimize suspension deflection, providing crisp handling, simplified pinion angle tuning, and reduced wheel hop.

Key Features:

• UMI-designed and manufactured Roto-Joint spherical bearings for maximum strength and minimal deflection
• On-car adjustability using UMI's proprietary CrMo (chromoly) adjuster—no need to remove arms for tuning
• CNC laser-cut 1/4-inch thick upper mounting pads for superior strength
• CrMo threaded adapters provide enhanced thread strength and durability
• Heavy-duty construction with precision TIG and MIG welding
• Durable powder coat finish for long-lasting corrosion resistance
• Made in Philipsburg, Pennsylvania, USA
• Compatible with all rear end housings

These bolt-in replacement control arms install in approximately 1-2 hours using basic hand tools. The combination of UMI's in-house designed spherical joints and chromoly adjusters delivers ultimate strength and performance for demanding applications. Whether you're launching hard at the strip or carving corners on your favorite back road, these control arms provide the precision and durability your performance vehicle demands.