UMI Performance 4017-B Rear Upper Control Arms with On-Car Adjustability

The UMI Performance 4017-B rear upper control arms deliver race-proven adjustability and durability for GM vehicles. Engineered with premium materials and precision manufacturing, these control arms allow you to fine-tune pinion angle quickly and easily—whether in your garage or at the track.

Key Features:

• On-car adjustability for quick pinion angle changes without removal
• 4140 chrome-moly threaded tube adapters for maximum strength
• 4140 heat-treated chrome-moly adjusters with 1.000" solid construction
• Hard chrome plated Teflon/Kevlar self-lubricating spherical rod ends
• CNC machined 6061 aluminum step bushings
• Precision CNC machining with fully TIG welded construction
• Durable powder coat finish for long-lasting protection
• 0.250" CNC machined mild steel mounting points

UMI's unique on-car adjuster design allows you to lengthen or shorten arm length by simply loosening two jam nuts and turning the adjuster—no need to remove the arms from the vehicle. The Teflon-lined spherical rod end design provides bind-free operation, making these arms ideal for drag racing, autocross, and street performance applications. Proper pinion angle adjustment reduces 60-foot times, increases traction, and eliminates wheel hop.

Built with aircraft-quality materials throughout, these Ultimate Arms replace weak points found in competitor designs with heavy-duty 4140 chromoly steel components. This is true overkill engineering for serious performance enthusiasts who demand the best.