So you’ve read the title and now you’re curious as to how UMI Performance‘s Roto-Joint offers such superior articulation, and what exactly a Roto-Joint is, right?

The Roto-Joint (short for Rotational Joint) is designed to perform a number of functions, most importantly offer 28 degrees of total rotation and unrestricted movement in suspension applications. It’s designed to prevent suspension bind, yet retain the ride quality that softer bushings offer. 

How does it do this, you ask? By using a Delrin bushing race and a 4140 chromoly chrome plated spherical ball design that is encapsulated within the end of the suspension arm. The ball rotates in the CNC-machined bushing to allow unrestricted movement. The Delrin bushing material that supports the ball offers high resistance to wear, and the joint is completely rebuildable. 

The use of the Delrin material also means that the Roto-Joint design is fully streetable, without the road-to-chassis noise transmission issues that are seen with typical steel rod-end designs. 

The Roto-Joint is even adjustable; if the Delrin material starts to wear, the built-in adjuster ring allows it to be snugged up to maintain the tight feel, retain tension on the ball and remain quiet on the street. The Delrin race also absorbs shock and reduces bushing deflection to provide improved traction, and is outfitted with a grease fitting to allow for long life. These are built exclusively in UMI Performance’s facility in Philipsburg, Pennsylvania – made in the USA.

Check out the UMI Performance website for more information on the Roto-Joint, which can be had in many of the company’s rear control arm systems.