UMI's on-car adjustable lower control arms are supplied with a spherical rod end and polyurethane bushing combination. This set-up is designed for street performance and street enthusiast. The polyurethane bushing end is designed to be bolted to the vehicle chassis side while the rod end attaches to the rear end side. Since the polyurethane bushings are softer they are designed to absorb more road noise and shock before it enters the passenger compartment of the vehicle. The adjustment of the control arms allows them to be adjusted longer or shorter moving the rear end back or forward to squeeze those larger tires in the fender wells. Adjustable control arms are also recommended for most aftermarket rear end installs to center the rear end and prevent tire rubbing. These control arms feature on-car adjustability. Making adjustments is as simple as loosening two jam nuts and using UMI’s chromoly on car adjuster. Simply turn the adjuster with the control arms attached to the vehicle to quickly lengthen or shorten the control arm to the desired length. Control arms are CNC machined and TIG welded for superior strength and perfect fitment.