J&M On Car Adjustable Upper Control Arm w/ Extreme Joint (1979-2004 Ford Mustang)

1979-2004 Mustang On Car Adjustable Upper Control Arm Extreme Joint

Just like the lower control arm bushings in the Mustang the upper control arm can have a significant impact on the vehicle's ride, comfort, handling, acceleration, noise and vibration. When the car leans (i.e., rolls) in a turn, one side of the chassis moves upward relative to the rear axle, the other side moves downward, and the upper control arm must twist (rotate) to allow for the axle to articulate through its suspension travel. This rotation causes the control arm bushing to bind. If this bind becomes excessive, it will raise the rear wheel rate and produce sudden, uncontrolled, undesirable changes in handling (e.g., snap oversteer).

Ford minimizes this suspension bind by using compliant rubber bushings in the upper control arm. This very "soft" bushings help accommodate the necessary motion of the control arms during body roll. However, the rubber bushing does not provide much in the way of forward and aft support, which can cause wheel hop during hard acceleration and braking.

It has become common practice to replace the stock rubber control arm bushings with solid or two piece polyurethane bushings to resolve the shortcomings of the soft rubber bushings. Hard polyurethane bushings eliminate wheel hop, reduce axle deflection, and improves straight line grip. However, the downside of common aftermarket bushings such as delrin, steel, stiffer rubber, solid or two piece polyurethane bushings is they prevent the necessary movement of the control arm during body roll, which in turn produces significant binding in the suspension when the vehicle is cornering. The polyurethane bushings also place unnecessary high stresses on the upper torque box mount, which is the attachment point for the control arm to the chassis. Standard aftermarket control arms do not allow for rotation of the control arm during cornering because of the stiffness of the bushings.

The Solution:
J&M Products then solved the shortcomings of the factory rubber and other aftermarket polyurethane and stiffer rubber bushings. J&M Products accomplished this with their Extreme Joint which uses a metal ball bushing sleeve that’s captured in hard synthetic elastomer bushings. By spending countless hours looking and dissecting the geometry and the need of the rear suspension we have come out with street/race capable bind-free bushing set up. J&M Products incorporates a steel bushing sleeve ball which is captured by hard synthetic elastomer bushings. This combination allows the bushing to articulate like a spherical bearing during cornering but the ball sleeve and hard bushings does not allow the bushing to deflect during acceleration giving you great traction during acceleration like solid bushings but remains completely bind free during cornering for great predictable traction in the corners.

Features and Benefits:

• Reduces wheel hop & improves traction by eliminating control arm flex
• Rugged 1"-14 threaded adjuster for added strength over conventional 3/4" threads
• Durable black or red powder coated finish
• One piece saddle axle housing mount for a stronger design
• On Car Double Adjustable for easy adjustment
• Made in the USA!