Adjustable Rear Upper Control Arms with Del-Sphere Joints | 1971-1976 GM B-Body

Price: 209.00 USD

Application: 1971-1976 GM B-Body – Impala, Caprice, etc.

Part# 675

These adjustable rear upper control arms for the 1971-1976 GM B-Body Impala, Caprice, etc. outperform the flexible, stamped steel arms and soft rubber bushings that come from the factory.

Eliminate wheel hop, increase traction, and drastically improve handling with an easy bolt on installation. The Del-Sphere ™ pivot joints provide for “bind-free” handling and no deflection launch performance. They’re available powder coated in your choice of bright red or gloss black for a brilliant and durable finish.

These adjustable rear upper control arms are constructed from 1.25″ x .095″ wall DOM tubing and CNC laser cut and formed 1/4″ steel mounting brackets for maximum strength and durability.

The adjustability feature allows for setting the pinion angle. Our right hand and left hand threaded silver zinc plated CNC machined 4140 chrome moly double male adjuster allows for easy on-the-car adjustments, no need to unmount the control arm to make adjustments!

The control arm bushings on B-Body vehicles have a significant impact on your vehicle’s ride, comfort, handling, acceleration, noise and vibration. When the vehicle leans (rolls) in a turn, one side of the chassis moves up relative to the rear axle and the other side moves down.

The control arms must twist to allow for the axle to articulate, this causes the control arm bushings to bind. If this bind becomes excessive, it will raise the rear wheel rate and produce sudden and uncontrolled changes in handling such as snap oversteer.

The factory minimizes this suspension bind by using compliant rubber bushings. These soft bushings help accommodate the necessary motion of the control arms during body roll. However, the rubber bushings do not provide much in the way of forward and aft support which can cause wheel hop during hard acceleration and braking.

It is common to replace the stock rubber control arm bushings with polyurethane bushings to resolve the shortcomings of the factory’s soft rubber bushings. Polyurethane bushings eliminate wheel hop, reduce axle deflection, and improve straight line traction. However, the downside of polyurethane bushings is they prevent the necessary movement of the control arms during body roll, which in turn produces significant binding in the suspension when the vehicle is cornering.

The polyurethane bushings also place high stresses on the control arm mounts on the vehicle. Polyurethane bushed control arms do not allow for rotation of the control arm during cornering because of the stiffness of the bushings.

Del-Sphere™ Pivot Joints:

The Spohn Performance Del-Sphere? pivot joint solves the shortcomings of the factory rubber and aftermarket polyurethane bushings. Our Del-Sphere? pivot joint incorporates a spherical ball which is surrounded by Delrin® bushing cups.

Think of the Del-Sphere? pivot joint as a Delrin® bushed spherical rod end. After over a year of R&D testing here at Spohn Performance on a streetable spherical joint the Del-Sphere? pivot joint is the final result. Designed and manufactured exclusively by Spohn Performance, we have taken street suspension performance to the next level.

Our Del-Sphere? pivot joint features a one piece forged and heat treated chrome moly housing, a heat treated and chrome plated chrome moly spherical ball, Delrin® bushing cups, heat treated retainer washer and snap ring, heat treated and chrome plated chrome moly threaded adjuster ring, an external grease fitting, and a beautiful silver zinc plated housing finish.

The Delrin® bushing cups absorb shock and road noise so you get the quiet and smooth ride of a bushing as well as 28 degrees of rotation! Our Del-Sphere? pivot joints will always ship to you fully assembled, however, we also offer an optional adjusting tool that will allow you to do two things.

First, you can disassemble the Del-Sphere? pivot joint for cleaning, inspection, etc. Second, you can adjust the amount of tension on the spherical ball. The amount of tension can be easily adjusted by using our optional adjustment tool to tighten or loosen the end retainer ring.

What that means is if over time and miles the tolerances open up you can simply re-adjust the retainer ring and have your pivot joint as tight as it was the day it was brand new. We doubt you’ll ever need to replace the Delrin® bushing cups, but they certainly can be. Unlike a spherical rod end, the Del-Sphere? pivot joint is 100% rebuildable.

Specifications & Features: