Rear Upper Control Arms - Tubular with Del-Sphere Pivot Joints - Adjustable - 1973-1977 GM A-Body: Chevelle, Monte Carlo, etc.

Application: 1973-1977 GM A-Body: Chevelle, Monte Carlo, etc.

Our adjustable rear upper control arms for the 1973-1977 A-Body cars outperform the flexible, stamped-steel arms and soft rubber bushings that come from the factory.

Eliminate wheel hop and increase traction with an easy bolt on installation. The adjustability feature allows for setting the pinion angle. Our right hand and left hand threaded CNC machined male/female double adjuster allows for easy on-car adjustments, no need to unmount the control arm to make adjustments!

The control arm bushings on A-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.

This combination allows the bar to articulate like a spherical rod end (28 degrees of available rotation) during cornering but the spherical ball does not allow the bushing to deflect. Therefore the bar remains completely bind free like a spherical rod end during cornering for predictable traction in the corners.

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 friction on the spherical ball. Do you want a very low friction pivot joint or a very tight pivot joint? It's up to you, the amount of tension can be easily adjusted by using our optional adjustment tool to tighten or loosen the end retainer ring.

What that also 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.

What is Delrin, and why did you choose to use it? Delrin is an acetal homopolymer made by DuPont. It is characterized as having an excellent combination of physical properties that make it suitable for numerous applications.

With extremely low moisture absorption and a low coefficient of friction (self-lubricating), Delrin is uniquely tailored for wear applications in high humidity or moisture environments. Delrin will maintain constant physical properties under high moisture conditions and out-perform nylon or polyurethane under these conditions. Delrin has a 10,000 psi tensile strength and a 120 Rockwell Hardness rating making it ideal for our Del-Sphere application.

Build Specifications:

• 3/4" Del-Sphere Pivot Joints
• Right hand and left hand threaded CNC machined and silver zinc plated 4140 chrome moly double adjuster threads into 4130N chrome moly TIG welded threaded tube adapters
• Ship to you jig set at OEM length
• Extended length CNC laser cut and formed 1/4" steel mounting brackets fit all OEM and aftermarket rear ends
• Re-uses OEM mounting hardware, no need to drill out your car's mounting bracket holes.
• These are the highest quality, easiest to adjust on the car rear upper control arms on the market!
• Available powder coated in your choice of the above colors for a brilliant and durable finish

4130N Upgrade: The ultimate in bullet-proof lightweight strength, 100% TIG welded chrome moly construction! Same as above, but constructed entirely from 4130N chrome moly tubing.

Priced per Pair -- Qty. 1 = 1 Pair