Making A-Body Strut Bushings Work

or, How to get replacement bushings not push the lower control arm back

The original Mopar strut bushings had a thicker and thinner section (right photo). If this is not done the lower control arm is pushed back causing it to slip on its pivot bushing if polurethane, and/or causing undue wear and reducing caster in either rubber or poly.*
To obtain the thin rear section on a strut rod bushing, it appears one could buy the "Moog Improved", or one can modify a standard polyurathane (or rubber) A/E body set as shown below.
 Note: there was also a one piece rubber bushing that originally came on most if not all a-bodies. It wasn't much fun to remove, and apparently was not used as the prefered replacement even by Mopar.

- photo & and comparison thanks to SteveWall

Top Drawing - Strut Position in K-Frame:
Reaction strut installed without the front bushing assembly. to determine The frame thickness and space available for bushings on each side of the frame was measured.

Middle Drawing - Strut Bushing Assembly Hardware:
The washer and tube assembly that came with the poly bushings was measured. The overall length including the nut is 2.65", so 0.15+" will compress (tube into the washers).

Bottom Drawing - Unmodified Poly Bushing Installed:
Installed and tightened to spec. with the 0.920" thick bushings, the strut rod was pushed back.  Measurements with clay found the strut rod shoulder was  0.88" from the frame (minimum).  (Bushing showing measured 0.50" + washer measured in the drawing above 0.38").

 Since the distance from frame to the strut shoulder should only be 0.45 to 0.50"(top drawing), but with the replacement bushings it was at least 0.88". Therefore a total of 0.38 to 0.53" needed to be removed from the back bushing.

It seemed important to keep some of the cone shape for good assembly fit.  As these parts were clearly not engineered specifically for the A-bodies, whether all the extra thickness was really needed is not known.  My decision from several trials was no. So, about half the thickness to be removed was sliced off the cone side and half off of the full diameter side.  The full diameter part was moved to the front half of the assembly. Also some of the original shoulder was sliced and that was saved for the spacing through the frame if it was needed. 

* A lower control arm being pushed off a nylon bushing from a too thick strut bushing can be seen at They offer an adjustable strut rod as an alternative way to get the same results I did.

Home:'67 curve to another

More Tech:
Fuel Delivery Facts and Figures
Improving Forward Lighting & Electricals
Ignition Wire Comparison
Handling Theory for late-'60s to mid-'70s Mopars

    If you take advice, or copy something I have done, you are on your own.  I'm just trying to be helpful. You need to make your own decisions, and know about or discover the risks before barging ahead on any endevour.

copyright Mathew Grubel, December 10, 2003
2nd edition. February 28, 2004