Fully Isolated Suspension System
Below are images showing Chrysler's design for the fully isolated suspension system consisting of an isolated front subframe (k-member) with a transverse (crosswise) torsion bar front suspension, and an isolated rear spring setup (Iso-Clamp Rear Suspension). The design was used in all M-bodies.
The isolated subframe design began around 1973 in B-bodies. The transverse torsion bar design first appeared in the F-body (Aspen and Volare) platform in mid-1976. The complete undercarriage design was touted by Chrysler as offering a "big car ride". The design was later carried over to the M-body platform, which was pretty much identical to the F-bodies underneath. Design Highlights
- The transverse torsion bars were fully attached to the k-member instead of attaching to the lower control arms and the rear crossmember like the longitudinal torsion bars. This was a departure from the traditional longitudinal torsion bar design that Chrysler had used since 1957.
- The k-member was fully isolated from the body by the use of rubber "biscuits" or isolators with through bolts.
- Although M-bodies used conventional rear springs, they were also isolated from the rear axle on the top and bottom by rubber pads held by the shock plate and a special lower clamp. The design was called the "Iso-Clamp Rear Suspension".
- All M-body (and F and J-body) springs are mounted in a tapered fashion, so that the distance between the springs is narrower at the front and wider to the rear. As a result, the spring center to center distance measures 44" at the front hanger and about 45" at the rear hanger. The correct place to mearure for axle swaps is at the spring locator pins which gives a measurement of 44.46".
- With the exception of C-bodies, M-body (and F and J-body) spring front segments are the longest of any Chrysler car built from 1960 through 1989. The "front segment" is the distance from the spring center bolt centerline to the front spring eye bolt centerline.
- Diagram of a fully isolated k-member showing rubber isolators with through bolts (Courtesy Just Suspension)
- Iso-Clamp Rear Suspension (Courtesy Chrysler Corporation - Mopar Chassis Manual)
- M-body k-frame removed showing mounting locations (Courtesy of Roger Mingle)
- Underside shot showing transverse torsion bars (Courtesy of Woodvark)