Chrysler Torsion-Aire, Torsion-Quiet, and Torsion-Bar Suspensions

Torsion bars were not new when Chrysler started using them in 1957; Packard had a complex four-wheel torsion bar setup in 1955 and 1956. The Chrysler switch to the torsion system marked a first for a major American manufacturer, though, and possibly a first in the low-price and medium-price fields.

Chrysler’s torsion bar suspensions were used across the entire lineup, from Plaza and Valiant to Imperial, for decades after being devised by Bob Batchelor; torsion bars were also used in European cars and the Cadillac Eldorado / Oldsmobile Toronado. Chrysler’s implementation was unusual for its universal use and for the use of rear leaf springs with the front torsion bars, instead of rear coil springs. The rear leaf-springs were used mainly because they were cheaper, though there were some advantages as well.

The torsion-bar front suspension debuted in 1957 across the corporation’s models, and were the mainstay for Chrysler Corporation cars until the appearance of the K-cars. There were two major types of system, the original Torsion-Aire with longitudinal torsion bars, and the “Volare-Aspen” transverse torsion bars, used on all rear-drive cars to follow until the LX series.

The front end of the torsion bar connected to the front wheel’s lower control arm; the rear end of the torsion bar was anchored in the sub frame so the bar could not turn. When the front wheel rose over a bump, the lower control arm pivoted around the points where the torsion bar was mounted, twisting the bar. The chrome steel in the bar resisted the twist, holding the wheel on the road.

The torsion bar front springs used a high proportion of chromium in their steel (though snapping was still not as infrequent as it could have been). The anti-sway bar resisted lean in turns, with various degrees of success depending on its thickness and the suspension tuning. Shock absorbers limited suspension oscillations. Diagonally mounted steel struts reinforced and positioned the front-wheel lower control arms. Widely spaced, off-center mounted rear springs cut acceleration squat and also resisted brake dive.

The suspension was sold for some years under the trademark Torsion-Aire. In the company’s words, “When you twist a length of rubber hose, you can feel the spring action, as the hose tries to retain its normal position. Torsion springs act in the same manner. Bumps are absorbed by the twisting action of the torsion bars.”

The angled upper control arms resisted brake dive; and in newer versions of the torsion-bar suspension (used in the 1970s and later) the upper control arm had a front pivot higher than its rear pivot instead of at equal height so that weight would shift forward when the brakes were applied, counteracting the extra weight caused by braking and helping to keep the car level. Likewise, the rear leaf springs were off center, with the rear axle mounted on the thick forward sections of the springs instead of on the centers, so that the stiffer forward sections of the springs would support the body during acceleration and braking shifts. The long, flexible portions behind the axle benefited the ride.

One advantage of the system used by Mopar tuners through the years has been the ability to easily raise or lower the front end of the car by adjusting the torsion bars; with coil springs, the springs must be replaced. Likewise, if the car sagged with age, the torsion bar on that end could be replaced while a spring would be shimmed or replaced.

In 1960, Dodge wrote:

Dodge torsion bars smooth out bumps with more positive control than coil springs. Rubber-cushioned diagonal struts help pull the front wheels over bumps. Dodge rear leaf springs, with axle mounted forward of center ("asymmetrical" springs), help keep the car level during sudden starts and stops-and let the rear wheels glide over bumps instead of bouncing. Oriflow Shock Absorbers control spring action better than valve-type shock absorbers-do not "bottom" on bad bumps.

Widely spaced upper and lower ball joints provided a wide base of support for the front wheels to improve stability and reduce undesirable wheel motion. Rubber-isolated nylon bearings allowed easier action than metal-to-metal, spring-loaded joints.

Used throughout the front suspension, rubber bushings eliminated the need for lubrication, reduced friction, and absorbed road shocks. There were only eight lubrication points on the 1960 Dodge running gear; most other cars of the time had at least 16.

Torsion bars absorbed road shocks with less bounciness than coil springs. They needed only minor adjustment to compensate for any change in resilience, and allowed a lower engine mounting than with coil springs ... a safer, lower center of gravity. The extra space provided a better location for steering linkage which resulted in easier steering.

Rubber-cushioned struts ran diagonally from each lower control arm to the front crossmember of the underbody structure. They braced the front suspension against backward push, when the front wheels hit a bump.

Torsion-Quiet System

The Torsion-Quiet system launched in 1971 described rubber cushions which isolated the subframe and leaf springs, reducing vibration and noise the same way that rubber engine mounts do. The problem, though, is that as isolation was added, stiffness was necessarily and by definition reduced, so that cornering was degraded somewhat — though still better than Ford and GM.

For decades, using torsion bars rather than the systems used by GM and Ford on most of their vehicles helped Chrysler to have a smoother ride with better cornering than they would have with a more conventional (given the times and costs) system. Through the years, Chrysler vehicles tended to corner better than their domestic counterparts - or felt better. The company eventually went to other designs, when their cars were downsized, and the advantages of torsion bars were outweighed by the disadvantages - a clear and unavoidable tradeoff between noise, vibration, and harshness on one hand, and cornering capabilities on the other. The more isolation was added, the worse the cornering would be.

Rick Ehrenberg of Mopar Action magazine suggested numerous modifications for cars equipped with Torsion-Quiet. First, he recommended a complete suspension check to make sure all components were in good shape, and adjusting the steering box to be as tight as possible; and aligning the front end. The specifications Rick provided for general street use were 1.5 degrees caster; -0.5 degrees camber; 0.1 inch total toe; and wheels and tires consisting of 15 x 7 inch wheels with 235R75 at minimum. A full description of how to set alignment without a shop is in the October 2009 Mopar Action.

Following this alignment, Rick recommend replacing the front sway bar with a stiffer one to take advantage of the better tires now available; in his project car, he went from the OEM 0.938 or 1 inch bar to a 1.25 inch bar, saying it made a tremendous impact. Further actions are in the same October 2009 issue, but in short, he then replaced the rear sway bar, rear springs, shocks, torsion bars (from Firm Feel, moving from 1.06 inches to 1.18 inches), and steering box (Firm Feel stage 1) with a power steering pump cooler.

Second generation torsion-bar suspension

Ed Hennessy wrote: “The Aspen-Volare chassis design was typical Mopar, incorporating a unitized body and chassis, with torsion bar front suspensions and leaf spring rear suspensions. However, the front suspension was a totally new design. Instead of the traditional longitudinal torsion bars found on every Chrysler product since 1957, the F bodies used a transverse torsion bar, which placed the bar anchor near the control arm on the opposite side. The bar on each side was roughly L-shaped, and ran across the front of the car just ahead of the K-frame. This was supposedly to give the compact cars a "big car" ride. The rest of the front suspension was similar to that of the A body, with upper A-arms and lower control arms. A front sway bar was standard.”

Lanny Knutson wrote about the transverse torsion bar system:

Chrysler's traditional longitudinal torsion bars would have occupied space needed for exhaust emissions control systems. Not wanting to abandon Chrysler's trademark torsion bars for coil springs, engineers devised a transverse torsion bar system incorporating L-shaped bars. The shorter arm of the L acted as a lever to the lower suspension arm. No strut bars were necessary; the torsion bar located the longer arm longitudinally.

Each bar, made in multiple diameters to equalize stresses, was adjustable as Chrysler's torsion bars had been since 1957. All components were mounted in a self-contained bolt-on unit that would find its way into street rods in years to follow.

Most reviewers considered the new system to be novel but of no real advantage over the common coil spring suspensions. However, Motor Trend enthused:

...the wagon is no race car, but thanks to the new transverse torsion bar front suspension, it almost handles like one. We found ourselves batting around curves and turns that would have normal wagons cornering on the door handles...The Volare stuck to the road like the painted centerline and with no rear end hop or tendency to plow. Most pleasant. The steering is pleasantly quick, and the wagon was able to dart in and out of holes in traffic like a car half its size.

Bob Sheaves added: “Chrysler developed longitudinal torsion bars into a high science, but the transverse bars of the M-body (when used in police service) had an annoying tendency to allow the front suspension to lose alignment whenever a curb was hit. The same engineer responsible for the M-body design corrected the problems on the [Eagle] Premier, in that the bars were "folded" together into a single, more compact design that was more rigid in bending and smoother riding, due to lower rate and greater travel.”

In 1978, Chrysler gushed over the LeBaron’s suspension, shared with Volare, Aspen, and Diplomat: “Isolated transverse torsion-bar front springs, mounted ahead of the front wheels and iso-clamp multi-leaf rear springs-all rubber-isolated from the car structure. The transverse front torsion bars and multi-leaf rear springs contribute to ride stability, smoothness and handling responsiveness; the rubber isolation quiets the ride and increases the degree of smoothness. Mounting the transverse torsion bars to the isolated front structural crossmember is particularly effective in isolating noise and ride roughness from the car body.

“Torsion bars can be adjusted easily to keep the front end of the car at the proper height, regardless of the car's age or its mileage. Turning an adjusting bolt raises or lowers the front of the car.

“To keep level during braking, Chrysler engineers raised the front pivot of the upper control arm higher than the rear. This design causes the control arm to impart a lifting force to the front of the car as the weight shifts forward during braking. The lifting force resists brake dive to help keep the car nearly level when the brakes are applied.”

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