Chrysler claimed many advantages for its vaunted 1957 “Torsion-Aire” suspension, which featured torsion bar springs rather than coil springs in front. Over the years, the success of this suspension has led to many misconceptions about what it was and why it worked — in particular, the advantages of the torsion bar springs. To set the record straight, let’s take a look at what Chrysler engineers had to say about the Torsion-Aire suspension (along with some pretty pictures for those whose eyes glaze over with too many technical details!).
“The Exclusive New Torsion-Aire Ride”
Torsion-Air suspension was newly standard on all Plymouth, Dodge, DeSoto, Chrysler, and Imperial cars for 1957, so Chrysler’s 1957 brochures (like the Plymouth fold-out from which the lead illustration came) were full of copy and illustrations extolling the virtues of the new suspension, claiming that Chrysler had “broken the vibration barrier” and other such hyperbole. For a more detailed and authoritative discussion, let’s turn to the technical paper by Chrysler chassis engineers Oscar D. Dillman and R.R. Love, first presented at a conference of the Society of Automotive Engineers (SAE) in March 1957 and subsequently published in Vol. 66 of SAE Transactions in 1958.
1957 Dodge Custom Royal Lancer hardtop (with Torsion-Aire suspension) / Darin Schnabel via RM Sotheby’s
Dillman and Love claimed nine dynamic advantages for the Torsion-Aire suspension:
- Reduced high-speed float
- Reduced boulevard harshness
- Reduced impact harshness
- Reduced road noise
- Better directional stability
- Reduced nose dive and acceleration squat
- Fewer lubrication points
- Reduced body roll
- A better balanced ride
An impressive list, to be sure, but what exactly was a Torsion-Aire suspension? If you ask a Mopar fan, they’ll probably tell you, “Torsion bars, duh!” True, all 1957 Chrysler Corporation cars now had longitudinal torsion bars rather than coil springs in front, but that was only part of the picture. Chrysler considered Torsion-Aire a complete suspension package, not just new front springs.
The 1957 Dodge was 212.2 inches long on a 122-inch wheelbase, with a Custom Royal Lancer hardtop like this weighing about 4,190 lb as equipped / Darin Schnabel via RM Sotheby’s
You might be asking, “What’s the ‘Aire’ part?” It tends to suggest air suspension, which was having a moment around this time, but as Dillman and Love explained, it actually referred to the new lower-pressure tires and 14-inch wheels specified across the line for 1957.
From the 1957 Plymouth brochure / via Old Car Manual Project Brochure Collection
At the extremes, the 6.70-15 tires that were standard on Plymouth cars in 1956 were replaced with 7.50-14 rubber, while the big Imperial traded 8.20-15 tires for 9.50-14. All models had wider rims than before, and now ran recommended tire pressures of 22 psi rather than the former 24 psi, making the new tires about 10 percent softer for the same load ratings. Reducing the wheel diameter by an inch also helped to lower the 1957 cars’ center of gravity, although the smaller wheels didn’t do brake cooling any favors.
14-inch wheels were part of the Torsion-Aire package; the Dodge Custom Royal line used 8.00-14 low-pressure tires on 5.5K-14 wheels / Darin Schnabel via RM Sotheby’s
Chrysler had already adopted ball joints for its front suspensions, but the Torsion-Aire system used simplified upper ball joints, preloaded with rubber springs. Both upper and lower ball joints also had new Super Oilite bearings to reduce friction and wheel fight; the steering links had rubber isolators and nylon bearings for the same reason. With fewer metal joints, the number of grease points in a chassis lube service was reduced from 23 to eight.
The basic suspension layout was completely conventional: upper and lower control arms in front, with semi-elliptical leaf springs in back. However, in front, the inner control arm pivots now had double-sheer rubber bushings, minimizing metal-on-metal contact, and also allowing camber and caster settings to be adjusted with shims.
The inner pivots of the Torsion-Aire front control arms had double-sheer rubber bushings
Each lower control arm was now located by a short radius rod with a rubber bushing on the leading end, allowing about 1/8th of an inch of fore-aft compliance. Essentially, the front wheel could shift slightly forward or backward to absorb small bumps.
Torsion-Aire lower control arms were located by rubber-bushed radius rods
Front alignment settings were revised for less caster, and for neutral toe through the range of suspension travel. Each upper control arm was also angled upward at the front by about 17 degrees, partly counteracting nose dive on braking.
The tilted upper control arm partly counteracted brake dive in hard stops
In back, the axle was now offset about so that it sat forward of the center line of the “outrigger” rear springs (mounted outside rather than inside of the frame rails), meaning about 2/3rds of the spring was actually behind the rear axle. (This wasn’t altogether new for Chrysler: The 1956 Dodge D-500 cars had done that as well.) Because the stiffness of a leaf spring depends on its length, this meant the portion of the spring ahead of the axle was much stiffer than the section behind the axle (by more than 8 to 1), improving the springs’ ability to act as torque arms and resist acceleration squat without making them stiffer in jounce and rebound. The trade-off was that they were also more prone to axle hop on hard braking. Dillman and Love tiptoed around this point, and the reduced nose-dive and firmer rear springs of early Torsion-Aire cars compensated at least in part, but it was something that became a bigger problem as spring rates decreased in later years.
The rear axle was offset towards the front of the rear leaf springs, with the shocks angled inward
Chrysler claimed that overall roll stiffness for Torsion-Aire cars was increased by about 30 percent in front and 35 percent in back, although some of that was due to the lower center of gravity (by up to 3 inches on some models) and wider track. Some extra roll understeer was dialed into the rear suspension geometry so that the overall balance would still be moderate understeer; with the increased front roll stiffness, many lighter models now dispensed with a front anti-roll bar. Since the softer tires and rubber-isolated suspension reducing harshness, Chrysler felt comfortable in re-valving the Oriflow shock absorbers for firmer low-speed damping, giving better body control. Spring rates were generally higher as well.
The Custom Royal Lancer had softer front torsion bars, but stiffer rear springs and a front anti-roll bar / Darin Schnabel via RM Sotheby’s
The Famous Chrysler Torsion Bar Springs
All of these Torsion-Aire advances — which really did produce better ride and handling, at least by 1957 standards — could have been (and subsequently were) adopted on cars with coil spring suspensions with the same results. So, what advantages did the famous torsion bar springs actually provide?
From the 1957 Plymouth brochure / via Old Car Manual Project Brochure Collection
From a dynamic ride and handling standpoint, not many. Dillman and Love claimed that with the rubber-isolated suspension arms, torsion bar springs made the front suspension less sensitive to wheel imbalance than with coils. Another advantage was that the torsion bars were significantly lighter: about 10 lb each, compared to over 15 lb for a coil spring of comparable rate, since unlike a coil spring, they didn’t need extra “dead” coils at either end for mounting.
Although Dillman and Love said nothing about the new suspension’s unsprung mass, the torsion bars probably saved a few pounds in that area as well, both because the springs themselves were lighter and because the rear anchors were mounted on the frame and were thus part of the sprung mass. A savings of 10 to 15 lb for a set of front springs was hardly very significant in cars this heavy, but a similar reduction in unsprung mass would have been a worthwhile improvement.
The rear torsion bar anchors allowed ride height to be adjusted by increasing or decreasing the spring preload
The bigger advantages of the torsion bars were more prosaic: They were a bit better for packaging, and the rear anchors (pictured above) were adjustable, so ride height could be easily set on the assembly line without changing the springs themselves. This doesn’t seem like a big deal until you consider that coil-sprung cars of this era often had to specify an assortment of different spring sizes to give the desired ride height with different combinations of powertrain and optional equipment — cumbersome on the assembly line, and an extra hassle for owners during repair or restoration.
Equipped like this, a 1957 Dodge Custom Royal Lancer listed for about $3,600 / Darin Schnabel via RM Sotheby’s
Chrysler’s famous tagline in 1957 was “Suddenly, it’s 1960.” In chassis dynamics, Torsion-Aire lived up to the slogan, providing ride and handling it would take most U.S. competitors several years to match. There was nothing flashy about it, particularly compared to the more complex air suspensions that popped up in this period, but it worked. As Dillman and Love said at the conclusion of their paper:
Probably our most effective summary came from one new Plymouth owner who said, in effect, that “I don’t see anything so spectacular about this Torsion-Aire suspension. I admit it has no front-end dip on braking, it doesn’t sway on curves as before, it’s softer on rough bumps, and at highway speeds it’s as stable and quiet a car as I’ve ever driven, but that’s about all you’re getting out of it.”
We had to admit that that was about all.
Within a few years, however, it really was 1960, and other automakers were beginning to apply the same principles (low-pressure tires, rubber isolation, controlled wheel recession, anti-dive geometry) — usually with coil springs. The incremental advantages of the Torsion-Aire design gradually shrank, leaving only the modest production convenience of the torsion bars’ height adjustment.
This car has the optional D-500 engine and TorqueFlite / Darin Schnabel via RM Sotheby’s
By the mid-’60s, if a new Chrysler product still boasted superior handling, it was because it had stiffer spring and damping rates rather than because there was anything special about its suspension design or its vaunted torsion bar springs. However, in their late ’50s heyday, the ride and handling of Torsion-Aire Chryslers were — briefly — as good as it got for American-made passenger cars.
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Best benefits for my APS..
No unsprung weight because no vertical movement of spring.
Easy to adjust ride height . I kept the adjustment bolts well oiled so a minute each side with the ratchet is all it took.
No spring in the way to work on the front end so Easy to work on eg to change shockers.
Thanks for the historical research.. and my 58 vw also runs torsion bars all round!!!
Thank you for this, it is good to see a source that gives the changes in the rear leaf spring system their due in contributing to the success of the overall package.
I can attest that in my 1959 Plymouth sedan, the ride and handling was on par with much newer cars, certainly anything in its size class built up through the mid-to-late 1960’s. It was a night and day improvement over a friend’s 1962 Bel Air sedan.
The other benefit of the torsion bar height adjusters was that on an older car you could fix the typical spring sag in the front without having to replace tired coil springs. I remember that adjusting bolt as being in the lower control arm, which would have been the front mount for the bar, rather than at the back. But my experience was on an early 70’s version, so perhaps that mount was in a different location early on.
Thanks Aaron for a great article. I wasn’t aware of the ‘Aire” part of the system, though I’d long suspected that there was nothing about the system that conventional coils couldn’t match.
By the 1970s, at least one of the Australian car magazines was complaining about the NHV allegedly fed into the passenger compartment from the Valiant’s torsion bar anchor points.
Any similar feedback from the other side of the Pacific?
Less unsprung weight, and the unibody could keep the heavy reinforcements low to the ground, and not up into the fender wells.
If nothing else, not tensing up anytime you have to remove a coil spring is worth it for people working on these cars today, along with the aforementioned ride height adjustability. On the other hand, if the torsion bar anchor rusted out, you were sunk…literally. By that point, it was maybe wise to start shopping anyway.
No experience with Mopars but with my 4WD Toyota T100, replacing the front shocks was easy (and cheaper) with torsion bars than it will be on my Tacoma with coilovers. No spring compressor needed and the shocks are quite a bit cheaper too. The packaging benefits can be beneficial for front /four wheel drive vehicles, to clear front axle shafts, and can also provide some geometry benefits though the length and rear mounting have their own effects.
I’m curious – the 9.50×14 tire on the Imperial seems very large for the time. Did other manufacturers go that wide on their big luxury cars? As someone whose current fleet is all 15 and 16 inch wheels, with sidewall profiles ranging from 60 to 75, I like my squishy tires. For ride quality and potholes. “Aire” suspension without the hassles.
Well I can say that my Polara does ride differently from my Park Lane and have to say the Park Lane has more of the luxury ride.
Get a load of those tires pressures. My 72 Ambassador wagon specifies 20 lb. for the front on bias ply.
Now if Chrysler had just bought at some point from Studebaker-Packard the Torsion-Level patent, they could have had self-leveling torsion bars all-around. The might have been enough to push Imperial ahead of Lincoln!
Well, probably not, at least until Elwood Engel had gotten rid of all the Exner Excess, and probably too late.
There is of course some effective unsprung weight, because of the rotational inertia of the torsion bars – but since they aren’t physically moving up and down to coil/uncoil, there is much less.
The full-size Chryslers from the 1960’s always handled a lot better than they should have, considering their weight and size.
Thanks for this article!