"The Magic Touch of Tomorrow"
The 1964 Belvedere wagon that my family had while I was growing up was, overall, a pretty average piece of mid-century Detroit iron. It certainly didn't have the twenty-minutes-into-the-future aura of something like an Avanti, but it did have one gee-whiz feature that impressed the daylights out of the young Jonny Quest and Project Gemini fan in the back seat: the automatic transmission was controlled by a set of pushbuttons on the left-hand side of the dash.
It's now the 21st century, and modern cars have enough computing power to fly a dozen Gemini spacecraft while simultaneously playing a Jonny Quest marathon on streaming 4G video for the kids in the back seat--and those with automatics have traditional shifter levers controlling the slushbox, not "space-age" buttons. The pushbutton automatic transmission has gone from being "The Magic Touch of Tomorrow," coming soon to a future near you, to something that appears on nostalgia websites for folks of a certain age, indexed between the entry for "Polaroid cameras" and the one for "Quake cereal." The rise and fall of the pushbutton tranny is a story of ergonomics and mechanical engineering and, strangest of all, General Services Administration procurement rules.
As you can see from the animation, if the stick is right on top of the gearbox and the gearbox is in its traditional location in a front engine-rear drive car, just aft of the firewall, the stick ends up in a relatively convenient location for the driver and the linkage necessary to move the locking collars around is pretty simple. This uncomplicated linkage system results in the familiar "H" pattern that we who row our own gearboxes know so well.
The disadvantage to this arrangement is that there is a big lever sticking up out of the floor right in the middle of the front row. If the car is intended to seat three across, as so many full-sized cars were, the middle passenger has the driver reaching across her lap with every upshift--and in a smaller car, the lever may even end up in the middle passenger's lap.
The solution was a lever mounted on the steering column and connected to the transmission by a set of linkages. The "three-on-the-tree" came into vogue in the late 1930s. It shifted in an H-pattern similar to the floor shifter, which added a bit of complexity to the design of the linkages, but paid off in ergonomics. The three-on-the-tree was sufficiently similar to a floor shifter that drivers used to one adapted easily to the other.
(I should also point out here that the same issues of linkage design and ergonomics also arise when you move the transmission from its traditional place amidships to a rear or front transaxle. Again, so drivers aren't met with an unfamiliar interface, designers go to the trouble of rigging everything up so that the shifter still follows the classic H-pattern.)
While I don't personally believe in automatic transmissions--if God had meant me to drive automatics, He wouldn't have given me a left foot to work the clutch with!--they are a triumph of mechanical engineering, and were welcomed enthusiastically (along with power steering and power brakes) by people like my parents who'd grown up driving old iron with user-unfriendly controls. The story of their development is a fascinating one, and if you're interested in it I commend you to the two-part series on GM transmission development written by Aaron Severson at Ate Up With Motor. (Part 1, Part 2) For purposes of the present discussion, I'd like to concentrate on the development of the automatic transmission's control interface.
The early automatics used a hydraulic control valve to signal hydraulic servos, at the appropriate times, to engage or disengage various parts of the planetary gearsets which gave the transmission its different ratios. This is all done with microprocessors today, of course, but in 1939 this hydraulic system was pretty sophisticated stuff. There was no need for a shift lever, obviously--the hydraulic control valve was taking care of that part--but the driver did need a way to tell the hydraulics when it was time to get moving, and what direction to go in. The solution Oldsombile came up with for the first Hydra-Matics was to mount a control lever on the steering column in the same place as a conventional three-on-a-tree. Moving the lever to the "D" or "R" position pushed or pulled on a steel cable which ran down to a lever on the control valve and switched the appropriate parts on or off. This eventually evolved into the familiar column-mounted P-R-N-D-L thingy we all know (and some of us might even love) today.
In the 1950s, when swank was king, automotive design and brand-naming were heavily influenced by aviation, rocketry, and even science fiction. This was the age of "Forward Look" and "Futuramic" styling, cars with tail fins and fake jet intakes and air vents disguised as ray-gun emitters, with "Rocket" and "Ramjet" V-8s under the hood. It occurred to someone--probably several someones--that a jet-age/space-age car should have a more jet-age/space-age way of controlling the automatic transmission than an old-fashioned lever. This line of thinking led to the development of three different pushbutton interfaces, only one of which worked properly.
Packard was the only one of the "independent" auto manufacturers to engineer its own automatic transmission in-house. Introduced in 1949, the Ultramatic featured a "lockup" torque converter for better highway gas mileage--a feature not used by other manufacturers until the "gas crisis" years of the 1970s. Overall, the Ultramatic was at least as good as any other automatic of its day, and Packard continued to refine and improve the design right up to the end of production of the last "true" Packards in 1956. (The '57 and '58 Packards, the last of the line, were thinly-disguised Studebakers.) When you take into consideration the fact that Packard had only a fraction of the resources of one of the "Big Three." and was in financial distress the whole time, the fact that the Ultramatic existed at all is something of a minor miracle.
For the 1956 model year, Packard introduced the "Touch Button Ultramatic" as standard equipment in top-of-the-line Caribbeans, and an available option on other models. In place of the usual shifter lever, there was a small pod mounted on the side of the steering column with six buttons, three for the Ultramatic's three forward operating modes ("high," "drive," and "low"), and one each for "park," "neutral," and "reverse." The transmission had a small electric motor, a modified starter, connected to the actuator on the control valve. The buttons controlled the motor through a series of electrical relays.
The Touch Button system was troubled from the start, in ways quite unbecoming of a Packard. The relays and contacts were unreliable when new, and only got worse with age. The shift motor was directly connected to the "parking pawl" which locks the drivetrain when the transmission is in park. If you'd parked your Packard on a steep hill, the motor would often be unable to overcome the mechanical tension when trying to disengage the pawl, and it would stall and pop the circuit breaker--or, worse, stall and not pop the breaker and burn out instead. To make the Ultramatic ownership experience even more ultra-traumatic, subcontractor Auto-Lite scrapped the tooling for the Touch Button Ultramatic when Packard discontinued it, so not long after it went out of production, replacement parts were nearly impossible to find.
The "Teletouch Drive" system which Ford used on the 1958 Edsel was, like Packard's Touch Button Ultramatic, an electromechanical system. The buttons were mounted in the hub of the steering wheel, and maintained an upright orientation no matter which way you turned the wheel thanks to a clever system of planetary gears inside the column. The buttons actuated the hydraulic control valve on the tranny by means of a solenoid rather than the Packard's modified starter motor. Nevertheless, the Teletouch Drive had major reliability issues, just like the Touch Button Ultramatic, mostly due to problems in the solenoid and its controlling relays.
The Teletouch Drive also had a major ergonomic flaw. It placed the transmission controls where many cars had their horn button, and where most drivers were used to having a horn button. If some jerk cut a new Edsel's driver off in traffic, and the driver reflexively bonked the center of the steering wheel to register his displeasure, it was possible, if the driver's fist hit the wrong combination of buttons in the wrong order, to put the transmission in park or reverse while the car was still moving--an event with unpleasant and expensive consequences for the drivetrain.
The Chrysler pushbutton system introduced in 1956 had none of these problems. On a recent episode of Desert Car Kings, the restoration crew working on a '64 Barracuda was amazed by how clever and effective and simple the Mopar pushbutton mechanism was. Like the TorqueFlite automatic it controlled, it was an elegant piece of engineering.
Instead of coming up with a whole new system, Chrysler stuck with the tried-and-true control cable. The pushbuttons on the dashboard had no electrical wires running to them, and there was nary a relay nor a solenoid to be found. The buttons were connected instead to a mechanical linkage that replaced the column shifter, and which itself was connected to the control cable. Pushing the buttons moved the end of the cable back and forth, just as a conventional column-mounted lever would. Like the station presets on an old-school car radio, the mechanism was set up so only one button could be pressed at a time.
On the '56s, the "neutral" button also functioned as a starter button; this was eliminated for the 1957 model year, as it occasionally resulted in people unintentionally grinding the starter while the engine was running. That was the only change in the mechanism, and the only one it really needed. The design of the buttons themselves did vary greatly from year to year and car to car, as they were styled to match whatever interior they were being mounted in.
So why did this simple, reliable, effectively goof-proof and thoroughly cool interface go out of production? You can blame the government.
The General Services Administration, which is the federal government's purchasing agent and oversees, among other things, a 210,000-vehicle motor pool, issued a specification for automobiles in 1966 which required that all vehicles sold to the GSA have either a column-mounted or floor-mounted shifter. While Chrysler's pushbuttons were stone-axe reliable, they were also a little polarizing--customers either loved them or hated them. The people who liked the buttons weren't so strongly attached to them that they'd stop buying Chryslers if the buttons went away, and the government fleet market was too valuable to lose for the sake of stubbornly clinging to a non-standard (albiet very cool) interface. Chrysler undoubtedly did the right thing by its shareholders by phasing out the buttons, but it is hard for Car Lust not to mourn their passing.
Today, automatic transmissions have their shift patterns managed by a microprocessor, and we have yet another gee-whiz interface in the form of paddles on the steering wheel that the driver can use to override the automation and shift the gears herself. If someone wanted to bring back the Chrysler-style pushbutton tranny--assuming the regulators would let them--modern digital control technology is more than equal to the task.
A modern digital pushbutton gearshift system would have a neat futuristic feel to it--like something from NASA or maybe even Jonny Quest.
--Cookie the Dog's Owner
The cutaway illustration of the Ultramatic came from Ultramatic Dynamics, the website of a gentleman who does rebuilds on Packard transmissions. The site has a lot of background information and scans of old Packard literature. The dashboard photo of the swank circa-1964 Chrysler button set comes from the nostalgia website I Remember JFK. The illustration of the touch buttons on a Touch Button Ultramatic came from a Google Image search. Our very own Virgil M. Exner, Jr. generously provided me the scan of the '56 Dodge ad from which this post got its title. All other illustrations are from the invaluable John's Old Car and Truck Pictures.