Hat tip to “B-Squared” for inspiring this post by sending this photo:
In the days before automatic transmissions became widely available, Chrysler introduced its Fluid Drive.
Fluid Drive is a transmission driveline combination offered from 1939 through 1953 in Chryslers, 1940 through 1953 in DeSotos, and from 1941 through 1954 in Dodge models. The fluid drive element was a hydraulic coupling inserted in place of the flywheel, and performed the same function as a modern torque converter, only without torque multiplication. A conventional clutch and three-speed manual transmission was installed behind the fluid coupling, although a semi-automatic was optional from 1941 for Chrysler and DeSoto and from 1949 for Dodge.
Fluid Drive eliminated the need for gear changes using the clutch in most cases. DeSotos and Dodges equipped with Fluid Drive thus became a favorite of taxi fleets – the taxi driver could drive all day and rarely use the clutch.
Chrysler’s Fluid Drive took its operating principals from a system developed in the 1900s by a German engineer named Foettinger who licensed the development of the fluid coupling to the British engineer Harold Sinclair. Sinclair then formed Fluidrive Engineering Co Ltd.
Sinclair in turn licensed the fluid coupling, now also known as ‘Fluidrive Coupling’ to many companies including Chrysler. Automobile historians often confuse Chrysler’s Fluid Drive with Chrysler’s so-called semi-automatic M5/M6 transmissions, which were marketed under various names as “Simplimatic” (Chrysler), “Tip-Toe Shift” (DeSoto), and “Gyro-Matic” (Dodge). Unfortunately, Chrysler itself contributed to the confusion by referring to both the standard-shift fluid drive and M6 installations indiscriminately as “Fluid Drive” in much of their marketing and sales literature. General Motors used a fluid coupling rather than a torque converter for the fully-automatic Hydra-Matic transmission, introduced for 1940.
The first fully automatic transmission was introduced in 1935 on the R.E.O. R.E.O. was the company started by Ransom E. Olds after he sold his pioneering Oldsmobile to General Motors. The Depression took its toll on R.E.O. and they ceased car production at the end of the 1937 model year, though they continued building heavy duty over the road truck tractors into the 1970s.
In the mid-to-late ’30s, General Motors began experimenting with automatic transmissions. Oldsmobile introduced Hydra-Matic Drive in 1940 and Cadillac offered Hydra-Matic soon afterwards. Oldsmobile was once known as GM’s “engineering division” and was often the first GM division to introduce new technology. Cadillac, as GM’s prestige division would often be the next to offer the new technology. We see this in the way GM introduced Hydra-Matic, and after World War II, Oldsmobile was the first out of the gate with a modern overhead valve V-8 engine followed in very short order by Cadillac. GM used tanks in World War II as test beds for Hydra-Matic – many tanks were fitted with Hydra-Matic Drive so that GM engineers could learn from hard, on-the-road conditions how to improve their automatic transmission. The very early Hydra-Matic prototypes were built with eight forward speeds. When introduced to the public, GM had whittled Hydra-Matic down to four speeds and was working toward a three speed gearbox. Ironically, many modern automatic transmissions have six, seven or eight forward gears.
In the meantime, Chrysler slugged along with Fluid Drive as an option to the 3 speed manual gearbox through the end of the 1953 model year (1954 for Dodge and Plymouth). Fluid Drive was available in Chrysler, DeSoto and Dodge products. Chrysler’s low price line, Plymouth, didn’t get the equivalent of Fluid Drive until 1953 when Plymouth offered Hy-Drive. By sticking with Fluid Drive while GM and others were developing fully automatic transmissions, Chrysler was late out the gate with fully automatic drives. It wasn’t until 1955 that fully automatic transmissions were offered across the entire Chrysler line. The public quickly embraced GM’s Hydra-Matic. Fully 45% of the 1941 Oldsmobiles were fitted with Hydramatic.
Packard was the first Independent automaker to offer a fully automatic transmission, Utlramatic Drive, in 1949 with the 23rd series “Golden Anniversary” Packards. Packard’s Ultramatic Drive used a lock-up torque converter at highway speeds to eliminate power loss through the transmission. When the torque converter locked up, power went directly from the crankshaft to the drive shaft, in effect by-passing the transmission.
Studebaker was the next Independent to offer a fully automatic transmission, introducing their Automatic Drive (co-developed with Borg-Warner) in 1950.
When Chrysler did finally fully warm to the idea of automatics, they developed their Torque-Flite which became one of the very best automatics of the late ’50s through the ’60s. In the meantime, Packard’s use of the lock-up torque converter was forgotten about as Packard closed – until CAFE standards made engineers take another look at the principles behind Ultramatic Drive. Now all modern automatics use a lock-up torque converter.
There is an interesting discussion of how Borg-Warner tried to sandbag Packard on Ultramatic Drive at PackardInfo.com