Chrysler’s Fluid Drive

Hat tip to “B-Squared” for inspiring this post by sending this photo:

Fluid Drive

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 - bumper

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.

Screen Shot 2015-01-10 at 3.25.43 PM
Chrysler’s Fluid Drive

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.

Chrysler-Fluid-Drive-09

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.

50pkd1

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.

Ultramatic Drive
Packard was the first Independent automaker to develop a fully automatic transmission, Ultramatic, which was introduced as an option on the 23rd Series “Golden Anniversary” Packards of 1949.

Studebaker was the next Independent to offer a fully automatic transmission, introducing their Automatic Drive (co-developed with Borg-Warner) in 1950.

Automatic Drive
1950: Studebaker introduces its Automatic Drive, co-developed with Borg-Warner’s Detroit Gear Division.

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.

PB Ultramatic
By 1956, Packard’s Ultramatic Drive had morphed into “Twin Ultramatic” actuated by pushbuttons.

Sources:

Wikipedia

Allpar

There is an interesting discussion of how Borg-Warner tried to sandbag Packard on Ultramatic Drive at PackardInfo.com

10 Comments

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  1. That was something. I was a kid but I remember seeing it, thinking, better push in that clutch! To me it was a combination of straight drive and automatic. Neat and at the time amazing. Good background and story… Thanks.

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  2. Lot of good information here. The technology way back when was pretty good.

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  3. Yes! The fluid coupling differed from a torque converter only in that the blades on the half facing the impeller weren’t tilted and thus didn’t multiply the torque coming from the impeller. The fluid coupling held two gallons of oil!

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  4. christofear 15/01/2015 — 06:28

    Excellent work, I learned a lot of new things today!

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  5. Thank you for the history of automatic and semi-automatic transmissions. Did the Ford Motor Company get involved in automatic transmission designs and research?

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    • Thank you for visiting and for leaving your comment.

      In answer to your question – Ford was somewhat late to the automatic transmission game. Ford introduced “Ford-O-Matic” and “Merc-O-Matic” in 1951 while Lincoln initially used GM’s Hydramatic.

      The Ford-O-Matic and Merc-O-Matic units were essentially a Borg-Warner design that had been cribbed from the Studebaker Automatic Drive that Studebaker had jointly developed with Borg-Warner.

      At first Ford-O-Matic and Merc-O-Matic were produced both by Ford and by Borg-Warner, but by the mid-1950s, Ford was building all automatics, including Lincoln’s, in-house.

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  6. My first car COULD have been a 1952 Dodge coupe, which a widow was selling for $100 after her husband’s death (apparently he was the only driver in the family). It was in immaculate shape inside and out. It started right up and no red flags went up engine-wise. I backed the Dodge out of the garage into the driveway, and it felt like I’d found myself a car. Then when I tried to put it into first gear (low) it wouldn’t go — I could only get it into second or third gear, so coaxed it back into the garage in second. I told the lady I really did like the car but couldn’t get it into first gear, so I’d have to pass on it. I was 17 at the time. Later my Dad told me it was probably a Fluid Drive car, which only used forward gears in the “second” or “third” position. I called the lady back, but she’d already sold it to a neighbor by then. My inexperience (and ignorance of Fluid Drive’s shift pattern) cost me a decent first car. I wasn’t a hot-rodding teenager would would run a car into the ground, just needed reliable transportation. I often wonder if that car might still be around someplace or if it’s been melted down. Anyway, I enjoyed your story on Fluid Drive. Thanks!

    Liked by 1 person

  7. My first car COULD have been a 1952 Dodge coupe, which a widow was selling for $100 after her husband’s death (apparently he was the only driver in the family). It was in immaculate shape inside and out. It started right up and no red flags went up engine-wise. I backed the Dodge out of the garage into the driveway, and it felt like I’d found myself a car. Then when I tried to put it into first gear (low) it wouldn’t go — I could only get it into second or third gear, so coaxed it back into the garage in second. I told the lady I really did like the car but couldn’t get it into first gear, so I’d have to pass on it. I was 17 at the time. Later my Dad told me it was probably a Fluid Drive car, which only used forward gears in the “second” or “third” position. I called the lady back, but she’d already sold it to a neighbor by then. My inexperience (and ignorance of Fluid Drive’s shift pattern) cost me a decent first car. I wasn’t a hot-rodding teenager who would run a car into the ground, just needed reliable transportation. I often wonder if that car might still be around someplace or if it’s been melted down. Anyway, I enjoyed your story on Fluid Drive. Thanks!

    Liked by 1 person

  8. Larry Aiken 06/07/2020 — 13:49

    Where did the Buick Dyna-Flow” fit in the mix? And What a bout Chevy’s “Power-glide” Buick drove like today’s CVT, Was it? Power-glide was 2 speed.

    Liked by 1 person

    • The short answer to your question about Buick’s Dynaflow being like today’s CVT is “no”. Dynaflow was developed separately from the Hydramatic (or, if you prefer, Hydra-Matic) used by Cadillac, Oldsmobile and Pontiac. Conceptually Dynaflow was closer to Packard’s Ultramatic Drive than to GM’s Hydramatic. Both Dynaflow and Ultramatic were developed to work well with the power band of the straight eight engines both Buick and Packard used. Hydra-Matic was developed to accept the power band of GM’s V-8 engines, though Pontiac (like Buick) stuck with a straight eight engine longer than did Oldmobile or Cadillac. Dynaflow used fluid-driven vanes rather than the same type of gear set used in Hydra-Matic. This is what gave Dynaflow the feel that is similar to today’s CVT transmissions. Unlike Packard’s Ultramatic, Dynaflow did not use a lock-up torque converter. Ultramatic was the first automatic to use a lock-up torque converter, something all modern automatic transmissions (except those cursed CVTs) employ. PowerGlide – a misnomer if there ever was one – was built with one goal in mind: to be cheap to build. Consequently PowerGlide only had low and high gear sets. PowerGlide was developed when Chevrolet was the leader in the low price car market so PowerGlide was built to a price – a low price. I hated driving a Chevrolet with PowerGlide. Lacking a mid-speed gear set, the shift from low to high meant that low disengaged early and it was a long climb to 60 mph in high. I always called it “PowerLessGlide” …

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