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Fluid drive question-first year available?


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What was the first year for fluid drive? Have a customer telling me 38 Chrysler had fluid drive and the handbrake is located on the floor. Others had the handbrake under the dash starting in 38. 37 was the last year for the floor hand brake except for the truck line. We have 2-38 Chryslers, C19 and 20. 19 has a regular 3 speed and the C20 has OD.
Thanks
Dave

Edited by countrytravler (see edit history)
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I think this will explain things....

Fluid Drive is the trademarked name that Chrysler Corporation assigned to 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 or four-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.

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https://youtu.be/p-wfIrtVUmk

It really depends on what year, make & model as to which version of Fluid Drive you got. The original M4 was a two-speed unit. Then came the M5 three-speed and later, the M6 a four-speed. Multiple names were used to add to the confusion: Vacamatic, Prestomatic, Fluidmatic (Chrysler), Simplimatic, Tip-Toe Hydraulic Shift (DeSoto) and Gyromatic (Dodge). None used a Torque converter, it was in actuality a fluid coupling. There was no torque multiplication, it simply allowed slippage while the engine was running. In later models, the clutch was only needed to change between "ranges". You had a low range, a high range and reverse. Low Range when selected started you in first gear with an automatic upchange into second. To get into high range, the clutch had to be used, High range selected, and then the car would proceed from third, upshifting automatically to fourth. A car could theoretically be driven all day long in high range as long as a quick take-off was not necessary.

The Fluid Drive is really a mechanical marvel of it's time. When working properly, they are great performers and actually quite fun to drive. Still, it makes you wonder when Studebaker and even Packard beat Chrysler to market with a functional, fully automatic. Makes you wonder if somebody at Chrysler was just a little too proud of their invention.

Edited by countrytravler (see edit history)
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The fluid drive fluid coupling was also used in conjunction with Chrysler’s M6 Presto-Matic semi-automatic transmissions. The M6 was in reality a two-speed manual transmission with a conventional clutch mounted behind the same fluid coupling unit that was installed in straight Fluid Drive cars.

The M4 Vacamatic had two forward speeds and reverse. There was a manual Pull-Cable to lock out the underdrive in the early models. From 1949-1952, Dodge models with the conventional 3-speed Fluid Drive carried front fender emblems that said “Fluid Drive.” The M6 Models had emblems that proudly proclaimed “Gyromatic.”

In the 1941 brochure for Chrysler automobiles, a silhouette of the car's drivetrain was depicted against an outline of the car body, with the astonishing caption of an arrow pointing to the transmission: "Miracle Happens Here"! The transmission shown was an early variant (M4 "Vacamatic") of the later M6 transmission and was marketed to compete with the new Oldsmobile fully automatic, clutchless Hydramatic transmission, introduced in the fall of 1939 on 1940 Model year Oldsmobiles. The Hydramatic was embraced enthusiastically by consumers, and was installed in 45% of 1941 Model Oldsmobiles.

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I have a Chrysler parts book printed in November, 1938, and there is no mention of Fluid Drive or different floor pans. That's not to say Chrysler did not build some special models in 1938 if only to test the Fluid Drive with normal drivers and in real life driving situations. Proving grounds and test tracks do not expose all the design / engineering flaws. But parking and stop light mishaps along with owners' lack of maintenance generally do.

The big thing about Fluid Drive is that it is NOT a transmission. The pre-1953 parts books had Fluid Drive in the clutch section.

Personally I view the Fluid Drive era as the beginning of a slide by Chrysler management sitting back and resting on their laurels. The British-built Daimler adopted a fluid coupling (fluid flywheel) in 1931 and coupled it to a pre-selector form of transmission. In the U.S., Chrysler introduced Fluid Drive for 1939 and two years later a semi-automatic transmission. But the semi-automatic arrived one year after GM's Hydramatic which used a fluid coupling and a self-shifting automatic transmission.

The line up of post-war automatics included Buick with Dynaflow in 1948, Packard Ultramatic in mid-1949 (similar to Dynaflow but with a locking torque converter), Chevrolet with Powerglide (a smaller version of Dynaflow) for 1950, Studebaker in mid-1950 (3-speed automatic with locking torque converter) and Ford (Fordomatic) and Mercury (Mercomatic) with a three speed box for 1951. All the automatics introduced after the war used torque converters. Pontiac, Cadillac, Nash, Hudson, Kaiser, Frazer, and Lincoln all adopted Hydramatic.

Ten years after the semi-automatic was introduced, every manufacturer but Chrysler offered an automatic. And only Packard was slower in introducing new post-war body designs, although Packard did a major restyle of the 1941 body for 1948. And Chrysler styling was always a year or two behind. Chrysler slid from #2 in 1936-42 to #3 by 1952 while Plymouth went from #3 before the war to #5 in 1954.

For all the hype about Fluid Drive and the M-series transmissions, they were a dead end street and a sign of gathering storm clouds at Chrysler.

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I disagree. The Fluid Drive and M6 self shifting transmission were a good effort at automatic drive. They had the advantage of simplicity and reliability. I know a large part of the public was afraid of automatics because they could be troublesome, few mechanics could fix them, and a rebuilt trans was a very expensive proposition. Chrysler had the best system from the standpoint of long trouble free service.

The only thing I don't understand is why they never did away with the clutch pedal. They could have very easily added a vacuum clutch, in fact Chrysler offered a vacuum clutch before they made Fluid Drive.

I do agree that they should have gotten busy on the Powerflite sooner. Maybe 2 or 3 years sooner. And that their styling was not the most up to date or fashionable in the period 1948 - 1954. But, they were not exactly style leaders in the thirties when they had the most sales success.

But, times change and public taste moved away from practicality to style and performance. Chrysler did move with the times but it would have been better if they had moved a few years sooner.

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I don't know when the torque converter was invented but it must have been during WW2 or shortly after. The first automatics, from the late thirties, all used a fluid coupling because that is all there was.

Different companies handled it in different ways. Lincoln's Liquimatic was such a dog they were all recalled and changed for manual transmissions. Packard, Hudson, Reo, and possibly others had one legged drives that avoided the fluid coupling. GM's hydramatic was the most sophisticated and some called it the best of the early automatics and it was, if you ignore questions of cost, weight, complexity, service, and repair.

Chrysler's system was less sophisticated but got the job done and was extremely rugged and reliable, did not require adjustments, seldom required repairs, and if they did, 9 times out of 10 the repairs were easy and cheap.

For cars that were in every day use by the public, serviced by every day garages, the fluid drive system had a lot of advantages. That is, if you wanted an automatic drive in the first place.

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Fluid Drive was standard on the 1939 Chrysler C24 Custom Imperial and became optional on C23 Imperial at serial number 6,748,188, C23 New Yorker at 6,612,367 and C23 Saratoga at 6,673,247. The 1939 Chrysler models were introduced in the fall of 1938.

In 1940 Fluid Drive was available on the eight cylinder Traveler, New Yorker, Saratoga and Crown Imperial models. Both 1939 and 1940 models were mated to a 3-speed manual transmission. The same arrangement was used on 1941 Dodge Luxuryliner, DeSoto and Chrysler models.

For 1941 the semi-automatic transmission with Fluid Drive was listed as an option on DeSoto and Chrysler models. It was called Vacamatic on US-built Chryslers and Simplimatic on DeSotos and Canadian-built Chryslers.

Allison transmission came up with a torque converter and transmission in the 1940's, used on Yellow Coach and then GMC Coach buses - "H" in the model number for "Hydraulic transmission". Allison also used the transmission in tanks. From that experience with torque converters Buick developed Dynaflow for 1948.

I am afraid Chrysler's statement they "pioneered" the use of the fluid coupling in passenger cars is not quite true. They "pioneered" for American-built cars, perhaps, but the British Daimler firm introduced fluid coupling on their cars in 1931.

Studebaker's Turbo-Drive and Lincoln-Mercury's Liquamatic were built by Borg-Warner. Both had a fluid coupling with a regular clutch (vacuum operated) and a three-speed transmission with overdrive. Grears were shifted by vacuum control. Studebaker actually eliminated the clutch pedal but the system was a little too complicated and things had to be just so or problems arose. Thus both manufacturers recalled the cars built with the units and replaced them with the normal three-speed manual. In the case of Studebaker, all but two had the Turbo-Drive replaced. One was known to exist fifteen years ago.

By the way, Studebaker was the first manufacturer to use a wide brake pedal on its models with automatic transmissions. Most people believe Studebaker started that with their Automatic transmission in 1950, but the 1942 models with Turbo-Drive used a wide brake pedal.

GM's Hydramatic and Chrysler's semi-automatic were the only cars built in North America that used a fluid coupling successfully. The two failures were Studebaker and Lincoln-Mercury. Packard and Hudson rigged up systems that you could shift gears without using the clutch by means of vacuum assistance. The clutch pedal was still there but the vacuum lines were a plumb's nightmare. Reo had a self-shifter, but it had a clutch and no fluid coupling.

And the reason Chrysler did not use a vacuum clutch probably had to do with the set up already in place. You shifted gears within each range by lifting your foot off the accelerator and waiting for the clunk. Which is basically how a vacuum clutch works. Lift your foot up and the clutch disengages. Only difference is you need to reapply your foot to the accelerator to reengage the clutch.

The war interrupted development of car engines, transmissions, etc., but after the war manufacturers spent their time developing new automatic transmissions and not semi-automatics or vacuum assisted clutches. Only Chrysler continued to work on a semi-automatic. And none worked on fluid couplings. The torque converter was the preferred choice. Chrysler did adopt a torque converter for 1951, the same time the last competitor (Ford) introduced an automatic transmission.

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  • 6 months later...
Guest jasndal

I have a 1941 Windsor 6-cylinder with 42,000 original miles.  The Vacamatic transmission, (Fluid Drive appears on the steering wheel cross-bar,) which has been problematic for several years. As I understand it, the shift from 1st to 2nd and the shift from 3rd to 4th are effected by vacuum, with a system of electric control.  I have heard that Chrysler discontinued that system after the 1941 models and the very few 1942s because it was so troublesome, even when new. Also, I believe that Chrysler redesigned it to a non-vacuum (I believe fluid control ) system for 1946 and later models.  I spent a lot of money trying to diagnose random upshifts at even high speeds, without success.  For about $1,400, I had a transmission built (and installed) that does away with the Vacamatic system and the four-speeds and operates like a three-speed manual, using the clutch for all shifts.  It retains the fluid coupling and operates beautifully.  I still have the rebuilt, original four-speed transmission with the troublesome Vacuum control attached, which I need to sell.

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Edited by jasndal (see edit history)
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I rebuilt a early 1942 DeSoto Vacamatic...early diaphram shift type and it has always worked well for the customer.

 The other style of M-4 vacamatic was the improved piston type shift.

 

Then 1946-48 Chrysler Corp cars had the M-5 "Hydraulically Operated" (Chrysler) or "Simplimatic" (DeSoto). It used an oil pump to push a piston to cause the automatic upshifts. It too was a  Hi/Lo range four speed transmission similar to the 1949-53 M-6 transmissiom.

Edited by c49er (see edit history)
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