The Chrysler-Plymouth-Dodge-DeSoto Fluid Drive
The full story from Chrysler Corporation
When Fluid Drive was first introduced, an entire brochure was devoted to its workings. Here is the full text:
Fifteen operations are necessary to start a car and get into high gear in the usual way. Compare this exhausting routine to the simple operations with Fluid Drive in the new 1941 Dodge Luxury Liner. With Dodge Fluid Drive, you can start in high, STOP in high and start again in high ... without shifting gears! You can drive for hours at varying speeds from as slowly as a mile an hour to your car's top speedall in high gear! Here's the comparison:
THE OLD WAY OF DRIVING
Step on starter
Depress clutch pedal
Shift to first
Release clutch pedal
Step on accelerator
Release accelerator
Depress clutch pedal
Shift to second
Release clutch pedal
Step on accelerator
Release accelerator
Depress clutch pedal
Shift to high
Release clutch pedal
Step on acceleratorTHE NEW 1941 DODGE FLUID-DRIVE WAY
Step on starter
Depress clutch pedal
Shift into high
Release clutch pedal
Step on accelerator
... AND AWAY YOU GO!
THE MAGIC OF FLUID-DRIVE (BY MAJOR EDWARD BOWES)
In my opinion, it has been years since the automobile industry has produced an operating improvement as revolutionary as the Fluid Drive, now offered for the first time in the low-priced field on the 1941 Dodge.
My long association with and my keen, natural interest in this field of transportation makes me seek an apt comparison which the average person who is not an engineer will understand.
I believe the majority of car owners are parents. At least, they have reached their majority in years. As parents, they appreciate that children seem to grow in jumps. Children go along for months without any apparent change, and then-all of a sudden-the older folks realize that Johnny is fast outgrowing his clothes; and that Mary, who only yesterday was screaming in her crib, is still screaming-but this time for an evening dress.
It seems to me that automobiles have "grown" in much the same way-by a succession of giant strides in the form of basic developments, each one of which has added tremendously to the ease, the comfort, the economy, the safety of driving a car.
I am particularly happy to say a word here about Dodge Fluid Drive, because the engineers of Dodge enjoy a reputation as pioneers in a number of those advancements which have helped make the automobile what it is today. For example, with the great emphasis that they have always placed on the preciousness of human life, the engineers of Dodge gave the world such fundamental improvements as All Steel Bodies and Hydraulic Brakes-both magnificent contributions to your safety in driving.
Now they bring a great new advancement to the low price field! Only this time, their contribution emphasizes greater ease and pleasure in driving-a "consummation devoutly to be wished."
This brochure brings you news of achievement as significant to me as these others of which I have spoken. For it deals with the NEW and BETTER WAY to run an automobileby Fluid Driving.
From the questions so frequently asked of me, I judge that there is widespread curiosity as to how Dodge Fluid Drive differs from other methods of power transmission. The fundamental change is an elimination of the fixed mechanical connections between the engine and the driveshaft. In place of this, a new and far more flexible medium is used-namely, a BODY OF OIL.
Picture yourself at the wheel of a Dodge equipped with Fluid Drive. You step on the starter and, the minute she "purrs," shift right into high gear. Soon as you're ready to move, release your clutch and step on the accelerator. Immediately, as if soaring away on an invisible cloud, the car sweeps smoothly forward. Not a jolt or a jar -no "bucking" such as would happen with conventional cars if you attempted to start in high. It's the smoothest, cleanest, most noiseless getaway imaginable!
How about stopping? That's even simpler. You merely apply your brake gently as usual but don't touch your clutch or gear lever. Don't bother to shift at all. Stay right in high gear, even when coming to a complete stop. With Dodge Fluid Drive, your brake keeps the car from moving, even though it is in gear. And despite this, the engine will not stall.
All this means that you can start in high, stop in high, and start right out again in high-without ever shifting gears unless you want to. It means that you can drive all day under ordinary conditions without touching your gearshift or your clutch pedal. In densest traffic where you may often have to throttle down to a speed of a mile an hour-where you are constantly compelled to pause and shift with a conventional transmission -Dodge Fluid Drive permits you to stop and go at will merely by braking or accelerating as the case may be.
Another tremendous advantage comes when your Dodge runs into soft sand or mud holes or deep snow heaps. No doubt you've had the discouraging experience of seeing your wheels spin around aimlessly without your car budging an inch. Perhaps you've had to call for a tow car to free you from this awkward situation.
With Dodge Fluid Drive, remember, there's a cushion of oil to absorb the sudden surge of engine power which is the cause of wheelspin without gaining traction. Now, the power is applied so smoothly and evenly that you can creep right out of these "tight" places without difficulty. By the same token, on icy roads or streets Dodge Fluid Drive will save you this same annoyance; and the cushioned power goes far to eliminate the frequent cause of skidding.
And what a pleasure when driving on hills! The car can slow down to a mile an hour in high gear with no danger of stalling the motor. Think of the feeling of security that gives you! Then, coming down hill Fluid Drive is an automatic speed check with the engine acting as a brake, the same as with other methods of transmission.
Understand-despite these many advantages, there is nothing new to learn about Fluid Driving with Dodge. Simply far less work at the wheel. And far smoother performance. The clutch pedal is there as always. The gearshift lever, too-right on the steering post. The big difference is that under ordinary driving conditions you don't have to use them unless you want to.
When Dodge Fluid Drive was first demonstrated to me, I was thrilled. But more than this, I was consumed with curiosity. I couldn't rest until I saw what made it work. And I believe many of you will react the same way.
It is really very simple. In fact, that very virtue is its strongest recommendation. For there is practically nothing to get out of order or require adjustment or replacement throughout the life of the car.
Fluid Drive, in a word, takes the place of the conventional flywheel in power transmission. There are but two moving parts and even these two never touch-never are subjected to the wear that cannot be avoided where parts are moving and creating friction.
What Fluid Drive Looks Like and How It Works
These moving parts are merely two bowl-shaped shells of steel almost identical in appearance, into which a series of evenly spaced blades or fins are welded. Imagine an orange cut into halves and you have the picture, except that the "halves" of Dodge Fluid Drive measure about thirteen inches in diameter. One 'of these halves is mounted at the end of the engine crankshaft, its open end facing toward the rear. This is called the driver or impeller. The second half, or runner, is mounted on the propeller shaft, its open end facing the impeller-almost, but not quite, touching it. A tightly sealed, close-fitting steel housing surrounds these two Fluid Drive parts. The interior is filled with two gallons of a special grade of oil with very low viscosity, so that the impeller and runner are completely submerged.
I have stated that a small gap exists between these two parts. Now picture what happens when the engine is running. The impeller naturally turns because it is fixed on the crankshaft. This rotating action throws the oil by centrifugal force against the fins of the runner, causing them to rotate in the same direction. It is exactly like one electric fan forcing a current of air against another idle fan and setting the latter in motion-just as a breeze turns a windmill. Only the medium of motion is oil in this case-NOT AIR.
After the engine has picked up speed, the car moves much as it would if this "fluid coupling" were mechanical. One important and very noticeable difference is that you experience no jarring or jerking. Not only in starting, but in driving and stopping, the motion is emphatically smoother.
Perhaps the most astonishing difference in Fluid Driving with Dodge is the marked increase in flexibility and control. This is due to the fact that impeller and runner may now travel at different speeds. This Dodge with Fluid Drive may be started, driven for hours, stopped repeatedly in traffic, and started over and over again always remaining in high gear. It is like having a car of literally limitless speeds in this one gear.
The experience of thousands of motorists, once they try Dodge Fluid Driving, is that ninety per cent of the work is eliminated. The whole operation becomes simpler, safer, more pleasurable and relaxing in the 1941 Dodge with Fluid Drive than was ever before possible in a low-priced car.
Before you buy your new car, let me urge you to go for a ride with Dodge Fluid Drive. I promise you it will be an altogether thrilling experience.
Here's what Dodge had to say about their “all fluid drive” in a different brochure:
Dodge All-Fluid Drive provides the entirely fluid transfer of engine power to the drive line of your car. It thus affords a life preserving cushion for all vital mechanical parts of engine and power line, protecting them from shock and strain. For the driver, All-Fluid Drive continues to mean new extremes of comfort, safety, and control. Clutching and shifting have been greatly reduced and, when shifting is required, for special occasions, it is done silently with the move of a finger.
More details
S. Berliner III wrote:
The fluid drive unit was a self-contained coupling that bolted to the flywheel inside an extended bell housing, with the output shaft on the rear rotor.
The stator was part of the flywheel side and the rotor was almost identical but facing the other way (forward); fluid was pulled around by the stator and pulled the rotor with it. It was a 1:1 coupling (no torque multiplier).
As you note, it could be ordered with both standard 3-speed manual or M4 vacuum-operated or M6 hydraulic semi-automatic trannies.
If you mean the wording on the trunk light cluster and some bumpers, yes, it was always two separate words. As I just wrote, "bracketing the back-up light" on my '49, with FLUID on the left side and DRIVE on the right (naturally).
68RT wrote:
There is no stator. Just the drive and driven members. In the fluid coupling, you just have the friction of oil between the two fan halves to transmit power. On the torque convertor, the stator helps direct the oil into a circular flow that actually increases the speed of the oil coming out of the drive member before it hits the driven member giving a torque multiplier effect.
Bill Watson wrote:
Fluid Drive referred to the fluid coupling between the engine and the clutch, and had nothing to do with the transmission. Depending on year, Chrysler offered the Royal, Windsor and DeSoto DeLuxe with Fluid Drive and the normal 3-speed manual. This was also the only way Fluid Drive was offered by Dodge prior to 1949. Fluid Drive first appeared on the 1939 Chrysler Custom Imperial, and spread to the rest of the Chrysler line in 1940, and then the DeSoto and Dodge in 1941.
The Fluid-Torque Drive (torque converter) arrived for the 1951 model year and was an option. This combination got a shift quadrant, but as it was coupled to the M-6, it still had a clutch.
James Hale wrote:
The Fluid Drive created a crossbreed between manual and automatic transmissions. It was mounted on the steering column and instead of following the "H" shifting pattern of regular three-speed manual trannies of the time, this one had a "Y" pattern (or, more descriptively an H with one leg missing]. You pulled the lever toward yourself and then moved it up, that would be reverse.
From the neutral position you pushed the lever up, you got first gear. Interestingly enough, the transmission would change to second gear automatically.
Then you had to shift manually, putting the lever in the lowest position, and that gave you third which also had an automatic shift to overdrive.
The beauty of this system is that it had a hydraulic clutch, foot operated like any other regular clutch. However, this setup allowed the car to idle in gear much like an automatic. You could get the car moving directly from third gear, no need to shift down to first unless you wanted better acceleration.
Genciu added:
You only used the clutch to change gears; but didn't have to ease the clutch when starting out. So you would depress the clutch, put it into low, release the clutch and then press the accelerator and then it would automatically shift into second when you momentarily let off the accelerator (still remember the clunk sounds it made). Then you would depress the clutch and put the lever into high range, release the clutch and repeat the process. In most everyday driving, you didn't need low range and could use it as a two-speed (semi) automatic.
"68RT" write:
The fluid drive a standard everyday clutch and a separate fluid coupling [similar to a modern automatic transmission torque converter, where the engine drove one set of vanes - a propellor like arrangement - and the transmission received power through another set of vanes. The motion of the thick transmission fluid drove the transmission]. That allowed the clutch to remain engaged while stopped and eliminated the posibility of killing the engine at engagement.
There were two styles of transmissions available. One was just a standard manual transmission and I only saw a few of them. The most common was the hydraulic shift manual transmission that worked as follows:
- LOW Range was in the normal 2nd speed posistion of the "H" pattern and had two speeds available.
- HIGH Range was in the 3rd speed position and it had two speeds available.
- REVERSE was in the normal back and up of the "H" pattern. The transmission had a hydraulic pump and a mechanical governor along with a related switch built in the carburetor.
The clutch was used to select one of the three options you wanted. It was acceptable to start out in HIGH range and never use the clutch until you needed to back up. There was no safety and you could start it in gear if you desired.
When you reached the acceptable range that was programmed into the governor, the transmission would shift to the higher range as soon as the throttle was released and gave its signature "CLUNK" when completed. The oil from the pump would shift the gears for you in lieu of a mechanical shift.
If you had not exceeded the maximum shift speed and needed to downshift again, you stepped on the gas to the floorboard and the ignition would be turned off (releasing pressure on the gears) and a spring returned you to the lower ratio. When it completed the downshift the ignition came back on.
The actual gears available were four different ratios. As a teenager, the shift went like this: LOW gear-lowrange TO LOW gear-highrange TO HIGH gear-lowrange TO HIGH gear-highrange. This gave you four actual gears (2nd and third were very close ratio). I spent many hours behind the wheel of a 1950 Chrysler Windsor 6 with that setup. It was great on hills and almost impossible to break the tranny.
Mike Sealey clarified:
"Fluid Drive" was always written as two well-defined words (not "FluiDrive"). Chrysler was very proud of this feature in the 1940s... the words "Fluid Drive" appeared on the diecast housing surrounding the 1946 through the first series 1949 Chrysler center-mounted brakelight, under the "DeSoto" script on the front of DeSotos of the same era, and in red script stamped into the rear bumper on fullsize Dodges of this era. Fluid Drive references also appeared on the dashboards of these and other Chrysler cars... but never Plymouths, which did not get their own semiautomatic until the 1953 HyDrive.
The M-6 semiautomatic transmission was marketed under the name "Prestomatic" at Chrysler, "Tip-Toe Shift" at DeSoto, and "Gyro-Matic" at Dodge. Dodge was the only division to put the fancy name on its cars... check out the model name badge on 2nd series 1949 through 1952 Dodge Meadowbrooks and Coronets; if it says "Fluid Drive" below the model name, that originally meant the standard transmission with the fluid flywheel action, while if it says "Gyro-Matic", that emblem belongs on a car with the M-6. The M-6 transmissions often confuse modern drivers who believe them to be 3-speed sticks that refuse to go into first.
In later years, this transmission was modified to shift quadrant-style like a modern automatic, although it still had the clutch pedal for use when changing ranges. Some of these quadrants are marked "Fluid-Matic Drive". Besides the clutch pedal, these can be told apart from the later PowerFlite by their strange "D-N-R-L" range of gears - the position of reverse making a strong argument for keeping the clutch pedal!
The Plymouth Hy-Drive functioned somewhat similarly, but was a much different transmission. It's never been successfully explained to me why Chrysler spent what had to be enormous sums not only reinventing the wheel with this new transmission, but making HyDrive-specific engine blocks and floors as well (yes, the HyDrive does share oil with the engine; nobody's been able to explain the alleged advantages of that to my satisfaction either). These expenses took place just as Chrysler was being pushed out of its #2 position by Ford, and more specifically at a time when Plymouth found itself vulnerable to sales challenges from Buick and Oldsmobile as well. It is not hard to conclude that this money could have been better spent elsewhere, perhaps on accelerating the PowerFlite program to come out a year earlier.
If this wasn't confusing enough, this whole situation repeated itself in Canada, where all 6-cylinder Chrysler vehicles used the longer Windsor/DeSoto block, Plymouths and Dodges getting a smaller displacement version (228 cubic inches, or about 3.8 litres). HyDrive was offered on Canadian Plymouths and Plymouth-based Dodges as well, which had to retool a HyDrive-specific version of the 228 block in what had to be relatively small numbers. I once passed on a beautiful 1954 Dodge Regent (a Plymouth-Belvedere-based car with Dodge grille and badging for the Canadian market) because the thought of trying to find another 228 HyDrive block if anything happened to the one in the car was just too intimidating.
Bill Watson wrote:
Mike Sealey is correct about the Hy-Drive offered by Plymouth (and its Dodge and DeSoto versions) in 1953 and 1954. The engine, torque converter and transmission all shared the same oil. The transmission was a normal 3-speed manual with no automatic or semi-automartic shifting. To change from one gear to another you used the clutch. You could start the car, put the transmission in 3rd gear, and drive with accelerator and brake all day, never needing the clutch unless shifting to reverse, neutral or 1st or 2nd.
Acceleration was not neck-snapping, but it was comparable to Buick's Dynaflow and the first version of Chevrolet's Powerglide. Both those GM transmissions used the torque converter to help increase power to the rear wheels from a dead start without using gears. (You can tell a shiftless Powerglide by the whine, something lost on the shifting 2-speed version.)
Ron Riopelle:
Just finished reading the material on Chrysler Corporation's Fluid Drive of the 1940s and early 1950s. It's a great summary for those of us who are always trying to explain it to the "youngsters" who don't remember it. However, the sequence of an acceleration starting in the available, but rarely-used, Low Range is described incorrectly.
Genciu describes starting in low, accelerating, and automatically shifting into second by momentarily letting off the accelerator; then manually shifting into high range and "repeat[ing] the process". Similarly, "68RT" says it goes "LOW gear-lowrange TO LOW gear-highrange TO HIGH gear-lowrange TO HIGH gear-highrange.
The only other mistake I noticed is Mike Sealey's statement that "In later years, this transmission was modified to shift quadrant-style like a modern automatic." What did happened was done on 1951-1953 Chryslers only (not DeSoto or Dodge), and it was merely the addition of a quadrant-style gear indicator on the steering column. It was labeled "Fluid-Matic Drive" (or "Fluid-Torque Drive" if equipped with a torque converter), and the gear positions were "RLo Nu Dr."
Hope you can add these corrections to your thorough and otherwise excellent discussion of a widely-misunderstood subject.
"68RT" -
Ron Riopelle commented that it was not possible to get four speeds and I strongly disagree. I do agree that only one "clunk" occurs but a quick shift from low gear/low range to high gear/high range does not allow time for the hydraulic shift (that hydraulic shift does take some time) and you will be in low gear/high range and when you shift back up to low range, you let the clunk happen there and you do get four speeds. The second and third speeds are somewhat of a close ratio but they are definitely different ratios.
Mike Sealey again:
As far as I know (and I'd be surprised to be proven wrong on this), the Plymouth HyDrive was the only Chrysler transmission that shared oil with the engine. HyDrive cars had special engine blocks with oil galleries connecting to the transmission, and required eleven quarts of oil at every oil change. While Plymouth HyDrive police cars probably existed, Ford had the majority of the squad market in this era by virtue of their fast and relatively inexpensive V8 engines.
During this era, the California State Police was a small agency primarily devoted to security around the state capitol and other state buildings. Unlike the much larger California Highway Patrol, CSP did not buy vehicles in the kind of numbers that would prompt manufacturers to build to their specs. I am not sure what kind of squads CSP used during this era. CSP was merged with CHP in 1995. Not sure what makes of squads CHP was using in the early 1950s, but for many years their specifications called for a 122" wheelbase, which would have required medium-priced cars.
It is likely that the reference to police specs calling for shared lubrication actually referred to the Los Angeles Police Department's requirement that squads with automatic transmissions be able to run 30W motor oil in place of ATF. Ray Wynne, legendary LAPD director of police transportation and father of the modern "police package", believed that this was necessary, but I have not been able to determine exactly why he felt that way. In any event, Chrysler automatics were the only ones on the market at that time that would operate as well on 30W motor oil as they did on ATF/Dexron. (The attached pic is from an AMC press release.)
I ran this by my uncle, a former CHP officer, at a recent family dinner. Somebody asked if it was possible that someone at Chrysler misunderstood these specs and the HyDrive was the result, in much the same way the smaller 1962 Plymouths and Dodges came about as a result of Bill Newberg misunderstanding remarks about the Chevy II to mean the fullsize Chevrolet was going to be downsized. I can see where a later Chrysler, one which listed Dexron as the ATF of choice in shop manuals when production transmissions used a different fluid, might have made a mistake of this magnitude and expense... but Chrysler Engineering simply did not make mistakes like this during the Keller years.
Curtis Redgap wrote in a somewhat related note: "Yes, I wrote about this in my history section concerning the Plymouth Hy-Drive. It was 11 qts of motor oil shared by the engine and transmission. Of course, you only had to change it every 6 months or so. The LAPD specified that the transmission had to use motor oil. That particular transmission was the Powerflite 2 speed transmission used in the 1960 Plymouth and 1961 Dodge Darts. I have little or no knowledge about the California State Police. I knew that they did exist, but to what extent they are as a department, or were, that is, I have nothing to be able to pass, especially about equipment.
Charlie Pfefferkorn: "In the early 1960s, my 1953 Firedome needed a little extra help. By placing a switch in line with the kick down circuit, I was able to use all four speeds. After the pause shift from low-low to low-high, I would then throw the switch as the shift lever passed neutral. The Desoto was then in hi-low with the next shift the normal pause shift into hi-hi. The switch had to be turned off any time before the last shift or it would just free wheel after letting off the gas peddle. The best acceleration was achieved by short shifting lo-lo to lo-hi. The split shift was the quickest. Then wait forever for hi-hi. I drove it like that for a long time with no trans trouble."
S. Berliner III noted that Fluid Drive was trade-named Gyról Fluid Drive, a Frenchified meaningless word.
Fluid drives on trucks
Paul Sahler wrote: "I believe it was offered as an option in 1948-52 1/2 ton pickups I have seen and driven both the 3 speed on the column and a 4 speed on the floor. They used standard truck transmissions with longer input shafts and the bell housing is a longer cast piece.
"One other thing, you can push start a Fluid Drive vehicle using 2nd gear in the three and four speeds and 2nd gear low range in the wait and clunk, starting with the clutch depressed at about 15 mph ease the clutch out. If you start with the clutch out you need to reach 20-25 mph before the oil in the fluid drive has enough oomph to spin the engine.
"As far as pulling power in the pickups, not a problem, we regularly pulled 4-41/2 tons of hay with a four speed 1/2 ton. Dad and I also used to put a yard of gravel on this same truck. I have wondered how a fluid drive would do in a military style Power Wagon. The action of the Fluid Drive seems like it would work real well in low speed rock and hill applications. The other nice thing is I don't ever remember replacing a clutch in any of our Fluid Drive Mopars."
The controversy and argument resolved? (by Paul Sahler)
First off, people need to remember that before the mid-1950s Fluid Drives were not transmissions, they were couplings between the engine and clutch, the shared oil ones were an attempt to build torque by using pressurized oil. The only basic difference in the pre-1950s transmissions, between the fluid drives and non fluid drives is the length of the input shaft, fluid drives shafts are longer to reach the pilot shaft bushing. The bell housing is also longer to accept the thicker fluid drive unit.
I'm no expert but I do remember getting four shifts in a 1948 New Yorker straight 8, however Dad had mentioned something about it not being quite right, to correct the problem he wired some switches and the car could be driven both ways. By using the correct switch and revving the motor at the same time, you could downshift to low range and use engine-braking to help you to stop. Helpful in a 2 ton car.
As for the most common style of fluid drive cars and trucks only the build numbers will show that. I do agree with about the shared-oil fluid drives being in more than just the Plymouths. When dad would come across those years cars, that was one of the things he would look for. He did not want a car that the oil is shared, to easy for things to go wrong in his opinion.
Explaining a Fluid Drive unit to somebody who has never seen one, is not an easy task. I tell them it replaces the flywheel, it looks like a torque-converter with a clutch-assembly attached and it has no mechanical coupling between the front and back. The way the power is transmitted from the engine to the clutch is done with oil and turbine-like fins. The fins are attached to the crankshaft and the output/clutch, with only the oil between them. The crank spins one set of fins, which spins the oil, which spins the output/clutch fins. A good table top example would be to take two cooling fans place them in front of each other, turn one on and watch it spin the other one. As far as driving the fluid drives, other than the wait and clunks, we drove them like you would a normal 3 or 4 speed, because that's what they were. The wait and clunks had a normal 3 speed shift pattern with first gear blocked off.
What makes them different to most people is the ability to be in gear with your foot on the brake not the clutch. Although difficult you could stall the motor by dumping the clutch and if you tried real hard you could spin the tires. And if you want to really have fun with someone who has never seen one, with the motor running, making sure they notice, put the car in gear, with your foot on the brake, ease the clutch out, then ask them what's wrong. One person was so convinced the clutch was slipping he walked home just so he would make it.
Dave Stragand of forwardlook.net supplied the following notes from current owners:
from Terry and Andree Hoeman
The original intention was to only put it into high range and use the two speed feature in it. Low range was only for high load usage and towing type stuff. Hard to believe towing with one of the old flatheads isn't it!
We are used to quick acceleration now and feel we must use the low range first. Ought to time it but I bet it doesn't add much to speed up the start up when you throw in the slow shift time from low to high range.
from Tom Stroup: We have a 1948 DeSoto and you have described (shifting) it perfectly. Put stick in second gear position, start out, lift foot on accelerator, hear the clunk, go some more, shift into third gear position.
from Semodave: Technique to get all 4 speeds was start in 1st, rev to 25mph; clutch and quickly jerk shifter to just touch "high" then back to 2nd--no clunk here. As more speed was gained, clutch quickly to "high" kicking down in the process, then 4th would come in when you let up on gas--usually around 70! (hundreds of times!) Always used 4 speeds in all races I was in; and usually won--that 120 mph speedo wasn't just for show (should have shown higher, though).
from S. Keller: Why make this so complicated? In my youth I had/drove MANY fluid drives, like this: push in clutch, put in Hi, let out clutch and drive all day. Never used Lo except to squeal the tires to show off in my 1953 Dodge 6 cylinder. Even back then in 1966 my friends couldn't get it, so they had to drive Fords and Chevys.
Click here for the Hy-Drive transmission
Click here for the Powerflite transmission
Click here for the engines and transmissions page
Still want more on the Fluid Drive? See this excellent 1948 brochure posted at the Imperial Club site!
