Mr. Kelly, thank you for doing all your videos. They are absolutely fascinating and well-produced. It is obvious you are passionate about the subject matter, and those of us watching are fortunate you've taken the time to put the vids together and share your expertise.
Thanks for the video. A couple of observations. I owned a 1951 Cadillac with this transmission and "Park" was putting the transmission in reverse with the engine shut off. With the band and the "pawl" it acted just like a modern car with park. If you were moving when you put it in reverse with the engine shut off it would "grind" just like a modern Park. After the plant burned down at least Cadillac went to the Buick Dynaflow transmission (highly sought after) for that 9 months till they got the Hydra-matic plant back up and running. the "original" hydra-matic was put in the Cadillac till 1955 when GM came out with the dual coupling Hydramatic transmission.
Mr. John, your videos are the best. I have a 2008 Prius and watched all your videos on the Gen 2 operation and HV operation, including the Ecvt. Would like you to maybe do a short video on the "drive damper" or whatever the part is on a Prius that connects the engine and CVT. I'm not getting the concept of how it works due to lack of information. Keep up the good work- I;m eagerly anticipating the rest of this series, because I've owned several GM cars from the late 50's and newer, and it's cool to see the roots of these transmissions. My favorite? The Turbo 400-- indestructible!!!! Had this transmission coupled to a 1968 396 BB in an Impala and stayed in trouble, The only automatic that I know of that keeps burning rubber after shifting to second!!
Very clever how the transmission is basically two, two speed transmissions together, and also how fourth gear is driven directly by the engine eliminating slippage through the fluid coupling. You do a great job with your videos, thank goodness there is someone like you to take the time to do this.
The Torus casing driving the intermediate shaft directly (bypassing the 'as we now know' highly inefficient designed pump & turbine) in 4th gear is highly innovative; it is almost functioning as a locking torque converter before it was invented. Also interesting is the lack of overdrive in these early gearboxes; figured since motorways aren't invented yet & roads are still terrible you won't be going anywhere quickly.
The old Hydramatic transmission design is what they call "elegant", a simple way of doing something complex. Now it's time to show us how the Turboglide tranny worked. It was an awesome transmission. One of the first CVT transmissions. Again, thanx!
John inspired me to look into it, Hydra-Matic in 1940, a 3 planetary 4 forward speeds design, was more than 10 years ahead of everybody else IMO. Buick did Dynaflow which has a torque converter but only one planetary/2 forward speeds, Chevrolet Powerglide was one planetary/2 forward speeds, and those GM divisions would eventually come to heel using the superior technology of Hydra-Matic, Borg Warner / Ford-O-matic was 1 planetary 3 forward speeds Ravegneaux starting in 1951, and Simpson / Torqueflite 2 planetary 3 forward speeds wasn't until 1956. Aaron Severson of ateupbymotor has excellent content on the Hydra-Matic.
dynaflow still has the better ideas of a torque converter as the blades can be pitched and it's a 3 row style add in a lock-up mode and or remove/redesign the sprag with a electric or hydraulic holding and or power recovery and it's 👌
Hello John, 68 year old George in MI here. Nice videos! I really enjoy watching such things even if they're about things that I already have a basic understanding of. You seemed to concentrate a bit about the fact that the torus has a drain plug on that transmission and I'm sure it's because none of the modern automatics do anymore. My 1966 Comet Cyclone GT's C-6 did and I had a hell of a time once getting the guys at a trans shop in Biloxi MS to drain it when I took in in for a fluid change. I really wonder why they stopped putting those little 1/4" pipe plugs on them? Balance issues?
Hi George, Thanks for your feedback. Yes, I am sure balance was the major reason for it's removal I am sure leakage was another issue. Have a great day!
Finally a builder on YT... Brother I'm so sick of seeing these guys watch a video and proclaim wow now I'm a "Transmission Rebuilder". First of all in Indiana we were called "Builders". I started building about 1975/76 Retired 2011. These guys tell these guys things to ruin their units!. So they start adjusting bands,turning screws and be4 long it quits working!. Building an Automatic Transmission requires SKILL,There is SO MANY things that require FEELING!, How can you tell you didn't bust a piston seal?...I know you watched a guy do it and now your an EXPERT!. Right?😚
Mr. Kelly, Thanks for this demo....My Dads family bought a brand new Oldsmobile... maybe around a 1950....Rocket V8 w/automatic.... I remember my Dad saying that that car was so great....and that it was such a great road car...they used it to travel from coast to coast....
Interesting video and easy to follow power flow. Pretty simple from today's technology but that was amazing technology back then. Pretty neat how the reverse pawl evolved into the parking pawl. So back in the beginning they took the driving & driven member and it became the first lockup converter. Looking forward to the hydraulic flow video. Great video John and it's interesting to see the earlier design and how it has evolved.
If you look at the blade spacing on the fluid coupling you will see there are three distinct patterns of unequally spaced blades. The impeller is identical to the runner side by side but when they are face to face they are opposite each other. This is done to prevent the blades from aligning with each other as they rotated. If ever they exactly align they will create an axial pulsation that eventually will lead to failure.
Many thanks for sharing your knowledge and research! Question about 4th speed - you say it is a totally direct drive bypassing the fluid coupling, but I cannot see any mechanical connection between the front and rear planetary set, it must still go through the fluid coupling. Am I missing something? The front clutch is engaged in 2nd speed too, so the torus housing is locked to the entire front gear set and the driving member in the same way. The only difference between 2nd and 4th is the rear band/clutch changing the rear planetary from a reduction to a direct drive. What is the mechanical connection bypassing the fluid coupling in 4th gear?
Never mind, just saw Part 5 and your correction answering this very question. Fascinating how many innovations had to come together to make this happen!
Great job! I was under the impression that the rear pump was used to relieve the engine for better effeciency. That was the case in Ford's cruiseomatic and Chrysler's torqueflite. I would very much appreciate you going over how it evolved and in particular why a second fluid coupling was added (jetaway) on later models and also the lock-up clutch on the Pakkard's (ultramatic) - that was decades ahead of its time!
Thanks for the feedback. That is a great idea. As you may have seen in this video, this fluid coupling locks up in 4th gear without an internal clutch, it uses an external clutch.
Hi, I'm from Argentina and it's very difficult for me to follow. Follow your videos due a queue. No subtitles, they're all. It's a shame. Because it shows what you know
I have a leak from the bottom of my flywheel cover. I sure hope it's that drain plug. Any other leaks could be the gaskets and that looks like I'd have to remove the trans to do so?
The very first mass produced automatic transmission was very complex and sophisticated for its time. Also the fact that this transmission had a direct drive in fourth gear from engine to output of the transmission with no slippage would not be seen again in future automatics transmissions until lock up torque converters were developed.
the locking lug that mates with the reverse drum IS the parking dog and engages when you put the transmission in reverse and shut off the engine. my 55 pontiac had this also. that dog has to release to back up or go forward as the output shaft is locked when its engaged.
Great and interesting explanation of the Hydra-Matic! It is fascinating how the engineers at that time made this historical transmission possible with so little technical resources. You mentioned that the number of damper springs in the torus cover indicates typically the number of cylinders. Is there a explanation for it?
Thank you! Yes, every 4 stroke engine had normal pulsations in the rotational speed of the engine's crankshaft. This is due to the power stroke (of the 4 stroke cycle) rapidly pushing the piston down in the bore after the spark plug ignites the fuel. On a 6 cylinder there are three of these pulsations per revolution of the crankshaft, on an 8 cylinder there are 4. The number of springs in the damper is typically half of the number of engine cylinders.
what does the pressure relief valve on side of box do and for what as mine develops a massive leak after a 30 mile run at approx 60 mph, these boxes in 4th are direct drive and dont develop any pressure as such, torus , flywheel etc are bone dry with new gaskets, new torus main seal, but it can only come from main seal , this will be 3rd time out of car,
Hi, the valve on the side of the transmission is the pressure control valve. It controls the internal line pressure (the pressure that applies all of the clutches and bands). I am a little confused. Is your pressure regulator valve leaking or something up front by the Torus? If it is the valve leaking, remove the valve, it should have an o-ring and a copper sealing gasket. Your o-ring or gasket may be leaking. If the leak is from the Torus area, the front oil pump is supposed to have a gasket to seal it to the front of the transmission case; fluid can leak there and look like the front pump main seal is leaking. Of course it could be the pump main seal too. The seal could be leaking because the pump-to-Torus support bushing may be worn out (allowing the Torus to move laterally inside the seal and bushing). There are also some drain back holes in the front pump main seal area that allow fluid leaking past the Torus cast iron seal ring to drain into the oil pan. If those holes get plugged with gasket sealer, they will not drain and the fluid will leak out of the main seal (even if the seal is good). I hope that helps. Feel free to send me photos jkelly1@weber.edu when you get it out again. I am happy to help diagnose. Best wishes.
great , will do when i remove it shortly, did not go as far as drain holes in front pump , that could be one of the problems, either way its coming out again, it was spotless inside when i first took sump off, previously rebuilt but when who knows, cheers ,steve ,uk
Excellent! My Dad had several Oldsmobiles from 1940-1948, and my first car is a 1950 Pontiac which I still have - all with Hydra-Matic drive. I remember that the older Oldsmobiles from 1940-1948 had much more than 30 bolts (I remember 48 bolts) around the flywheel. I remember as a kid helping my dad remove these bolts and slowing moving the flywheel around with a big screwdriver wedged against the bell housing.
Thanks so much for the explanation! This is the only video demonstration I could find of an old Hydra-Matic like this one, and it's great! The only question I have is how do the gear ranges work? I know there are low and drive (high) gear ranges on automobiles with these transmissions, and I would like to know which gears are in which range. Is 1 and 2 low, and 3 and 4 drive, or is it a completely different mechanism? Sorry if my question sounds dumb, but I'm a rookie, just learned how an automatic transmission works.
Thank you. The transmission starts in second and then shifts through fourth. Low must be manually selected to get 1st. There is no park, you just put it in reverse, set the park brake, and shut off the engine
Yea no tow company subscriptions back then. Also you could tow these cars with no damage as referring to the output shaft pump that would lube the internals. If they had the fluid tech and cooling we have today they would last forever. No stamped drums we see today.Yea for fuel economy due to rotating mass.But they split at the snap ring groove.
Thank you for the information! You are correct about towing and the rear oil pump (with the transmission in neutral). You could push start one of these of you could get the vehicle up to 25 mph and put it in gear (with the key on). The oil pump would generate enough pressure to apply the front band and turn the engine over.
During world War 2 Ford built a plant at Willow Run to build B 24 Liberator bomber planes. Ford sold the factory to the government and leased it from the government at this time. After the war this plant was used to produce these transmissions after the original factory burned down.
Is this transmission the predecessor to GM's Powerglide 2 speed? (Or Poweslide as we used to call it!) Your are the master of tutorials, thanks for helping us in our understanding of this subject matter!
Hey John, more than a year after we talked about it and that 1st and 2nd gear had me stumped again, even after looking at Aaron Severson's drawings. Your video explained it to me (again ...). It is unusual (and clever) to power the ring from the flywheel and have the cage drive the pump, indeed. Watched your Honda 5 speed automatic a couple days ago, that was great, and your Getrag dual clutch transmission is next on my list.
FYI Cadillac did use this transmission until 1955, changing in 1956. In 1953 a few Cadillacs were produced with Dynaflow transmissions as a result of the fire in the Hydramatic plant. Great videos.
Apart from the direct drive fourth ratio, the drive through the Torus [fluid flywheel?] must have been quite inefficient. The lack of roller and ball bearings also indicates to me that there was probably a high percentage of friction and heat loss along with a probable high wear rate compared to modern transmissions. What sort of mileage did these do between overhauls? What makes me wonder what the service life of these was, typically, is that I recently visited the British Imperial War Museum North at Manchester UK and looked at an extremely complex and advanced looking [even by today's standards] multi cylinder, fuel injected, supercharged engine. A notice to the side of this beautifully engineered marvel indicated the average service life of these engines, which must have cost a small fortune each back in the day. What do you think it would have been? 6000 hours? A bit less. Maybe 3000 hours? Actually it was an incredible 35 hours [give or take and excusing my memory]. That was mostly due to planes being shot down of course, which begs another question. What was their actual design life? Hence my curiosity as to how long the Hydra-Matic lasted between overhauls and whether they were mostly reliable.
Hi, that is a good question. I do not know the answer. I do know that the fluid needed to be changed every 15,000 miles. Todays transmissions typically go 60,000 to 100,000 miles between fluid changes. Thanks for the feedback.
I'll add one bit: the higher the impeller speed, the thicker the boundary layer of the fluid, which allows it to transmit more power to the turbine. Efficiency of the fluid coupling increases with engine speed.
I wish you would do a series on the basic differences between the different automatics brought out to compete with the Hydra Matic from Ford and Chrysler, with the 2 and 3 speed variants and include the Powerglide to show why the Hydra Matic was the superior design, if, in fact it was.
Question: Of the 6 damping springs in the torus cover hub )at about 5:00 into the video) are all 6 tight so that you cannot move them with your fingers or are two (opposite each other) tight and the other 4 can be moved? If 2 tight and 4 loose, do the 2 tight ones look the same (length, number of turns, wire size), while the others look different?
In third gear, the power flow goes through the front planetary gearset, through the torus and then back to the output shaft. But doesn't power get divided between the torus and direct drive to the rear gearset? So, that suggests that the drive member of the torus would be turning at a ratio of 1:45 reduction relative to the driven member. You would think that the Driving Torus would lag behind the driven member. How did they avoid drag between the two members when operating in 3rd gear? I must be missing something here. Anyone have an explanation?
How did it survived winter without a trans cooler connected to the engine radiator (for heat) 🤔. My guess the fluid coupling is so inefficient first gear it generated enough heat 😅
Nice video, I have a 1953 Oldsmobile 88 rocket v8 with a 4 spd hydromatic transmission.. over 300k miles in almost original condition.... still running as daily driver when parked in 1972.... enjoyed this explanation on how it worked.... one day I'll have to rebuild this transmission and this video will be valuable to review operation of it. I'm afraid that the 'how to rebuild knowledge' will be lost in time as the experience will pass away with our elders. ... it would be great history to have a complete video on the rebuild (start to finish) of one of these great transmissions..... I say almost original as in 1953 the rear axle was to small in diameter to handle the torque these transmissions produced... dad replaced the rear axles till he could not get anymore because the torque from dead stop if stomp on the gas would snap the axles. In 1954 Olds increased the axle size beefing it up... dad replaced the rear axle on next snap...to a 1954 rear end and snapping of the axle stopped... great video...
As a young Auto Mechanic many many years ago in New Zealand I remember the older tradesmen referring to this transmission as a Slipamatic. I remember the powerglide transmission that succeeded it on Australian GM vehicles being a great improvement
@@WeberAuto Thank you for replying and the great video. I particularly valued your videos on the 9 speed ZF transmission that I have in my Fiat based motohome.
Great videos!--thanks so much. My dad's '64 Olds had a three-speed HydraMatic, the last year before GM introduced their new-design torque converter Turbo HydraMatics. To my recollection, these latter-day three speed Hydramatics were missing the 2nd gear of four; gear changes between one and 'two' resulted in quite a reduction in motor speed--from "floating the valves" in 1st gear to lugging in 2nd, especially noticeable under heavy acceleration.
I worked on a torus unit very similar to this one earlier this year. I'm pretty sure it was from a 1956 Cadillac. The only difference was that the planetary gear that drives the impeller was inside the torus shell between the damper and the impeller. I believe the transmission was a Jetaway 315. You make very informative videos!
I have a 1960 Caddie, and had to look long and hard to find someone who could work on the Hydromatic Jet Away trans. Your explanation is very interesting, as auto trans were a complete mystery to me. This was the first overhaul on the trans since 1960 BTW. It works great.
According to GM, Dexron 3 is backwards compatible. Some use Ford Type F. Some do a 50/50 mix of both. Type F has the proper viscosity and was recommended by the rebuilder of my unit who specifically attended courses at Hydramatic in 1958 to rebuild theses transmissions. Using Type F in the power steering system sealed all of the leaks that Dexron created. Just my experience.
Wow++++! What a simplistic transmission for its time! And seaming pretty robust and reliable enough to be used in the sherman tanks! But if they were capable of moving an Oldsmobile or Caddy land barge.....I guess they thought it would be suitable for tanks!?!? I've rebuilt many turbo hydromatic 350s 375s and 400, 700r4s 2004rs along with a few computer controlled 4L60Es and this thing seems to be a walk in the park for transmissions compared to what they were building and how bad GM would cut corners and make purposeful failures in these I've listed by using low grade part's inside them! Knowing first hand that plastic bushings and other weak garbage parts wouldn't last much more than 100K miles or less on many of these transmissions like that of the 700R4 and 4L60E's! I've found them stuffing clutch packs with large spacers to save money on a couple clutches! SMFH as I'm sure you've already seen this sickness too. But yeah to build something that they know is ultimately weak or going to fail is exactly why I don't drive a domestic vehicle anymore and switched to driving a Honda Civic sadly. The Japanese at least do everything in their power to make a good reliable product which I was a denialist at the beginning of my ignorant life. It dawned on me one day at work why don't we ever see a Honda in here with catastrophic transmission failures??? Well I learned why when I bought one and have well over 200k on the original everything but suspension and tires and brakes! There's not a chance in hell a GM would have been so trouble free that long except for the Chevy Colorado I bought brand new in 04. It....come to find out why it lasted me amazingly 200+k was due to the fact that Isuzu built them for chevy and GMC and it wasn't made here! That was the last GM I'll ever buy new unless they've changed their ways in screwing people over by doing what they do best! Cutting the fat and putting the 10 cents here and the 5 cents there back into their products rather than their profits 📈! They given themselves their own black eyes over the decades now and they are no longer what they use to represent. But I Thank you for making this video! I learned a great deal about these Oldsmobile transmissions. My mother use to talk about her 57 Olds convertible and automatic transmission and I still remember how much this was emphasized about not being a manual 3 on the tree! And why I was looking up what transmissions were used for moving Sherman tanks I stumbled upon your videos who gave me exactly what I was looking for. An in depth experience with the thing apart so I could absorb it and fully understand how simple yet small it really was to move such big equipment and reliably no less! that's to me is incredible! Here I'm picturing some sort of heavy equipment system or totally hydraulic system or maybe an Allison would have been necessary to move a sherman tank? Lol guess I was going a bit overboard on the torque capability of the original cast iron transmissions? Thank brother and God bless you 🙏
Mr. Kelly, thank you for doing all your videos. They are absolutely fascinating and well-produced. It is obvious you are passionate about the subject matter, and those of us watching are fortunate you've taken the time to put the vids together and share your expertise.
Thank you very much
Thanks for the video. A couple of observations. I owned a 1951 Cadillac with this transmission and "Park" was putting the transmission in reverse with the engine shut off. With the band and the "pawl" it acted just like a modern car with park. If you were moving when you put it in reverse with the engine shut off it would "grind" just like a modern Park. After the plant burned down at least Cadillac went to the Buick Dynaflow transmission (highly sought after) for that 9 months till they got the Hydra-matic plant back up and running. the "original" hydra-matic was put in the Cadillac till 1955 when GM came out with the dual coupling Hydramatic transmission.
Thank you for the great information! It is good to hear from someone who has actually owned or driven one of these.
Absolutely fascinating! This is information that, without your effort, would be lost to time. Thank you!
Thank you very much!
Mr. John, your videos are the best. I have a 2008 Prius and watched all your videos on the Gen 2 operation and HV operation, including the Ecvt. Would like you to maybe do a short video on the "drive damper" or whatever the part is on a Prius that connects the engine and CVT. I'm not getting the concept of how it works due to lack of information. Keep up the good work- I;m eagerly anticipating the rest of this series, because I've owned several GM cars from the late 50's and newer, and it's cool to see the roots of these transmissions. My favorite? The Turbo 400-- indestructible!!!! Had this transmission coupled to a 1968 396 BB in an Impala and stayed in trouble, The only automatic that I know of that keeps burning rubber after shifting to second!!
Very clever how the transmission is basically two, two speed transmissions together, and also how fourth gear is driven directly by the engine eliminating slippage through the fluid coupling.
You do a great job with your videos, thank goodness there is someone like you to take the time to do this.
Thank you very much!
Imagine during the war, there were techs in the army who could rebuild these things blindfolded.
The Torus casing driving the intermediate shaft directly (bypassing the 'as we now know' highly inefficient designed pump & turbine) in 4th gear is highly innovative; it is almost functioning as a locking torque converter before it was invented. Also interesting is the lack of overdrive in these early gearboxes; figured since motorways aren't invented yet & roads are still terrible you won't be going anywhere quickly.
Thanks for your feedback!
This absolutely blew my mind. That fluid coupling operates a lot differently than a torque converter.
Thank you!
The old Hydramatic transmission design is what they call "elegant", a simple way of doing something complex. Now it's time to show us how the Turboglide tranny worked.
It was an awesome transmission. One of the first CVT transmissions.
Again, thanx!
John inspired me to look into it, Hydra-Matic in 1940, a 3 planetary 4 forward speeds design, was more than 10 years ahead of everybody else IMO. Buick did Dynaflow which has a torque converter but only one planetary/2 forward speeds, Chevrolet Powerglide was one planetary/2 forward speeds, and those GM divisions would eventually come to heel using the superior technology of Hydra-Matic, Borg Warner / Ford-O-matic was 1 planetary 3 forward speeds Ravegneaux starting in 1951, and Simpson / Torqueflite 2 planetary 3 forward speeds wasn't until 1956. Aaron Severson of ateupbymotor has excellent content on the Hydra-Matic.
dynaflow still has the better ideas of a torque converter as the blades can be pitched and it's a 3 row style add in a lock-up mode and or remove/redesign the sprag with a electric or hydraulic holding and or power recovery and it's 👌
Hello John, 68 year old George in MI here. Nice videos! I really enjoy watching such things even if they're about things that I already have a basic understanding of. You seemed to concentrate a bit about the fact that the torus has a drain plug on that transmission and I'm sure it's because none of the modern automatics do anymore. My 1966 Comet Cyclone GT's C-6 did and I had a hell of a time once getting the guys at a trans shop in Biloxi MS to drain it when I took in in for a fluid change. I really wonder why they stopped putting those little 1/4" pipe plugs on them? Balance issues?
Hi George, Thanks for your feedback. Yes, I am sure balance was the major reason for it's removal I am sure leakage was another issue. Have a great day!
Finally a builder on YT...
Brother I'm so sick of seeing these guys watch a video and proclaim wow now I'm a
"Transmission Rebuilder".
First of all in Indiana we were called "Builders".
I started building about
1975/76 Retired 2011.
These guys tell these guys things to ruin their units!.
So they start adjusting bands,turning screws and be4 long it quits working!.
Building an Automatic Transmission requires SKILL,There is SO MANY things that require FEELING!, How can you tell you didn't bust a piston seal?...I know you watched a guy do it and now your an EXPERT!. Right?😚
Is like the old DG Borg that was in jags Humber ford zephyr
Mr. Kelly, Thanks for this demo....My Dads family bought a brand new Oldsmobile... maybe around a 1950....Rocket V8 w/automatic.... I remember my Dad saying that that car was so great....and that it was such a great road car...they used it to travel from coast to coast....
Awesome! Thanks for the feedback.
Interesting video and easy to follow power flow. Pretty simple from today's technology but that was amazing technology back then. Pretty neat how the reverse pawl evolved into the parking pawl. So back in the beginning they took the driving & driven member and it became the first lockup converter. Looking forward to the hydraulic flow video. Great video John and it's interesting to see the earlier design and how it has evolved.
Thank you very much!
If you look at the blade spacing on the fluid coupling you will see there are three distinct patterns of unequally spaced blades. The impeller is identical to the runner side by side but when they are face to face they are opposite each other. This is done to prevent the blades from aligning with each other as they rotated. If ever they exactly align they will create an axial pulsation that eventually will lead to failure.
pbooth001 thanks for the information. I did not know that.
That original GM transmission fluid was made from WHALE oil !!
High dramatic transmission! They was wrong calling it a hydramatic! This thing us crazy compared to more modern transmission!
lol, thanks for your feedback. It was an amazing transmission
Many thanks for sharing your knowledge and research! Question about 4th speed - you say it is a totally direct drive bypassing the fluid coupling, but I cannot see any mechanical connection between the front and rear planetary set, it must still go through the fluid coupling. Am I missing something? The front clutch is engaged in 2nd speed too, so the torus housing is locked to the entire front gear set and the driving member in the same way. The only difference between 2nd and 4th is the rear band/clutch changing the rear planetary from a reduction to a direct drive. What is the mechanical connection bypassing the fluid coupling in 4th gear?
Never mind, just saw Part 5 and your correction answering this very question. Fascinating how many innovations had to come together to make this happen!
Great job!
I was under the impression that the rear pump was used to relieve the engine for better effeciency. That was the case in Ford's cruiseomatic and Chrysler's torqueflite.
I would very much appreciate you going over how it evolved and in particular why a second fluid coupling was added (jetaway) on later models and also the lock-up clutch on the Pakkard's (ultramatic) - that was decades ahead of its time!
Thanks for the feedback. That is a great idea. As you may have seen in this video, this fluid coupling locks up in 4th gear without an internal clutch, it uses an external clutch.
Hi, I'm from Argentina and it's very difficult for me to follow. Follow your videos due a queue. No subtitles, they're all. It's a shame. Because it shows what you know
Thank you! We will work on that in the future
I have a leak from the bottom of my flywheel cover. I sure hope it's that drain plug. Any other leaks could be the gaskets and that looks like I'd have to remove the trans to do so?
Yes, that is true
@@WeberAuto wah....I mean, thanks!
The very first mass produced automatic transmission was very complex and sophisticated for its time. Also the fact that this transmission had a direct drive in fourth gear from engine to output of the transmission with no slippage would not be seen again in future automatics transmissions until lock up torque converters were developed.
Good information
The Packard Ultramatic had a lock up torque converter, as did the Warner gear transmissions that Studebaker used.
Thanks for the video. I find it fascinating. Keep up the good work.
Thank you!
the locking lug that mates with the reverse drum IS the parking dog and engages when you put the transmission in reverse and shut off the engine. my 55 pontiac had this also. that dog has to release to back up or go forward as the output shaft is locked when its engaged.
Thanks for your feedback
Great and interesting explanation of the Hydra-Matic! It is fascinating how the engineers at that time made this historical transmission possible with so little technical resources.
You mentioned that the number of damper springs in the torus cover indicates typically the number of cylinders. Is there a explanation for it?
Thank you! Yes, every 4 stroke engine had normal pulsations in the rotational speed of the engine's crankshaft. This is due to the power stroke (of the 4 stroke cycle) rapidly pushing the piston down in the bore after the spark plug ignites the fuel. On a 6 cylinder there are three of these pulsations per revolution of the crankshaft, on an 8 cylinder there are 4. The number of springs in the damper is typically half of the number of engine cylinders.
Thank you for the explanation!
what does the pressure relief valve on side of box do and for what as mine develops a massive leak after a 30 mile run at approx 60 mph, these boxes in 4th are direct drive and dont develop any pressure as such, torus , flywheel etc are bone dry with new gaskets, new torus main seal, but it can only come from main seal , this will be 3rd time out of car,
Hi, the valve on the side of the transmission is the pressure control valve. It controls the internal line pressure (the pressure that applies all of the clutches and bands). I am a little confused. Is your pressure regulator valve leaking or something up front by the Torus? If it is the valve leaking, remove the valve, it should have an o-ring and a copper sealing gasket. Your o-ring or gasket may be leaking. If the leak is from the Torus area, the front oil pump is supposed to have a gasket to seal it to the front of the transmission case; fluid can leak there and look like the front pump main seal is leaking. Of course it could be the pump main seal too. The seal could be leaking because the pump-to-Torus support bushing may be worn out (allowing the Torus to move laterally inside the seal and bushing). There are also some drain back holes in the front pump main seal area that allow fluid leaking past the Torus cast iron seal ring to drain into the oil pan. If those holes get plugged with gasket sealer, they will not drain and the fluid will leak out of the main seal (even if the seal is good). I hope that helps. Feel free to send me photos jkelly1@weber.edu when you get it out again. I am happy to help diagnose. Best wishes.
great , will do when i remove it shortly, did not go as far as drain holes in front pump , that could be one of the problems, either way its coming out again, it was spotless inside when i first took sump off, previously rebuilt but when who knows, cheers ,steve ,uk
Really cool! as a prospective engineer, it's always cool to see complex devices explained. Thanks for your work!
Thank you! It is fun to explore this old technology.
Excellent! My Dad had several Oldsmobiles from 1940-1948, and my first car is a 1950 Pontiac which I still have - all with Hydra-Matic drive. I remember that the older Oldsmobiles from 1940-1948 had much more than 30 bolts (I remember 48 bolts) around the flywheel. I remember as a kid helping my dad remove these bolts and slowing moving the flywheel around with a big screwdriver wedged against the bell housing.
a ferramenta de ajuste da banda front voce tem para venda
Thanks so much for the explanation! This is the only video demonstration I could find of an old Hydra-Matic like this one, and it's great! The only question I have is how do the gear ranges work? I know there are low and drive (high) gear ranges on automobiles with these transmissions, and I would like to know which gears are in which range. Is 1 and 2 low, and 3 and 4 drive, or is it a completely different mechanism? Sorry if my question sounds dumb, but I'm a rookie, just learned how an automatic transmission works.
Thank you. The transmission starts in second and then shifts through fourth. Low must be manually selected to get 1st. There is no park, you just put it in reverse, set the park brake, and shut off the engine
@@WeberAuto okay, thanks for the reply
Couldn't the stall of the torrus be changed a bit, by slightly changing the gap between them?
That would affect it
boa noite voce tem essa ferramenta para venda
Yea no tow company subscriptions back then. Also you could tow these cars with no damage as referring to the output shaft pump that would lube the internals. If they had the fluid tech and cooling we have today they would last forever. No stamped drums we see today.Yea for fuel economy due to rotating mass.But they split at the snap ring groove.
Thank you for the information! You are correct about towing and the rear oil pump (with the transmission in neutral). You could push start one of these of you could get the vehicle up to 25 mph and put it in gear (with the key on). The oil pump would generate enough pressure to apply the front band and turn the engine over.
During world War 2 Ford built a plant at Willow Run to build B 24 Liberator bomber planes. Ford sold the factory to the government and leased it from the government at this time.
After the war this plant was used to produce these transmissions after the original factory burned down.
I read about the fire, it was terrible. Thank you for your feedback.
Is this transmission the predecessor to GM's Powerglide 2 speed? (Or Poweslide as we used to call it!) Your are the master of tutorials, thanks for helping us in our understanding of this subject matter!
Yes, this was before the PowerGlide. Thank you!
So there is no stater in this converter?
No Stator
Hey John, more than a year after we talked about it and that 1st and 2nd gear had me stumped again, even after looking at Aaron Severson's drawings. Your video explained it to me (again ...). It is unusual (and clever) to power the ring from the flywheel and have the cage drive the pump, indeed. Watched your Honda 5 speed automatic a couple days ago, that was great, and your Getrag dual clutch transmission is next on my list.
I wonder if that transmission fluid had whale oil in it like the original Dexron did
FYI Cadillac did use this transmission until 1955, changing in 1956. In 1953 a few Cadillacs were produced with Dynaflow transmissions as a result of the fire in the Hydramatic plant. Great videos.
Apart from the direct drive fourth ratio, the drive through the Torus [fluid flywheel?] must have been quite inefficient. The lack of roller and ball bearings also indicates to me that there was probably a high percentage of friction and heat loss along with a probable high wear rate compared to modern transmissions. What sort of mileage did these do between overhauls?
What makes me wonder what the service life of these was, typically, is that I recently visited the British Imperial War Museum North at Manchester UK and looked at an extremely complex and advanced looking [even by today's standards] multi cylinder, fuel injected, supercharged engine. A notice to the side of this beautifully engineered marvel indicated the average service life of these engines, which must have cost a small fortune each back in the day. What do you think it would have been? 6000 hours? A bit less. Maybe 3000 hours? Actually it was an incredible 35 hours [give or take and excusing my memory]. That was mostly due to planes being shot down of course, which begs another question. What was their actual design life? Hence my curiosity as to how long the Hydra-Matic lasted between overhauls and whether they were mostly reliable.
Hi, that is a good question. I do not know the answer. I do know that the fluid needed to be changed every 15,000 miles. Todays transmissions typically go 60,000 to 100,000 miles between fluid changes. Thanks for the feedback.
I'll add one bit: the higher the impeller speed, the thicker the boundary layer of the fluid, which allows it to transmit more power to the turbine. Efficiency of the fluid coupling increases with engine speed.
I wish you would do a series on the basic differences between the different automatics brought out to compete with the Hydra Matic from Ford and Chrysler, with the 2 and 3 speed variants and include the Powerglide to show why the Hydra Matic was the superior design, if, in fact it was.
Question: Of the 6 damping springs in the torus cover hub )at about 5:00 into the video) are all 6 tight so that you cannot move them with your fingers or are two (opposite each other) tight and the other 4 can be moved? If 2 tight and 4 loose, do the 2 tight ones look the same (length, number of turns, wire size), while the others look different?
In third gear, the power flow goes through the front planetary gearset, through the torus and then back to the output shaft. But doesn't power get divided between the torus and direct drive to the rear gearset? So, that suggests that the drive member of the torus would be turning at a ratio of 1:45 reduction relative to the driven member. You would think that the Driving Torus would lag behind the driven member. How did they avoid drag between the two members when operating in 3rd gear? I must be missing something here. Anyone have an explanation?
Most fascinating indeed! But why is the output-shaft and housing so long?
i just found a texaco texamatic type F auto trans fluid. 16 oz ford m2C33F. must have been in the garage for 30 years.
How did it survived winter without a trans cooler connected to the engine radiator (for heat) 🤔. My guess the fluid coupling is so inefficient first gear it generated enough heat 😅
Happy New year 2021 - incredible technology for 1940.
Thank you for doing this. It should really help with my lack of shift,
Really appreciate your hard work the effort you put into explaining. Great job sir👍🙂
Thank you very much
but instead of that they could make it complicated. LOL.
We pulled my 47 Chevy with the Olds Drive Line to start it for the first time. Rear Pump worked great. Fun.
Sure brings back memories....
Thank you!
Nice video, I have a 1953 Oldsmobile 88 rocket v8 with a 4 spd hydromatic transmission.. over 300k miles in almost original condition.... still running as daily driver when parked in 1972.... enjoyed this explanation on how it worked.... one day I'll have to rebuild this transmission and this video will be valuable to review operation of it. I'm afraid that the 'how to rebuild knowledge' will be lost in time as the experience will pass away with our elders. ... it would be great history to have a complete video on the rebuild (start to finish) of one of these great transmissions..... I say almost original as in 1953 the rear axle was to small in diameter to handle the torque these transmissions produced... dad replaced the rear axles till he could not get anymore because the torque from dead stop if stomp on the gas would snap the axles. In 1954 Olds increased the axle size beefing it up... dad replaced the rear axle on next snap...to a 1954 rear end and snapping of the axle stopped... great video...
As a young Auto Mechanic many many years ago in New Zealand I remember the older tradesmen referring to this transmission as a Slipamatic. I remember the powerglide transmission that succeeded it on Australian GM vehicles being a great improvement
Interesting. Thanks for watching
@@WeberAuto Thank you for replying and the great video. I particularly valued your videos on the 9 speed ZF transmission that I have in my Fiat based motohome.
@@thatafact9553 Thank you
Great videos!--thanks so much. My dad's '64 Olds had a three-speed HydraMatic, the last year before GM introduced their new-design torque converter Turbo HydraMatics. To my recollection, these latter-day three speed Hydramatics were missing the 2nd gear of four; gear changes between one and 'two' resulted in quite a reduction in motor speed--from "floating the valves" in 1st gear to lugging in 2nd, especially noticeable under heavy acceleration.
I worked on a torus unit very similar to this one earlier this year. I'm pretty sure it was from a 1956 Cadillac. The only difference was that the planetary gear that drives the impeller was inside the torus shell between the damper and the impeller. I believe the transmission was a Jetaway 315.
You make very informative videos!
Love the technical videos! especially the old technology, I'd love to see how the Buick dynaflow works.
Thank you! I would too, but they are hard to find.
Ha ha, just found one on ebay, i thought they would be expensive, www.ebay.com/itm/Buick-1948-Dynaflow-Transmission-/272567116437
Cool, thanks! I will try to get it.
Any luck?
I have a 1960 Caddie, and had to look long and hard to find someone who could work on the Hydromatic Jet Away trans. Your explanation is very interesting, as auto trans were a complete mystery to me. This was the first overhaul on the trans since 1960 BTW. It works great.
The slip and slide I believe they were nicknamed.
Hard to listen to heavy breathing
thank you for this all-good information ...
Thank you!
Thanks for sharing. 😉👌🏼
Great explanation
Thank you!
What kind of fluid would you use in one of these today?
According to GM, Dexron 3 is backwards compatible. Some use Ford Type F. Some do a 50/50 mix of both. Type F has the proper viscosity and was recommended by the rebuilder of my unit who specifically attended courses at Hydramatic in 1958 to rebuild theses transmissions. Using Type F in the power steering system sealed all of the leaks that Dexron created. Just my experience.
thanks again man,i llove acual knoledge
Thank you sir
Very cool
Wow++++! What a simplistic transmission for its time! And seaming pretty robust and reliable enough to be used in the sherman tanks! But if they were capable of moving an Oldsmobile or Caddy land barge.....I guess they thought it would be suitable for tanks!?!? I've rebuilt many turbo hydromatic 350s 375s and 400, 700r4s 2004rs along with a few computer controlled 4L60Es and this thing seems to be a walk in the park for transmissions compared to what they were building and how bad GM would cut corners and make purposeful failures in these I've listed by using low grade part's inside them! Knowing first hand that plastic bushings and other weak garbage parts wouldn't last much more than 100K miles or less on many of these transmissions like that of the 700R4 and 4L60E's! I've found them stuffing clutch packs with large spacers to save money on a couple clutches! SMFH as I'm sure you've already seen this sickness too. But yeah to build something that they know is ultimately weak or going to fail is exactly why I don't drive a domestic vehicle anymore and switched to driving a Honda Civic sadly. The Japanese at least do everything in their power to make a good reliable product which I was a denialist at the beginning of my ignorant life. It dawned on me one day at work why don't we ever see a Honda in here with catastrophic transmission failures??? Well I learned why when I bought one and have well over 200k on the original everything but suspension and tires and brakes! There's not a chance in hell a GM would have been so trouble free that long except for the Chevy Colorado I bought brand new in 04. It....come to find out why it lasted me amazingly 200+k was due to the fact that Isuzu built them for chevy and GMC and it wasn't made here! That was the last GM I'll ever buy new unless they've changed their ways in screwing people over by doing what they do best! Cutting the fat and putting the 10 cents here and the 5 cents there back into their products rather than their profits 📈! They given themselves their own black eyes over the decades now and they are no longer what they use to represent. But I Thank you for making this video! I learned a great deal about these Oldsmobile transmissions. My mother use to talk about her 57 Olds convertible and automatic transmission and I still remember how much this was emphasized about not being a manual 3 on the tree! And why I was looking up what transmissions were used for moving Sherman tanks I stumbled upon your videos who gave me exactly what I was looking for. An in depth experience with the thing apart so I could absorb it and fully understand how simple yet small it really was to move such big equipment and reliably no less! that's to me is incredible! Here I'm picturing some sort of heavy equipment system or totally hydraulic system or maybe an Allison would have been necessary to move a sherman tank? Lol guess I was going a bit overboard on the torque capability of the original cast iron transmissions? Thank brother and God bless you 🙏