[Safari Larry]

This thread is for discussion of the Dual Range Hydramatic transmission. It continues another thread where we got side tracked discussing the Dual Range.

I agreed with others that the transmission was "locked" in third/fourth gears and power (torque) did not flow though the fluid coupling. In an attempt to validate that was truth, I studied the transmission mechanical operation. The result of that study is that I now know I was wrong, the transmission is not locked in third and fourth gears, power always flows through the fluid coupling.

See Dual Range Hydramatic Power Flow. That is my attempt to explain the actual power flow through the transmission in third/fourth gears and set the record straight. It is not a light read so put your thinking cap on.

[Safari Larry]

I just updated the Dual Range Hydramatic Power Flow document. I changed wording where I said the "transmission is locked". That could be interpreted as the transmission is locked up but I meant it was locked into purely mechanical operation.

I also added some info on the Wikipedia Hydramatic description referenced in my document. After additional contemplation of the power flow, I now believe there is incorrect information in that article about the dual range.

In my post above where I say

I agreed with others that the transmission was "locked" in third/fourth gears and power (torque) did not flow though the fluid coupling.

I should have said "...was locked into purely mechanical operation in third/fourth gears ...". We don't need any more confusion!

[d2_willys]

Originally Posted by Safari Larry

I just updated the Dual Range Hydramatic Power Flow document. I changed wording where I said the "transmission is locked". That could be interpreted as the transmission is locked up but I meant it was locked into purely mechanical operation.

I also added some info on the Wikipedia Hydramatic description referenced in my document. After additional contemplation of the power flow, I now believe there is incorrect information in that article about the dual range.

In my post above where I say

I should have said "...was locked into purely mechanical operation in third/fourth gears ...". We don't need any more confusion!

Larry: I really enjoy talking about the grand-daddy of them all, the hydramatic. IMO this IS the finest automatic ever made! For the era of the design, this is a masterpiece created by a team of geniuses. Luke Beach, Earl Thompson and the rest of the design team will always be in my heart and mind, as I have been a fan of the hydramatic for 46 years. I originally started to gain automotive knowledge in high school and was fortunate enough to have a friend and a neighbor that had hydramatics. I started reading about them as a freshman and could not get enough books to keep me happy. After getting my drivers license, my neighbor had a hydramatic that was just rebuilt and was a R54 hydramatic, which was installed in a 53 Olds 98. My neighbor said, take it out and it is all yours. Well my friend and I yanked it out. I later installed it behind a 60 Olds 371 and installed in a 62 chevy Nova. Fast was not the word for that car. It was blazing fast, and the hole shots were unbelievable. One of my other friends said he had never seen a car launch like that did. I told him it is all in that transmission! Gears!!!!

Well now I am almost 60 and still messing with those transmissions. Having about 15 of them around the house, along with having them in Oldsmobiles, Lincoln, Hudson, and even have one from a Willys Bermuda attached to the Continental six.

Reading your post made me understand the lock up feature more clearly. 3rd and 4th gear does do the torque splitting of the rear planetary, but you are correct, that the coupling provides a means of slip, not much, but some. Perhaps it was there to safegaurd the transmission from blowing up on a quick brake lock at high speeds, who knows. I am basing this on the super and lo range safeguards when the TV and governor pressures match, the transmission will shift up to save engine, etc.

Who would have thought that a valve body the size of a pak of cigarettes could do all the things that the hydramatic does? Other novel ideas: reverse blocker, reverse park pawl, running the engine power thru the front planetary to reduce creep, automatic shift up in super and lo ranges. I would call this invention the 8th wonder of the world.

Only issue the hydramatic had were the mistimed 2-3 shifts, and on the early single range hydramatics, the reverse mechanical clutch. Oh, and the fact that instead of fixing the few issues it had, GM went to work on the Jetaway. Sorry, but sprag clutches and dump and fill couplings are not my favorite types of transmissions. Accelerotors too.

But then transmissions like dual path and Flight Pitch 3T transmissions do have my interests. The 50's and 60's were the good times.

Keep the hydramatic articles coming! Thanks

[Safari Larry]

d2_willys... Wow, you read that and understood it! That's good to know. It seems we think somewhat alike -- so I'm a little worried about you

I wrenched a few of the dual-ranges and Strato-Flights (Jet-a-way) back in 1962-63 as the "transmission guy" in a Caddy/Buick/Pontiac Dealership. Also rebuilt a couple of Buick Dynaflows. Good days but I had to find another career because garage exhaust gasses gave me headaches every day. So I changed careers to Mathematics and Computer Science -- I know it was a step backwards but it worked out. I haven't worked on a transmission since then except for installing seals in my '56 Strato-Flight.

I only recently really learned how the dual-range really works. I'm still working on fully understanding the Strato-Flight. My '56 Safari is the first car I've had with an automatic transmission. I had considered converting it to stick shift (I have the parts) but decided that's not a good idea. Better to use those parts on a 2-dr Pontiac hotrod.

I agree, the Hydramatic is a work of art, a product of engineering geniuses. Quite an amazing development for the time. The dual-range had a long lifetime and an interesting history.

I just recently put both '56 Pontiac Hydramatic Manuals online -- on my site "Pontiac Garage" page. Good reading! You can to directly to them at these links.

1956 Hydramatic Manual - Part I Strato-Flight

1956 Hydramatic Manual - Part II Dual Range

[Jack Gifford]

D2- My infatuation with the 'Hydro' began in 1961 when I watched Ohio George win AA/GS at the NHRA Nationals (and again in '62 and '63). So when I built my first HydroStick in '66 I naturally bought the majority of the "hard parts" from Hydromotive, where George got his built.

An elegant piiece of engineering that you didn't mention is the variable-displacement main (front) pump, which allows more efficient operation than most "modern" automatic transmissions. This efficiency is evidenced by the fact that most Dual-Range applications didn't require any fluid cooler.

[d2_willys]

Originally Posted by Safari Larry

d2_willys... Wow, you read that and understood it! That's good to know. It seems we think somewhat alike -- so I'm a little worried about you

I wrenched a few of the dual-ranges and Strato-Flights (Jet-a-way) back in 1962-63 as the "transmission guy" in a Caddy/Buick/Pontiac Dealership. Also rebuilt a couple of Buick Dynaflows. Good days but I had to find another career because garage exhaust gasses gave me headaches every day. So I changed careers to Mathematics and Computer Science -- I know it was a step backwards but it worked out. I haven't worked on a transmission since then except for installing seals in my '56 Strato-Flight.

I only recently really learned how the dual-range really works. I'm still working on fully understanding the Strato-Flight. My '56 Safari is the first car I've had with an automatic transmission. I had considered converting it to stick shift (I have the parts) but decided that's not a good idea. Better to use those parts on a 2-dr Pontiac hotrod.

I agree, the Hydramatic is a work of art, a product of engineering geniuses. Quite an amazing development for the time. The dual-range had a long lifetime and an interesting history.

I just recently put both '56 Pontiac Hydramatic Manuals online -- on my site "Pontiac Garage" page. Good reading! You can to directly to them at these links.

1956 Hydramatic Manual - Part I Strato-Flight

1956 Hydramatic Manual - Part II Dual Range

Larry, no need to worry, I am harmless. But as you, I too went on to a bigger and better profession. I am a hardware engineer and have been for over 30 years. Electronics is my #1 interest. Will never fade away as long as I continue to keep up with all the new technologies.

But there still is the love of the 50's cars. I happen to own 12 1950's vintage automobiles. Working on cars is one of my many hobbies. There are so many people out there in the old car hobby and most of them are really good people. Love to go on drives with one of my oldies. We have some poker runs that sometimes pay off. My wife and I go to the swaps too to see the old stuff. She has put a restriction any more cars, so till we move back to AZ and establish a nice big shed for the cars, I will not be buying anymore.

Strato-flights (dual coupling hydramatic) is a similar but way different beast. Similar in operation, way different in construction. I happen to have one in my 59 Olds Dynamic 88, but that might be temporary. I have a 54 Caddy dual range, that I might just put into the 88. The 54 Caddy had the extended bell, which I believe has the same bell pattern as the Olds Rockets. So it might be really easy to do. Who cares if the P on the shift indicator is not used, the rest of the quadrant should be the same. Biggest issue is that the Cadillac valve body had the 2nd gear start in LO.

You will really wonder about me as I tell you about the newest project.

It is a 59 Renault 4 CV that is getting a Buick 225 V6 with a 55 Pontiac dual range hydramatic bolted to it. The engine will be mounted in the back of the car (original rear engine and transaxle) exactly opposite to front mounted engines. The hydramatic rear is pointing toward the front of the car, with the rear shaft connected to a Dana 20 transfer case, which in turn drives a front axle out of a Jeep. I am designing a 4 link suspension for the rear axle.

But for now I am in the process of taking the front bell housing from the Pontiac hydramatic and designing an adapter plate that will adapt the bell housing to the V6, which is a BOP pattern. Fortunately, the two bolts at the top of the bell are the same as the BOP, so the adapter plate and crank spacer will not be too difficult to get done. I plan on using the Buick flex plate and a mini starter, then put the crank spacer between flexplate and hydramatic flywheel.

The transfer case adapter may be the stumbling block. But we will see.

This project is for my oldest grandson when he gets to driving age. I have 9 years to get er done.

In case you haven't noticed, there are quite a few newbies out there looking at the old hydramatics as possibilities for their rods. I have told many a car buff that till you drive a car with a hydramatic you a missing a real experience, and of course, a good experience. Long live the hydramatics of this world!

[d2_willys]

Originally Posted by Jack Gifford

D2- My infatuation with the 'Hydro' began in 1961 when I watched Ohio George win AA/GS at the NHRA Nationals (and again in '62 and '63). So when I built my first HydroStick in '66 I naturally bought the majority of the "hard parts" from Hydromotive, where George got his built.

An elegant piiece of engineering that you didn't mention is the variable-displacement main (front) pump, which allows more efficient operation than most "modern" automatic transmissions. This efficiency is evidenced by the fact that most Dual-Range applications didn't require any fluid cooler.

Jack, you have me curious now, with the variable displacement front pump. I know of the coolerless hydramatics, but always thought that was because of no torque multiplication of the fluid coupling.

They (dual range hydramatics) are one of the finest efforts of engineering of all time. Thanks for the information.

[Pontirag]

I think the hydro was one of the top ten automotive engineering achievements in history. Not just the automatic tranny in general but specificly the dual range hydro.

[Safari Larry]

Thanks for the background D2. Cool toys you have! Interesting and unique project.

1956 was the last year Pontiac used the Dual Range. GMC continued to use it for several years in trucks. What was the last year the Dual Range was used in any auto/truck?

[Bill Hanlon]

Originally Posted by Safari Larry

Thanks for the background D2. Cool toys you have! Interesting and unique project.

1956 was the last year Pontiac used the Dual Range. GMC continued to use it for several years in trucks. What was the last year the Dual Range was used in any auto/truck?

1966.

[Safari Larry]

First used by Olds in 1940, last used by GMC in 1966. 26 years of the same design is a long life. It surely was a good design, now appreciated by a select few.

[Bill Hanlon]

It wasn't GMC that used it in 1966. Last GMC use was 1962 I think.

[Safari Larry]

So what make last used the dual range?

[Bill Hanlon]

Originally Posted by Safari Larry

So what make last used the dual range?

A hint: It wasn't produced by GM.

And now that I look deeper, it may have been made into 1967, not 1966 as I previously stated.

[Safari Larry]

Wasn't produced by GM??? Rolls Royce is the only non-GM company I know of that made hydramatics. Was it Rolls Royce?

[Bill Hanlon]

Yes, Rolls & Bentley built it under license from GM until 1967.

Check this out: http://www.kda132.com/Technical/Sect...amatic2_1.html

That "disk" in the first photo was part of RR's parking brake solution.

[Pontirag]

where would one find information on rebuilding a 1962 GMC hydro matic? I have not seen a separate hydro service manual like the one for 57's.

[Bill Hanlon]

Use the 57 manual. Or Larry's latest post at http://www.pontiacsafari.com/Hydrama...ange/index.htm

Other than throttle linkage settings, you've seen one dual range Hydra-Matic, you've seen them all.

[d2_willys]

Originally Posted by Safari Larry

Thanks for the background D2. Cool toys you have! Interesting and unique project.

1956 was the last year Pontiac used the Dual Range. GMC continued to use it for several years in trucks. What was the last year the Dual Range was used in any auto/truck?

Yep, hydramatics all over the garage, and shed too. Can't pass up a good hydramatic. IIRC hydramatics were used in 62 Chevy and probably GMC trucks.

But the real deal maker was hydramatics used in WWII tanks! Somehow they put more clutch plates in them.

Great articles on the grand daddy of them all, the HYDRAMATIC! Rolls Royce did GM proud by selecting the rights to the hydramatic.

With Lincoln, Kaiser, Hudson, Nash, Willys choosing to use the hydramatic, it must have been good in many a car designer! Poor Buick and Chevy with their torque converter fiascos. (They did however refine the switch pitch converter)

Keep the hydramatic info coming!

[d2_willys]

Originally Posted by Bill Hanlon

Use the 57 manual. Or Larry's latest post at http://www.pontiacsafari.com/Hydrama...ange/index.htm

Other than throttle linkage settings, you've seen one dual range Hydra-Matic, you've seen them all.

Biggest issue I have had is finding the square cut o-ring for the torus to flywheel for my Hudson. I used the Chevy truck o-ring, and fortunately no leaks.

think I am going to try and find o-ring through some seal manufacturers.