[Bill Hanlon]

Originally Posted by d2_willys

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.

GMC 6 cylinder Hydra-Matics used a square cut torus cover to flywheel gasket too. GMC Master Parts Book calls it a "seal ring - 11.24 diameter" part # 8614291". Try running that number by http://www.fatsco.com/ or David Edwards at http://www.autotran.us/ and see if they have it. Also try http://nwtparts.com/.

[Bill Hanlon]

Dave Edward's site lists the gasket on this page:
http://www.autotran.us/hmparts1.html
*Fluid Coupling Cover (Torus) O'Ring (rectangular x-section) for 1954-62 Chevrolet PU, 1952-57 GMC
6 Cyl. Models 100-340, Also fits some Nashes (1953-56 E & Y) and Hudsons (1952-56 Z) HG-10
3333
8614291
$ 10.00
I don't know if he actually has it.

[d2_willys]

Originally Posted by Bill Hanlon

Dave Edward's site lists the gasket on this page:
http://www.autotran.us/hmparts1.html
*Fluid Coupling Cover (Torus) O'Ring (rectangular x-section) for 1954-62 Chevrolet PU, 1952-57 GMC
6 Cyl. Models 100-340, Also fits some Nashes (1953-56 E & Y) and Hudsons (1952-56 Z) HG-10
3333
8614291
$ 10.00
I don't know if he actually has it.

Bill: I purchased the rectangular cut o-ring from Northwest Automotive. It does fit Hudsons, but is harder to keep from coming out than a square cut ring would be. (Mine had a square cut originally) This is why I have looked into buying a proper o-ring for the Nash and Hudsons.

[Bill Hanlon]

May have found a newer use of the Dual-Range Hydra-Matic.

US Army M114 used a 283 Chevy V8 backed by a Dual-Range Hydra-Matic. Was deployed by the Army in the 60s and early 70s, but I can't find when they were actually manufactured.

[Safari Larry]

Good info Bill. This is from discussion with Pontiac Pat (Bill, you might recall e-mails with him). Pat is a '55/'56 Pontiac "expert" and a Rolls Royce "expert" (in my opinion). He has 55/56 Pontiacs, has worked with them for many years, and just purchased a '57 RR.

Re the Hydramatics- ... re the RRs, they used the Hydramatic as late as the 1990s (others are saying 1962 and 1967 for the last) on the VERY limited production Phantom VI limos (P IVs, PVs, and PVI are/were only sold to heads of State). The reason being, the same as the early ones---part of the brakes are driven off of the trans output shaft. This is called the servo. As new as the P VI is, the tech in it is considered very old, as cars goes--this is for coach building requests (custom bodies), which require a frame to fit the heavy body. (uni body cars can not take custom body)
And, interestingly enough, all RR Hydramatics are of the 1951 and older type--or in other words, there was no more development. (Hydra's are broken into two gens, '51 and back, and '52 and up)

So he's saying the RR Hydramatic was based on the first single-range Hydramatic, not the dual-range which came along in '52. Quite interesting -- and seems odd they would use the older design. Here's what the Wikipedia Hydramatic Article says:

In 1952, Rolls-Royce acquired a license to produce the HydraMatic under license for Rolls-Royce and Bentley automobiles. It continued production through 1967.

But according to Pat, early 90's were last years of building the first Hydramatic design (single-range and dual-range). Perhaps building a few of them would not be considered "production".

[Rocky 389]

Originally Posted by Bill Hanlon

May have found a newer use of the Dual-Range Hydra-Matic.

US Army M114 used a 283 Chevy V8 backed by a Dual-Range Hydra-Matic. Was deployed by the Army in the 60s and early 70s, but I can't find when they were actually manufactured.

From '67 to '69 I was deployed in an Armour battalion in Germany and we had about 10 M-114s with the 283/4 speed hydros. The guys that drove them were in heaven! These little personel carriers were made from aluminum and only stood about 4 feet tall..they were nimble and quick! Those guys usta race them and pulling a "trackee" was as simple as doing a "neutral drop" at full throttle...man, they'd stand up on the very back of the track and go. Those hydro transmissions took a lickin and kept on tickin. One more checkmark for the hydro.
IN high school I had a string of pontiacs and olds cars with the hydro...loved them.

[U47]

Originally Posted by Safari Larry

Good info Bill. This is from discussion with Pontiac Pat (Bill, you might recall e-mails with him). Pat is a '55/'56 Pontiac "expert" and a Rolls Royce "expert" (in my opinion). He has 55/56 Pontiacs, has worked with them for many years, and just purchased a '57 RR.



So he's saying the RR Hydramatic was based on the first single-range Hydramatic, not the dual-range which came along in '52. Quite interesting -- and seems odd they would use the older design. Here's what the Wikipedia Hydramatic Article says:


But according to Pat, early 90's were last years of building the first Hydramatic design (single-range and dual-range). Perhaps building a few of them would not be considered "production".

Hi Larry, you missed the flathead reunion! So my question to you is when are you going to start a theory thread on Controlled Coupling HydraMatic? My logic has it that 315 CCH works the same (power flow) as Dual Range, but the design of the guts is the difference. They hold up very well, can be modified, especially the cars that were ordered with the police/taxi cab HD trans.

Don

[Safari Larry]

Don, I had the flathead reunion on my calendar and really wanted to go -- but sometimes life gets in the way of the important stuff (Pontiacs). Bummer!

Regarding the Controlled Coupling (aka Strato-Flight) HydraMatic... I was thinking of starting such a thread but waiting until I had a firm understanding of how it works. The power flow through the CC is like the dual range but the control of the planetary units is quite different and more complex. I'll go ahead and start a thread on it.

[drain89]

My truck has 3.90 gears but I’m swapping to a 3.08 rear. What drive or driven Speedo gear do I need? Can one from a car hydramatic be used? Part numbers? Thanks

[Goatracer1]

I have been a fan of these transmissions since my first car, a 1953 Chieftain L8. From just reading what is written here I have learned more. I thought the reason GM discontinued the Hydra-Matic was the torque converter was better but from what you said it would seem that is wrong.

[stevep]

Originally Posted by Goatracer1

I have been a fan of these transmissions since my first car, a 1953 Chieftain L8. From just reading what is written here I have learned more. I thought the reason GM discontinued the Hydra-Matic was the torque converter was better but from what you said it would seem that is wrong.

Hydramatic division did not use a torque converter until the THM 400.
Buick built the converter