Adapting a trans cooler to a '49-'55 Hydramatic?

This is my first post here (though I've been a lurker for a while), so please do be kind...

My question is in regards to the '49-'55 Hydramatic 4-speed transmission. The original unit in my '55 Pontiac blew out a few months back after several days of relatively hard, mountainous driving. I had it rebuilt locally, and the rebuilder gave me the culprit of its demise: a toasted spring (about that size of an engine valve spring), that had broken into about 4 different pieces. I have always wondered if it may have been due to thermal overload; I know the trip certainly tested the limits of the engine's cooling system.

Nevertheless, I am gearing up to put the trans (and the engine, which is undergoing a rebuild) back in the car, and am seriously considering the possibility of an external transmission fluid cooler. The car will be used to tow a vintage Airstream, and I know that with modern transmissions at least, a transmission cooler is almost always recommended if towing a trailer.

The problem—how do I hook up cooling lines to a transmission that was not designed for them? Clearly, I would need to hook them up in such a way so as to provide pressurized fluid through the cooler, but to my knowledge, there are no such outlets designed into the transmission, or at least not in standard duty form. Apparently, in heavy duty applications of the Hydramatic—when used in taxi cabs and police cars—an external cooler was actually an option, however I have never seen one, so I do not know how it was hooked up. I have also heard that some Cadillacs of the era came stock with a trans cooler, though I have not verified this.

Any ideas or suggestions on how or where to hook up the cooling lines would be greatly appreciated.

 

You know, I have a couple of B&M Hydros and have read about early 50s era hydramatics for taxis and commercial vehicles that supposedly had cooling lines to attach to a cooler in the radiator, but I have never seen one. I have also collected a mess of early 50s GM hydramatic rebuild and maintenance manuals from swap meets, and best I can recall, not one mentioned this cooled transmission. I would welcome anyone with real information.

 

Found this via a Googole search:


"In 1954 a heavy-duty Hydra-Matic conversion package was available. It has an external transmission oil cooler, larger annular pistons, a modified engine water pump, and some other parts. It was intended for police cars, taxis, and road mail carriers. it could not be used on air conditioned cars. The cooler mounted on the transmission."

By the 56 model year the Jetaway had replaced the old style "4 speed" hydramatic. This 54 Conversion package may have only been available/used in the 54-55, or possibly even in just the 55 model year. I'm betting few were made and fewer exist in junk yards today. I'd be interesting in seeing one.

 

I was reading over this and wondered if anyone has thought of a way to add a trans cooler to one of these transmissions

 

That spring was not bothered by the heat that can be generated in a transmission. It failed due to fatigue. The evidence of heat failure in a part like a spring would be bluing of the metal and relaxation of its temper, not fracture. It was 55 years old, had flexed at least several 10s of millions of times, most likely exceeded its design cycle life many-fold. If the rubber and friction parts of the unit were not fried, and the fluid turned chocolate brown and stunk up the neighborhood, it didn't have an overheating problem. those grand old units have logged billions of hours in millions of cars with exemplary performance. Just replace the spring, check out the rest of the parts and get confidently back on the road!!

You could easily add a cooler by extending the pan and putting a fin/tube heat exchanger in the bottom. That appears to be what they did for the Hydramatics they used in WWII military tanks in picture below. Bottom photo shows they circulated hot water from the engine block thru the ****** pan heat exchanger. Heating the ****** fluid to operating temp is at least as important as cooling it if too hot. Prevents damaging water condensation inside case.

I think I have seen ads for outfits who sell conversion kits like that. Or maybe it is an hallucination brought on by my advanced Partzheimer's.

 

I really do think this trans will be great without any trans cooling and just yearly fluid changes.

I saw they had done it for the military ones but from what I understand those trans and parts dont transfer over to the civilian trans, plz correct me if im wrong.

On a very interesting note, right after I posted this I found a 1954 trans and engine with the trans cooler setup.. guy has removed it and cut/damaged the lines but I'm going to go check it out. The plumbing is very different than the military one. It came out of a 450 dump truck.

If anyone has ANY do***entation or info on these I'm very interested/

 

Don't worry about cooling on a p***enger Hydro. Not necessary. A pretty good endor*****t; $$$$$$$$$$$ Rolls Royce and Bentley cars used them until 1967, a decade after GM quit. No cooling.

 

The 56-55 hydro doesn't have a stator, it doesn't multiply torque, so there no need for a cooler since the fluid isn't being worked.. It would be like putting a cooler on a Muncie..

 

I'll be be using mine in a truck to tow but I do agree with you guys. Just the thought of finding this conversion On one of these transmissions is pretty cool. I kind of just want to get it to see how it works

 

In pre- Dual Coupling Hydra-Matic trans, a external trans fluid cooler was made by Harrison Radiator Division of GM, Pontiac actually used it first in 1953 Chieftains built with the Chevy Power Glide trans (Hydra-Matic Plant fire Aug/1953), and was available for extreme usage cars like taxi cabs and patrol cruisers starting in 1954, Buick even used the Harrison cooler for their Dyna-flow trans before trans coolers started being built inside radiator lower tanks, the part number for the Harrison cooler is 8520972. You can tap the cooler supply line to the trans main line pressure port, and have your trans pan modified for a cooler return line, What I am building for my B&M Hydro Stick slant pan Hydra-Matic trans is a deeper pan, having an internal large heat sink under the screen filter, and an external large heat sink, both welded to an aluminum plate, serving as the new bottom of the pan, internal heat sink absorbs heat from the trans fluid, heat transfer to the external heat sink fins exposed to air flow p***ing under the car, no moving parts, no plumbing, no fittings, should provide a 20-25 degree temperature drop in trans fluid.
Charles L. Coker
1953 & 1954 Pontiac Technical Advisor
Pontiac Oakland Club International