1956 hydramatic oil cooler

[VikingCaddy]

I have a bit of a cooling problem on my transmission - when driving in the city or at high speeds the transmission oil gets very hot to the point where it starts spilling from the trans. I can't seem to find a cooler on the transmission (since car is 56 I assume it is a Jetaway) but could anyone tell me where to make the connections to an extra cooler ?? 
Car is 56 Sedan de Ville.

[J. Gomez]

I have a bit of a cooling problem on my transmission - when driving in the city or at high speeds the transmission oil gets very hot to the point where it starts spilling from the trans. I can't seem to find a cooler on the transmission (since car is 56 I assume it is a Jetaway) but could anyone tell me where to make the connections to an extra cooler ?? 
Car is 56 Sedan de Ville.

Jesper,

There should be one located just below the tranny bell housing; there should be two rubber hoses that circulate coolant from the radiator.  An inlet and outlet metal tube routes out from the cooler up to the tranny, these are for the ATF.

Question is do you have this piece on yours? If yours have it is there a good flow of coolant through it?
If coolant is restricted at the tranny cooler you could experience those symptoms of ATF overheating.

Good luck..!

[G.Perd]

Hi Jesper, yes an extra cooler is always a good idea as they are more efficient than the factory cooler that is within the radiator. They can be mounted anywhere up front between radiator and grille where there is a good air flow. The old coolers within the radiator whilst cooling the oil to some degree have the added problem of being within one big lump of hot copper, so they will never get the trans oil as cool as a remotely mounted cooler. They are readily available and good ones cost between $100 and $150 with all the mounting hardware and hose and comprehensive fitting instructions which will tell you where to make all the connections to your original cooler pipes. They can be plumbed independently or in conjunction with the original radiator cooler. I have fitted many to my own and other cars and they are very effective. All the best, Geoff Perdriau.

[Roger Zimmermann]

Just for your information Geoff: on '56 and 57 cars, the cooler is located under the transmission, not within the radiator.
I have 3 cars with that system, I never had the impression that the transmission's oil was too hot.

[J. Gomez]

I second Roger’s comments the cooler provides a way to warm the ATF faster for normal operation as these tranny tend to run cooler.

[CEC #20099]

Jesper: Is there a trans cooler, as described above, in your car, or is it missing ??
I had a 55 with a 56 engine/trans swapped in. I had the correct factory cooler & burnt up the trans fluid in a 100 mile city trip.
I pulled the cooler, soaked the entire core in oxalic acid for a few hours, flushed it with hot water, dried it & reinstalled it , with a complete trans flush. No more problems. It`s got to be there, & clean.
c chleboun #20099

[CEC #20099]

CEC Again; The cooler is pictured on P. 2-7 of the 56 shop manual.
c chleboun #20099