I wonder if there are different Dynaflows for 1956. Some people told me about long necks and short necks, other say they are all the same. Does a Dynaflow from a Special or Century fit in a Super or Roadmaster ? What to look at when buying a used Dynaflow to make sure that it fits ? Some part of the drivetrain must be longer due to different wheelbases ? Thanks for any help.
This is an interesting question. I've been looking for an answer most of the day. It would appear there has to be a different transmission based on the specs I found in my 56 manual. But the manual does not confirm there is any difference. I can tell you this, according to the manual the big and small cars both have the same length from the center line of the front wheels to the front of the car. Also the book shows only one torque tube length, so it appears they would be the same. The overall wheelbase length difference is 5 inches, while the width difference is one inch. Normally the one inch width difference could be the rims but the book shows the Century, Super and roadmaster have the same rims while a Special has a rim 1/2 " narrower. So that would indicate a different rear axle banjo. This would be reinforced by the dimensions of the frame, which on a 50/70 car is a full 1 1/2 " wider. I'd be very interested in what the real answer is. By the way, the manual shows that 56 transmissions are marked with a code on the bottom of the tranny near it's oil pan. The area would be next to the drivers side accumulator. JD
Thanks John, the only code i can find is on top of the cast iron, saying Dynaflow 1342992-1. I wonder if that stands for the Dynaflow specs or if it's just the part number of the cast iron. The overall length including the torque ball is 29.5 inches for the roadmaster 73. Can someone please be so kind to measure on another model ? Thanks
I measured the dynaflow out of my 56 Special, model 48. 322 / 2 barrel. From the bell housing mating surface to the rear of the torqueball / torquetube housing is 28 inches. Appears there is a difference. The casting numbers are the same except it has a -2 at the end. Hope this helps. I can measure the separate sections over the weekend if you need more information. Will be interesting to see where the difference is. Ross
The Hollander Interchange Manual lists one transmission for all '56 models. It shows a Part Number 1388895. However it shows different Drive Shafts for Special/Century P/N 1388712 and Super/Roadmaster P/N 1388713 which more than likely would account for wheel base differences. Doug
The Super and Roadmaster definitely have longer propeller shafts AND they are splined differently. The Roadmaster has 16 splines. I don't know what the others have.
If memory servs right, Doug is right, there was just one trans. Different prop shafts, ect. tough as a boot, very difficult to tear up. never shift. could run up to 60 in low. good old trans.
According to the manual the code I refer to is a parts code. It is stamped on an extension of the flat surface for the tranny oil pan, and is a must when ordering parts for the trans. It shows in the book a letter and three numbers. Once you have the tranny upside down this would be in the area next to one of the accumulators. This is not a big area. If the tranny was right side up this code is on a surface pointing directly towards the ground. JD
There's only one version! '56 only too, I believe. Part# in parts book is 1392404 if you wanted to order a new old one, probably out of stock though
Thanks for the replies. I checked the length of Dynaflow again, all this is from the 56 Roadmaster 73: Bell housing mating surface to rear of the torqueball : 29.3" Bell housing mating surface to rear of extension : 25" Bell housing mating surface to the rear of cast iron housing : 15.4" Bell housing alone : 6.5" Propeller shaft tube : 69" As i can tell by the pic my propeller shaft has way more than 16 splines, maybe 32 ? I will check exactly later when the transmission is out again. I also found that code : P097, thanks John. No idea what that code on top of the cast iron means, saw pics of a 53 Dynaflow with that same code on top as mine but the part looking quite different. So it is common sense that there is only one Dynaflow for 1956, but different propeller shafts. Still to be verified. Overall length: Ross has 28" for model 48, i have 29.3" for model 73. Seems too much for tolerance of measurement and too small for a different assembly ? Number of splines and/or different splining of propeller shaft. If there's different splining, how can that be fixed ? I know 3 other people here in Germany whose '56 Dynaflows need a complete rebuild. Plan is to get a spare transmission that makes it's way around while people work on their own. That only makes sense if they are all the same. Thanks again to everybody who helps to clear this up, thought it was just a simple question in the beginning.
