1941 or 1946 Hydramatic ?

[halsey999]

Working on finishing my brother's estate and found a Hydramatic transmission under the work bench. He used to have a '41 Cadillac that got sold but it had manual transmission. I'm not sure if this transmission is for a 1941 or 1946 (the gear ratios are different). The stamping on the casing is 8608721C-S and it has a serial number of 6-4075. The first number of the serial number makes me think it might be from a '46 and that's why he never used it on his '41.

R. Halsey

[jackworstell]

The drain plug.....in the side of the pan or in the rear of the pan ?


Jack Worstel      CLC 7558

[halsey999]

The drain plug is in the rear of the pan.

[Bobby B]

1940-1942 Hydramatic units can be identified by not having a pressure regulator plug. Also the transmission oil pan is 15" long.

1946-1956 Hydramatic units can be identified by two pans, one on the bottom and a side pan. Manual shift shaft goes through the side pan. 

                                                                                                                                                        Bobby             

[halsey999]

I'm still confused. Don't know what a pressure regulator plug is. Got a single pan on the bottom that is 13 inches long. Have a side pan. Plus, I see I misread the serial number. It actually is C-4075.

R. Halsey

[Steve Passmore]

If it had the plug it's an external thing on the bottom in front the side pan as I recall. Didn't they change something on the tail too?? One has a bolted flange and the other a slider spline?

[Bobby B]

That round silver "thing" is the pressure regulator. I have to find my literature regarding decoding the transmission plate. Looks like a later model from the picture. Uncover the mount Please...
                                                     Bobby

[jackworstell]

Looking at the photo above posted by R. Halsey......no doubt it is a post WWII   Hydramatic

At the end of the tailpiece...there's an annular indentation...pre WWII units did not have the annular indentation.

The pan drain plug was at the rear of the bottom pan on pre WWII units.....but on the side of the bottom pan on post WWII units.

The large external "hex" plug ( part of the oil regulator assembly)  must be  hidden by the support member that is laying across and on top of the transmission.

On the hidden side of the case there should be an oval IDtag with the model number/SN  stamped on it.
For a 1946 unit..I'd expect something like   46-CXXXXXX

So far as there being two bottom pans on post-WWII  units...I've never seen a Hydramatic with two bottom pans??

....Where is the unit .....state/town ?

Jack Worstell     CLC # 7558

[Jay Friedman]

According to my 1935-55 Master Parts List, a Hydramatic with unit number C-4075 is a 1946.

[halsey999]

You all convinced me that the transmission is from 1946. My pressure regulator value isn't nice and shiny like Bobby's. Mine is still painted green. When I took the photo I didn't realize that support wasn't connected.
The next thing to do is to try to sell it.

Richard Halsey
Rochester, NY