1939 Series 75 transmission questions

[SHOVELHEAD]

I've posted a couple of times here as I am helping a friend with his 1939 Series 75. I'm not a Cadillac owner so my knowledge is sorely lacking.

It appears that the transmission is pretty much hopeless as there are chipped gear teeth and the syncros are worn out.A t least this is what was explained to him by the shop that worked on the car.

While the bulk of my experience has mainly been in cars of the 50's and 60's I have exhausted my parts connections for a gear set or a complete transmission.

What years transmissions will interchange or use as a parts donor for his original 39 case? I have been told that Series 75 had their own gear sets different from other models but I'm totally at a loss as I have no parts books to cross reference these.

Any and all help would be greatly appreciated, thanking you in advance.

FYI I'm in southeast/midstate Michigan

[Steve Passmore]

As far as my master parts book go's all 1938 use the same transmission but I think there may be differences in the tail shaft and housing which is interchangeable. 

[SHOVELHEAD]

What about 41's?  are they all the same also?

[Steve Passmore]

According to my book some of them have different main drive gears but thats probably just improvements over the years.  The basic box is the same except for the tail shafts and housing as I said.  The box will fit to the back of any V8 as far as I'm aware.

[Classic]

There currently are at least 3 1938-1947 transmissions for sale on eBay.  For instance, see item # 111732605124.

[Steve Passmore]

Well spotted there Gene.  This guy has the long shaft ones as well and a reasonable price.

[Mike Simmons 938]

Folks- Besides tail shaft length, the main problem with interchanges is the drive shaft. The 1937 thru 1940 Cads and LaSalles have a sliding connection in  the driveshaft. The 41 and later trans have the yoke at the front of the driveshaft as a tube that slides into -and out of- the rear of the trans case. This means that you can't utilize the 41-52 transmissions without utilizing a later driveshaft ( or at least the front driveshaft yoke).
Mike Simmons 938

[Steve Passmore]

Hard to see from the picture if the trans that Gene found is the earlier type but it looks like it.  The definition is whether that rear flange is bolted on or is a slider.  I never trust the 'Hollender' interchange too much but they state the rear shaft and housing is interchangeable??