1941 Cadillac Automatic Trans Fluid

[bullrun]

Just brought a 41 Cadillac out of a 25 year slumber. Auto transmission was full to top of dipstick and no leaks evident. Car shifts thru all 4 forward gears-not as smooth as a Turbo 400. I have put about 300 miles on it and it drives better each time I take it out. It sometimes clunks when it down shifts from 4th to 3rd. I also have to place it in drive-wait for the trans to lurch and then quickly drop it in revese or else it grinds. If you just try to drop it in reverse it always grinds. I want to change the fluid-does anyone know if our "Dexron" of today is what I should use? Also a source for a filter kit. I'm ordering a transmission repair manual. Can the bands in these transmissions be adjusted with ordinary tools? Any help or suggestions are appreciated.

[Owen_Dyneto]

The fluid on the market today which is the closest to the old Type A which was used in your Hydramatic is Type F.

As to the clunkiness of the shifts as compared to modern transmissions, they didn't call the early Hydramatics "leap and lurch" for nothing, it may well be perfectly typical.

I'm not really knowledgeable about these transmissions so take better advice from someone who is, but with the engine off, isn't Reverse used as a Park feature when the engine is not running? If so, grinding while going into Reverse may be related to engine vacuum or whatever allowed the Reverse position to have two functions, with and without the engine running.

[61polara]

The operation of your transmisson is correct. Just a few tips........the proper way to put it into reverse is to let it shift into Drive for just a moment and then it will slide right into reverse. To use the Park feature, turn the engine off in Drive, then shift into Reverse without the engine running. This locks the transmission for Park.