I'm in the process of rebuilding my B20B for my 67 122S wagon. Engine is going fine but tonight I spent some time on the trans, The trans is leaking so I bought a gasket kit for a M40 trans. The brass tag on the bottom of the trans say that it is a M400 254648 301267. It has a J-type OD attached. The front shaft was reduced and has larger U-joints & flange than the rear. It has a solid rubber bearing support, without the spring.

The filler and drain are located on the passenger side and appear to be the same as the M41. The fill is higher that the M40 by about 1.5"- 2". It is attached to a bell housing from the rear of the housing with hex bolts (4). The top is set up with the OD switch and a separate switch for the rear back-up lights.

What is it? My quick research says that it is out of a 164? If I'm going to rebuild or clean it up it would be helpful to know from where it came? I thought it was a M40, than I thought because of the filler and drain hole locations and offset, I thought it was a M41. The brass tag says M400. Now that I have it out, OD off and opened up, I'm not sure what it is..... It was working just fine but leaked between the gear box and OD sections.

Any thoughts?

Thanks, Bill, LaGrange, Illinois.