I have a T-50 with two grooves cut into the input shaft...does anyone know what 1st gear ratio would be? Did these transmissions really come in more than one version or were they all 3.41 1st? Unit has a stamped number on the main case - can this be linked to original application? Any thoughts appreciated, not much turning up via google. Jim Evans
Jim, I think the 2 groove was the V8 box. 3.10 first and .84 OD. An old article on the T50 by Jim B. I would try Synchromesh fluid instead of ATF.
http://www.britishv8.org/Articles/Borg-Warner-T50-Transmission.htm