That does NOT matter if it had the JW Transbrake in it. MOST TBVB require the Drum to have a hole drilled in it and the input shaft might have a milled notch in it also for the JW Brake to work correctly. Don't matter that the trans was built by Tranzact.
I think you are mis understanding the question............
IF the JW Brake was in the Tranzact Trans and the JW Brake needed the mods I am talking about for it to work then THAT is most likely why Joe's TBVB does not work correctly in that Trans. Joe's TBVB Does NOT require the drum or the input shaft to be modified to work. All is handled internally by the VB. IF this is the case you have a leak inside the trans when using Joe's TBVB