Im looking at different trans options and was just curious if the gears on all Bseries trans are interchangeable. For example taking a type r final and putting it in a y1 tranny. Thanks in advance

 

Not all b series parts are interchangeable. The Y1 is a early cable tranny and has very few parts shared with the later hydro units. 92-01 hydro trans have many parts that are interchangeable but it's a lot to break down piece by piece.

I have found that the older 89-91 cable trans with two letters (S1,A1,Y1,J1) are getting hard to find replacement parts for. Oem stuff is getting discontinued and it's generally not worth rebuilding if you have a damaged or heavily worn unit. The YS1 cable trans from 92-93 shares the same internals as the 92-01 and has great aftermarket support and parts availability.