734b versus 743

[cmb7684]

I have a mid 80's 743. I saw a complete hydrostatic tranny for sale on ebay for a 743B. WHat is the difference between the 743 and the 743B and will the tranny fro the 743B work in my 743? My 743 on the left side makes a whining sound and has little to no power forward or reverse. Let me know if there is an easy fix to it.

 

[professorbolin]

are you sure its not a drive motor on that side? switch the lines around and if the noise comes from the other side its the pump, but if it does not, then its the drive motor on that side, that gets its power from the main pump.