Shaft seals

Hello,

thanks for having this forum. I am trying to do some maintenance on the shaft which requires the shaft seal to be replaced.
Does anyone have information on what part number is required and where I may find it?

Thanks in advance,
Ermal

what engine do you have? 

what is the diameter of the shaft?

for example this is mine its a volvo 2003 with 25mm propeller shaft 
volvo

 

I have a Yanma4 4JH! 

I have to go and measure it (its a bit of long flight for me) hence asking if anyone else has similar configuration.

ok nice,

If you know what gearbox you have, for example, ZF Marine, Kanzaki Gears, and SD series. that will tell you the shaft size, it wont be the SD series as that is the yanmar saildrive range