the part the coupling gear connects to(the final drive shaft assenbly) which is not sold seperatly f

the 1 spring goes in the recessed area of the end of the final drive shaft assembly between the drive shaft and in the middle of the coupling gear ... so, it should still move as planned as the Rear axel Gear case assembly is bolted drectly to the frame and cannot move at all.
I tried that part number and got no results. (Must be me!?!?) Could you be a Little more exact about what it is you are looking for. I think I can help you with this one. Are we talking about the final drive, or the drive shaft, or the U Joint and middle gear?
They do not offer the final drive shaft assembly seperately which is the part that is splined on one end has a recessed hole for the spring and which the coupling gear slides on. Believe its because its helical on the other end must match exactly(with lash adjusted) This is also the part that has the splines worn off ...hence my wanting to weld coupling gear on...
the part the coupling gear connects to(the florida vacations and disney cruise final drive shaft assenbly) which is not sold seperatly from the Rear axel Gear case assembly (which is the silver 10 hub you put 90 weight oil in) the aluminum triangle piece you have pictured bolts on to the 4 studs on this hub with 4 nuts and washers.
The part number you listed is for 2008 models and up (see the list of models that it fits on the boats.net site you linked). Your Avatar info says you have a 2005. If its a 2005 according to this its a different florida vacations and disney cruise part number ( 5FB-Y4617-00-00 ) but its the same from 1998 to 2007. Click the part number for the assembly in the link below and it will show all the models that part number fits fits. boats.net is one of the few parts sites that does this.
Was thinking i could line everything back up on the bike tighting everything down and simply push back on the coupler as it would be sliding on the driveshaft and weld. then push aluminum cover over tighten 4 nuts down and I'm done.