Craig, the C20 nut does not come loose as standard. It is locked into place by the tang on the C45 spring. Originally, and possibly even now on new ones, this tang was bent through 90 degrees with rather a sharp bend. This would fatigue and break. Whenever this happened I would bend a new tang with a generously radiused corner and I have never had one break after that.
There are not multiple seals applied.. The early ones had a bonded item under the C20 and sealing compound on the gearbox mainshaft where it passes through the C3 shoe carrier tube. Later this was replaced by the C20 being modified with a recess to take the now cylindrical end of the gear box main shaft. Both ideas were intended to stop oil getting out of the splines inside the C3 and on the outside of the gearbox main shaft. My idea stops it getting in there.
Your paragraph concerning indexing of C20/C3 etc is not correct and you need to go back and either read the books/ instruction sheets or look at the parts and understand how they are intended to work.
There are not multiple seals applied.. The early ones had a bonded item under the C20 and sealing compound on the gearbox mainshaft where it passes through the C3 shoe carrier tube. Later this was replaced by the C20 being modified with a recess to take the now cylindrical end of the gear box main shaft. Both ideas were intended to stop oil getting out of the splines inside the C3 and on the outside of the gearbox main shaft. My idea stops it getting in there.
Your paragraph concerning indexing of C20/C3 etc is not correct and you need to go back and either read the books/ instruction sheets or look at the parts and understand how they are intended to work.