JD 4300: opening up the gearbox to repair broken PTO and range shift

[shock]

I very much appreciate your help! Apologies in advance for not getting all the terminology of the parts correct, I realize it makes it harder for folks to understand my questions. For me, a picture really is worth a thousand words.... I think there are snap rings (20) on the end of the forks that hold them to the support body (16)? If that is correct, I am trying to determine if they are accessible from the top of the rockshaft opening so that I can get another fork in there and the snap ring on the end of it?

 

[shock]

I decided not to split the tractor to fix the range shift selector fork. I'm going to button it back it back up and just run it.
My question is, when I removed the PTO cover, there was no gasket. It wasn't leaking, but I want to be sure when I put it back together, that it doesn't leak. I was planning to use

Permatex 82180 Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker​

Can anyone confirm if this the "right" stuff to use? I was also planning to use a light film of it on the suction tube manifold (where the metal screen is located) underneath the tractor as well.

 

[dfkrug]

My question is, when I removed the PTO cover, there was no gasket.

I use RTV silicone like that.

Even if you are too generous with the sealant, dry chunks will just fall into the sump and not cause problems.

 

[LouNY]

Just a thought with the pto brake issues have you considered installing an over running clutch on your implements.