Mystery part RF-45.

[AlexPeel159]

New to me RF-45. Want to give it a good cleaning and relubing. I want to change out the gear oil puzzled by these fixtures on the top of the head. I cant tell which one is for the gear oil. There is this brassish knurled nob and right next to it a black hex head marked oil. It seems like its the black hex head covering the port for the gear oil or is it just a "sign" for the brass knurled nob? I don't want to wrench on it without knowing because I am afraid if its just a "sign" I might snap it off or something. If that is the port for the gear oil what is the brass knob for? I know you might be shocked but the manual is really light on info for these. I see these features in the rough drawings but there is not callout of part numbers or labels for either of them.

 

[C-Bag]

Is there a dip stick on the brass knob?

 

[AlexPeel159]

Ok some more investigation. The black oil marked hex nut does seem to be the fill for the oil. It came off and had either some old teflon tape or maybe stringy paint around the edges of the hole. The brass screw is even more of a mystery now. I took it off and noticed that it had a hole in the bottom through the center which did have some oil inside of it. Then I looked in the hole in the top and thought I saw part of a spring. Sure enough the very top part is a cap ontop of the bottom part. Seems like there is a spring holding down a ball bearing on the inside. Maybe this is a relief valve for the oil box? Its not a dip stick. There is a sight glass on the side of the head so it wouldn't need one.

 

[pontiac428]

It looks like a breather to me. When the machine warms up, the air in the case expands and if it has nowhere to go, it can push oil out from various places. The check ball lets it burp.

 

[AlexPeel159]

That sounds like what it probably is. Thanks.