Someone will hopefully chime in... Although I am thinking it is supposed to be left alone so the arm has room to move and doesn't get bound up.

I am also wondering about the hinge pins again. I got my reamer today and I reamed so that when I drop the pin thru it falls thru flush to other end. When I hold the pin and move the arm it has very very slight friction still but very free moving. I read the pin is supposed to fall all the way thru. But I thought maybe I shouldn't go that far with it cause dirt might get in easier? Should I leave it how it is or keep going til the pin can fall thru all the way out the other end?