You know what we call guys like you at the track? "Noodle"!
Just so YOU know, the reason you don't give guys instructions by the book on this particular application is because after the first year of ownership, you can't turn that shaft with your fingers and most resort to a pair of pliers ending up with buggered up threads then nothing works. Thus, simply pull the pin from the clevis and adjust the fooker and replace the pin. So simple even a "Noodle" can do it!
So you tell um YankeeNoodle!
You guys are getting funny. I will see how hard it is to turn. Does anyone know what that nut next to the rubber is for?
From experimentation, there is no way to turn it without turning the bolt.