Right here where the arm bolts on is where your referenceing correct?
see that's just like mine and the adj nuts look just the same way in..... I took out the three bolts on the arms and still no movement w/ a chain... even broke a mid sized chain... dam... how'd yours turn out? oh one other thing I jacked up the side of the cat i'm working on so as to free up the tracks from ground friction.... no dice good luck Doug