Could there be a couple of roll pins holding it to the shaft? Maybe covered up with paint, or some sort of rust preventive sleeve??
And by the looks of the end it could be pressed onto a spline, the hole at the back of it looks to be a centering point for some lath work, a gear or bearing press may be needed to push it (the shaft) out the one end.
Look at the ends of the internal worm gear, see if there are any splines or key-ways, if so then it's a press fit.
i had take better measurements : offset+declinaison is adjustable from 22° to 27° ! (with this polar mount from channel master) but in france where i live declinaison is about 7° (6.5 to 6.91) if CM180 is 22° offset : i need 22+7 = 29° minimum ???
@dreambox1959 CM180 has 22.6* offset angle, take is as axiom. And offset angle can not be changed, it is built-in by manufacture. I think you have drowned in the issue of wrong positioning of the feed. The issue is simple.... CM has made feedarms and LNB-holder in the way that they do not hold the feed (LNB ) in proper position and not properly point it towards the surface of the dish. And when we add the polar-mount to the system whish is already has too many mistakes then we finish with totally messed-up construction. My advice to you would be: make sure the feed is placed and pointed correctly and then start to adjust the polar-mount.
thanks rimantss this dish was a gift from a english guy who live in france but the mount is rusted , the whole dish is correct i have arms (lnb holder) for ku and C (2 set of arms) and 2 feedhorn especialy a big one for C-band. these days i build a new polar mount based on AJAK-h-180 i ll post some pictures soon.