Singer Inspiration 4220, PLEASE HELP!!!?

I'm still having some trouble fixing the hook timing on my machine.

I took the machine apart and finally got the front off, so I sat there for a while just looking at the coned nylon gear with my allen keys in my hand but there are no allen screws on the sides of the gear. I looked everywhere and I can see how if it would just loosen I could slightly move the raceway and fix the timing but there are no allen screws or regular screws on this nylon gear. I looked at a few pictures online of nylon timing gears and could see where the allen screws are on them but mine has none. WHAT DO I DO???

The only thing on my nylon gear is a black metal circle at the very top of the gear I don't know if that could be taken off and / or what's under that. I am so close to fixing it.

Please Please let me know what I should do or if I am missing something. I also can take a picture of the gear if that would help. Thank You so much for helping!!!