Canon Serenar 100mm f/4 not focusing properly

[Kirks518]

My Serenar 100mm won't focus to infinity on my IIb or Canon 7. The coupling piece doesn't retract all the way, so the rangefinder won't match up. I'm waiting on a roll to see if anything I shot on a test roll was in focus (doubt it).

Is this because someone took the lens completely apart then didn't hit the correct threads when reassembling the helicoid, or is it to do with the coupler? The coupler does look adjustable, but not sure if adjusting it would correct the problem or make it worse.

Any help is appreciated as always.

 

[John Koehrer]

Are the pitchers sharp?
But incorrect assembly would cause this sort of thing in addition if someone had it apart, the focusing ring may have been
put on incorrectly or If there's an infinity stop in the FR