I have a few doorknobs in an old 1960s house we just moved into that have a loose/wiggling collar (rose?). I can remove the knob on the inside by pushing in the silver tab on the side and pulling the knob out, but I can't figure out how to tighten or even remove the collar. I'm assuming it has something to do with the small circular hole in the collar, but I can't figure out what to do with that. I've tried a hex screwdriver and just pushing a pin into that (with and without turning or pulling on the knob at the same time), but no luck. Help!
There's a type of spanner that amounts to a semicircle with a pin on the end. The pin hooks into the hole, and the semi-circle wraps around the shaft.
This one looks to have too big a hook. Try amazon looking for hook spanner wrench and/or pin spanner wrench.
This is easy see the threads on the shaft ? You need to twist the “hole cover” maybe after releasing a set screw at about 2 o’clock in the photo. Turning that cover clockwise will tighten it , if their is a set acres in that 2 o’clock position turn it the set screw or grub screw ccw and tighten the cover ,when it is tight turn that set screw CW to hold it tight. To me this hardware looks older and of higher quality than a 60’s house unless early 60’s , but this should help.