I went to tune my 1919 Gibson A this morning and one of the knobs spins on the shaft. It doesn't wiggle - just slips. It does have some friction and is possibly capable of getting halfway up to proper tension.

I did a search here and see that superglue is a common fix. Either dripped down the shaft or remove the knob and place it directly. It there anything unique about these original tuners? Super glue still ok or is the knob particularly sensitive to it? Is the shaft smooth or knurled? If knurled perhaps I shouldn't try to pop it off.

thanks,

Jim