Hi gentlemen

On my Kenwood R-5000, my IF Shift inner knob doesn't stop turning at the
positive and negative marks like it should. It works fine, but the knob
spins freely all around and around if you wish without stopping like the
other knobs on the radio. I know that some sort of catch is not stopping it
from turning freely as it should. Broken off?

Since the control works, is there any way to fix this myself somehow?

If not, does anyone know what part number or type of control is used for
replacement?

Thanks guys
Lucky