I have been using a Tele Graflex (@1925?) 3 1/4x4 1/4 fairly successfully for a few months. The shutter curtains are good, and the speeds are fine. However, it recently started behaving oddly - when the shutter was released the gear sometimes seems to skip - I can hear it - , and the slit ends up out of place. And of course when wound up again the curtain and slits are in the wrong place, etc. I can get them all aligned again and it may work correctly a few times, but the problem always repeats.

I am familiar with Graflex/Graphic mechanisms and I have fixed other problems before, but this one has me at a loss.

The small gear at the end of the top shutter shaft looks like its chewed up. More than half the gear on the body end looks like it has been worn or ground down, but the further half looks unused. The large brass gear inside the top shutter escutcheon looks like its in good shape, the teeth are sharp enough, etc. It seems that the large gear is bearing on only part of the small gear and destroying it.

I suspect I need to replace the small gear. I have not fully disassembled this camera, not needing to as it was working fine. What do I need to do to replace the gear, and what gear from what camera would be compatible ? Would I have to replace the whole top shaft ?

Any suggestion would be very welcome.