What would cause smashed teeth, and completely gone pinion teeth?
Hour and minute gears from an otherwise undamaged Hamilton 936. Serial # 637207

I need to find these parts, and I'll post in the parts wanted also.

A nice clean running, fully marked movement.

Only a hairline between 8 and 9.

The only way to get this much torque to these wheels is with the stem in the set position.

Something else had to be locking up the hour wheel sufficiently to absorb this much torque.

The person twisting the crown had to be incredibly heavy handed.

I've had hour wheels fit the cannon too tight to allow the watch to run, which can also be felt as unusual resistance when rotating the crown in the set position. Ironically, it didn't appear until after I mounted the hour hand, which compressed the tube on the hour wheel causing it to bind the cannon.

Other than that way out theory... I couldn't even imagine. Unless, no dial washer was installed and the hour wheel was able to engage/dis-engage the intermediate wheel and wear on each other... but that should look a lot different and would show up as a fussy set function.

I have seen this happen when an Hour hand with an undersize hub bore was forced on the Hour wheel hub and "locks" the hour wheel clearance bore to the cannon pinion hub. Then when you try to force-set time, you simply strip the teeth off the intermediate wheel pinion and/or bend/break wheel teeth.

Thanks, Paul and David.
When I got it the hour and minute hand turned together when you tried to set the time.The hour hand hub didn't seem to be too tight.
No other parts are damaged, so all I need is a new set of gears, I hope. I won't know for sure until I get and install them.

Thanks again!

Steve

Since the hands were turning together when you got the watch were they stuck together...If they were tangled up with each other when someone tried to set the watch this to could have stripped those gears...I might have them in the shop but I won't have time to check until Tuesday..If you haven't found them by then I will be back in touch..

How about a kid that didn't know when to quit winding.....or an Idio*.
I have actually COA'ed a watch and putting it back together I wound it to be sure it was OK and seen with my own eyes one of the wheels just loose a section of teeth. There was no load on it to speak of. Placing it under the microscope I could see stress (Age) cracks all around the parameter of the gear.

Cannon Pinion is maybe to tight

Replacement gears found and installed, no binding, everything works fine.
Owner is happy and so am I.

Steve

Like I said, it was probably stress cracks in the wheel.