Automatic bumper winding not working

[arron]

Good day everyone,

I am almost done restoring this Mido 817 automatic bumper wristwatch from the 40's.  The only problem left is to fix the automatic winding mechanism.  If the watch is fully run down and I move the watch around, the weight will go back and forth as it should to wind the watch.  but, if i give it even a half wind of the crown the weight will not move in the winding position/direction (it will ratchet back to the winding position and then stick again).  i can still move the weight manually in the winding direction.  when it does wind automatically (or by me pushing the weight) all of the gears seem to turn appropriately.  I noticed that the two main winding gears (red arrows) have no end shake; are they suppose to?  or do they always have tension on them so that they can't be moved manually.  i read the maintenance manual on the omega bumper movement that someone posted here but that didn't help.   I plan to take it apart but thought i'd check for any advice first.  Thanks.

[Nucejoe]

57 minutes ago, arron said:

 I noticed that the two main winding gears (red arrows) have no end shake; 

Both should have noticable end shake.

[watchweasol]

Hi   find enclosed parts sheets for the 817 1nd 816.     As Joe explained endshake is impor.tant on all gears/wheels 

2964_Mido 817.pdf 2963_Mido 816.pdf

[arron]

Thanks to you both.  that's very helpful. i've saved the parts list so i'll have it for future reference.  and so just to be clear, even when a watch is wound up and under tension, there should still be end shake on the gears; is that right?

[nevenbekriev]

End shake must be checked when the wheels are free of tension. Release the main spring and check it - I guess it will be OK. The problem is not the end shake, but lack or bad function of some of the clicks in the winding movement.

Edited November 5, 2023 by nevenbekriev