Galloping/Banking Fix?

[Kirby6365]

Hi all,

Strange problem with a A2824 I have in a Tudor BB. Partially wound and just out of the watch box it sounds fine, keeps good time, good readouts on my timegrapher...

When I get closer to the end of the day wearing it all day, I'll notice the time is off pretty wildly (5+ minutes). I noticed if I put my ear up to the watch it sounds like its galloping or knocking. It has a 'pinging' sound to it which I assume is the galloping issue. Putting it on the timegrapher just gives me garbage, and if it can read a time its something like +600s/d or equally ridiculous (which might explain the +5 minutes).

If I let the watch wind down a bit (10 minutes not on the wrist or so), the sound goes away and all is well on the timegrapher... so it seems to me to point to the watch just isn't happy being wound up to the max.

Any idea what the fix is here? Almost sounds like it needs more resistance somewhere to keep it running properly. Could this damage the movement over time? Any help would be appreciated!

EDIT: Also, as a note, the amplitude when the noise just goes away is around 350 degrees

 

[Raddave]

My guess is you got a bad mainspring....too short or it doesnt slip in the barrel, (no braking grease ?)



I think your problem is called pin banking

 

[Kirby6365]

Think it would be easiest to just replace the entire mainspring + barrel? I can tear down and take out the barrel - not sure if it'd be easiest to just replace the whole thing, or if the spring + grease would be just as easy (and likely cheaper)

 

[Kirby6365]

My guess is you got a bad mainspring....too short or it doesnt slip in the barrel, (no braking grease ?)



I think your problem is called pin banking

Finished putting in a new ETA mainspring, it's purring along nicely! Amplitude caps out at ~340 and no more horrible time inaccuracies. Thanks Raddave!

 

[Raddave]

Yay I win ( and so do you )