Watch will run accurately for a day and then stop running

[GregG]

I have a vintage Timex watch (though similar symptoms have happened with regular movements) that will run well for a day, keeping time to a minute, and then inexplicably stop.

The first time around, it was running for about an hour on my bench.  When I went back, it had stopped.  I verified that the hands were not fouling against each other or the crystal.  I took the movement out, and gave it a flick to manually start the balance.  The balance rotated freely, but otherwise, nothing.  Zero power making it to the balance.  I applied some force to one of the gears to get it moving and it sprung back to life.

It ran very well for about 36 hours.  It was still running well this morning, and I wound it up, and continued to run for some time.  I eventually took it off and placed it on my desk.  I just came back to it right now, and it's dead.  What could be causing this behavior?

When I received it originally, it could sustain a tick, though I didn't test it long-term.  Therefore I didn't really "repair" this watch, I figured it just needed a good cleaning, and I am pretty thorough about that.

Edited January 23, 2023 by GregG

[JerseyMo]

11 hours ago, GregG said:

I have a vintage Timex watch (though similar symptoms have happened with regular movements) that will run well for a day, keeping time to a minute, and then inexplicably stop.

The first time around, it was running for about an hour on my bench.  When I went back, it had stopped.  I verified that the hands were not fouling against each other or the crystal.  I took the movement out, and gave it a flick to manually start the balance.  The balance rotated freely, but otherwise, nothing.  Zero power making it to the balance.  I applied some force to one of the gears to get it moving and it sprung back to life.

It ran very well for about 36 hours.  It was still running well this morning, and I wound it up, and continued to run for some time.  I eventually took it off and placed it on my desk.  I just came back to it right now, and it's dead.  What could be causing this behavior?

When I received it originally, it could sustain a tick, though I didn't test it long-term.  Therefore I didn't really "repair" this watch, I figured it just needed a good cleaning, and I am pretty thorough about that.

possible casues:  worn metal, dry parts, debris\grim.  it does not take much to stop a movement.  add a picture of the watch and movement.   

[GregG]

Hi Mo, I know you're the resident Timex expert, so you probably already know what a Model 27 movement looks like.  And those dial tabs only have a certain amount of life in them before they snap.   But I will get a picture of what I can when I have it next to me.

I pegged every hole in the movement, ran it through an ultrasonic in lighter fluid, reassembled and oiled it.  I don't know what else I can do to clean it, and everything is oiled.  What parts could be worn in such a way that it allows it to run for 36 hours perfectly, then stop abruptly?

 

[JerseyMo]

does it stop only dial side up or dial side down?  these would likely indicate issue with balance an or the vconic bearings.  my guess is there is wear to something and causing friction.

I've also seen the issue be the tension of the mainspring as it unwinds.  If it were me at this point I'd go to my parts stash and get a NOS \ refrub m27 out.

 

2 minutes ago, JerseyMo said:

does it stop only dial side up or dial side down?  these would likely indicate issue with balance an or the vconic bearings.  my guess is there is wear to something and causing friction.

I've also seen the issue be the tension of the mainspring as it unwinds.  If it were me at this point I'd go to my parts stash and get a NOS \ refrub m27 out.

 

could alos be associated with the day date bits.  try to run the movemement without the day and date wheels in place.