seconds hand not running smoothly cal. 601

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paulgard

·Apr 28, 2026

Hi everyone,

I've just serviced this Omega 601. It's working great on the Timegrapher, but I've noticed that the seconds hand isn't running smoothly. I checked the toothing and adjusted the tension spring for the seconds gear, but found nothing unusual. Does anyone have any idea what the problem might be? There are no anomalies on the Timegrapher. Since this happens every 5–7 seconds, I thought it might be the escape wheel, but I couldn't find anything wrong with it.

Thanks in advance

 

IMG_5027.mov - 26.2 MB

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ErichKeane

·Apr 28, 2026

That looks like the spring is disengaging/letting it skip. Can you take video zoomed into the spring /second pinion?

I had it happen similarly (mine would eventually totally stop) until I 'flattened' the part of the spring that touches the pinion. Installing hands 'incorrectly' can cause damage to it. The correct way to install a second hand on the 601 movement is to either remove the spring, or put a piece of metal between it and the pinion when pressing down on the second hand, else it will damage the spring.

 

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tritto

·Apr 29, 2026

Likewise, I suspect the second hand tension spring - I had a similar start, pause, jump after servicing a 354. The end of the spring was a little bent and it was catching on the gear then releasing.

 

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Endshake

·Apr 29, 2026

Did you oil the second hand pinion? Between the tension spring and the gear?

 

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ErichKeane

·Apr 29, 2026

Endshake

Did you oil the second hand pinion? Between the tension spring and the gear?

Note you are NOT supposed to do this, according to @Archer.

 

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Endshake

·Apr 29, 2026

I know
Thats why i‘m asking.
I once had this issue because of oiling an 564 on this spot

 

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redpcar

·Apr 29, 2026

Common problem for me when I'm installing the second hand. Alignment / retainer spring issue. Did you assemble this watch yourself or a watchmaker?

 

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ErichKeane

·Apr 29, 2026

Endshake

I know
Thats why i‘m asking.
I once had this issue because of oiling an 564 on this spot

Cool, wanted to make sure we didn't mislead op 😀

 

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paulgard

·Apr 29, 2026

Hello, and thank you for the many replies.

I've just checked, and it seems that the spring is bent under the gear, pushing the entire seconds wheel and pinion upwards. (See the slightly exaggerated drawing below.) To be honest, I found it a bit strange that the spring was pushing from underneath, but it arrived like this without this problem (the owner never mentioned it and can't remember).

Now, in reply to the questions:

@Endshake: I didn't apply any oil between the spring and the gear.

@redpcar: I assembled it myself. I'm a watchmaker, but this is the first time I have serviced this calibre.

The question now is whether the spring should be under the gear, touching only the pinion, or whether it should be pressing from the top.

I will bend it flat so that it doesn't touch the gear, and I will report back.

 

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redpcar

·Apr 29, 2026

If memory serves, below the gear. Closer to the movement.

 

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ErichKeane

·Apr 29, 2026

It should sit flat against the bottom of the pinion, and push the pinion against the jewel. Just confirmed looking at a 613 I have with a screw off back 😀

 

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Archer

·Apr 30, 2026·Omega Qualified Watchmaker

ErichKeane

It should sit flat against the bottom of the pinion, and push the pinion against the jewel. Just confirmed looking at a 613 I have with a screw off back 😀

Correct - it presses the pinion up into the jewel.

 

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paulgard

·May 6, 2026

Hi everyone,
Good news! It’s fixed 😀😀
I also noticed that it works better when you put the spring on the left side of the pinion. This may be because the rotation is turning away from the spring rather than pushing into it.
Thank you so much for all your help!