Omega Speedmaster 3861 post service accuracy problem

ninman · Mar 26, 2024

So I just got my 3861 back from a service, and pre-service it was very consistently averaging between 3.5 and 4.5 seconds a day.

Now the accuracy is fluctuating wildly and averaging out to around 8 seconds a day.

I haven't changed my lifestyle or habits in that time. Should I take this back to Omega to get them to fix it?

YY77 · Mar 27, 2024

I would first try and see the positional variation by winding it fully, resting it in every position for 24 hours so you can see after 6 days how it performs.

GrouchoM · Mar 27, 2024

Multiple measurements in one day are not beneficial unless the watch is gaining or losing a lot of time per day. On average, your watch is gaining roughly 5 Seconds a day (20.8sec gain in 4 days). I would continue to wear it, winded daily, and measure daily. You could also try leaving it for 24 hours in each of the six positions to see how it performs when it's static.

ninman · Mar 27, 2024

It's averaging about 7-8 seconds a day. By comparison here's how it was prior to the service.

Note, I have not changed my wearing habits, I wear the watch all day, including when I sleep, so there's a clear difference.

YY77 · Mar 27, 2024

ninman
It's averaging about 7-8 seconds a day. By comparison here's how it was prior to the service.

Note, I have not changed my wearing habits, I wear the watch all day, including when I sleep, so there's a clear difference.

But the Omega printout you got after the service is within specs, isn't it?

ninman · Mar 27, 2024

YY77
But the Omega printout you got after the service is within specs, isn't it?

They didn't give me a new print out after the service. Only a list of replacement parts. I don't know if they retested the watch.

YY77 · Mar 27, 2024

ninman
They didn't give me a new print out after the service. Only a list of replacement parts. I don't know if they retested the watch.

Should have been done incl. a pressure test to pass QC.

ninman · Mar 27, 2024

YY77
Should have been done incl. a pressure test to pass QC.

How do I see the results of that? The only thing I can see are the original tests when the watch was made.

Also, on its original test it averaged 4.1s/d, which is pretty much what I got from my normal wearing habits.

YY77 · Mar 27, 2024

ninman
How do I see the results of that? The only thing I can see are the original tests when the watch was made.

Also, on its original test it averaged 4.1s/d, which is pretty much what I got from my normal wearing habits.

I got a print out of the WR test and accuracy after service, you should call your AD/OB/OSC.

ninman · Mar 27, 2024

OK, I will call and ask tomorrow.

ninman · Mar 28, 2024

I called, they said they don't have the test results right now, but they'll get back to me when they find it.

ninman · Mar 29, 2024

So Omega told me they got 3.1 s/d when they tested it. I said I'm getting 7-8 s/d, so they offered to take the watch back and regulate it for me again.

I'm thinking it might just be that when I wear the watch it's spending most of it's time in a fast position.

I'm going to get it regulated anyway though, because 7-8 s/d isn't really good enough for me.

YandB · Mar 31, 2024

That wild bother me to be honest for a 3861.
My 1863 and 321 do like +12-15 but I forgive them because they are old design movements. The 3861 should be 0-5

ninman · Mar 31, 2024

YandB
That wild bother me to be honest for a 3861.
My 1863 and 321 do like +12-15 but I forgive them because they are old design movements. The 3861 should be 0-5

Exactly, which is what I was getting prior to the service. Plus the crown is making a weird creaking noise when I wind it. It was doing that before and it sounds like it's still not fixed.

So it's definitely going back.

Canuck · Mar 31, 2024

My calibre 863 from 1990 consistently runs -1 second per day, worn 24 hours. I serviced it myself January 2023. Pretty good for a 34 year old watch, I’d say! You won’t likely be happy until your watch performs at least as well as did prior to service. (My Rolex calibre 3135 is within one second in the last 20 days!)

Dimitar Adamski · Sep 18, 2024

Why so early for a service?

bsowers34 · Jan 9, 2025

I have three 3861s. All 2024 production, and the white one has already been serviced (basically rebuilt) for a runtime issue. I set all three at the same time to the NIST clock, and when I wind them in two days the white one is 10 seconds slower that my FOIS and Hesalite. I find that interesting, but don't stress over it. I haven't really looked too closely as to how accurate they are vs NIST.

Evitzee · Jan 9, 2025

I also have three 3861s, two from 2022 and one from 2024. All are running fine, even the two older ones which were from that time period where some issues were in play. In fact the latest one I got from 2022 (NIB but sold to me in Nov '24) shows zero deviation when wound every day and rested crown up at night. I play with the chronos to see if the past dreaded issue crops up with the older ones but so far no issues. It's really the luck of the draw.

bsowers34 · Jan 9, 2025

Evitzee
I also have three 3861s, two from 2022 and one from 2024. All are running fine, even the two older ones which were from that time period where some issues were in play. In fact the latest one I got from 2022 (NIB but sold to me in Nov '24) shows zero deviation when wound every day and rested crown up at night. I play with the chronos to see if the past dreaded issue crops up with the older ones but so far no issues. It's really the luck of the draw.

Indeed it is.

Omega Speedmaster 3861 post service accuracy problem

ninman

YY77

GrouchoM

ninman

YY77

ninman

YY77

ninman

YY77

ninman

ninman

ninman

YandB

ninman

Canuck

Dimitar Adamski

bsowers34

Evitzee

bsowers34

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