Hey all, this is my first post on this forum so be gentle with me. I am looking for some information regarding the reliability of the Seamaster AT Co-axial 8500 movement. I have several Omegas I have picked up on the used market over the years and have never had a problem with any of them. Five years ago for a landmark birthday I bought my first new one, the Seamaster 8500. Just over two years later the winder went very stiff, hard to adjust, advance the hour etc. It was returned under warranty and when returned to myself I was told there had been a lack of lubrication in the final assembly of the watch. Not very reassuring info to receive.
Anyway the watch has gone faulty again two years later, same area causing problems.
The hour hand will not jump in hourly increments to advance the date, it glides forward. The time cannot be advanced past the nine o'clock position and if I back wind the watch to get it running it will not run past 9.05.
I will have to return the watch again for repair outside the warranty period with a possible £380.00 charge.
Is this a problem with these movements ? if so I may have to consider my options. Two years between repairs at these service costs is just too much, I have bought an old Seamaster for less.
Regards
Peter.

 

This particular fault is a failure of the hour wheel. It is what provides the one hour increments of the hour hand. They can fail after a time and I replace them at every service because of this. How long they last will depend on how much it's used, so if you are advancing the hour hand a lot, say to change the date after you have not worn it for a time, then this will cause it to fail sooner.

So they do fail, but really you are at the typical 5 year service interval now, so it's not really two years for this particular part.

Cheers, Al

 

Cheers, Al
Hi AL, many thanks indeed for this insight, you are probably right about the cause of my watch failure, just before it failed I had advanced the date probably about twenty days and only noticed a couple of hours later it had stopped.
Having said that, I do not wear this watch a lot, it has probably been on my wrist less than 300 hours since new. I will have to be a bit gentler with it in future when advancing the date or get a winder. I have a 1961 Constellation I wear on a weekly basis always setting the date and it has never caused any problems, don’t make them like they used to.
Is it ok to rewind the hours to reach the current date if this was quicker? I was always led to believe a watch should be advanced only, or is this a myth.
Regards
Peter.

 

You can change backwards as well.

 

Is the fault particular to the 8500 or is it common among other movements that have the jumping hour feature? I have 2 Omegas and 1 JLC that have jumping hour hands and it has become a major concern. It seems like a disaster waiting to happen in just 5 years.

 

If you consider the possible failure of a part that costs about $20 at a point in time where a full service should be performed anyway, then you have a very different view of what a disaster is than I do.

But to answer your question, I can't speak to the JLC design but all Omegas that use this system have a similar design - at least the mechanical watches do. So this includes everything from the Cal. 1128 in the 90's GMT watches up to the current models.



Cheers, Al

 

In that case, I'm taking out my watchwinder. I know it's not the best practice, but I intend to have my watches serviced every 7 years. Full service cost from where I live is US$900 so I'd like to extend the life of my watches a bit.

Many thanks for the info, Al!

 

Hi, full marks to the Omega service department, the watch was returned today at no cost to myself even though it was outside its warranty period. The hour wheel and hand were replaced. Perhaps the advice of the retailer to include a letter of complaint containing the wording, grave concerns, bitter disappointment, frustration etc did the trick. Anyway I will be a bit more wary changing the date in future.
Regards
Peter.

 

This just happended to my 8500 Planet Ocean. I'm also experimenting power reserve issues, It was on my wrist all day yesterday, I took it off by 8pm and today afternoon it was like 8 hours behind. I believe they are supposed to have 60+ hours power reserve.

 

Maybe it's time to revive this old thread a little. I am heartened that the issue has been unreported since 2019.

Anyways I have two teak dial ATs with the 8500 movement, the white dial and the Skyfall blue dial with the date window frame. Both came to me pre-owned. When it comes to winding and detectable problems the white dial behaves like any and every other automatic watch I own: problem-free.

The blue dial has a stiffness to the crown for winding and adjusting: I'd describe it as an overall friction resistance, no highs and lows. The watch has been a safe queen for most of the years we've been together but retirement affords me more days when I can just wear a really nice watch without the worry of banging it into an office desk or whatever.

It sounds like I might have to get it serviced by Omega.

 

Interesting that this thread has just been revived. Just put my Planet Ocean 45.5mm titanium (232.90.46.21.03.001) in for service for this exact reason. Hadn't worn it in a week so wound it up and set the correct time when the hour jumping function went from clicking to smooth. A worry but the time set correct and ran, looked at it later in the evening at 11pm and it read 9... confused I took it in the next day and they have said the part may have to be replaced and paid for. Considering the service cost is at £625 as standard, I think Omega are out of order asking for more on top for their own parts that break.
Will keep this updated when I get the watch back from service... in 6 months time!

 

This part, like almost all others, is included in the service price. I suspect this is an AD that is telling you it would have to be paid for on top of the service? If so, they are just uninformed, like a lot of AD's are.