Seiko 5 / Finding exact year of production

[BlueHarp]

Hello all of you,
As I wrote in another post, I've got an old Seiko 5 which works now very well (I just have to put a new crystal). I would like to find out when it was produced. From the serial number (6N8222), I understand that it was manufactured in November xxx6, and the reference of the caliber (6309) would point to November 1976 or 1986. Is there a way to guess which of these two years is correct? The case back mentions 6309-8840 (A6) and here are a few pictures.

[AndyGSi]

To my knowledge there's no way of narrowing it down any further.

Sometimes you can dig further with the Strap Code and/or Dial Code to get a Model No. but yours appears to be missing.

[Nucejoe]

This talks about this kind of stuff .

https://www.plus9time.com/seiko-case-back-information

Edited September 22, 2024 by Nucejoe
correction

[AndyGSi]

43 minutes ago, Nucejoe said:

This talks about this kind of stuff .

https://www.plus9time.com/seiko-case-back-information

All that tell you is what's common knowledge for month and possible years or manufacture.

[BlueHarp]

Thank you for all that information. I rea

I read the indications on that very good website, but it seems I won't be able to have further details.

 

[BlueHarp]

I got it ... probably! I read that Seiko added a letter every 10 years to the number of the movement. The Seiko 6309 was produced from 1976 to 1989, so it became 6309A in 1986. My serial number 6N8222 sould indicate that the watch was made in November 1986, if the explanation is correct.

[AndyGSi]

12 hours ago, BlueHarp said:

I got it ... probably! I read that Seiko added a letter every 10 years to the number of the movement. The Seiko 6309 was produced from 1976 to 1989, so it became 6309A in 1986. My serial number 6N8222 sould indicate that the watch was made in November 1986, if the explanation is correct.

Not sure where you got the letter for 10 years but I've never heard of it and doesn't line up with any other movements.

As far as I'm aware there aren't any movements mark 6309 just 6309A.

There is a parts list for a 6309B dated October 1990 but not sure how this works.

https://myretrowatches.co.uk/wp-content/uploads/2022/03/Seiko-6309B-Parts-List.pdf

Edited September 23, 2024 by AndyGSi

[BlueHarp]

Thank you. That information about spare parts dated 1990 for the 6309B should confirm that my watch was made in 1986 rather than 1976.