Seiko 66-9990 - Identifying/Sourcing parts and crystal

[Jacacanta]

Hello Forum,

I started this project of servicing a Seiko 66-9990 (my first "real" project).

I would like to replace the crystal and started looking for information but am struggling to find any specifically for this model (maybe too old ?)

My questions:

- Is there a way to find the correct Seiko reference part number for the crystal for this model ?

- Is there a way to get a "tech sheet" with all Seiko part numbers for this movement (66 A) in case I need to order any replacement parts ?

Many thanks in advance for any help and/or advice 

Best

Joao

[FLwatchguy73]

Hopefully this will help. If you don't want to buy from eBay, this has the part number you're looking for.

https://www.ebay.com/itm/318N02AN00-GENUINE-GLASS-NICE-DOMED-SEIKO-66-9990-6600-9990-6600-9991/303513451934?epid=755225504&hash=item46aacfbd9e:g:aDgAAOSwEzxYc8Rr

Edited April 23, 2020 by FLwatchguy73

[aac58]

Here is the parts list

 

 Seiko 66A - Parts List.pdf

Seiko 66B - Parts List.pdf

Edited April 23, 2020 by aac58

[Jacacanta]

2 hours ago, FLwatchguy73 said:

this has the part number you're looking for.

Thank you watchguy! 

One question though: I came across some ebay listings with that part number for the specific case but how to be sure that the ref is the right one ? You can't allways trust the listings/sellers ...

Thanks again for your help! 

[Jacacanta]

2 hours ago, aac58 said:

Here is the parts list

Excellent! Thank you very much, this is exactly what I was looking for!

[FLwatchguy73]

Further investigation revealed that the Crystal I initially suggested may not be correct. Boley in Germany has all cases and crystals listed for nearly every model and brand of watch. Please see the screenshot and link below. I would trust the accuracy of Boley's information over anyone on eBay.

https://boley.de/en/case-parts/seiko/20719.6600-9990?q=9990&p=0&s=50&l=18

That said, Jules Borel in the states lists the original part number I posted. Jules Borel is also very reputable. Looks as if the original part number is easier to come by though.

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=W]bcWFdcTH

Edited April 23, 2020 by FLwatchguy73

[aac58]

1 hour ago, FLwatchguy73 said:

Further investigation revealed that the Crystal I initially suggested may not be correct...

I think that both references (318N02AN00 and 318N01AN) refers to the same type of crystal, a 31,8 mm non water-resistant with no accesory (like tension ring etc) acrylic crystal. The 01/02 in the middle of the code is just a serial number for production classification, and the 00 at the end, not specified in the first code, means a transparent crystal.

Cousins have this crystal out of stock, but they say it's expected by 2 June

https://www.cousinsuk.com/search?searchTerm=318N02AN00

Edited April 23, 2020 by aac58

[Jacacanta]

Thank you for the links watchguy ! Am starting in this hobby and was not aware of these two providers.