I am an experienced watchmaker working on one of my first Seiko divers.(6309-7290) I have overhauled the movement without trouble and have replaced the crystal, gaskets etc with factory parts. I have the factory crown gasket. The watch had no gaskets to speak of when I started working on it. There does not appear to be room inside the crown for this o-ring, and there is no groove at the base of the treaded portion of the crown post that looks like most o-ring grooves I have seen. So, my question is, where the heck does this crown gasket go? There may be an accumulation of crown crud inside the crown that is keeping the o-ring from fitting inside, but I do not think so. Any advice??

Kevin

I don't have an answer for you either,but maybe if you posted your question on the green board you might get an answer.

Kevin,

Check this site. Its a PDF so it loads slow.
Seiko 6309
Appears to be an O ring on the stem from the pictures.
Joe

You need the case part number to see if it needs an o-ring. The numbers or letters after the movement grade number on the caseback. From that go to Jules Borel and find out if that Case comes with that configuration.

Frank "431" Kusumoto