Help me Seiko modding community, you're my only hope.

Hello crunchers! I need help.

I made a big whoopsie (or maybe not) with my seiko sumo GMT, after using the bezel for a while it became stiff and hard to use, I rotated it under warm water and that solved the problem, for a bit... After a while the action became stiff again so I decided to pop it open to clean the gunk that was getting it stuck or maybe see what the problem was.


And I noticed the rubber gasket was broken, this could have been causing the stiffness but it could have also been me by accident. My questions are, where can I find a replacement gasket (maybe a ceramic insert too), are these the same size as the automatic sumo models (because the case on these is slightly shorter by a mm or so), and is the water resistance okay without the gasket (maybe since it's not a proper gasket more so there to create friction)?

Help me seiko modding community, you're my only hope.


I鈥檝e had good luck with crystal times USA. Picked up a lumed ceramic insert, sapphire crystal and gaskets for my Srpd a while back.

Crystaltimes is pretty good, but I don't know if they have what you're looking for. has ceramic inserts for the Sumo, but I can't tell you if yours is the same size as the non-GMT version. That's something you could email them and ask. The description says it's compatible with 3rd generation, but I'm not sure which models that is. As far as the bezel gasket goes, it's there to create friction. It won't hurt to use the watch without it, but the bezel may spin freely. You might have to try Cousins UK, or another Seiko dealer/watchmaker to get the right gasket.

Had the same problem with my stock skx. They do tend to make two different o ring sizes. When I bought mine I got a oem spec which tend to be a smaller diameter than a lot of the after market bezel.

1. Cleaned the bezel and the watch itself. Make sure to fully dry, preferably with some sort of compressed air or fan. The less lint from towels the better.

2. I used a silicon lubricant and coated both the inside of the bezel, the entire o ring, and any other contact points.

3. Give or more than a handful of good turns. Then wash the excess.

Crystals times is the best great customer service!