Seiko 6139-6000 April 1969 - Multi part Stem

JAHM · May 21, 2023

Afternoon all. I have a 6139-6000 notch case from early 1969. I was looking at the stem and realised that it was made of two parts (I guess for easy replacement of the gear and spring) which I thought unusual. If this was the thinking I am not surprised at the number of crowns that "popped out" as these are a pushed together (friction fit). Is this usual as I have not seen it before? Even the crown is push fit. I've added a picture below. If anyone can provide comment, that would be great. Cheers, John

AlexeiJ1 · May 22, 2023

Must be an early model anomaly. The later ones just had a stem that screws into the crown.

The proof models of a lot of seikos were 'alpha/beta' versions.

I would imagine the reason a lot of 6139s lost their stems was moisture ingressing into the case, sitting on the stem quick release lever and causing it to rust in position causing the stem to fall out when date quick change is attempted.

I would probably fit a newer style stem if you have one with a crown.

JAHM · May 22, 2023

Thanks for that Alexei. I will have to keep a lookout as these bits seem to be either expensive or "few and far between". Cheers

Waggy · May 22, 2023

Probably a stupid question, but have you tried a regular stem?

JAHM · May 23, 2023

Hey Scott. As I want to ensure that the inner chapter ring engages with the chapter indicator wheel properly, I would need to get a 357612 stem. This would mean I also need a threaded crown as mine is a push fit. As the current friction fit set up works, I will use that. I just wanted to see if anyone had come across this type of crown/stem before or is it an early "beta" type anomaly as Alexei suggested. Cheers, John