Seiko 6138

[Jeremy]

Hi I have a seiko 6138 panda and I noticed that the hour subdial is continuously running when the Chrono function is not engaged. Any thoughts to why this would happen? 

[thor447]

Couple of potential causes I'd think:

1.  The spring for the hour recording wheel stop lever has come dislodged, broken, or the eccentric pin has been turned (see Fig. 9 in diagram below), causing it to not apply the correct amount of tension to the stop lever

2. The stop lever has slid under the hour recording wheel (I've seen this on two 6138's I've worked on), although this would probably cause the wheel to not function at all rather than always run.  

 

 

There's really only one way to find out though, and that's to take it apart and have a look.  Thankfully you can check the brake without having to remove the front chrono plate.  Pull the dial and hands off, remove calendar works, and there's a window that shows you the hour recording wheel and the stop lever meeting together.

Here's one I recently came across where the stop lever was on the underside of the wheel (probably not your issue, but you can check):

It should sit like this:

Edited January 28, 2023 by thor447

[Jeremy]

Thank you!  I really appreciate the info!!

[thor447]

My pleasure.  I had just finished working on a 6138-0040 Bullhead for a friend of mine, and he had requested a few pictures of the watch while it was apart.  When I read your post I knew I had the photos available.

[JAHM]

Hi all. This is a related topic and although the original poster has had their query answered, I could use some advice.  I too am putting together a 0040 Bullhead and it appears that the PO had turned the eccentric pin (hour recording stop lever spring axle) 90 degrees away from where it should be.  Attempting to turn it back I managed to shear half the axle head off after 45 degree rotation (so still out of alignment).  Any thoughts as to what is the best way forward now.  
My thinking was to either:
1) Drift out the existing axle, turn it to correct position and refit.  I feel that there is still enough of the axle to hold the spring in the correct location. 
2) See if the axle is available as a spare (though I can't see it in the parts listings) and replace OR
3) Get a scrap main plate, remove and clean up the axle from that one and replace into mine

1) is probably doable as a short term fix;  2) I doubt if this is a spare part; 3) anyone selling a main plate seem to be selling good ones at great expense.

Anyway, suggestions would be greatly appreciated and if anyone has a rubbish, not really salvageable main plate they were going to get rid of, I be more than happy to pay for postage and reuse one part of it rather than chuck the lot out.   Cheers, John