Jump to content

Worn pivots on a Seiko

anilv

By anilv
in Watch Repairs Help & Advice

 Share

Recommended Posts

anilv Distinguished Member

anilv

Posted
Posted

I have several movements sans watches and in my free time I service them (the more popular ones at least)  so I usually have one on hand for a quick swap. I've been working on a Seiko 6309 recently, an ebay special.

This movement was marked '6349' on the auto-wind bridge but on removing this I was a bit disappointed to see that the third and fourth wheel pivots were unjeweled... this was the plain jane, vanilla 17 jewel 6309 with a 6349 autowind bridge thrown in!. Ah well, the 6309 is good enough in its own right.

or is it?......

Pegging out the holes it didn't 'feel' right, on taking a closer look the pivot-hole just didn't look right.

P_20161125_063825.jpg

Looking at it from the other side and ... looks like I have a problem.

P_20161125_063814.jpg

Viewed against the light..

P_20161125_063758.jpg

Some serious wear! This is not typical of Seikos (in fact I can't remember coming across another Seiko with this problem) but can happen if a pivot gives way suddenly, allowing the mainspring to release all its energy at once. The wheel itself was fine but since this watch was already a 'mongrel' it could have be.en swapped out in a effort to get it running.

Well I have a bunch of 63xx movements so a replacement was soon found. In the pic below, the damaged bridge is on the right and the bad pivot is clearly visible.

P_20161125_064245.jpg

The replacement bridges shows some wear on the plate where the ratchet wheel has been rubbing. There was some slight movement when I fitted the barrel so what can be done?

On these seikos, the barrel runs in a steel bushing, slight better than running in bare brass but not as good as running in a jewel. So with a suitable drift (too big for normal staking tools) the bush from the damaged bridge was removed and installed onto the replacement bridge.

One thing to note, the barrel pivot usually wears on one side, so when re-installing the bush I try to install it 180 degrees from its original orientation (use a marker for a reference).

While there was still some movement when I installed the barrel, it was markedly less than before.

Rest of the re-build is your standard Seiko.. no problems except for a wobbly rotor-bearing..

Looking at the pics while writing this post I realised that it was possible that the pivot-holes could also be steel bushes, will check this out on the damaged bridge later.

Happy weekend!

Anil

 

Link to comment
Share on other sites
clockboy Distinguished Member

clockboy

Posted
Posted

I have seen pivot holes made of steel on the real low grade pin lever movements but was not aware some Seiko Calibers also have this poor design. I think I see one of Marks vids where he reams out the centre wheel pivot hole & replaces with a jewel. A while ago I did replace a barrel arbour bushing. I had to make the bushing out of brass because although conventional jewels had the correct internal & external dimensions they where all to thick.  This is a very interesting vid that shows the method I used.

 

  • Like 1
Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
Posted

Barrel arbor bushing do very often have that wear? If i can find a better one from an other movement i use my staking tool to replace it? The 6349 auto.winding bridge probably had a better bearing then the old 6309 had. 

Usually is a lot of different parts in the old 6309 watches. As NOS parts are hard to find. 

Link to comment
Share on other sites
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • Marc
      Seiko 6309a diver crown replacement

      By Marc · Posted

      Interesting interpretation of "traditional". I would say that Loctite is definitely the up-to-date and appropriate stuff to use, however, it is a relatively modern solution. Before the advent of such esoteric solutions I believe that the "traditional" thread locker of choice may well have been a sugar solution. Once applied the water would evaporate and the sugar would crystalise, locking the threads tight.
    • Marc
      Pocket watch winding stem sleeve

      By Marc · Posted

      @steve1811uk close but no cigar 🙂 I don't smoke anyway. I checked in my stock of parts and that's the closest I got to your dimensions. Good luck in your search. @RichardHarris123 I have an accumulation of all sorts of odds and ends that I acquired as a result of buying up the tail ends of old watchmakers estates. Usually after all of the great stuff has been stripped out, which means that the sweepings off of the workshop floor can be had for peanuts, but if you have the patience, can often be found to contain gold (both literally and figuratively 🙂 ). These came to me through on of those purchases. I doubt that I will personally be able to make use of even 10% of my accumulated stock, but having it, and knowing what I have, means that I can at least pass bits on to those who can use it whenever possible.
    • Curare
      Spell Check

      By Curare · Posted

      Hi and thank-you for your suggestions, as per Mark's instructions I checked my browser "Safari" and spell check and grammar was not ticked. So all sorted. Thanks CJ  
    • RichardHarris123
      Seiko 6309a diver crown replacement

      By RichardHarris123 · Posted

      As an alternative, clear nail Polish, the advantage is you can have a manicure at the same time. 
    • VWatchie
      Spell Check

      By VWatchie · Posted

      I use Grammarly. It works really well and If English is not your first language, you will also receive help with formulations. There is a free version that covers most of my needs. It installs as a plug-in and works with all browsers and word processors.
×
×
  • Create New...