Leaderboard

https://www.ebay.co.uk/itm/Seiko-401-110-Mainspring-Ressort-Muelle-Zugfeder-Molla-1104A/162358367342?hash=item25cd50146e:g:kmAAAOSwZQRYepH-

The 550 and the 551 are listed as the same reference

Looks like the Omega 551 mainspring interchanges with quite a few Omega watches list below.. Then what's interesting is this is the best fit list of cross references the mainspring catalog doesn't 100% agree with this. Although looking at the catalog it looks like all of the spring is if there is a variation are so close it's not going to matter. OME 550 (CD1) OME 551 OME 552 OME 560 (CD1) OME 561 (CD1) OME 562 (CD1) OME 563 (CD1) OME 564 (CD1) OME 565 (CD1) OME 750 (CD1) OME 751 (CD1) OME 752 (CD1)

So that were all in the same page I have a link below it was just the first one that came up googling it shows the lubrication talks about its use.. You will note the word grease versus oil is used in the description. It depends upon the size of the watch for your lubrication requirements. Usually very small watches require a lighter lubrication than larger watches. Then there's a certain degree of personal preference as to what people like.. So 9010 is universally regarded as the lubrication for balance wheel pivots.. 9020 works good for gear trains. Then Moebius 9104 Synt-HP 1300 Is considered a very heavy oil. To get an idea of what I mean by light and heavy oils the second link lists lubrication's with their viscosity. https://www.esslinger.com/kt-22-microlubricant-watch-grease-and-moisture-sealer/ http://www.moebius-lubricants.ch/en/products/oils

If you're curious as to what the procedure is for servicing these the manual is attached.. Unless you have prior experience with tuning fork watches and electric watches I wouldn't recommend because the parts are not readily available. The manual is a interesting mix of two manuals PDF page 29 and page 31 has the electrical tests related to the coil resistance. Then this watch has an interesting feature four screws and the electronic module and the index wheel all are removed as one unit.. ESA 9162 Repair Manual.pdf

That's not a quartz watch That's a "hummer" tuning fork movement. Not sure a linefree box will be so good on this? ESA 1260 is that the daydate model? Bad coils can be one problem. They are very difficult to work with as you need a microscope and now what you are doing. There are a few watchmakers that service this watches. Check electricwatches .....out.

According to the GR catalogue, both the 550 and 551 use the same MS, see page 10 of this link. https://www.cousinsuk.com/PDF/categories/7810_GR Pages 141 - 150.pdf