Seiko 7S26 Mainspring

[Don]

For those of you who are servicing Seiko 7s26 movements, are you removing and cleaning the mainspring? I've read that the Seiko barrels are difficult to open and maybe not meant to be opened. However, the mainspring and barrel complete seems to be discontinued.

[Mark]

Its a bit tricky to open but it really should be so that the mainspring can be removed, cleaned and lubricated. The barrel lid is not flat but has a side which is a bit different from regular barrel lids. And the lip of the lid goes right down to the barrel teeth.

 

The lid does come off like any other barrel but because the lip it is quite easy to damage it or the barrel teeth. I usually use a fine stanley knife blade to gently prise it away - the blade should be super sharp in order to get in between the lid and barrel. Slide the blade along the teeth inwards and apply a bit of pressure being careful not to twist the blade. And once you see a gap appearing then very carefully twist the blade, being cautious not to damage the soft metal of the lid or barrel teeth.

 

The mainspring is also left handed on these movements.

 

Hope this helps.

[Don]

Thanks for the info Mark. I guess I'll jump right in and give it a try. *Gulp*