Service Seiko Chronograph (UFO) Calibre 6138

A customer has sent in his Seiko chronograph. It’s funky, complicated and stops when the chronograph is engaged. This will be fun;)

Eww dirty case! It needs a little clean up.. Movement does not look to bad at fist sight, but it will need a service.

This chronograph also features a day and date mechanism. Unlike it’s close relative the 6139 this calibre can also be manually wound.

The minute recorder wheel has come loose of it’s pinion and is the reason this watch stops when chronograph is engaged. I rivet the wheel back onto the pinion.

I measure the old Seiko 6138 mainspring, to my positive surprise it’s very close to a ETA 2892-2 mainspring.  105X.115X420mm so I will order mainspring no: GR25341X

The movement is cleaned and ready to be put back together. I put the shock protection jewels back in place and see that the balance moves freely. The new mainspring goes into the barrel.

I fit the winding/setting mechanism before the gear train. 

Movement comes together and I see that it works well with the new mainspring. 

I put the rest of the watch back together and it looks and works great!:)

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