Updated: Mar 7
The Seiko 6139 chronograph movement was released in 1969 and was in the race for the world's first automatic chronograph. Who got there first isn't a subject we will get into here! The Seiko 6139 is a great movement, but it has its wear points. Many watchmakers don't like to service vintage Seiko as parts can be difficult to obtain. We have quite a stock of parts we can tap into at our workshop and pride ourself on being able to restore them. Due to their external gasket structure on the pusher's and crown most of them can be made water resistant again. The common wear point is the barrel arbor bearing surface in the main-plate. To rectify this wear we bore out the hole in a watchmaker's lathe and install a custom made jewel for this purpose. The movement was serviced, barrel wear rectified and new crystal was installed. The watch had new gaskets all around and passed a 70m water resistance test, just like when it was new.