Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

This blog post includes narrated video's, these can only be seen on the ClockSavant Instagram page. This is a beautiful vintage Seiko 4502-7001 I recently serviced for a ClockSavant customer. As can be seen, it’s in pristine condition. As shown in the pictures of the back of the watch, there are two inscriptions running underneath the top and bottom lugs in Japanese.  Two video’s on the ClockSavant Instagram page discuss the unique hack stop and date quick change mechanisms in this watch and the value, and increased work, involved in full disassembly. After servicing, the watch is exceptionally accurate, to within a second or two a day across all positions.

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms

Servicing a Seiko 4502-7001 and a discussion of the hack stop and quick date change mechanisms