Seiko 6139 Service Manual |best| Official

The 6139 is a unique beast. It features a vertical clutch and a column wheel—complications usually reserved for Swiss chronographs costing ten times as much. However, the service manual is essential because the assembly order is counter-intuitive.

Note: The 6139 is a modular movement. The chronograph mechanism is built on top of the timekeeping gear train. Disassembly must proceed from top to bottom. seiko 6139 service manual