One of my earliest memories of taking any sort of interest in a wrist watch was as a child in the early 1970’s admiring my Dad’s Seiko Bell-matic 4006-7010, hanging loosely from the underside of his wrist on its steel bracelet. He bought it on a business trip to Japan, I think, sometime in the late 1960’s and it was a permanent fixture on his wrist until the mid to late 1980’s when it stopped and instead of getting it serviced he replaced it with a rather nondescript Seiko quartz. The Bell-matic disappeared into a drawer somewhere, and somehow has been lost in the intervening period.
For some time I had been keeping an eye out for a replacement and then in late 2009, after a couple of false starts, I found a nice looking 27 jewel 4006-7011 from June 1970 from a UK Ebay seller. When I received it however, it became clear that all was not well. Although the dial and handset were in superb condition and the movement looked clean and tidy, it was running catastrophically slow, had a rather poorly refinished case, a slack cannon pinion, a misaligned day wheel and the date wheel had a gungy brown line running along part of its outer edge.
Although by this point I had serviced a couple of 6309 movements, I had no experience with the 4006 movement and more importantly no spare parts to draw on and so at this point I thought I had best leave it to an expert and contacted a Bell-matic enthusiast who kindly agreed to service the movement. Before sending the watch off, I cleaned and refinished the case, removing the worst of the previous refinishing job. During this process I noticed that, although the crystal was new (a Sternkreuz), the tension ring was missing.
So off it went and within a couple of days I got a email reporting damage to the top of the screw on the gear that flicks the date and day over (the date finger). This had almost certainly been inflicted during a previous service by someone attempting to unscrew what is a left handed threaded screw anticlockwise. You can see the damage here:
(Photo credit: John Bentley)
With the damaged screw and a few other bits replaced, including the cannon pinion, date wheel and a tension ring for the crystal, and following a day or two fine tuning, the watch was running sweetly again. Here is a shot of the movement with the date finger replaced and awaiting the new cannon pinion:
(Photo J. Bentley)
I added a new case back gasket and popped it onto a new Hirsch rally strap:
a side view showing the dual purpose date quickset and alarm priming button
and a more recent photo, the watch now on a Hirsch Duke: