# Sorting A Vostok Amphibia With Handwinding Issue



## horz (Aug 24, 2008)

I bought this watch from the forum a while back, with a handwinding issue. The problem was described as a grinding sound and, on arrival, that's exactly what it was like. It felt as if something had stripped teeth, so I set about looking at the movement to see what was up.

Here's the watch as I received it. Quite fond of the white dial, it makes a nice change after having a black dialled scuba dude amphibia for a while.










So, opening it up. This was interesting, the rotor was much nicer than I had seen on vostoks before. The rotor (left) was on this watch, while the other (right) is from my other amphibia. Maybe someone else worked on the watch before and swapped it? I don't know why it would have a Vostok Europe rotor but, in any case, it was a nice surprise.

















After removing the rotor the movement ring and screws were also removed. The movement was then removed from the case










With the hands and dial taken off, I started to look at the crown wheel and winding pinion for signs of wear.

Looking at the winding pinion from the dial side of the movement, everything looked fine. The teeth appeared well formed and there was nothing indicating the cause of this strange grinding.










I moved on to check out the crown wheel and see what it was like. After removing the autowinding bridge this is how everything appeared:










continued in next post...


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## horz (Aug 24, 2008)

Again, the crown wheel teeth look perfectly fine. Here is a better photo which shows the winding pinion and crown wheel side by side.










So, after deciding that there was nothing wrong with the two wheels, I thought I'd try putting everything back in place and see if the problem remained.

Oddly enough, there was no more winding issue! Puzzling...

After thinking about it my best guess at the cause was that the washer which sits atop the crown wheel must've been seated incorrectly. The crown wheel screw does not mate with the top of the wheel (of course, otherwise it woud not move) and instead stops when it is tight against the post which it screws in to. The washer is there to take up the gap between the screw bottom face and the crown wheel top surface, while still allowing movement. I think that the washer must've been trapped between the screw and post, leaving too much space between the crown wheel and washer. Although not much, it would have been just enough for the crown wheel to move out of position and stop teeth meshing correctly with the winding pinion.

Anyway, I thought this might be of interest to some, and hopefully useful to anyone encountering the same problem.

The culprit:


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## PC-Magician (Apr 29, 2013)

Interesting and worth remembering. :thumbup:


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## luckywatch (Feb 2, 2013)

Excellent post, thanks. :yes:


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## greasemonk (Oct 4, 2012)

very interesting post,well described and enjoyable,thanks...


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## mel (Dec 6, 2006)

Good result, and good posting for us other tinkererers to follow in the pictures. :yes:

It's always worth remembering when fault finding, that often it's the simplest things that you find causing a problem. When fault finding at WORK (spit), I always made 1) a visual check of "all parts seemed to be there", followed by 2) check the mains plug wiring and fuse, and then 3) check any other fuses in the kit. :lol:

You'd be surprised how many times this either cured, or narrowed down a fault :yes:

These principles apply to all fault finding, check the simple things first!


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