sleepyastronaut
·Thanks, now makes sense.
Regarding the pinion, it was bent and I think that it is not in a good shape. The second hand is ok, except when I pull the crown and turn it anti clockwise, the second hand turns anti clockwise too... When I turn clockwise, the second hand just keep running as it should.
I believe this is an implementation of a hacking mechanism. On my 552, when you turn anti clockwise, the seconds hand stops until you let go. Sometimes when you do this, the seconds hand runs anti clockwise.