Slipping of the gears when setting time on my 1680 & 16750.

[Jetkopite]

Good morning guys,

Just wanted to ask you the experts with regards to an issue I come across once in a while when setting the time on my 1680 REd and Gmt 16750. Sometimes when I go to set the time on above pieces after a number of turns on the crown I find that they slip ie I turn crown and hands dont move. I then push crown in wind the watch a little then try again and they move again so I can set them..

Can anyone shed any advise as to this being normal on old vintage watches, has anyone else experienced this??

I am not sure on the service history of both watches but they both run pretty accurate, the GMT loses 3 secs every day worn or unworn and the RED Sub gains arouns 2-3 secs when worn and runs 7-9 secs when not worn and in resting position...

Any advise would be appreciated...

Cheers

Andy..