I recently purchased a TC sub LV v4 (2836-2 ETA) and after having it in my possession for 1 day, I sent it off to a friend on this forum to have a gen crystal (AR LEC) and gen insert installed.
It came back with the gen parts and realized that when I screwed the crown all the way in, after about an hour the second hand stopped at the 50 second marker. To get it ticking again, I tapped the watch on my hand and it started moving. I wound it up about 100 times and screwed the crown in all the way and stopped at the 55 second marker this time after about 45 minutes. Did the same steps and stopped at the 15 second marker this time. I have ruled out that the second hand is touching the crystal.
I finally wound up the watch one last time and left the crown in the winding position and it has been going strong for almost 50 hours now. It seems that the watch stops only when the crown is screwed in.
I was talking to correctime and he mentioned that the problem is likely a long stem and needs to be shortened a thread or two.
What do you guys think? Any suggestions or similar stories/experience with the TC Sub?