Tissot cal 2481 date wheel to hands syncronisation problem

[thewatchdoctor]

Hi I'm seeking from any anyone who has had this puzzling problem I have on a Tissot cal 2481 that I recently serviced. When setting up the hour and date hand to coincide with date click over at 12pm I observed the following. When I revolve the hands through 24hrs the date no longer clicks over at the same hand position. It is now at 12.10 and so on the more days I revolve the hands . First time I've experience this on a watch, any ideas?

[watchweasol]

Hi I think the convention was to set the hands the start changing the day/date at 11.50 allowing the wheels time to overcome the detent spring, the completion being in or around 12.00. Thats how i set them up. I may be wrong but I am sure other  members will have their own ideas.

[jdm]

31 minutes ago, thewatchdoctor said:

When I revolve the hands through 24hrs the date no longer clicks over at the same hand position. It is now at 12.10 and so on the more days I revolve the hands . First time I've experience this on a watch, any ideas?

Looks like a good look at the calendar works, dial removed but hands fitted is in order to understand what causes the timing shift. Was the watch keeping a good time, is a dial washer fitted. 

[thewatchdoctor]

Watch is +2sec, dial washer was fitted, tested as per pics with hands on same problem. Checked spring on date wheel maltese cross assembly good. date wheel assembly good not slipping,

[thewatchdoctor]

Finally worked out the cause. 4 complete revolutions the date clicked over at exactly the same. The next 1 was out, the following 3 was perfect, then out again and then twice perfect. Took it apart again and their it was, uneven wear on some of the date wheel teeth. This was causing the date changing arm of the star wheel to not turn the date wheel enough so that the sprung loaded locking arm couldn't flick the date wheel that final bit. There is always a first time to learn something new.

[jdm]

Topic moved to the proper section - the introductions one if for that exactly, not technical discussions.