|
The last time I sent one of mine in for a service, it was due in terms my lived history(5 - 5.5 years as a daily wearer), but it was for an obscure and barely perceptable reason.
Interestingly in this instance which was an all time first for me, the watch was running particularly well as it normally ran about -1.5 seconds per day, but it had started to speed up and was much closer to being absolutely spot on.
So to answer your question there is no hard and fast rule, except to say that the Achilles heel for a 31xx movement is known to be the lubrication requirements of the bearing arrangement for the oscillating weight which is crucial for the Automatic winding mechanism.
|