2013 GMT Running +8s/day : time for a service ?

[copernic83]

Hi All,

My 2013 GMT Master II currently runs at about +8-8.5 s/d, although the deviation is VERY constant. Always +8.5, and not a day at +5 and another day at +10.

Otherwise everything is fine. Should I send it in for a full service or would a simple regulation do the trick for now ?

Thanks

[padi56]

Originally Posted by copernic83

Hi All,

My 2013 GMT Master II currently runs at about +8-8.5 s/d, although the deviation is VERY constant. Always +8.5, and not a day at +5 and another day at +10.

Otherwise everything is fine. Should I send it in for a full service or would a simple regulation do the trick for now ?

Thanks

Many things effect accuracy in all mechanical watches such as mainspring power-reserve gravity and so on.But before you rush to get back off, first give your watch a full manual wind thats 40 plus full crown turns clockwise only.Then set your watch with a reliable time source for this test any quartz watch/clock will do that's accurate enough.Wear your watch for 8 hours plus a day with reasonable wrist activity to wind it and keep power reserve at peak, check time once only every 24 hours with same setting source, write down the lose or gain do this for 7 complete days.Then average out the lose or gain over those 7 days for a accurate result.The most important factor with any mechanical watch is consistency which yours have, but remember there are 86400 seconds in a day. After 7 day test if watch is then showing accuracy well over the COSC spec say a average of -4 to plus 6 seconds a day, or a few seconds either way get it regulated.

[interestedwatcher]

Have you tried sleeping with the watch crown up/crown down, dial up/dial down. If it's consistent you might be able to balance it out that way overnight.