GMT hand running slow every day.

[Alexccmeister]

I noticed a few days ago my GMT was running about 3-4hr slow. I adjusted it and today noticed its 2 hours slow. Anyone know why this is the case? Aren't the gears supposed to work in tandem? My hour and and minute hands are perfect running. Would like to hear some opinions from the experts before I go to the TD. Got this late November.

 

[KJ2020]

What watch and what movement?

 

[yodog]

gmt gear probably getting unseated

 

[Alexccmeister]

What watch and what movement?

Tudor GMT A2836

 

[Alexccmeister]

gmt gear probably getting unseated

I did complain to TD about the gear not meshing when I first got the watch. There is a spot when I pull the crown out fully where when I turn the crown, the hands would rotate with a stutter. Like the gears weren't meshing. I am wondering if this the cause of the slow GMT. It was ok for the 1 month plus I had the watch though. So not sure if the slight bump I did to the watch may have cause the gear to misalign. All hands will turn, just the GMT turning slower and losing time per day. But hour and minute hand working fine. What should I do?

 

[KJ2020]

The watch will need to be taken apart and examined. Sounds like some gear teeth are stripped. You will have to decide whether to have it fixed locally or see if your TD will help. The GMT wheels are not part of an ETA 2836 (it's a special mod) and are not easily available separately that I know of. The other parts can be ordered from Ofrei or ebay. A dead GMT movement with good GMT wheels would be a good option. Many modders or hobby watchmakers would likely have one. I do not, sorry.

 

[KJ2020]

I said what I did about gears stripped because you said hands (plural) were stuttering. As yodog mentioned, it's possible the smaller GMT wheel screw became loose and it is riding up (unseated) and not driving the larger GMT wheel properly all the time. This would be an easy fix but still requires the movement to come out and the hands and dial to be removed. It's possible this is happening without any gears being stripped. I would not try to set the hands any further until this is looked at.

 

[KJ2020]

GMT 2836's also have an extra gear on top of the intermediate date wheel that drives the larger GMT wheel when the watch is running. This is also a possible point of failure.

 

[Alexccmeister]

Thanks guys. This watch is going back to the TD. Not going to take it apart. Will let TD resolve the matter. It should still be under warranty. TD is well aware of the issue prior. Will chat with him now.

 

[hulkamaphone]

This is always my concern with more complicated rep movements. Please keep us posted OP with how it turns out!

 

[Alexccmeister]

This is always my concern with more complicated rep movements. Please keep us posted OP with how it turns out!

Will do. I suspect its gear meshing issue. I fiddled around with it and its keeping the right time again. Normally around this time I would be losing 2 hours on the GMT.

 

[KJ2020]

Is it possible the GMT hand is catching on an hour marker? IDK how tall those markers are but the GMT hand is on the bottom of the stack and I had one do this. As a result the hole in the GMT hand where it mounts to the pinion became slightly enlarged and it would slip sometimes.

 

[Alexccmeister]

Is it possible the GMT hand is catching on an hour marker? IDK how tall those markers are but the GMT hand is on the bottom of the stack and I had one do this. As a result the hole in the GMT hand where it mounts to the pinion became slightly enlarged and it would slip sometimes.

I will have a closer look at it. But honestly though since day one they is a spot when I pull the crown out the crown would turn but the hands just won't turn and if they do turn, they kind of stutter. Like gear not meshing. I suspect this is the reason.

Here is a video when I first got the watch.

At around 43 seconds when I found that spot in the crown.