BP 3186 - strange behavior

[Duckguy]

Hello,

I recently purchased a BP GMT II in RG/SS with the 3186 movement. I really, really like this watch and even under a loupe find it hard to pick out too many flaws. Unfortunately, something is goofy with the movement it seems. It runs well for a time, keeping good time - I hand wind it and wear it, but seemingly at random (sometimes I wound it hours ago, but sometimes less than one hour), the watch will start to lose large amounts of time. The second hand continues to sweep, but it will end up 20 or 30 minutes, or sometimes a couple of hours, behind (depending on how recently I looked at it I suppose!).

What are some things I could look into to troubleshoot this problem? I imagine that the movement would benefit from a service. Is it possible that the hands are hitting at some point? I guess I expected it to happen at consistent times if this was the case, and when moving the hands with the crown I cannot feel an interference. However, that is the only thing I can think of. Thank you in advance for any advice you might offer.

 

[Asmodeus]

What movement is it? ICHS or CHS?

 

[Duckguy]

Oh, sorry, correct hand stack.

 

[BLK.W.EXPRESS]

I have an explorer gmt but 2836-2 with a very similar problem.
timegraph reads perfect on all angles.
Runs perfect when it sits on the table
Runs slow when worn

 

[Rx4Time]

Esh...the curse of the CHS. Could be any number of things. I'd first decade the movement and let it run to see if it's still loosing time. My first instinct is the second hand is barely touching the crystal and depending on position dragging at points.

 

[Duckguy]

Thank you for the input, those are things I can check out. Now I need to look up what "decade the movement" means .

 

[KJ2020]

Thank you for the input, those are things I can check out. Now I need to look up what "decade the movement" means .

Decase = take the movement out of the case

 

[Duckguy]

Oh...decase! Yeah, I can figure that one out. Yep I will do that when I get something good for magnification and can create a clean enough spot. I'll try to report what I find, if I find something.

 

[Rx4Time]

Sorry...big fingers and small cellphone combined with autocorrect...ugh...decase, not decade.

 

[Duckguy]

Just wanted to update and say "thank you" so far. It will be a while until I'm able to pull the movement and figure out what is really up. However, for some reason I had not considered, until you guys pointed it out, that the issue may vary by position. I had an idea, after it was mentioned, that the slowing/stopping of the time may have been happening when the watch was resting off my wrist and on the non-crown side (crystal more-or-less vertical). So for the last 3 days or so I've left it flat when not wearing it and thus far it has kept very good time.

So, either the hands are hitting something when it's on the side, or...well, I don't know. It's hard to imagine how something could move enough when placed on the side to make a difference, but whatever the case at least I now know how to lay the watch to get it to keep time. THANKS AGAIN. If I learn more I'll update.

 

[OldNavitimer]

There were two small screws floating around in my CHS 3186 Batman that would cause the same problem. I’m no longer surprised by anything anymore.

Well, except maybe the Epstein “suicide”...just didn’t see that coming...


Sent from my iPhone using RWI

 

[Duckguy]

I didn't see it coming either given the recent suicide watch. I mean, it's straight out of a recent movie or show, where the camera shows nothing until the blood flows out the cell.

I took the back off once but will do so again and check for any loose material. I did notice some damage that I believe was to the movement holder ring? Or the hardware, I can't recall at the moment, but I remember thinking "well, if there wasn't a dead give away, that sure is." thank you for the suggestion.

 

[KJ2020]

Just wanted to update and say "thank you" so far. It will be a while until I'm able to pull the movement and figure out what is really up. However, for some reason I had not considered, until you guys pointed it out, that the issue may vary by position. I had an idea, after it was mentioned, that the slowing/stopping of the time may have been happening when the watch was resting off my wrist and on the non-crown side (crystal more-or-less vertical). So for the last 3 days or so I've left it flat when not wearing it and thus far it has kept very good time.

So, either the hands are hitting something when it's on the side, or...well, I don't know. It's hard to imagine how something could move enough when placed on the side to make a difference, but whatever the case at least I now know how to lay the watch to get it to keep time. THANKS AGAIN. If I learn more I'll update.

See what happens with the movement face down. Sounds like maybe a problem with your dial side (bottom) balance staff jewel. The staff and assy are working fine when resting on the top jewel (face up) but not when on the side so the bottom of the staff may be dragging on a damaged, dirty, or dry bottom jewel.

 

[Duckguy]

Okay! Makes sense. I will do just that and report back in a couple days or so. Thank you.