DIY GMT Master Crystal Replacement

[TonyMonatana44]

@Artyfowl - This might be one of your problems:



The metal part that holds the movement to the case does have a slight raised step as you can see in the picture above. The part where the screw goes is higher than the part where the metal end going into the case. The part that goes into the case is lower to accommodate the spinning weight rotor as a channel to be able to freely spin around.

Only reason I'm saying this might be your problem is because after you posted today that you're having issues your seconds hand, I looked at mine closer and I was have the exact same thing happen to mine. The reason you didn't see the issue right after doing the crystal swap was because the movement had some power reserved in it already. Once you completed the work, the rotor wasn't able to spin freely and caused the watch/movement to stop. this is what happened to me atleast.

The reason your second hand started up again after hitting the crystal is because you moved the case a little which caused the movement to get some power and thus move the seconds hand again. It probably moved it enough to have it stop at the same exact stop over and over again.

I opened mine up about an hour ago and viewed the entire movement under a magnifying glass. Come to find out my rotor wasn't able to spin 100% 360°. As soon as I flipped the movement metal tabs over, it was able to spin. Easiest way for you to tell if this is your issue without opening up the case again is to just shake the watch in a circular motion and try to hear the rotor. If it sounds like it's spinning completely 360°, then it's more than likely not your issue. If it doesn't sound like much movement like mine sounded, then it's your problem too.

I hope you resolved your problem with the work you did yesterday, to save you from opening the case again. But I highly doubt your issue is because of "over tightening the movement" or "changing to a PROF" xtal. I put a 2.5mm gasket in mine and it still works. You've mentioned that you used the gasket that came from CF, which is as high as Mt Everest. You should not have any clearance issues whats so ever.

I've been holding my watch in my hands for the better part of an hour now and absolutely no issues. Hasn't stopped once. I let it down on my desk for the past 3 hours and still no issues.

 

[Artyfowl]

I think you’re right Tony. I got my tabs secured better (they were always raised section lower) and left it running overnight, the big test will be when I check the watch later this morning.

I’m interested in the clean gasket depth you mention. My crystal is flat on the rehaut edge and there was still about half a mil gap from the bottom of the gasket to the watch case before I put the retaining ring on last night. I don’t see how the crystal could go any lower? I compared the prof and clean crystal thicknesses and both are identical.

 

[Artyfowl]

Ugh Pepsi operation being an arse. Bezel came off with everything. Crystal and retaining ring. Have popped the crystal out but the retaining ring is firmly in the bezel ( spinning inside so not locked) Just need to figure out how to remove it. Can’t press it out as the bezel insert is flush to it

 

[Artyfowl]

Decided to shave the crystal gasket. The prof ones were 3mm

This was a pain, the stuck retaining ring royally bummed me I need a new insert now, I assume my TDs can get? Or is there an acceptable Ali express one? This is the v3 clean…. To be fair you can’t see the crack on the wrist so I’ve re installed it until a replacement comes

 

[TonyMonatana44]

Decided to shave the crystal gasket. The prof ones were 3mm

This was a pain, the stuck retaining ring royally bummed me I need a new insert now, I assume my TDs can get? Or is there an acceptable Ali express one? This is the v3 clean…. To be fair you can’t see the crack on the wrist so I’ve re installed it until a replacement comes

I'm sorry it didn't go as planned. But just to confirm when you tried to remove the bezel it pulled everything out along with your retaining ring? I believe you could've just used a tiny flat head screw driver and pried it out. I did that to my Batman retaining ring when everything came out together.

And you're talking about the actual bezel insert that cracked, correct? Like the Pepsi blue/red ceramic bezel? If so, I would reach out to @CTime via whatsapp and ask them if they sell just the insert. I believe they sell the V3's separately. Although it might be a little expensive compared to just buying a whole new watch. But the latest version (the one that you have) is the most appealing on on the market right now in my opinion.

I would suggest you do the following: Buy a 2.7mm gasket from Clarks (eBay), buy the bezel insert from CTime (hopefully they can just sell you that), separate the bezel and retaining ring and use fishline instead of your current hytrel ring which more than likely caused this whole thing to happen. Then try it all over again.

 

[Justin_thyme]

I'm sorry it didn't go as planned. But just to confirm when you tried to remove the bezel it pulled everything out along with your retaining ring? I believe you could've just used a tiny flat head screw driver and pried it out. I did that to my Batman retaining ring when everything came out together.

And you're talking about the actual bezel insert that cracked, correct? Like the Pepsi blue/red ceramic bezel? If so, I would reach out to @CTime via whatsapp and ask them if they sell just the insert. I believe they sell the V3's separately. Although it might be a little expensive compared to just buying a whole new watch. But the latest version (the one that you have) is the most appealing on on the market right now in my opinion.

I would suggest you do the following: Buy a 2.7mm gasket from Clarks (eBay), buy the bezel insert from CTime (hopefully they can just sell you that), separate the bezel and retaining ring and use fishline instead of your current hytrel ring which more than likely caused this whole thing to happen. Then try it all over again.

why do you recommend getting a 2.7 over the 2.5 when 2.5 worked for yours? does 2.7 fit better with stock xtal?

 

[Artyfowl]

I sanded down one of my spare gaskets with 400 paper and it worked a treat. Just keep an eye on even depth with a digital caliper

 

[TonyMonatana44]

why do you recommend getting a 2.7 over the 2.5 when 2.5 worked for yours? does 2.7 fit better with stock xtal?

2.5 mm gasket worked great with a Deep Xtal.

With the Stock CF xtal I would recommend a 2.7mm.

With a Gen I’d recommend a 2.5 or a 2.7mm - which ever one you think looks better.

The CF Xtal magnification window looks kind of distorted/blurry with a 2.5mm gasket in my opinion. The Deep has a way better magnification and crystal clarify than the CF. So I think that’s why it works better.

Best thing to do is to try a bunch of options and see what best fits your needs. I matched mine with a Gen Batman and you literally cannot tell a difference with the Deep xtal + 2.5mm gasket.

I am putting a Gen Xtal in on Friday when it arrives though.

 

[TonyMonatana44]

I sanded down one of my spare gaskets with 400 paper and it worked a treat. Just keep an eye on even depth with a digital caliper

That is one way of doing it. I just could never keep the watch water resistant/proof when I shaved the original CF gasket down. I'm not sure if it's because it wasn't flat on the bottom portion of the gasket, or if the sandpaper made the surface unflat, but I couldn't see it with the naked eye.

The Clarks 2.5 gasket I used was water resistant up to 3 bar. Failed at 4. But i used UV glue and tested again and it passed 7 bar

 

[Artyfowl]

I’ve got about 30 watches now, it likely will never ever see rain let alone a pool

 

[TonyMonatana44]

I’ve got about 30 watches now, it likely will never ever see rain let alone a pool

I get it. Understandable.

I just don’t have to time or attention span to remember to remove my watch I’m wearing before I wash my hands or go swim.

I disassemble my Gen watches too and water proof them before I get them wet. My Batman was the first one I didn’t get waterproofed and it had fogging inside the case. So I had it serviced and then water proofed it my self.

 

[Justin_thyme]

2.5 mm gasket worked great with a Deep Xtal.

With the Stock CF xtal I would recommend a 2.7mm.

With a Gen I’d recommend a 2.5 or a 2.7mm - which ever one you think looks better.

The CF Xtal magnification window looks kind of distorted/blurry with a 2.5mm gasket in my opinion. The Deep has a way better magnification and crystal clarify than the CF. So I think that’s why it works better.

Best thing to do is to try a bunch of options and see what best fits your needs. I matched mine with a Gen Batman and you literally cannot tell a difference with the Deep xtal + 2.5mm gasket.

I am putting a Gen Xtal in on Friday when it arrives though.

Do you happen to have pics comparing deep xtal v2 w/ 2.5 vs 2.7?

 

[TonyMonatana44]

Do you happen to have pics comparing deep xtal v2 w/ 2.5 vs 2.7?

Unfortunately I don't. But for what it's worth, here is a pic of the 2.5mm gasket with the Deep.



I would also tell anyone reading this thread to not change to a Deep Xtal if you have a V3 Clean GMT. The Deep Xtal is not what the hype is about. I would keep the stock CF Crystal and just change the gasket height to either 2.5mm or 2.7 (i'd do 2.7, just to be safe). You can find out more info here:

Clean fixed the muddy dial!

Here are two clean GMTs: the lefty has the clean crystal, and the Pepsi has the deep crystal. Do you notice how the font on the Pepsi looks a bit grayer? Any thoughts on why that might be, KJ? Do you think it could be due to the crystal, or maybe the dial itself? Ctime also sent me the old clean...

forum.replica-watch.info

I commented as well towards the end of the thread saying the Deep made my dial dull and didn't make it pop like the CF Xtal did. I am putting a gen in mine because of this reason and throwing the deep in the trash.

 

[Justin_thyme]

Unfortunately I don't. But for what it's worth, here is a pic of the 2.5mm gasket with the Deep.



I would also tell anyone reading this thread to not change to a Deep Xtal if you have a V3 Clean GMT. The Deep Xtal is not what the hype is about. I would keep the stock CF Crystal and just change the gasket height to either 2.5mm or 2.7 (i'd do 2.7, just to be safe). You can find out more info here:

Clean fixed the muddy dial!

Here are two clean GMTs: the lefty has the clean crystal, and the Pepsi has the deep crystal. Do you notice how the font on the Pepsi looks a bit grayer? Any thoughts on why that might be, KJ? Do you think it could be due to the crystal, or maybe the dial itself? Ctime also sent me the old clean...

forum.replica-watch.info

I commented as well towards the end of the thread saying the Deep made my dial dull and didn't make it pop like the CF Xtal did. I am putting a gen in mine because of this reason and throwing the deep in the trash.

thank you for the pic and the comparison! and yes, i noticed that clean improved their crystals, esp with their 2024 watches. i also dont know what the hype around deep is about because it looks worse in certain lighting

 

[Artyfowl]

Prof is WAY better than my v3 clean crystal

 

[TonyMonatana44]

thank you for the pic and the comparison! and yes, i noticed that clean improved their crystals, esp with their 2024 watches. i also dont know what the hype around deep is about because it looks worse in certain lighting

I think the hype was because Deep is actually better than the older CF crystals. But CF has come a long way. I would say that VSF and CF are on par with gens. Prof is okay as well, but in my personal opinion it's not as good as the VSF crystals.

 

[Justin_thyme]

I think the hype was because Deep is actually better than the older CF crystals. But CF has come a long way. I would say that VSF and CF are on par with gens. Prof is okay as well, but in my personal opinion it's not as good as the VSF crystals.

i just compared gen, deep, and clarks to my clean crystal. clarks and deep are about the same/on par w/ clean imo, and gen is really clear. this was all done under direct lighting from my desk work lamp. should i be comparing them under direct sunlight instead?

 

[TonyMonatana44]

i just compared gen, deep, and clarks to my clean crystal. clarks and deep are about the same/on par w/ clean imo, and gen is really clear. this was all done under direct lighting from my desk work lamp. should i be comparing them under direct sunlight instead?

Each lighting situation will make the reflection and dial pop more or less. After installing the Gen crystal last night I noticed that in darker lit areas the Gen really pops even more than the others which wasn’t the case with deep and CF. With the others it looks quite obvious that the clarify isn’t there.

I would in my opinion do it in direct sunlight tomorrow. You’ll be surprised.