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GMF DJ41 frankening

McPwn

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New updates so far.

Was able to find a Gen 25-315 crystal which was a direct swap using the GMF stock gasket. Gen gasket was a bit thicker and needed more force to go on, and i didnt want to take a chance forcing anything too much and breaking something.

Installed Gen smooth bezel, also a direct swap.

However, noticed that now the date seems too large in the window compared to gen. Guess what? The date font and date window on the stock GMF dial are slightly larger to make up for a lower mag on the GMF cyclops!

So now i will try an aftermarket 3136 dw and see if it looks better.

With Gen crystal you can also see a more prominent halo effect surrounding the crystal, and it protrudes/sits higher than rep crystal. Of course, AR/black hole effect is better and LEC is less prominent. Definitely recommend changing the crystal.
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KJ2020

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These are some very nice mods bro, well done.

I've encountered the same date mag issue with GMF GMTs and had to adapt by using different thickness crystals and gaskets. ARF also does the same thing with some of their DWs (smaller font, higher sitting crystal) for whatever reason.

Which way does your SA3235 set time and quickset date - crown CCW or CW? I would be surprised if either version of VR3235 (if a 2nd version for DJ41 is released) isn't CW.
 

McDuck888

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Gen crystal and your bezel are gorgeous! Such worthwhile swaps!! I love your watch man.
I only read this most recent post and I wonder if anyone’s got a datejust 41 ARF crystal gasket kicking around spare. Because the ARF has a microscopically thinner wall in depth thickness than the gen Rolex crystal gasket lol. (But it’s much easier to press onto a watch than the Rolex gasket for it), but it’s also got a little shorter 2.00mm ARF gasket height. So maybe you’d not have to even worry about swapping your datewheel if you tried out the ARF low, cute gasket. Whatever you go for, it’s already looking A1 to me ;-)
 

McDuck888

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(Also in your pics, I noticed I really love the date number’s size in the cyclops as it is just now. And with a smooth bezel I always anticipate that the crystal is going to ‘appear’ to be sitting taller cos the bezel in my mind is lower being smooth than fluted. I just love it! Superb watch!)
 

McPwn

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McPwn can you post a pic of your GMF dial for comparison?
Yup, i had to take a picture myself to be sure. I've been trying to fig out why the dw didnt have quite enough 'white space' around it, and finally came to this conclusion.

You can see in the below pics, the gen date window fits exactly inside the 14 and 16 minute tick marks. On the GMF blue dial, the window extends very slightly past the 14 and 16 markers.

Also, the movement is not a 'true' SA3235. Ive looked through past posts, and the SA3235 in other reps (like REF for example) has a gen like dial mount and movement diameter BUT a slow date change that starts at 10pm. My guess is, GMF switched to a 3135 base with a 3136 date wheel so they could have the quick date flip like Gen.

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McPwn

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Gen crystal and your bezel are gorgeous! Such worthwhile swaps!! I love your watch man.
I only read this most recent post and I wonder if anyone’s got a datejust 41 ARF crystal gasket kicking around spare. Because the ARF has a microscopically thinner wall in depth thickness than the gen Rolex crystal gasket lol. (But it’s much easier to press onto a watch than the Rolex gasket for it), but it’s also got a little shorter 2.00mm ARF gasket height. So maybe you’d not have to even worry about swapping your datewheel if you tried out the ARF low, cute gasket. Whatever you go for, it’s already looking A1 to me ;-)

Thanks man! appreciate the comments.
Even with a diff magnification level, the 'white space' around the number wont change, which gives it the more 'centered' appearance..the size of the date window in relation to the date number would be the same no? Once i have both date wheels side by side I'll compare.
 

Sundek

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hello everyone very interesting discussion too bad my english is not the best and i probably missed some useful information I just wanted to ask you if the wimbledon DJ of gmf has a real clone of the 3235 movement or is it a decorated eta clone? I'll post a couple of links I thank in advance those who will help me
Best regards

Paolo

https://jtime.cc/us/datejust-41-ss-...roman-markers-on-jubilee-bracelet-sa3235.html

https://geektime.cc/product/datejus...en-roma-markers-on-ss-jubilee-bracelet-a3235/


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KJ2020

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hello everyone very interesting discussion too bad my english is not the best and i probably missed some useful information I just wanted to ask you if the wimbledon DJ of gmf has a real clone of the 3235 movement or is it a decorated eta clone? I'll post a couple of links I thank in advance those who will help me
Best regards

Paolo

https://jtime.cc/us/datejust-41-ss-...roman-markers-on-jubilee-bracelet-sa3235.html

https://geektime.cc/product/datejus...en-roma-markers-on-ss-jubilee-bracelet-a3235/


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The GMF DJ41 movement is neither a true clone 3235 nor an ETA clone. It's a hybrid SA3135 with some proprietary parts made to make it look like a 3235. The dial has feet that go into the movement holder at the 2824 feet positions. The SA3135 has widely been regarded as the least desirable rep 3135 movement.

3135 movement comparison Gen-SA-SH-VR
 

Sundek

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The GMF DJ41 movement is neither a true clone 3235 nor an ETA clone. It's a hybrid SA3135 with some proprietary parts made to make it look like a 3235. The dial has feet that go into the movement holder at the 2824 feet positions. The SA3135 has widely been regarded as the least desirable rep 3135 movement.

3135 movement comparison Gen-SA-SH-VR

Thank u so much [mention]KJ2020 [/mention] for the explanation

I have now abandoned the eta clones to switch to real clones do you think this is a good model to have in your collection?


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McPwn

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Added Gen hands and aftermarket replacement 3136 datewheel. Affermarket Datewheel needed some sanding around the edges, otherwise it wouldn't move freely within the datewheel seating plate tabs, as theres extra paint around the edges compared to rep. Sometimes at midnight though, the date moves a bit too far, so may need to adjust the tightness of the 'tabs'' holding the DW a little more.

Gen 3235 hands fit without issues. So thats a benefit, as ARF needs a pinion mod to fit gen hands.

Here you can see the font difference: GMF on left, ebay 3136 DW on right.
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McPwn

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Got tired of dealing with the dial alignment issues and bit the bullet on a DJ41 version VR3235 from thrillofhunt . Heres some pics of it, top is SA3235. Datewheel font looks good so probably will leave it for now.
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McPwn

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So you are not going to use your gen DW bro? (I know that would be pretty complicated).

Nah, feel like it'd be too much work to get a 3136 DW to work due to the teeth alignment, given that a gen 3235 DW can be had for a reasonable sum. If i used it as an overlay, it might be too thick and not flip properly.
 
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McPwn

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As expected, VR3235 is a direct swap, everything fits as it should. Gen Dial/Hands drop right in as they should. Date window and alignment is perfect. Also, to advance time, you turn counter clockwise instead of clockwise (3135), which is correct as per gen. Crown haptics are not as buttery smooth as gen, winding has some resistance and time setting feels 'bumpy' to put it best. Though a servicing would probably help if thats what you want.

jiXfho.jpg

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One thing i noticed is that the thickness is around 12.6MM, gen should be around 11.70. Some of that is due to using GMF crystal gasket with the thicker gen crystal. So a shorter gasket will prob help some. But wondering where the rest comes from, perhaps the caseback? If anyone has caseback thickness for gen/VSF/ARF for me to compare, that would be helpful.

jiXGsP.jpg
 
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McPwn

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So yup, looks like the extra height is all due to the crystal gasket being too high. I've sanded it down and was able to bring it down to 12mm or so. However, having problems with water leakage under the crystal now. It seems like it probably wasn't waterproof from the factory either. The gen replacement gaskets are like 0.60 mm thick out of the box, which is too thick for the bezel to go on. I've tried every which way and the bezel just wont go on at . However after sanding it down to 0.50 mm thick so that the bezel can go on, which is about the same thickness as the stock GMF gasket, i get water under the crystal just from running cold water over it. Hot water doesn't seem to leak, as I'm guessing the expansion helps.

KJ2020 Any tips here? Does boiling the gasket help? It seems like Datejust II's had a separate bezel gasket, but the 41's don't?
 

KJ2020

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So yup, looks like the extra height is all due to the crystal gasket being too high. I've sanded it down and was able to bring it down to 12mm or so. However, having problems with water leakage under the crystal now. It seems like it probably wasn't waterproof from the factory either. The gen replacement gaskets are like 0.60 mm thick out of the box, which is too thick for the bezel to go on. I've tried every which way and the bezel just wont go on at . However after sanding it down to 0.50 mm thick so that the bezel can go on, which is about the same thickness as the stock GMF gasket, i get water under the crystal just from running cold water over it. Hot water doesn't seem to leak, as I'm guessing the expansion helps.

KJ2020 Any tips here? Does boiling the gasket help? It seems like Datejust II's had a separate bezel gasket, but the 41's don't?

Ack that's not good. I recently put this one together from spare parts and ran into the same issue. The bezel wouldn't seat over the crystal plus gasket. The parts were all supposedly for 116x DJ41. So I just sanded down the bezel a little on an angle from the underside and kept checking to see if it would seat until it went down over the top of the gasket. Then I pressed it home to be certain and then pulled it off to finish the watch. I wanted to wait for final seating til the movement was done and installed.

I didn't check for WP but it was so tight going on it was all I could do to seat it fully so I'm not worried about it. I don't get any of my watches wet anyway and all my TT and FG are stored in a closed case with about 20 packs of desiccant.

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This is how it was sanded, same technique as sanding an insert down. I've done it on a few bezels too. Check widths around the bezel often to measure progress.

ji1qDF.jpg


Different watch, same work

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Note: You can keep most of the top inner flat ledge on the bezel intact if you're careful but it's likely a bit of it will have to go. On a smooth bezel I might start by taking a tiny horizontal slice off that ledge, then angling down from it, taking more off toward the bottom of the bezel inside.
 
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McPwn

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Ack that's not good. I recently put this one together from spare parts and ran into the same issue. The bezel wouldn't seat over the crystal plus gasket. The parts were all supposedly for 116x DJ41. So I just sanded down the bezel a little on an angle from the underside and kept checking to see if it would seat until it went down over the top of the gasket. Then I pressed it home to be certain and then pulled it off to finish the watch. I wanted to wait for final seating til the movement was done and installed.

I didn't check for WP but it was so tight going on it was all I could do to seat it fully so I'm not worried about it. I don't get any of my watches wet anyway and all my TT and FG are stored in a closed case with about 20 packs of desiccant.

16353615457891.jpg


This is how it was sanded, same technique as sanding an insert down. I've done it on a few bezels too. Check widths around the bezel often to measure progress.

ji1qDF.jpg


Different watch, same work

ZEMGqn.jpg


MOANt.jpg


Note: You can keep most of the top inner flat ledge on the bezel intact if you're careful but it's likely a bit of it will have to go. On a smooth bezel I might start by taking a tiny horizontal slice off that ledge, then angling down from it, taking more off toward the bottom of the bezel inside.
Interesting you mention that, as the GMF stock bezel has an inside ledge, but the gen smooth bezel has no such thing. Was wondering what that was for.
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KJ2020

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D'oh I forgot you had a gen bezel!

To answer a previous question of yours, boiling gaskets has never done anything for me. The melting point of nylon Is quite high like 500° F. I know because I've had to melt fishline (in an oven) to get it out of a bezel gasket groove - it was slightly too thick and wouldn't allow rotation and I couldn't pop it back off.

Man if the gen gasket is too thick and shaving it or using the rep gasket causes leaking, the only thing that will do it I think is glue.

I've used several different glues with gaskets, crystals, and bezels. UV glue can be used but I am very partial to JB Weld epoxy now. LMK if you are open to that approach, I can post some more info. I am confident a 0.2mm tall bead of JBW, half the width of the bezel, placed at the joint between the gasket bottom and the case would keep water out (at least at that potential entry point).
 

WatchSmith.US

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I solved leakage installing a gen green sapphire in a milgauss franken with GS Hypo cement. Messy to work with but 100% waterproof when I was done. The gen sapphire is slightly undersized for the rep case and leaked as a result. JBW is good stuff. I’ll keep that in mind.
 
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