MBK 1665 crystal installation

[straight_six]

Just finished modding my new MBK DRSD, while at it, i discovered something strange...namely, there is a groove in the case around the base of the crystal...and not the one under the retaining ring! A wild guess would be that an o-ring strategically placed right there, before pressing the crystal/ret. ring would do wonders for water resistance. Any insights into this? I attached a pic that i shamelessly stole from one of ubi's threads. Chime in guys...

Thanks,

Dean

[Pugwash]

Yes, an O-Ring goes there.

[straight_six]

Yes, an O-Ring goes there.

How sweet. I didn't put it. What size is it? Is it reasonably water resistant without it?

Dean

[Pugwash]

When I say an O-Ring goes there, I've never managed to fit one on.

On the genuine Rolex, I believe there's an o-ring, but I've not seen one on a rep. I tried to fit one, but I couldn't fix the crystal on it.

[alligoat]

It should be WR w/o it. Rolex didn't start putting an o-ring in the gens until the early 70's. I think that maybe the caseback gasket and this gasket are the same size.

Ha, your pic is of a 1680 w/ the cyclops, but same idea w/ the 1665. You could also put some silicone on the gasket to help w/ WR.

[straight_six]

It should be WR w/o it. Rolex didn't start putting an o-ring in the gens until the early 70's. I think that maybe the caseback gasket and this gasket are the same size.

Ha, your pic is of a 1680 w/ the cyclops, but same idea w/ the 1665. You could also put some silicone on the gasket to help w/ WR.

I think we're not talking the same o-ring. There is a place for one under the crystal lip, not under the retaining ring which is roughly the size of the caseback one.

[straight_six]

When I say an O-Ring goes there, I've never managed to fit one on.

On the genuine Rolex, I believe there's an o-ring, but I've not seen one on a rep. I tried to fit one, but I couldn't fix the crystal on it.

Funny This is a new challenge for modders then...how to slide the crystal over this thing. Size anyone?

Dean

[Pugwash]

You can see the groove clearer on my exploded 1680 pic:

[Justasgood]

I have a friend's Great White and it has the same groove. Pug, it is not the one under the Compression ring milled into the case body, this one is on the backside of the rehaut.

I managed to search through my watchmaker's collection of O-rings and I got one to fit nicely.

It needs to be the right circumfrence and very thin.

Good luck,

Kurt.

[geyper man]

Fit a greased gasket like this one into that groove if you want a better water resistance:

http://cgi.ebay.com/Crystal-Retainer-O-Ring-1665-1680-for-Rolex-Sub_W0QQitemZ230404162991QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a52885af

This is my 5512, I'm sorry for the pic's quality:

[Justasgood]

Not the groove we are talking about......I will get some shots of it shortly....

[Justasgood]

Here are pictures of the groove and the 2 O-Rings:

The O-Ring in the Vertical area of the Rehaut backside is thin and very tight.

I hope this helps.

I am not aware of any Rolex Gens with this feature so to me it's a mystery.

[jmb]

I think it's a pretty good idea for an O-ring to be here.

[straight_six]

Kurt, that's the one! Could it be a rep feature only? I'm failing to understand how metal-plexi-metal combo is enough for 60+ bar of design pressure resistance...?

Any chance to measure it? It would help a lot

Thanks,

Dean

[Justasgood]

Kurt, that's the one! Could it be a rep feature only? I'm failing to understand how metal-plexi-metal combo is enough for 60+ bar of design pressure resistance...?

Any chance to measure it? It would help a lot

Thanks,

Dean

I'll stop in at my watchmaker and pick up a few O-Rings.

Send me your address,

Kurt.

[straight_six]

I'll stop in at my watchmaker and pick up a few O-Rings.

Send me your address,

Kurt.

U've got a conditional PM sir!

Thanks!

Dean