Tudor 7804 - What’s The Correct Crown Size Please?

[lambstew]

Hi All,

I’ve ended with a Tudor 7804 which has had a more modern Rolex 5.3mm crown installed onto what appears to be the old or original threaded tube and I don’t believe it’s a correct fit and is leaving a noticeable gap towards the case side. After installing a new crystal and replacing the back gaskets it still fogs up in rainy weather. I have seen Oyster Patent crowns on these while doing a search however can’t find any specific info on the correct crown size.. Is someone able to assist?

Cheers,

Konrad

[linesiders]

Hi Konrad, I had a 7809 with the Oyster Patent + Crown - the replacement would be the 5.3 MM crown

[lambstew]

Originally Posted by linesiders

Hi Konrad, I had a 7809 with the Oyster Patent + Crown - the replacement would be the 5.3 MM crown

Hey man - it’s been a while and thanks for the advice. The odd thing is, the current crown is 5.3mm and a watch maker here is saying it should be 5.4mm as most of the older types took 5.4mm. Modern Rolex replacements seem to be 5.3mm but obviously this one doesn’t screw back all the way and leaves a gap. I wonder if the oyster patent crowns threading is different??

[TimeToGo]

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The old Oyster Patent crown will not fit in a regular (modern) 5.3mm tube. They are a different size. But if you have a regular/original tube trying to fit a modern 5.3mm, the threading (as you mention) may not be the same.

I have a couple of guides that show the crown tube type but with different refence numbers than the standard 5.3mm. See below.

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[lambstew]

Originally Posted by TimeToGo

.
The old Oyster Patent crown will not fit in a regular (modern) 5.3mm tube. They are a different size. But if you have a regular/original tube trying to fit a modern 5.3mm, the threading (as you mention) may not be the same.

I have a couple of guides that show the crown tube type but with different refence numbers than the standard 5.3mm. See below.

.

That’s excellent info thank you so much!

I strongly suspect my tube is the original and a modern 70’s era 5.3mm Rolex crown has been incorrectly fitted at some point. I’m a bit dummmy dums when it comes to translating the 7804 chart crown info - 8/34/-22 translates into??? Would this be a 5.3mm or 5.4mm Oyster Patent crown?

[TimeToGo]

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Not sure what that translates to, as others get referenced as 5.3mm, 6mm, etc.

As mentioned by @Linesiders, they are approximately 5.3mm. These are the Oyster Patent with the "Stick" Cross.

I've had them measure about 5.4mm+ as well, but generally referred as such.