Citizen tube replacement

clockboy · April 26, 2017

By any chance have any of you guys replaced a Citizen watch tube. It is a diver case No. 824164 fitted with a 8200A movement.

I have refurbished this watch and thought a new crown would resolve the poor fitting but of close inspection the tube thread is knackered.
I have read they are soldered in which is a real problem (I think) anyway see pics.

New & old crown

Tube that need replacing

rogart63 · April 26, 2017

Don't think they are soldered in . As the thread is brass and the case is stainless steel. Think they are pressed in. Have some old Citizen cases with crown a 4 somewhere. See if i can take the tube out.

clockboy · April 26, 2017

Thanks pushing the old one out is going to be a real challenge I have no ideas at present

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clockboy · April 26, 2017

36 minutes ago, clockboy said:

Thanks pushing the old one out is going to be a real challenge I have no ideas at present

Sent from my iPhone using Tapatalk

I have just removed a tube from a scrap Citizen just by inserting a broach & twisting and it came out. However this blighter is different. I have looked at it closer with a microscope & it looks like the threaded part is inserted over a tube or the tube is threaded.

clockboy · May 8, 2017

I can now give you a heads up on how these tubes are fitted & replaced. It was the most difficult job I have done in a long,long time. Despite a long time on the internet doing research I basically found nothing of any help. I received no help or advice from this forum or other forums apart from one bit of advice on another forum that suggested it was friction fit which was incorrect.

So after a lot of experimenting and measuring with some scrap Citizen watches I found that the tubes are friction fitted to their standard watches BUT their Diver style watches to improve water resistance are a screw fit. I removed the old tube by putting a slit into the top of the old tube with a slitting file and twisting it out.

Unfortunately with this watch a previous repairer had stripped the original case thread and had glued it in another tube and then packed it with a clear silicone.

The Citizen diver style threads put in these cases only have a depth of 2mm. After a lot of thought & weighing up all the options I decided to try and tap the remainder of the case with a 3mm thread & screw in a longer crown tube that was 4mm long. The tap used had to have a 0.35 pitch not the usual 0.50 pitch for the tap to work and the hole required for the tap is 2.6mm. This proved to be another problem as the drills I purchased marked as 2.6m were actually only 2.52mm so I had to broach out some extra.

HOWEVER despite this working fine on a scrap piece of metal I just could not get the thread to take in the watch case. I don,t know if it is because the case is a cast metal. I really don’t know why.

So plan B was to but a friction fit tube in but the problem I now faced was I had made the original hole bigger trying to tap the hole. So I fitted a friction fit tube & used Loctite 243 a micro seal at the top of the new tube. I then held it in place overnight to dry.

Unbelievably on test the case is actually watertight up to 5 bar. All I can say is I just got lucky and the loctite 243 really does do a lock & seal.

I am not 100% not happy with the result because I finished doing the same really as a previous repairer had done which is a bodge job which is not my style.

If I encounter this problem again I will just friction fit a tube and use the magic Loctite 243. If the original thread is OK then it would be a very simple job to just shorten a screw in tube and just fit.

See some pics taken during repair

TUBE REMOVED