I Started to have a little problem with the Crown and tube on my 2551.80 (1998), you know...the usual thread going thing.... Needless to say, it's guaranteed for 2 years with the store I bought it from, which is located in Sunny Brighton, UK. Thankfully they said the crown and the tube are covered, so posted it off.

2 and a half weeks so far.... and may take another 7-10 days...so having to rely on my Tissot for company.

I just wondered what happens in a crown and tube replacement? is it a big job?

Sorry for lack of pictures.....but I don't really have anything to take a pic of! haha

Though you could all cheer me up by showing me your wonderful SMP's!

 

The crown and tube replacement isn't overly complicated. It does require disassembly though. The wait is probably due to work previously scheduled before your job. Your watch is in their queue waiting for surgery.

 

Well, it depends...

While changing the crown is not complicated at all, changing the case tube very much depends on how it's held in the case. For simple press in case tubes like this one below, you just press it out, clean the hole in the case, apply retaining compound, and press the new one in - 5 minute job:



For a threaded case tube (one that threads into the case) it's nearly as easy...I use what I would describe as an "easy-out" and it threads left handed into the tube, and you just twist and it unscrews the tube from the case:





Omega sells a specific hex tool to screw the new case tube into the case. Rolex also sells special tools for removing and installing tubes in their watches:



The tool is sort of a splined shaft that goes inside the splines inside the tube to get the grip needed to torque it in properly:



There is one tool for removing and one for installing, and then one for new cases and one for old - so I have 4 tools for tube exchanges on Rolex...



Now sometimes you need to use heat to break the bond of the Loctite that is typically used to hold these into the case, and if you do that you must completely disassemble everything, including removing the crystal. But often they just unscrew without heat.

Now the last type of tube is not easy to replace at all - the soldered in tube. In this case the idea is that you drill out the existing tube, and replace it with a tube that threads into the case. Sounds simple, but to get everything aligned is not easy without proper fixtures, and of course Omega makes a tool kit for just this purpose. I used it while at the service center for training a few years ago since I finished before the others in my class, and had Friday afternoon to do what I wanted to, so I wanted to give this set a try before I considered buying one:



It includes a jig, drills, taps, tap handle, and a set of spacers that allow you to mount specific cases in the jig and line the case tube up perfectly perpendicular so the hole you drill stays in the proper alignment with the movement - this is with a Seamaster Professional case mounted and lined up for drilling out:



Then you take it to a drill press and drill out the case, removing the old tube in the process. Then you start with tapping the case - this is done twice actually, so first a tap that removes a bit of the material to form the threads, then you finish with a second tap. Go slow because stainless can be a bear to tap!!!



Now not many people have this jig set-up - it's not cheap at about $7,000. Soldered in case tubes are not something I get enough of to warrant the cost to buy the jig set. If I get a soldered in tube, or one that splits when I try to remove it, I just send the case frame to Omega and they do the tube exchange for a small fee.

So the 25518000 comes with 2 different types of case tubes - pressed in and screwed in. The pressed in version is the older type, and given the age of your watch it could be that type. Should not be a big deal to remove, but the last one I did split on me when I tried to remove it:



Took about a week to get it to the service center, and for them to drill out the tube, tap it, install a new one, and send it back. No idea how capable the place is that is doing the work, and I'm actually surprised they are covering it under warranty - this is almost 100% operator error...here is what the threads should look like:



And stripped:



Certainly time is taken in the queue, so a few weeks is not a long time to wait for something like this really, in particular if they have to send it off somewhere for repairs.

Cheers, Al

 

Thanks Al!

(love it when the good answers come out)

 

wow thanks so much for this detailed information on Tubes and cases etc! Its amazing what can go into making and repairing watches...it has certainly given some insight into what happens. Many Thanks

 

I always wondered whether watchmakers use torque screwdrivers or do you torque by feel? Do manufacturers specify torque settings for assembly? Apart from a few bracelet adjustments I don't experiment with watches, I rather leave that to the experts I'm just interested. I know ( unfortunately) from experience that even large bolts that require 200Nm of torque can snap easily.
Thanks

 

I've always wondered about this subject, and as is so often the case there's more to it than you might think. This is a routine full-service item, correct? Or is it only done when a leak is detected or advanced age?

 

Watch manufacturers like Omega do provide torque specifications for various screws on modern watches. There are screwdrivers that provide a torque reading, or that can be set to a specific torque, but they are not in widespread use that I am aware of, as they are very expensive. They would be more common in a factory setting with unskilled labour than they would be with a trained watchmaker.

I don't personally use them, not necessarily due to cost, but because I don't think they are really needed. Something like this might help a new watchmaker, but once you have some experience, you know by feel how tight a screw needs to be. The kicker is that some brands have very soft screws, for example on many Asian watches I find the screws can't be torqued like Swiss screws can be, and they snap VERY easily. Fortunately I don't work on a lot of Asian watches...

In the end the key thing is to have the screw tight enough that it doesn't come loose, and not so tight that it snaps. That range is generally not so narrow that I need a torque screwdriver to find it. If a screw comes loose on me, it will be more likely from me forgetting to put a final torque on it than it would be from insufficient torque.

Cheers, Al

 

In a service centre, this is done for every watch...so while people often talk about "original" crowns, it's a routine service replacement as is the case tube.

Cheers, Al

 

Makes sense to me, in the case of a full overhaul. Thanks as always!

 

Thanks for the detailed reply. Very informative as always.

 

UPDATE: wow, finally got it back yesterday!!! it took around 6 weeks, but received the watch in tip top condition....

 

Great feeling when you finally get it back, isn't it.

 

wow...it is isn't it! Never want to let it out of my sight again....

 

As usual Perfectly explained ....and photographs too. You really are the real deal al. I wish I could have you to look after my watches but I'm in the uk.

 

Yes exactly! a lot of great people on here are miles away from us peeps in the UK.....