This is #11 in my series of basic watchmaking tips.

This thread is the result of a direct request made to cover replacement of case tubes, but I will also include some other common replacement items on cases, such as pushers, correctors, etc.

Since case tubes was the specific item a member here requested that I cover, I’ll start there. So the case tube (also sometimes referred to as the pendant tube) is the tube that the crown either screws into, or seals against. These can require replacement for a few reasons, such as impact damage, wear, damaged threads, etc. Here is a simple case tube that is clearly worn:



You might wonder how the rubber O-ring causes wear like this, but over time the O-ring can harden, and become embedded with dirt, which acts as an abrasive. There have been instances where I have been able to polish a slightly worn case tube to make it functional again, but often the best route is complete replacement, with a new tube looking like this:




For case tube used with screw down crowns, they often need replacing because they are stripped – this is what a good thread looks like:



And what damaged threads look like:



Case tube can be attached to the case in different ways. Some are press fitted into the case, so are threaded into the case, and some are soldered into the case.

I’ll start with a simple press fitted case tube, and specifically the type that the case tube extends into the case, like this one:



You will note that at the red arrows, it shows that the case tube has been cut out partially, and this is for clearance. So if you come across a case tube like this, it should be replaced with a tube that is also cut out, and the cut out should be oriented “up” when looking into the back of the case like this.

I have this tool from Horotec that is designed for pressing items like case tubes and pushers out and into cases, so that’s what I’ll use here. The left side has a small tube installed in it, and this side is used for pressing items out.
The right side is used for pressing items in, and it’s very straightforward – just plastic on top and bottom, and you put the item between those, and turn the handle to press it in.



The tubes used come in different sizes, so it’s a matter of picking something that will make good contact with the inside portion of the case tube, so you can push it out:



Turning the handle presses the tube out pretty easily:



New case tube:



Before the new tube is installed, I apply Loctite 638 retaining compound to the portion of the tube that inserts into the case (this is what is called for in Omega work instructions):



The new tube has now been installed:



Sometimes these tubes go in with a very heavy press fit, so if this press is unable to get the tube all the way in, I often used the an old crown that I place over the tube, and then use my watchmakers hammer with the plastic impact surface, to finish tapping the tube in the rest of the way.

Next let's look at a screw down crown situation, where the case tube is threaded into the case. The first step in this instance is to disassemble the case, because we will need to apply heat to remove the tube:



Here I’m using an Omega bezel remover to take the rotating dive bezel off:



Note that prying these bezels off can lead to damage to both the case and bezel, so using a system that more evenly lifts the bezel off is safer.

Next, I press the crystal out, because the seal will possibly be compromised by the heat I’m going to apply to the case:



The case is now ready to have the tube removed:



I use a small torch fueled by butane for this, as I can focus the heat exactly where I want it. The heat will help break the bond of the Loctite thread locking compound that was applied to the threads of the tube at the factory:



The case will get very hot, so care needs to be used so you don’t burn yourself.

In this instance, the Omega case tube has an octagonal recess machined inside it:



Omega makes a tool to use this to remove and install these tubes, so I use that to turn out the tube:





Now the case can be cleaned, and you should make sure that the threads inside the case are free from any residue from the Loctite. Here is the new case tube:



You will note that in addition to the tube, there is a washer. This is a titanium washer that is installed between the case and the case tube – don’t forget this.



Loctite is again applied to the tube, per Omega work instructions:



The tube is then threaded into the case:



Note that if you are changing a screw down style case tube due to damage, it’s best to change the crown and case tube together.

I will continue with other examples in a subsequent post. If you have any questions, please let me know.

Cheers, Al

 

Wow! Very informative Al. You make difficult procedures appear routine. However there is a certain "feel" to mechanical work you perform that makes a huge difference in these successful procedures. I wouldn't attempt any of them myself as that's what trained EXPERIENCED experts are for

 

I love seeing all the special tools to dream about.

I have been soaking some crowns in alum to get the broken stems out. I notice this can affect the gasket and sometimes the threaded post come loose and wobbles. One of the 2576 crowns (I think that is called a clover leaf.) Is like that. Now it wobbles on the new stem. Personally not worried about water tightness. I suppose the 'proper' thing to to would be to get a new winding crown. Still I wonder if there is a way to save the existing crown. At least functionally and cosmetically.

 

somehow this double posted.

 

Makes me want to continue making knives….

Always great to see behind the bench @Archer
Thanks for posting

 

I hate reading these posts by Al.
I removed my last crown/stem tube using my bench drill, and also used it to press in the new tube.

Now I have to go and buy a Horotec 03.657. Oh well, what's money for anyway.

 

You made $15 changing a battery for me this week

 

Yeah, but I didn't charge you for my very expensive skilled labour costs, use of my highly expensive watchmaker equipment, my coffee break time or my toilet break time.

I'll have to remember that in future.

 

Amazing - thanks for sharing

 

Now moving on the screw down case tubes that are friction fitted into the case. These can be tricky to say the least...

So on many Omega models, these tubes press into what is essentially a blind hole, so the case tube doesn't stick out into the inside of the case like on the press in tube I showed above, so you can't press it out:



There's a hole there for the stem to go through, but that's it. So for these instead of using the tool that Omega supplies I use a very small "easy out" tool, and place that inside the case tube:



I use a pair of pliers, or an adjustable wrench, and twist the easy out so it grips, and that turns the tube out of the case:



I got lucky on this one, because I didn't have to apply heat, but I usually do the same here as I did in the previous Seamaster case above - fully disassemble it and apply heat.



New case tube and crown:



Again, Loctite retaining compound is applied:



Here I used the old crown to tap the case tube in place:





The risk with removing these types is that the tube snaps off, and you are left with a part of the tube stuck in the case - this has happened to me before. You can try to drill the tube out, and I have done that before, but I've also sent the case frame to Omega and they have removed it for me using the tools they have for a small fee.

Now the soldered tubes - I don't have examples of me changing those in my shop, because quite honestly this requires some specific tooling that is very expensive. When I was at Omega for training, I finished everything they had for me early with a 1/2 day to spare, so they asked if there was something specific I wanted to learn, and I picked replacing one of these tubes. They handed me a case, and sent me to the case area of the shop. The guys there walked me through the process, which involves a drill press and an expensive jig...



This set-up involves placing the case frame in a jig, using the appropriate spacers, and aligning it properly in the jig - you have to have the case rotated so that it's perfectly vertical with respect to the existing case tube, or the hole you are about to drill will be off on a tangent, and not pointing to the center of the case. Here it's ready to drill:



After the hole is drilled, which removes the case tube as part of that process, you follow up and tap the hole in two stages. First a tap that cuts the threads about 1/2 way, then a finishing tap that completes the threads:



Once that is done, you install a threaded case tube in the case. I looked at purchasing this set-up, but I simply don't have the demand to justify the expense. So although there have been many comments about the tools I use in my work, there are some that even I cannot justify purchasing.

Speaking of tools, let's talk Rolex for a minute. Here are the tools that are needed for changing case tubes in Rolex watches:



There are two sets here - the two on the left are for the "old" style case tubes, and the two on the right are for the "new" style case tubes. There are two in each set because one is needed to remove the old tube, and another is needed to install the new tube. So these are sort of just splined tools that grip in one direction only, on the inner diameter of the tube. In some cases with the older tubes (I think, going from memory) after you install the tube, you have to ream it out to allow the crown to actually go inside the tube. So these are a little different than how Omega does things.

Next post I will talk about some other items, such as pushers.

Cheers, Al

 

Let's looks at changing pushers next...

In a standard Speedmaster Pro, the pusher caps are held in place by screws, that are removed from inside the case:



With the caps removed, you can see the splines on the pusher tubes - there are specific tools used to grip those splines and tuen the tubes out of the case, as these are screwed in place:



Most of these I use the red handled tool for - this has P27 marked on the tool. There is a smaller version that I've used on some watches, that has a blue handle and P3 marked on it:



Once the pushers are moved, you can clean the case thoroughly, again making sure that any old Loctite that was on the threads in the case has been removed:



These pushers, like the threaded case tube above, come with a titanium washer. Not all cases use this washer though, so if there is a recess in the case where the pusher installs, the washer is used, and if there is no recess, the washer is not used:



Loctite is applied to the threads, and the pusher tube is screwed into the case:





The pusher is then assembled, with a small amount of Fomblin grease applied to the post inside the cap:



I also place a very small amount of Loctite in the threads of the pusher cap - the cap is placed on the tube (the springs and seals are inside the tube already) and then the screw is installed from the inside of the case again:



This process is repeated for the seconds pusher, and the job is done:



Now on some watches, these pushers are press fitted into the case. These are handled differently, and I find these most often in the Speedmaster Date watches:



Like the case tubes, I use this same tool to press out these pushers from inside the case:









Now the case can be cleaned, and the new pushers installed:



Note that these do not get disassembled for installation. I came across a rant by a watchmaker who complained about the quality of Omega parts, and has specifically stated that when he tries to remove the caps, the screws break off inside them - well that's because the caps are not meant to be unscrewed - the pusher is pressed into the case as an assembly:



The same Loctite retaining compound I use on the case tubes, is used for these pushers. It is applied to the pusher and the pusher is simply pressed into the case:





The last type I will cover doesn't use a screw to hold the pusher cap in place, but uses a small retaining clip:





The clips are removed (I just use a screwdriver to pop them off) and the cap comes out, with the integral post:





The rest of the pusher change is handled the same as the screw in style pushers above:











Then the cap are installed, and the clips hold it together:



The last thing I want to cover here is the corrector. A corrector is a device used to change some feature on the watch, such as a date, day, month, moon phase, etc. A corrector differs from a pusher in that the corrector is flush with the case, and requires a separate tool to actuate it.

Here is a corrector on the side of a case:



And here is a new one in the package:



I don't have images of changing one of these handy, because it's something I don't do often, but the procedure for this would be the same as the press fitted pusher - press it out, clean the case, apply Loctite retaining compound, and press it back in.

I hope you have find these posts helpful if you ever need to change any of these parts on a case, or just want to know what is involved.

Cheers, Al

 

Awesome posts as always, Al. I am really enjoying this thread.

I know this is really a moot point, since you would typically replace both crown and tube, but I'm wondering if you have noticed any pattern regarding which of the two is more commonly stripped.

 

Difficult to see the threads in an Omega crown, so I usually only really see it on the case tube.

 

Thanks @Archer , great read and i learned a lot.

 

Excellent! Thank you!

 

This is great summary! Thank you, Archer. May I ask about another type of the crown - the one for adjusting inner bezel. I have a few vintage watches. And I could not find any info on how to remove those. I assume it is press fitted, but not sure how to remove them from the case and not to damage the crown or the case. Any good advice on that? A few photos to show the case.

 

These can come in different types. Years ago I had a micro-brand watch in the shop from a company called Zixen - not sure if they still exist or not. Anyway, the pinion for the inner bezel was broken, so I bought replacements:



In this design, the shaft coming from the crown had a flat on one side that allowed the pinion to be driven, and then a slot cut in it for a small c-clip. Once those were removed, the crown could just be pulled from the case.

More common is a threaded design, like you find in an Omega Flightmaster:







So you need to hold the pinion on the inside of the case with something, then unscrew the crown. I use large diameter peg wood, which is basically a round wooden dowel to hold the pinion, while I unscrew the crown. These often have Loctite on the threads, so sometimes they can be tough to remove.

The other option that comes to mind would be a split stem system, and those would just pull apart.

Hope this helps.

Cheers, Al

 

thank you, Archer, for this advice. With more courage I have managed to disassemble this part. All good now.