In this section, we’re going to learn how to change a mainspring. Specifically, we are going to remove the mainspring barrel from the Submariner, open it up, and remove the existing mainspring.
This watch was serviced, but not by me. Who ever serviced this watch did not service the mainspring. You’ll see in the video, that the mainspring was very dirty, and that the oil had dried up and gotten very dirty.
Watch the video, then read the rest of the description…
Why not a full service?
In this case, I didn’t perform a full service on the watch for a couple of reasons. First, the watch belongs to a customer of another jeweler. (I do a lot of wholesale repairs for other shops). Their customer has already had the watch service, but they did not service the mainspring, as mentioned before.
The customer complained that the watch is running slow, and that it is losing a significant amount of time each week. There are many reasons a watch will run slow, and since the rest of the watch was rather spotless, I concluded that it was either a worn spring or a broken spring.
Once I opened up the barrel, I was greeted with a very dirty and dried up spring, which was caked with dirty oil. This makes a spring “sticky”, and that causes the spring to release poorly. You may have heard someone say that they wound their watch “too tight”. Well, that usually means that the spring is worn or too dirty to allow the watch to operate normally.
Should you take the watch out of the case?
In most cases, if the mainspring is dirty or not functioning, this is an indication that the rest of the watch is dirty also. Normally, I would take the watch movement out of the case, and do a full service.
this involves removing most if not all the parts from the movement, and cleaning them individually. This also means that the mainspring has to be removed from the spring barrel, and should be checked. If the spring is still good, then you can sometimes get away with cleaning the mainspring, re-oiling it, and then installing it back into the mainspring barrel. In a Rolex, or other high quality watches, this will work about 50% of the time.
However, in a Rolex, most of them are manufactured, to run specifically to the power of the mainspring. This means that unlike almost any other watch, there is no speed regulator on a typical Rolex. The efficient power of the mainspring keeps the watch running accurately.
In some cases, a newly serviced watch, even one that has had a refurbished mainspring can have a failure. Sometimes a mainspring breaks after service. In these cases, I don’t typically take the entire watch apart. This is mostly due to being able to fix the watch quickly.
What tools did I use during the repair?
I’ve used several different tools in this procedure. I’ve already covered screwdrivers, and you can read my review of the Bergeon screwdrivers here. They are the best in my opinion, and my have lasted about 20 years, and are still going strong.
I’ve also used tweezers. Several different kinds, and you can click here to get a list of tweezers I recommend for watch repair.
The newest tool we’re using is the mainspring winder. This is important to have.
There are some fundamental things you should know about watch mainspring winders. First, keep this important fact in your mind. Watch mainsprings come in all sizes, lengths and tensions. Mainspring barrels come in many different sizes also.
Mainspring winders have parts which are interchangeable so that the different winder sizes fit a variety of barrel sizes and spring lengths.
Ladies watches, especially watches from the 1950s, have extremely small barrels, while pocket watches from the 1800s have large barrels. You may find that it is not possible to purchase one mainspring winder kit that covers them all, and is “cost effective” for your needs.
You may end up purchasing several different winders over time. What ever you decide, you should remember that they are valuable tools that you will use quite often, and should be taken care of.
Mainspring winders provide a real benefit when you need to insert a mainspring into a barrel.
First, they allow you to wind it properly so as not to damage it. Second, they are much easier to use once you get used to them. When used properly, you will not damage a mainspring at all, and mainspring winders are much easier than your fingers.
Can I insert the mainspring with my hands?
Well, yes. This is frowned upon however. Trying to take a mainspring, and twist and force it into a mainspring barrel will cause damage to the spring, no matter how hard you try. It is easier and less fragile to do with a large pocket watch spring, then a small wrist watch, but you can still cause damage.
Inevitably, anyone who tries to insert a mainspring by hand into a barrel will ruin a lot of springs, and over time, this can become expensive. Even when a spring is hand wound into the barrel, you will notice that the watch will run erratically. This is due to the bending and body oil that gets onto the spring.
Practice, Practice and Practice some more!
When you decide to get your first mainspring winder, practice with it. Get used to how it works, and remember, you saw in my video, no matter how good you are, a spring will pop out once in a while. This happens.
Clean the spring off, oil it up, and try again. If it becomes damaged, you’ll have to replace it though.
Good luck guys, I hope that this information is helpful. Keep posted as I’ll be putting up more videos and instructions again next week.