Tudor Hack Repair

What is a hack? Well, in this instance and context, a hack is a small piece of a watch that stops the balance from spinning when the user pulls the crown out, usually to the second click position. The purpose of a hack, is to allow time adjustment of a watch, without the watch continuously advancing, making it easier to set the correct time, even up to the current second.

In This instance, the hack on this watch had dislodged its position, and needs to be re-seated into the correct detent so that it operates correctly. As you can see, I’m doing this repair while the watch remains in the case. This can be done, and for some repairs, it is all that is needed. Not having to remove the entire movement from the watch saves time and money for the repair, and allows quicker turn-around time back to the customer.

Watch the video here!

In this instance, this is actually a movement that was manufactured by ETA, and is not a Tutor movement, but, one manufactured for Tutor by ETA, a Swiss Watch Movement manufacturer.

Tools Needed

The tools you’ll need to do this repair are quite simple… Here is the list…

The process

To do this repair, I would suggest that you remove the band from the case, then open up the case from the back cover.

Remove the automatic winding system

Remove the barrel ratchet

Remove the barrel bridge (the bridge that holds the mainspring and clutch in position). There is no need in this case to remove the stem and crown.

Remove the mainspring barrel.

At this point, the hack (a small brass flat strip which is angled) should be exposed.

Rolex Balance Stop Spring (Hack)

There is a hole in the hack, that fits into a detent, and the ear of the hack (shorter end) should fit into the clutch gearing. It is the movement of the clutch winding gear that moves the hack in and out of position.

With the hack put back into the proper position, you can then insert the mainspring barrel, carefully so as not to dislodge the hack again.

Place the bridge over the barrel and clutch system, and tighten the bridge back into place with its screws.

Attach the barrel ratchet and replace its screw.

attach the automatic winding system.

Make sure, before you proceed to test the watch, by winding the spring, making sure the watch is running, then pull the stem out to the second click position to see if the hack once again stops the balance from spinning.

If all is well, close up the watch by putting the case back onto the case and tightening it down, put the band back on, and you’re done.


So, you can see these ETA movements are fairly simple to get into. They are used by many manufacturers, such as Tudor, Hamilton, Tag and many, many more. I even use them in my own custom designs when I make watches for my customers.

Thanks for stopping by, and I hope this helped you out.

Leave a Reply

Your email address will not be published. Required fields are marked *