Replace Rotor Bearing

Mark · August 5, 2013

How to replace a rotor bearing in two watch movements - the ETA 2892-A2 movement (on an Omega Dynamic watch). And a Valjoux 7750 movement (on an Ikepod watch).The rotor bearing on these watch movements and their variants often wear faster then the other parts in the watch due to constant movement and vibration.

When servicing these movements it is best practice to replace the bearings so that the automatic mechanism runs optimally.

Replacing them is a near impossible task without the correct tool. The bearing nut tool is made by Horotec and also Bergeon makes one.

There are two key sizes. The 7750 is smaller than the key for the 2892-A2.

Attempting to remove the bolt without the correct tool will likely cause damage to the weight. Refitting the bolt without the correct tool is almost impossible.

The tool is relatively easy to use. I recommend placing the weight on a small staking block so that you can apply pressure to the bolt without depressing the weight (causing damage).

I have created a quick video showing the removal and replacement of the bolt on both these watch calibres.

Feel free to comment below.