Balance Cock Height

[mikecj]

Everyone,

I'm working on an ETA 2472. Everything has gone well so far. However (there's always a however), when I install the balance it starts up just fine. When I tighten down the screws to snug, it continues to run. When I tighten the screws, the balance stops dead. The upper jewel is an Incabloc setting held in place by a u-clip on the underside of the balance cock. The lower jewel is an Incabloc setting held in place by a screw. I'm pretty sure the balance staff is straight and has no issues.

So, I need some advice:

1. Do I live with the screws in the snug position and hope they don't back out?

2. Try to install a shim in between the main plate and the balance cock. I used a dial washer on another watch for a similar problem and it worked.

3. Adjust the height of the jewels within the Incabloc settings. If so, how does one do this? I do have a Horia tool.

Thanks,

MikeCJ

[Randy55]

Is this a watch you've taken in for repair, or one of your personal watches ?
I'm asking, because if you took it in for repair, maybe at some earlier point in time, it was re-staffed with the wrong length staff, and the repairer at that time, just ran the screws down lightly.
I'm not sure I would start messing with the jewel depths yet..but you could first smooth/stone the pivots a bit, to ensure that there are no rough edges at the ends that could be hanging up. If that doesn't work, you could stone each side evenly a bit to see if you get enough end shake.

I've used the timing washer trick years ago on a balance I couldn't get parts for..but that was when I was 1st starting out.

[Nucejoe]

On 5/7/2025 at 9:24 PM, mikecj said:

3. Adjust the height of the jewels within the Incabloc settings. If so, how does one do this? I do have a Horia tool.

 Setting don't look to be moveable, unless you eliminate the u-clip.  Bad idea. 

I would check pivot ends with good magnification to make sure it needs smooth/ work.  

You should find whats wrong, before attempting to repair it. 

Seems to me shimming is best as its reversible & accurately adjustable.