tissot What is this Plastic thing on Tissot caseback?

[Yoni]

Little Tissot I'm working on.

Trying to figure out what is this Plastic piece on the back. Opened the case from the front and removed movement.

This seems like a plastic part, with some rust buildup on the outer face.

Anyone have any idea?

Can I clean this? Replace?

Caseback says 'Tool 108' on the outside, case number seems to be 44648.

 

[Kalanag]

Based on discussions I found in the WWW it should be an opening for regulating the watch in the factory after assembly. Please confirm by checking the position of this plug relative to the balance wheel. I would leave it alone.

Edited January 27, 2024 by Kalanag

[Kalanag]

Another Tissot with such a window. When new the plug in your case might have been crystal clear as well.

Edited January 28, 2024 by Kalanag

[Yoni]

Thanks a lot!

Now for the tough question - do you have any idea where I can find a replacement for this part?

[CYCLOPS]

you might have to cut down a mineral glass crystal to fit if no OEM part is available .....

[Nucejoe]

 I have worked on a Tissot like this , its for regulating and not limited  just to factory use.

Some Tissot had a mini back which screwed in the case back. 

I am sure spares were made for this, but old stock  might have not lasted so far.

 

Edited September 14, 2024 by Nucejoe
Typo