Watch was working but hands are very loose so opened the back to fix it ! Surprise this small part fall out from no where! Any body has an idea? Need help
Yes, that is a pallet fork for sure. The fact that it fall out without you removing the bridge that holds it is a bad news. Probably the pivot at one end of the arbor broke (see the picture http://watchmaking.se/onewebmedia/Figure%203_6.png ).You will likely need assistance of a good watchmaker to correct that problem. Good luck.
You are absolutely right! Thank you very much for advices! Watch was old neer serviced , will see what will happen! Thanks again @viem70
Gooy lucl buddy, hope you get it fixed soon 👍