B-1: silence expected?

Hello, all!

I recently was given a pre-SQ B-1. I noticed that when shaking the watch a bit, or even tapping the face gently, there's a slight rattle/clink sound. I'm wondering if this is normal, but don't have anything to compare against.

It's not the bracelet, because I had it replaced with a leather strap.

I also noticed it only occurs when the face is pointing upwards.