Yeah, it's metal,... dumb combination, eh?
The rest of the machine is relatively solid too. The crack is actually only about big enough to slip the tip of a fingernail in. The picture makes it look worse than it is. It looks similar to the crack that the Galaxie had. It's like they tightened the rivets a tiny bit too tight and cracked it. The two cracks on the cam gear on the Bernina 730 record I have here are way worse, especially since the broken part separated and tried to come off the cam altogether when I was turning things a little back and forward to get oil into places to free up the rest of the machine to see if it's worth saving. LOL! Peeled up like the rind of an orange.
The sound is what I think of as a small "thump" accompanied by ever so slightly harder turning. But I could see how it could be a pop too.