It has absolutely nothing to do with that karrrrr sound.
That tiny mechanism is there to avoid the over tightening the tank cap/lid. So once that sounds come, it means the lid is fully closed. You keep twisting it over and it will keep spinning. But it will not over tight.
After filling the tank, I too pull over and tight the lid by myself just to make sure.
Because once after the fill up, I drove and there was a signal in less than 50 meters and I stop. A biker told me that sir the lid is on the roof. I came out and put it on the tank.
You know, sometimes stupid things happens out of no-where. 