Noisy profile hard drive

72 years ago, I was in charge of an early 3Com LAN, with drives in stacked 'shoeboxes'. I came in one Monday morning to find one of the drives making this thin 'shrieking' noise. I of course did a panic shutdown and got the Vendor rolling - turns out that it was the Absolute Filter on top of the drive case making the same kind of noise that one makes by blowing across a piece of taut paper. The tech just pressed down on the aluminum cover at the edge of the filter 'pod' and that fixed it. I was sure the heads had crashed, but somehow the system was still running - though I couldn't see how, since it sounded like the heads were milling the platters into expensive red dust. Maybe this is what's happening here??