Whirlpool Making Loud Consistent Low Pitch Whine

Hi,
This is my first post here. I’m posting because I have no idea what to search for regarding this issue.

Yesterday, my wife says she heard a crashing sound like broken glass then the dryer started making a consistent low pitched whine while running. Here’s a link to a video clip (I only ran it for a couple of seconds): https://www.dropbox.com/s/9bftwdlfllxoqf1/Dryer.mp4?dl=0

It doesn’t make any sound when I manually spin the drum. I checked and it appears the belt is aligned correctly and it’s obviously not the bearings on the rollers, if it doesn’t make a sound when I manually rotate it (they seem to spin freely). I thought maybe it was the motor bearings, but once again, manually rotating the drum would’ve revealed that problem. Here’s the make and model, Whirlpool LGR7646JQ0.

Anyone have any ideas?