Got in my truck this afternoon to leave the college, put it in reverse and heard this weird howling sound as I was idling back out of the parking spot I was in. Put in in drive and no sound. Stopped at the end of the parking lot and put it back in reverse and no sound. Checked it when I got home and it didn't make any sound. Just went to move it out of the driveway and it made the same sound only in reverse again. Drove it around the block, put it back in reverse and no sound so it's only doing it when it's cold right after start-up. I took a quick vid and you can hear it when I shift into reverse and stop when I shift to neutral. Right after the vid, I gave it a little gas backing up and the sound seemed to change with the engine RPM too
Ignore the perverted breathing lol. The weather has got me all kinds of screwed up