Rear end/differential howl/whine

I'm posting this here in a new thread so as not to confuse my issue with the infamous 50-60 mph resonance howl that the TSB fixes, and so as to let folks know that just because you've got the howl doesn't mean you have the same resonance issue as lots of folks discuss here in other threads here on TW...

2019 Double Cab SR5 short bed 2WD here. At 2000 miles, a rear end howl/whine started. It's gotten louder, and is now loud enough to be un-ignorable, and unmaskable by the radio at any listenable volume. The noise peaks at 27, 45, and 59 mph but is very audible from 20 mph all the way up up to 80+. Took it to the dealership yesterday, lead tech there drove and detected the noise no problem. He drained the diff and found pretty dark fluid for a 2500-mile vehicle, along with lots of shavings on the plug magnet. He called Toyota, who is covering this under warranty. Bad differential. They'll install the the diff on Monday, assuming parts arrive in time. We shall see how it goes...

 

Followup: New differential installed on Monday. No noise, no howl, no whine. All good. I'll be back here if any problems crop up, but right now it ain't broke no more