I spoke with the seller of my 3.5FD Pumpkin who's agreed to swap fluids in there. We'll check both the fluids as well as the inlet to see if we can get to the root of the problem. Worst case, we'll have to swap back to my 3.3FD open diff pumpkin if we can't fix the whine/ howl effect.

We should be able to knock this out tomorrow. I'll keep everyone posted

 

Notice the AWD does not have the extra "candle wick" component. I might jack up my car and take a picture of the back of the differential tonight.

 

Please upload the video you recorded!

 

The only time I get any whine from my car is on the track, after 15-20 minute session and it's from the rear diff getting so hot. I'm working on a diff cooler setup next.

 

I live in florida and mine does this every once in a while at even 95F. Yeah, it sounds like my car grew a supercharger. It's the ABS self test. Ignore it.