Thank you sir!
Now this is a far more dangerous question.
What is considered high end or high quality diff fluid?
I know enough not to get the "house brand" at Walmart, Advanced Auto or Auto zone. And most of the time there is an upgrade that is better than OE.
My grandfather used to say that getting 3 men to agree to what is the best oil is lke getting 3 ladies to agree on the best way to make meatloaf. Consensus is rare!

 

The OE is pretty darn god stuff,

I have used Mobil1 synthetic on all of ours. We change the fluid out every 40,000 miles (we wheel our stuff). T-case every 15,000 miles (every 3 oil changes) and the fluid is dirty.
Front and Rear Axle: SAE 75W-90 Synthetic Axle Lubricant

 

I did the diff fluid change. What came out looked like black coffee. No real smell to it.
No real issues on the refill. I like the "pour it in until it runs out" measuring system. Makes it easy.
Test drive today to see if the hum is any different.

 

No difference in the hum. I feel better knowing that I have ruled out any mechanical issues.By the way, I only drained 3.1 quarts combined between the front and rear. I was high time to get the job done.
Thanks for the help.

 

Tcase? Did you drain (check for pieces) and refill?
Remember on the 06 H3 you need to add more fluid from the speed sensor hole. Plenty of info on HF about that.

 

I did Tainter. Pain in the butt to fill. Nothing there

 

Magnetic Tcase drain plug had nothing on it? they always have something.

If the noise is speed or rotational related (RPM), there are only so many items that it can be.

Rear diff, rear drive shaft, Tcase, Trans, Front prop shaft, front diff, half shafts, hubs, brakes (F&R)

 

TC plug did have a small amount of metal on it. however no chunks and no bits of plastic. Front and rear hub had just a bit sludge on the drain plug. Tranny had some filings on the magnet, again nothing alarming.
I took it to the tire store and had them balance and rotate. I also checked the alignment. Alignment spot on, 1 tire needed .5 oz to be in balance. They confirm it is tires starting to cup. I complained about all the noise at (now) 10k miles. The response was "what do you expect with 35 inch tires and open sipes?" In the end it was good to check everything underneath and freshen up all the fluids.
Thanks for all the help!

 

May I ask what tires you have (brand,DOT date & model)?