Front diff whining noise

[MASTERBrian]

I've been hearing a slight whine, when driving around in my 12 Yukon xl Denali AWD. It's been present when driving at 40mph, hwy, etc., when throttle let off it goes away some. I recently changed all my fluids in both diffs and that seemed to help, but they had fine shavings on the magnets and the fluid looked shimmery. I'm sure original fluid and never changed after break in when new. Truck has about 80k miles.

Today I took to trans shop to have transmission and transfer case serviced with new fluids. I had then drive and they say the sound is coming from the carrier bearing on the front diff. His opinion was its usually better to just replace the entire unit with a good used/ remanufactured unit. Says labor is only 2hrs and that generally he's found the aluminum housing is too worn to just replace bearing.
Suggested LQR, said he's had good luck with them. I don't see then having one.

I called another shop and they'd like to see and give second opinion. Again, he says replace with a jasper unit. Jasper is about $2000, 3 yr 100,000 mile warranty.

I called GM dealer and they don't seem to have it available. I thought I had seen on one GM parts sites, but lost it. I also found a rebuilt unit by ATP automotive for $1600 with 5yr 100000 mile warranty.

Any thoughts on this? I understand that the metal in there could have eaten other parts up, so im not crazy about tying to just replace that bearing, but it's $40. If easy to replace, maybe it's worth a shot.

I see this is somewhat of a common problem on GMs but 2012 was skipped on the problem years.