I just put a $300 junkyard axle in my truck and I've got this lovely noise to deal with now. I swapped the outer bearings already but it looks like I'm gonna have to pull out the gears to replace the inner bearings anyway, which is what I was trying to avoid. Alright, wish me luck.

https://photos.app.goo.gl/3U1ctmQJtb2QJGS27

 

Are you talking just an axle shaft or the entire differential? $300 is a lot of money for an axle.

How do you know the noise is not originating from the gears? If bearings are bad due to lubrication failure, chances are the gears could be bad too. If you do not have a small accurate 1/4 inch drive pointer torque wrench, you will never get the pinion preload set properly. Many shops do not get involved with rear ends because there is a good chance it will whine if it not precisely done.
Good luck with and hope it's quiet. The junkyard should have warrantied it to work at the time of installation.

 

I'm talking about the rear axle assembly. I know how to rebuild a diff; I was just hoping I wouldn't have to. I'm still hoping I just have to pull the carrier and not mess with the pinion but I'm not an especially lucky man.