Machinist's bluing will let you easily check the contact pattern and if that is good it will last a long long time even if it ' sings ' .

I usually drop a small rare earth magnet in the bottom of the axle housing to catch any wear particles .

Keep it full of clean 90W hypoid gear oil & change annually etc.

-Nate
There is no problem so difficult it cannot be overcome by generous application of brute force & ignorance