Maybe I can help some.
Pinion bearings- Faster high pitched bearing noise changes with acceleration load ( louder under load quieter coasting )
Carrier or Case bearings- Deeper rumbling that changes with vehicle speed but not effected by engine load or turning loads.
Axle bearings- Changes with vehicle speed and turning load.
If you had a damaged axle, improperly installed bearing, un-lubed bearing or incorrect lubricant level the bearing may have failed again. Are you sure you don't have a tire/road noise?