Also, I just reread the post. The hubs are likely not your issue.
I had this same problem when I had to drive home in fwd (for 2 hours on the freeway) because my rear end blew. The brass bushing seized to the long field, and was making squealing noises, especially when turning.
You probably did not grease the brass bushing enough. If it was a new bushing you need to hone it out for clearance.
If it is siezed, you'll need to chisel it off carefully with heat. My longs or the spindle were not destroyed at all.
If it is not siezed, ensure the grease pockets are on the bottom half of the spindle. New bushings only have two grease pockets. Older ones had 4. Make sure the grease pockets are on the bottom, either style you have.
Ensure the tolerance between the birf and the bushing. Iirc, there needs to be at least .002"-.006" tooerance. Take a dial caliper and measure the od of the bushing surface, to the Id of the bushing. If its too large, replace with new. If too small, double check the measurement, and hone out.
To hone out, buy a brake caliper hone, and stick it in a drill. Clean off all the old grease. Hone it out with the drill till the bushing is within tolerance.
To install a new bushing, stick it in the freezer overnight and tap it in with a hammer or press it. Be careful, if it starts sideways it will deform the id
Once everything is good, liberally grease the bushing, the grease pockets (the face of it and the id). Liberally grease the surface of the bushing area on the long field (face and od). Install
Every 6 months or so, I'll shoot grease through the grease port at the mating surface.
For this, I prefer hi temp bearing grease...
-phill