Except when the cast iron rots away . My Dodge had one of the bad AAM patches . The cast iron just disintegrated and leaked gear oil . Had to find a good one looked at three or four that were starting to go. Ended up with one that came out out of a Florida truckThat was my original plan, but the disc brake 14s (I think they're AAMs now) are cheap and plentiful. Except for the low-hanging pumpkin, they're better axles than the Dana 60 too IMO.
Found a couple of pictures. The cast disintegrated the cover and tubes were in good shape