Those mid level japanese spindles just didn't last.
Boy, that is the truth. I have pitched a fair number of them, myself. And, to the OP...
At the very least,replace the ball bearings,along with the spindle, even though they might look just fine. Chances are they did experience damage, even though you might not be able to see it. You might want to closely inspect the cups, also. Generally, damage, like that pictured, does not localize itself completely.