The strange thing about this failure is that the inner race pitted for half of the circumference while the remaining half does not appear to be damaged at all.
The outer race is not damaged and appear to be in relatively good order. Crown wheel and pinion gear teeth and supporting bearings are in good condition and were not replaced.
The park brake disk and propshaft are mounted to this shaft and it is not clear why the failure only affected half of the inner race circumference.
Have anyone seen something similar. What might have caused this strange occurrence.