[Banman]

Changing the new to me hydro-fluid in the trans/diff and noticed some odd marks on the ring gear (grooves on the teeth) and bluing on the transmission output gear.
If this was a car I'd be concerned but with a Cub I first need to ask is this normal machining marks on the ring gear or evidence of damage?
Is the bluing a sign of overheating in the past of from when the gear was made?