Planed on doing that and change the fluid. I have to get the undercoat off the bottom actually flaking off and clean meatal under it so far and no "dirt" buildup on it either. The cover also has a blue paint mark on it.
Get a picture of the blue paint mark on the axle cover... If it's paint marker, it could have been for a verified inspection at that time...
If there is a quality issue, the supplier has to certify parts and mark the "good" parts somehow... Many times they put a dot or slash with a paint marker to show that it was inspected for the defect and it was not found on that part... All good parts have to be marked....
Or it could have been an inspection on the assembly line when it was made....
