So with the new service requirements of changing the diff fluid once at 12K/1year, I'd like to go ahead and so on my front du diff. My rear was done twice already as they had to replace a leaking seal twice. The front has not been done. It's not a requirement for me from a warranty standpoint but if they're doing it now they must have enough data to show that breakin crud is a real thing from the gears. Is the fluid requirement documented anywhere? I think I'll ask service but I suspect they may not tell me. The owners manual does not specify the fluid viscosity.