Hope you're all doing well and staying mentally and physically it during this COVID-19 mishap. I was pondering about my manual transmission fluid and wondering when I should change it. Car is a 370z, last MTF change was in 2017, since then I've accumulated 13,000 km on the transmission fluid. Would it be overkill to change it now? I know brake and clutch fluid is hydroscopic so I change it every 2-3 years, regardless of the mileage. Same question would be for the differential fluid, should that be time or kilometres based? Thanks in advance for the help and insight l, it's greatly appreciated.