schedule maintenance mdx 2011 base

zoom08

I am looking for info regarding the flushing schedule for the cooling system (radiator)
My dealer is recommending that it is time to flush the rear differential fluid ($180+tax)
I was reading general info on the web but nothing really states when it should be done, other than when the dashboard shows the B6 code, menaing you need to change it right away.
any help would be appreciated

Mr_Shiftright

You should replace the engine coolant at Maintenance Minder #5 and the differential fluid at Maintenance Minder #6