Hi guys, how often automatic transmission fluid need to be changed?

On Warranty & care booklet it is marked with “I” (Inspection) on both intermediate and full services. But no replacement age/mileage. My is200se is 51 plate 32K on the clock with fsh, hasn’t done before.

every 20K or two years

mine was on the shedule for 80,000 or 7 years I think.

must be fairly black by then ... must be almost back to crude

nah still pinky red as I check it every month or so for level
funny smell tho

Thanks guys
mine is well overdue then???