- Mobil Synthetic ATF (It take about 9-10 qts for a flush).
- Every 20K miles.
Is this too excessive and not needed?
Transmission Flush Frequency
Drain and fill every other to every 3rd oil change.
Naturally the first time is a flush, depending on the condition and mileage.
I do not flush an (unknown) trans with over 60-70K milesJRL
Once a year no more than two depending on color or slight change in driveabily. On my other cars drain and fill if lazy or else flush especially on the Volvo.MoVolvos