TOYOTA62,
Most Toyotas have a drain plug in the pan. Both of mine do, so I change it annually taking out 4 QTS. for about a total cost of $14.00. I consider this cheap insurance against a $1200 tranny teardown. I have found that Casrol fluid seems to resist the heat better than other tranny fluids and being that it gets quite toasty where you are this may appeal to you.
