So my trans is probably has all 200k original miles and it's getting old. I don't know if the previous owner changed filter or fluid and now it's acting up a little: Pendulum Shifting, poor gas mileage, drag.

Every once in a while I hear that if you change trans filter and fluid that hasn't been regularly changed, you run the risk of breaking loose some deposits on the inside. Is there any truth in that warning?

Should I just drive it until it the trans dies so I can do the auto manual swap?