1997 Isuzu Rodeo 3.2L V6 mileage: 50,000. I would like to change the automatic transmission fluid in my vehicle (I am familiar with the procedure on older vehicles) but on my Isuzu the transmission is a sealed unit. It has an overfill and drain plug. I drained approximately 3 quarts and filled it with about the same amount through the overfill hole so the best I was able to do was a partial change (total capacity = 9.1qts). I have searched everywhere for information on how to service this type of transmission (4L30-E) to no avail. Regardless of whether or not it is supposed to be serviced at 100,000+ miles I would rather change oil than change a transmission. How do you change the oil on this type of transmission? The service manual I have gives no specifics.