Here is a stupid and cheap way to change transmission oil atf. Especially for hard shifting and gunky/dirty trannys. I own a 2000 crv that shifted very hard and late. Having nothing to lose, I drained the atf with dexron 3. I changed the atf three times with a short driving trip in between the changes to mix it well. It started to shift better. Then I drained it with Honda atf three times with driving in between. Now it shifts like new. Because there is no filter, the gunk blocks the inside of the tranny. But if you change the atf, it cleans it each time. So basically I used the cheap dexron 3 to really flush the gunk out before I really put the Honda atf in. But the correct way is to use Honda atf.