[dmarty]

I change the trans filter on my 99 every 75k. My pan has a drain plug, so every other engine oil change, I drain the oil out of the trans pan, but don't bother with the filter and add new trans oil. I get about 3 qts out and add 3 fresh. When you drop the pan and change the filter, you're not draining the oil in the converter, oil cooler or lines. By replacing 3 qts at a time, eventually I'm changing all the oil. I use Dex6. I have 315k on the original trans, so I think my method works.