Do you know when the filter was last changed? I've done mine a couple of times only to find that the filter was clean. Allthough it does give you the chance to remove any sediment. It is very important whem removing the pan not to allow dirt to get in. You can drain about 1/3 of the fluid by the drain plug. It is pretty easy to increase this to 2/3 by removing the tranny coolant line that connects to radiator. It goes like this. Drain pan and re-install drain plug and add 3 quarts of ATF. Remove the tranny coolant line and put it in drain pan. start car and idle till fluid comes out clean. Stop car re-install line and fill ATF.