Whoa wait a sec lets clear the air here.
If you drop the pan and replace the filter and gasket and just want to top everything back off, then the previous posters are correct, it will take about 7 quarts to put you back where you were, BUT WAIT>>>>>>>>
The system holds over 12 quarts of fluid, that's right, 12. The rest of your dirty stuff is in the torque converter and thru out the system. Why mix 50 percent clean with what is left in there to have only a partial fix. You need to remove the nasty fluid from the torque converter and then top the system off. How do you say?
Here is what you do: Seeing how this is after the fact, you need to know (or it would be nice to know) how much fluid you took out (I'm saying its probably 7 quarts). Now, add that much back in + 1 quart. Yea I know, it sounds fishy, but listen:
Disconnect the tranny cooler line on the drivers side of the car. It is the hose on the drivers side of the 3 x 18 inch small radiator that is in front of the car between the front air dam and the radiator. Not your big coolant radiator, not your ac radiator, this is just the long thin radiator that is used for the tranny.
Now, take that hose and put it in a bucket to catch fluid. Mark this bucket beforehand as to where the 6 quart level is.
Take a second bucket that is very clean. Put 5 quarts of new fluid in it. Connect a hose to the ****** of the little radiator where you just took the hose off of that is now in the dirty bucket. Follow me?
YOu now have a catch bucket with a hose in it that used to be plugged into the tranny cooler, and a second bucket with a spare piece of hose in it that is connected to the cooler.
If you start the car, the fluid that you added to the pan (remember the 7 quarts?) will go from the pump at the bottom of the atx pan, into the torque converter, thru the system thus pumping out the old fluid out to the hose that is in the dirty bucket.
Meanwhile, the 5 quarts you added to the clean bucket will go into the cooler, thru the hoses to the bottom of the pan.
Basically you start the car and the tranny pump will do the work, you just have to know when to shut the car off. Kapeesh? 12.5 quarts in the system, you took out 7 added 8 and will suck in about 5 (put 6 in there just to make sure you dont suck any air.
12.5 -7 + 8 + 5= 18.5 quarts. You will want to run the car until 6 quarts of fluid come out into the dirty bucket.
NOTE::::: Check the loop first by putting both hoses into the dirty bucket to see what direction the fluid moves. what ever hose does not have fluid coming out of it will go into the clean bucket with clean fluid to suck back into the system. Once you drain out the 6 quarts shut er down and reconnect all the hoses and check your level.
Now, as to fluids, I used Mobil 1 Synthetic at 4.99 a quart. You can use others, I just went that route for safety.
You have now flushed and filled the system and done the filter and gasket. Out of pocket expense with mobile 1 synthetic: about 14 quarts of fluid for 70 bucks plus a gasket/filter set for 21.00.
Piece of mind knowing you are giving your tranny the kindness it needs: WORTH IT!!.
Credits for this go to OLYMPIC the shopaz master who taught it to me online. By the way, there are bound to be snags so double check everything as you go.