Transmission

Nasty. Probably around 4 to 6 quarts, although some say about 7 quarts. Once you drain it I would put in 4 or 5 quarts and check the fluid level before adding anymore. I would drive it a couple of days and change the fluid again until it looks clean and red.

Don't forget to change the filter.

The best solution is to flush it via the trans cooler lines. That way you remove all of the fluid from the system including the torque converter. You need extension hoses. Any hose will do, garden, heater, etc. Use 2, 5 gallon pales. Orange home depot ones work perfect. One is filled with 10 or more? quarts of fresh dexron. Determine the flow of the lines. Once you get clean red fluid on the exit line, reconnect the cooler lines and drop the pan. Replace the filter, clean the magnet and then put back the 4 or 5 qrts the pan lost. Otherwise, you will be dropping the pan at least 3x to get to red fluid and changing the filter.

If it is black you likely have waited too long.