I have a 1999 Buick century custom v6 automatic trans. Today on my way home it was driving fine, all of a sudden I lost all power to the wheels, it revs, but it is a free rev as if I was sitting in park or neutral. I checked the fluid level and it was low so I added 2 quarts to it and tried again it got me maybe 100 ft after that same thing so I went and added another 2 quarts. I don't see fluid on the ground or on the cross member or motor area. How many quarts does a transmission call for and what could be causing this issue, I heard of some type of spring in the past that is inside the transmission but the name is not coming to mind right now. I have worked on cars for years and haven't ran into something like this before so what do you guys think. Thanks for your time and please have a wonderful day.
-Paul