I just put in a used transmission, soon after, my starter went. I put a new one in, and started my car, transmission fluis started pouring out of the dip stick. I kept it running, when it stopped pouring out, the radiator started steaming??!!!! The next day, I had to drive about 400 km for work, I had no problems for the next few days. Yesterday, I drove about 10 km, stopped, put it in park, and the same thing happened. Also noticed the transmission is making a knocking sound when it happens. My tranny fluid is the right color. What's going on???!!!

Help!!!

sounds like you're transmission is over-filled or has a major restriction in it; that's why it spits it out through the filler tube. The steaming thing can only lead me to believe that your transmission is overheating b/c inside your radiator is a cooler for the tranny fluid and if your fluid gets too hot, it could cause that steaming you saw. What you can have done is a flush of your tranny cooler, make sure there's no restrictions in it.