We have transmission fluid in the radiator so there has to be coolant in the transmission fluid. So how do we know if its the radiator thats bad or if its the transmission oil cooler?

get it to a radiator shop for a check up. use your yellow pages and make some calls for prices

Most likely the radiator. The trans oil cooler is a small unit that is slighlty below the radiator and it's about the size of a regular Hershey Bar. Yes fluid goes thru the cooler but if ithad a leak trans fluid would be on the ground. The trans oil line goes into the radiator tank for cooling and there must be a leak in the tubing in there and trans fluid is seeping into radiator and vice versa. Better raplace that radiator pronto! Radiator relatively cheap...Transmission-Expensive. Replace radiator and then change trans filter and flush trans. Let us know what happens. Good Luck!

changed the radiator and flushed the transmission everything seems ok so far. Found a site that I ordered the radiator from that cost $70.00 less than any others that I could find. I ordered it and two days later it was here with free shipping! The site is radiatorworld.com