I am sure this has been asked many times. I have a Suncoast 4R100 tranny in my truck and has 230,000 miles on it. The fluid smells and looks fine but I like to keep up on my stuff as best as I can. I called Suncoast and they said to run just good O Dexron 3 in it. My question for everyone is should I do a complete flush and what fluid do you all recommend cause they don't make Dexron 3 anymore that I am aware of? thank you for the help.