What is wrong when the trans temp light comes on? The cooler is working fine but replaced it anyway with a bigger one. Nothing in oil and we changed filter. Dealer says torque converter is going bad.
Something is wrong with the transmission. Sorry without knowing what year Stanley Steamer you have that is about the best we can give.
Make model year and current mileage date and miles of the last transmission fluid change would be a good start.
Right now the dealer is the only one informed enough to even guess.