2000 Excursion 7.3 unk transmission

Quick run down on the situation. It has been terribly hot here bumping 105 degrees. I was told by a man he could see fluid leaking and it was trans fluid. I checked it and filled it up and got it to the shop.

Next day they said it was not leaking and that it probably overheated. They recommended an after market trans cooler. They put it in and off I went. 60 miles later I got fluid all over the rear of the truck. I filled it up again and got it home.

Shop says I need a new trans. I am not comfortable with that as it is strong. I have had great success with this board and would rather get the input from yall before I let go the cost of a new transmission without them even pin pointing the problem.

I will thanl you all in advance.