I do the work on my daughters V6, 06 automatic Mustang.. I have to say we had a 01 prior to and I enjoy the slightly larger layout of the 06 much better. Anyway there has always been something off with the transmission since we bought it. We did buy it used but for the price I went into knowing it could need some work. The issue is that sometimes 2nd gear will not catch. It will try to shift into it, the car will rev, and no pull. You let up on the gas, and it will drop in and be fine. It seems to only happen in second gear, and the car is not driven hard. Since this is a sealed transmission I decided to let the dealership drop the pan and replace the fluid and filter. Just a very messy process in my home garage. They looked at it, said it had been over-filled, and the fluid was burnt. They recommended we not change the fluid for fear it could cause worse damage.... I don't understand that. They did drain some fluid out although I am not sure how, and I told them to leave it alone. Of course they wanted to sell me another transmission but if necessary I will just buy a used one for a quarter the price of a rebuild and slide it in myself. Why wouldn't changing the fluid and filter be a good idea?? Any input would be appreciated. I really respect the discussions that occur here and hope someone can get me in the know.