2012 Ford Fusion SE with 2.5 and 6 speed auto

In January of this year, the transmission took a crap in my 2004 Pontiac Grand Prix with 128k miles. I replaced the car with a 2012 Ford Fusion SE with the 2.5 liter and 6 speed automatic transmission. Prior to buying the car, I had read about transmission issued with the car, but mostly in 2010, and I thought maybe they had the issue fixed.

My car currently has 16,500 miles on it, and I'm having transmission issues. I'm curious if anyone is familiar with that transmission and might have any information. The three times it has been to Ford it has come back with "cannot duplicate", so it hasn't been fixed. The first trip in they did a software flash, which helped, but did not solve the problem.

The problem I am having is different then the issue I"m reading about in other forums. My transmission does not "flare" between the 2-3 shift. Instead, on rare occasion (about 10 - 12 times since January), when shifting from D to R it will have a long hesitation and the chunk into gear with a loud bang and a harsh shudder. I always back into parking spaces, and I always back into my garage, therefore I shift from D to R a lot.

I have been unable to notice a pattern to this situation. It will do it when the car is still cold, it will do it after a 2 - 3 mile drive and it sometimes does it after my 26 mile drive to work. Temperature does not seem to have an effect on it.

I have tried looking around the web for others with this issue, and I"m not finding anything. Just curious if anyone is familiar with this issue. My tech guy at Ford seems to be clueless.

If you would like additional information, let me know. I would appreciate any feedback. Thanks guys!