For those with performance in mind, after doing minimal research, it looks like the 545rfe and the 68rfe from the '07 2500 are basically the same trans. By swapping internals and solenoid/shift point programing, you would get the following ratios solving most of the complaints about the 2011 Durango in the press and making it a true six-speed. But then again I'm no transmission expert, surly there's a lot more to it. ?? just a thought.

• 1st 3.23:1
• 2nd 1.83:1
• 3rd 1.41:1
• 4th 1.00:1
• 5th 0.81:1
• 6th 0.62:1
• Reverse 4.44:1

 

 

Lol, I know... like I said, it was just a thought.

 

" a new six-speed automatic transmission, called the 66RFE. It replaces the previous Hemi V-8 gasser's 545RFE gearbox, which was shared with the light-duty Ram. The 66RFE transmission is a hybrid of sorts. It combines the internals of the 68RFE heavy-duty six-speed automatic (including the gear ratios) that's paired with the 6.7-liter Cummins six-cylinder diesel engine and repackages them in the 545RFE's case."

From

http://news.pickuptrucks.com/2011/06...smissions.html

 

Edmunds has the exact same MPG ratings on the 2011 and 2012 Durangos.

 

Yeah,
The 66rfe will only be on the ’12 Rams, the ’12 Durango will still have the same 545rfe with a retune that allows you to select either 2nd gear while in manual mode = new six speed…/ I just wonder how hard it would be to swap in a 66rfe since physically they are the same. Someone would just have to come up with a new program to flash in.

I just thought it was amusing that a few months after I made this post the 66RFE was announced, or at least until I was aware of it.