The E4OD/4R100 evolved from the C6, and is possibly the heaviest (weight & strength) automatic ever put in a 1/2-ton truck. It's also among the largest.
The 4R70W evolved from the AOD, and is used in trucks & cars.
2008 Ford transmission naming convention is as follows:
* The first character, a number, is the number of forward gears.
* The second character, either the letter 'F' or 'R' represents front (transaxle) or rear (transmission) wheel drive.
* The next characters, a grouping of numbers, represents 1/10 the design torque capacity of the transmission/transaxle.
* The last character, if used, is one of the following:
* * 'E' for electronic shift
* * 'N' for non-synchronous shift
* * 'S' for synchronous shift
* * 'W' for wide ratio