Ford 6R80 transmission ratios are
4.17/ 2.34/ 1.52/ 1.14/ 0.86/ 0.69/ (rev 3.40) it is a double overdrive and a rather low first, lots of jump between first and second.
Ford 6R140 used behind the diesel has the following ratios
3.97/ 2.32/ 1.52/ 1.15/ 0.86/ 0.67/ (rev ?.??)
These are German ZF designed transmissions built under license by Ford. Notice there is NO direct drive in these transmissions, gearsets are always doing the work.
In the 5R110 used behind earlier diesels, its gear ratios are,
3.11/ 2.20/ 1.54/ 1.09/ 1.00/ 0.71/ (rev 2.88)
Notice that it is actually a 6 speed, however 4th is not used unless the Outside air temp is below 5F at which time 5th is skipped. Above 5F 4th is skipped and 5th is used instead.
Older automatic transmissions used simple sprag clutches and hydraulic clutches or bands to engage the gears going up through the speeds. A new gear simply over rides the lower gear. In these new transmissions they depend on electronics to drop out of a gear and then engage a new gear, one cannot simply override the previous one.
Note that Ford is working on a joint deal with GM in developing a new 10 speed automatic.
http://www.thetruthaboutcars.com/2014/12/exclusive-inside-look-fords-new-10-speed-transmission/
http://gmauthority.com/blog/2015/01/details-on-upcoming-ford-and-gm-10-speed-transmission-reaches-the-internets/
Charles
