WHAT IS THE DIFFERENCE BETWEEN THE TREE TRANNIES THAT FORD OFFERS IN THERE TRUCKS?I HAVE A 94 F150 WITH A 4R70W/AOD-E WHAT WAS THE PERPOSE FOR THIS TRANNIE AS APPOSED TO THE OTHERS?

 

The 4R70W was an AOD-E with a wide range ratio gearset. All AOD-E/4R70W transmissions had a 2" overdrive band, and a lockup-type steel clutch drum, which is much more durable than the AOD's. The first gear in the AOD-E is a 2.50:1 ratio, wheras the 4R70W has a 2.79, which is lower and more desirable for performance. The second gear is slightly lower as well, I believe it was 1.80 vs. 1.72, and third gear is the same for both Ford automatic transmissions at 1:1, which is also the same ratio as the C4's third gear. The killer here is that you get a fourth gear, which the 4R70W has a .7:1 overdrive, which is not significantly lower than the AOD-E's .67:1 ratio, both will give you outstanding cruising speeds, even with very low (numerically high) differential ratios, especially because both torque converters will lockup at highway speeds. The 4R70W is the better trans of the two, it will be faster to drive, and easier on the engine and itself. AOD-E's can be easily changed over with Ford's wide ratio gearset, available at all Ford dealers, or with custom-forged hardware made by most aftermarket suppliers. Both are outstanding transmissions, and if yours ever fails, I am in need of a core. I can't get rid of my stock 2.75 differential until I have overdrive gear to makeup for the 3.73's I'm putting in the rear! -TK

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing