AOD 4-2 Downshift
 

When I am driving my truck at 50 MPH and above in OD (Overdrive), my AOD transmission will only downshift once to 3rd gear and accelerate from there under wide open throttle. Is this normal? :-huh

It would be a lot more fun if the AOD would would downshift to 2nd gear at that speed.

And before someone gives the standard response of "TV cable," I have it set at full throttle = full TV pressure. The up shifts are right on time and firm, and downshift is quick. It just doesn't do a 4-2 downshift at speeds higher than about 45 MPH.

It's not going downshift from 4-2 unless you manually do it by moving the selector from "D" to "1".

I noticed this for years from my AOD and anything from about 58 mph, it wouldn't shift into "2".

The internal governor will prevent it from dropping into 1st after a certain "factor" has been reached, usually from 4th to 3rd, to prevent damage.

Ive done the the "D" to "1" after learning about it and I was tired of not being to pass after 55-58mph.

Automakers like to avoid hunting of gears. It's like a downshift into 2nd over 50 or so would it put very close to the 2-3 shift point.

Thanks for the tip! My AOD *will* downshift from 4-2 from about 45 MPH (or lower). But at speeds higher than that, it will only downshift to third.

I wonder if this what Ford meant when they explained "Forced Downshifts?"


From the 1985 F-Series Owner's Guide under Automatic Overdrive:

"FORCED DOWNSHIFTS - To gain extra acceleration, in (D) (OVERDRIVE) or D (OVERDRIVE LOCK-OUT), as in passing, push the accelerator to the floor. The transmission will downshift to second gear at speeds from approximately 55 mph to 25 mph. At lower speeds the transmission will downshift to first gear in either position. At speeds above approximately 55 mph, the transmission will downshift from overdrive to third gear."


If so, they completely forgot to tell you that you must first pull the gear selector down to "1." If not, they were about 10 MPH off for the downshift to second gear. :-huh

Doesn't sound like they're 10 MPH? You said it won't go into 2nd from 50+ in your original post. They're off by 5 MPH, and it says "approximately" anyways. As the springs and governor valves wear inside the valve body, the shift points are going to move around.

For normal (factory) TV pressure, my AOD will shift into Overdrive at about 45 MPH under light throttle. At this setting, the maximum speed the AOD will perform a 4-2 downshift is also 45 MPH.

55 MPH - 45 MPH = 10 MPH.

If I set the TV cable for maximum TV pressure, shifts are firmer and Overdrive will come in at about 47 MPH under light throttle. At this setting, the AOD will perform a 4-2 downshift from a maximum speed of about 47 MPH. At speeds higher than 47 MPH, the AOD will only perform a 4-3 downshift.

I rounded up to 50 MPH because I am using a higher setting than what Ford calls for. Sorry for the confusion.