To Overdrive or Not to Overdrive

[Marcus Merritt]

1994 F150; 4.9; automatic; 134k miles.... Just had my A40d transmission rebuilt and the mechanic said to leave it in overdrive all the time. Why would I ever want to push the button and take it out of overdrive?

 

[clutch]

not too familiar with automatics, but I always heard you should turn it off when you are towing.

 

[SuperCab]

Like clutch said, if you happen to be towing the old wisdom was to always take it out of overdrive. Or if you are at a speed where it can't decide which gear to be in and its "hunting" between 3 and 4, then take it out of od.

Otherwise, there is no need to use the od cancel button.

 

[5.0Flareside]

I leave mine locked out unless above 50... No difference in gas mileage, higher trans speed means more fluid flow..

 

[Lost]

Yep over 50 mph . The 4.9 usually has 3:08 airplane gears . Unless you live out where its flat . If truck seems to shift up down take it out OD .

 

[m78]

You should down load the owners manual and read what it says to do.

 

[5.0Flareside]

It'll tell him not to toggle OD unless towing probably.. But that's so they meet fuel mileage.. But really there's no difference in mileage..

E4OD's stock engage OD at 35ish..


Plus I have my trans tweaked so even if I didn't leave OD locked out if won't engage below 50..

 

[Marcus Merritt]

Thanks to everyone for the information. I'll just leave it in overdrive all the time since I don't tow anything. However, how about when I have a load on the truck? Take it out of OD? Just took 1600 pounds to the dump and it did fine so far as I can tell with OD engaged. Yes, overloaded, I know.

 

[Lost]

Thats a load... in overdrive extra heat is build up . My trans temp guage would show difference even while empty if in the hills

 

[polarbear]

Thanks to everyone for the information. I'll just leave it in overdrive all the time since I don't tow anything. However, how about when I have a load on the truck? Take it out of OD? Just took 1600 pounds to the dump and it did fine so far as I can tell with OD engaged. Yes, overloaded, I know.

I disagree. '93 F150 went 238,000 miles on the original E4OD. '95 F150 has about 248,000 on it, on the original E4OD. Grand Marquis has about 203,000 on it, on the original passenger car version of the E4OD. I don't baby 'em- actually the pickup get used pretty hard.

I never pull out of the garage without pushing the OD off button on the shift lever. I won't push it again (allowing it to shift into OD) until I can average 55 mph or better. Freeway only, in other words. The older OD transmissions engage OD too soon, and have to shift back and forth constantly- which creates a lot of wear and tear in normal in-town driving.

 

[460Fanatic]

Ford never installed the E4OD in passenger cars; it is a truck transmission. Your Grand Marquis will have either the AOD, AODE, 4R70W, or 4R75E depending on the year. None of these units are related to the E4OD.

My manual (1990) claims that the E4OD can tow in overdrive. However, as others have said, you should cancel it if the transmission is "hunting". Usually this would occur at higher elevations, or towing a load up a steep grade. One can also lockout overdrive to provide engine braking on descending slopes.