Overdrive

[gandalf]

Over this past weekend I had to take my truck to my daughter's house. This meant driving over the Santa Cruz Mountains, over Patchen Pass, an elevation of 18xx feet, up and over highway 17. Its an easy enough drive.

My truck, however, was running a bit hotter than it used to. It generally runs at 190*, with the transmission, E4OD, at 150*. Going up the eastern slope It went up to 215*. At that point I took it out of overdrive, pushed the little button on the end of the gear selector. It immediately dropped down a gear, as it was supposed to, and the temp dropped back to 190*. All well and good.

At the top of the pass, about to start down the western slope, I pushed the button on the gear selector again to allow it to go back into overdrive. I did this at about 50mph. Nothing happened. I was on pretty level road, and the truck remained in 3rd gear. I had to pull into the Cloud 9 (now defunct) parking lot and shut the engine off. I took a moment to check my load, started up and continued driving. The transmission had no trouble going into overdrive.

Is this normal, having to shut the engine off to make the transmission able to return to overdrive after manually taking it out?

The truck is a '92 CC with E4OD, 7.3 NA engine. The load was light, a box truck ramp (think UHaul box truck loading ramp) on the roof of the shell.

 

[Black dawg]

NO, not normal. Does the light on the shifter work, and was it blinking by chance?

 

[BrianX128]

Only E4OD I have is on a gasser, but mine always shifts into OD immediately if the RPM's are high enough. It actually feels like a grenade button if you are going up a hill at 55, with the OD off, and press the button again to allow it to use OD it will shove itself into OD, realize that was a mistake in a few seconds, and shove itself down a gear.

 

[Greenie]

I towed a 7,700 pound travel trailer many thousands of miles with the transmission in OD. Across the US and over the Sierra Madre mountains in Mexico numerous times. I only took it out of OD when the transmission searched. The original transmission lasted 220,000 miles. I think the owner's manual recommended towing in OD - unless the transmission keeps hunting for the right gear.... 4.11 axle

 

[SultanofNACL]

I don't remember what logic I have read the transmission control module uses for setting the O/D light (whether a condition must happen 'x' number of times to set the light on versus flash), but I seem to remember that any code in memory is deleted when the ignition is turned off. Seems counterintuitive, I may be incorrect in my recollection.

-Has the fluid level and condition been checked, though this doesn't seem like an issue since everything has worked excellent.
-Are the electrical connectors for the transmission fully seated? The solenoid block connector can leak trans fluid through the internal seal and the locking connectors can become damaged if not disconnected carefully as well.
-There is always a possibility the O/D button is not commanding "O/D on-off" to the TCM consistently. If a wire becomes damaged between the button and the TCM that 'command' could become intermittent. Check for chaffing on a harness?
-Distinct possibility that the TCM has become damaged internally. Capacitors can become damaged, but I have not read of many people having this problem on Ford trucks.

 

[gandalf]

I don't remember what logic I have read the transmission control module uses for setting the O/D light (whether a condition must happen 'x' number of times to set the light on versus flash), but I seem to remember that any code in memory is deleted when the ignition is turned off. Seems counterintuitive, I may be incorrect in my recollection.

...

The O/D light never came into play in my case. The light never came on, it never flashed. The transmission did not go into "Limp" mode. It simply failed to re-engage overdrive when asked to do so.

I have not checked for transmission error codes. There is no rush to do so. Those codes are stored in the system until such time as power in interrupted, until the battery is disconnected.

 

[IDIBRONCO]

The O/D light never came into play in my case. The light never came on, it never flashed. The transmission did not go into "Limp" mode. It simply failed to re-engage overdrive when asked to do so.

I have not checked for transmission error codes. There is no rush to do so. Those codes are stored in the system until such time as power in interrupted, until the battery is disconnected.

Sounds like it's time to involve Trackspeeder.