The E4Od does not have a thermostat. It holds about 18 quarts, not 12.

 

The E4OD does have a "Transmission Oil Temperature" sensor in the solenoid pack. It is the O/BK leed thru C103 to the PCM. At least in 93 that was the case. I dont recall what the output causes the PCM to do, maybe kick some codes, maybe even trigger "limp home" mode.

Sure would be interesting if that output could be connected to an electrical temp guage. First thing "next" Monday I will try that. If not, then the Monday after that---

Most overheating of tranny oil is because of converter slippage (non lockup) or clutch slippage (lockup) in the converter. Overdrive mostly causes problems because of weakness in the sun/planetary gears and loss of ratio and gear hunting.

 

I have a 1993 E-350 Class-C motorhome and my E40D did the same thing -- in fact, it was right after the Ford Truck dealer had serviced the tranny -- drained it, new fluid, new filter -- and it dumped a couple quarts on my driveway. I use the RV to tow my track car -- about 5,000 lbs of trailer and car, so I have the tranny flushed every 20k or so. I also added a temp guage that's tapped into the pan, so I know, once hot, my tranny fluid runs 170 degrees, and might get to 180 or 190 on hot days when airflow over the cooler is reduced (traffic, backing up).

But backing into my driveway -- slight grade, but arguably flat -- really seems to strain it. I guess it heat soaks a bit, but it can climb another 10 degrees quickly. Given how slow tranny fluid heats and cools, it's surprising.

Anyway, I assumed the dealer overfilled it. The level has been normal ever since and it's now been about two years with no further issues. Also, it's my understanding that tranny fluid expands significantly when heated, which cause it to "puke" excessive pressure past the seals.

My RV came from the factory with an auxilluary cooler that's piped after the radiator.

So, for all these reasons: add coolers for trans and engine, they will live longer. Also, use Redline Oils in everything, even your lawn mower

 

I have seen some discussions about putting the sensor in the pan. It seems that the pan is not the best place for a sensor. The oil in the pan has been through the radiator tank first then through any aux coolers. By the time it reaches the pan, it has been cooled down considerably and is presumeably as cool as it will ever get. It dosnt get heated again until it is picked up from the pan by the pump, then pumped through the tranny for various uses, including the converter then sent out through the cooler/radiator tube and back.

My .02 is that the best place to measure the temp is at the outlet of the tranny, before the cooler/radiator. That would be a realistic measurement of the temp. Would be great to have 2 sensors (electric guage w/toggle switch), one at the output of the tranny and another at the inlet to the pan or the pan itself. Now that would tell you something

 

You raise an excellent point, and I agree.

Ironically, I orderd the gauges and meant to install them myself, then got lazy (after they sat for months) so I had the local Ford Truck dealer do it for me (at ridiculous expense) when it went in for a trans service and they brazed the sensor into the side of the oil pan while they had it out. You'd think they'd put it on the output flow, wouldn't you?

So I consider it the "average" oil temp, but this is similar to my engine oil temp guage, which also reads off the pan. I should install another trans sensor and a switch to the output side to get the "peak" oil temperature ... I'm scared to see the delta My IR gun indicates about 195 at the hot input on the aux cooler (this is past the radiator) when the pan reads 180 ... so maybe 220 peak?

I installed Doug Thorley headers on it, and they run directly parallel to the trans oil lines, so I had to insulate the trans lines because in traffic, with no airflow under the rig, the header downpipes were superheating the trans fluid!

So I strongly recommend headers (improved torque and gas mileage), but be sure to insulate the trans lines.

I might do a sensor and a switch ... myself this time!

 

You raise an excellent point, and I agree.

Ironically, I orderd the gauges and meant to install them myself, then got lazy (after they sat for months) so I had the local Ford Truck dealer do it for me (at ridiculous expense) when it went in for a trans service and they brazed the sensor into the side of the oil pan while they had it out. You'd think they'd put it on the output flow, wouldn't you?

So I consider it the "average" oil temp, but this is similar to my engine oil temp guage, which also reads off the pan. I should install another trans sensor and a switch to the output side to get the "peak" oil temperature ... I'm scared to see the delta My IR gun indicates about 195 at the hot input on the aux cooler (this is past the radiator) when the pan reads 180 ... so maybe 220 peak?

I installed Doug Thorley headers on it, and they run directly parallel to the trans oil lines, so I had to insulate the trans lines because in traffic, with no airflow under the rig, the header downpipes were superheating the trans fluid!

So I strongly recommend headers (improved torque and gas mileage), but be sure to insulate the trans lines.

I might do a sensor and a switch ... myself this time!

 

The vast majority of the heat a transmission generates is from the torque converter. And by far the best place to mount the temp sensor is the line pressure port.

Phaster, I would be curious to know about your experience with the headers on your van. What year and what motor? What style headers. I am considering doing headers on my 5 liter and was wondering which style (F150?).