I have a 96 F150 4X4 with 5.8L and E4OD transmission. It has what seems to be a fairly routine problem. The truck has 130K miles on it and I'm the original owner. It's never given me any real problems save the occasional O2 sensor, broken vacuum line and the such. I only use the truck these days to haul my hay trailer and pull our camper around. Coming through rural Georgia with the camper yesterday I stopped for gas and noticed a roughly 30 foot trail of fluid on the ground. My heart sank as I still had about 150 miles before I was home. I started the truck and a stream of fluid issued from the torque converter access plate area. I thought my rear main seal had given way so I pulled it into the shade started looking around. With limited tools and no creeper, I was able to ascertain it was ATF and not engine oil. I actually thought ok, front seal not rear main. But to my surprise, when I started the truck back up the leak had stopped. So I checked the fluid level, down some but still on the good side of low and eased on to the house. No shifting problems, no engine codes, or lose of power. I got to the next gas station stop and about one additional quart had been expelled from the transmission over those last 140 miles. Topped off and came on to the house. The camper is small, fully loaded its only around 6500lbs. I've pulled it quite often. So after much research today, I know my transmission was overheating. I was able to recreate it rather quickly by putting the truck in second gear, locking down the brakes and reving up to about 2k rpms for about 4 minutes. this started the ATF waterfall again. It has a LARGE OEM transmission cooler already installed. So here is my plan. Install a trans temp gauge, pull the tranny and replace the front seal, filters and new fluid. I'll also blow out the transmission cooler while I have it apart. Anything else I should consider. I'm hoping the additional heat I experienced this time isn't due to slipping clutches or clogged fluid passages. I should add, the fluid in the transmission is still bright red and has no odor of the Black Death about it.

 

I have one thought, are you sure the torque converter clutch is working as it should? Can you feel it engage? Were you pushing it hard enough that it was hunting gears a lot?

Gear hunting and no converter lock up will cause lots of heat..

It probably isn't slipping since you said your fluid looked OK and didn't smell burnt...

 

Didn't feel any slipping but the camper does load it up a bit. Some downshifting for long inclines but not too much. Is there a way to check if the torque is locking up other tan by the seat of my pants. I fear I may end up chasing symptoms and not the real problem.

 

Get cruising on a level road (or very slight grade) at a constant speed and pedal position. Preferably over 40MPH or so. While maintaining speed, press the brake pedal just enough to turn the brake lights on.

If your converter is locked, you will see (or hear) a sudden increase in engine RPM. Probably 200-300 RPM.

 

I'll try that Ian, thanks a bunch. Raining cats and dogs here right now so probably in the morning. Plenty of level ground here in South Georgia.

 

i think your on the right path.replace the front seal.when you do so,be sure to replace it with the updated viton seal.
example:
Transmission Seal, Front, E4OD / 4R100 1989-up * Updated VITON 36070G

the gauge is the first place to start and making sure the pump is flowing fluid quickly and through the coolers.
then you'll know if it was just a worn out seal (common.these are old trucks.) or if she really was running hot which caused the seal to fail.
then you can upgrade the aux cooler if needed.

another method to check if the converter is locked up properly once over 35-40mph,is to simply turn the hazards on.the converter will unlock when the flashers are active.

 

Thanks, the weather broke enough for me to take her down the road. The torque is definitely locking up. I was a bit dubious at first because I've never noticed the increase in rpm's when I touched the brakes but then I got to thinking about it, the engine always did rev a little when I bumped the brake pedal to knock off the cruise control. So that's not an issue. I also got to wondering how do I know it's locking with the trailer behind it? After it locked up, I slowly accelerated up to 75 and it stayed locked. It didn't unlock until it kicked out of OD or I touched the brake pedal. So...that's one less thing to worry about. One thing that I've noticed is when towing, even back when we pulled a popup camper around, it would roar a bit before taking off if starting on a hill. I always took it to be an increased stall speed due to the increased load. Not sure but it made sense in my feeble mind. I've rebuilt a few C6's, some C4's, a couple of FMX's, TH350's, and two manuals, a top loader 4 speed and the 4 speed in my mg midget. But this transmission seems to be a bit more advanced. If necessary I'll try to rebuild this one but the truck has bern fairly well maintained over its lifetime. i expected to get a few more years of service before retiring her to a full time hay truck. Hopefully we'll have good results with the seal change. On the bright side, it did give me an excuse to buy a transmission jack. Too old to do the tail shaft on the knees trick anymore. Broke a front pump learning to massage my first C3 in place that way.

 

The E4OD's are not too bad. Once you get past the overdrive stuff up front, it's basically a C6. The "roar" you hear might be your cooling fan locking up.

While the stock transmission cooler looks large, it's actually quite undersized. The later trucks moved to much larger coolers.

I'd recommend a full fluid and filter change, and blowing out/flushing the cooler and transmission lines. I'd also look into installing a larger aftermarket cooler.

 

At what temp are the e40ds considard to be over heating

 

@the E40D's test port:
150 should be your min temp.
175 being your perfect temp.
250 still ok,but there's no point in letting it get this high imho,for any length of time.id upsize my aux cooler if i saw this towing up grades personally.

Transmission Oil

i had a HD reman done up locally by a guy who had a .....ton of experience with fleets.
he put in one these:
http://www.dieselsite.com/specialord...ioncooler.aspx

it's working amazingly well.even behind my 3" thick turbo intercooler.more than likely overkill for the f150 trucks of course.

 

I plan on installing either the cyberdyne or autometer digital gauge with the sensor in the test port. I'd rather have something like the ultragauge tool but it doesn't offer transmission temperature as an available reading. The scan tool product is an option but I think overpriced. Thanks for all the advice guys. I'm really interested in the tru-cool transmission cooler. I'm wondering if since my truck has a factory cooler on it, what are the odds there is a thermostat already in the supply line. A cooler that large would be a menace without a thermostat in the line but with one, it would be extra peace of mind.

 

yeah that was just to show the temp info.i wasn't recommending any product there really.
an aux air cooler is always best with a t-stat imho.iv got one before mine so my temps get right up to 175-180 all the time.
without one,the trans just didn't get up to operating temp at all in the winter,unless i had my plow on,blocking the cooler.
i had one installed,and the reman shop also installed one when they rebuilt and installed the trans as well.
ford didn't place a bypass/t-stat inline with the e40d/4r100 so the odd's of you having one,without you putting one in there,would be pretty slim.

 

Are you sure its the front seal leaking? When a tranny over heats, the fluid will puke out of the vent which is top front of the tranny. It pours down and makes it look like the front seal is leaking.

Here's a prevous thread about this:
https://www.ford-trucks.com/forums/1...-radiator.html

 

I'll slide back under there and take a closer look but I'm pretty confident it was coming from the inspection port. Still leave no stone unturned. You might have saved me an unpleasant afternoon of knuckle busting. Thanks for the advice.
On the cooler used as an example above, the factory cooler is plumbed in series with the radiator. It is a 10x8 stacked plate and fin heat exchanger. Didn't count the number of plates but probably 10 or so. I am certain it could benefit from a larger cooler with a thermal bypass. Tomorrow, I'll check flows to and from the radiator and the aux cooler.

 

Ok was going to wait until tomorrow to see definitively if fluid is from the transmission vent or front seal. Mirror, flashlight, and a little bit of effort revealed only a small bit of dark smudge around the vent cover. Plenty of ATF inside the bell housing. So the leak is definitely from the front seal and not the vent. Full steam ahead on the seal replacement.