Hey everyone,

I've been without a Ford truck for a couple years, but I've recently purchased my dads 2003 7.3 and my folks trailer from them. A little background info to start with:
He was the original owner, Lariat trim package, FX4, Bank's Power Pack (with transcommander), 192K or so miles, transmission rebuilt around 150K. Truck has been used for work and towing a 32' travel trailer. Transmission fluid is full and not burned in appearance or smell.

The rebuilt transmission was installed by a very reputable local shop at around 150K+ miles. I will try to get more information, but all I know is it was shipped by some sort of specialty shop from Southern Cal, billet torque converter, Kevlar clutches, plate and fin cooler, warrantied for 3yr/500K miles, which is expired on the time side at this point. I don't think it's anything like a John Wood's, judging purely on what I remember him spending.

According to the factory instrument cluster gauge, it overheats. Before the rebuild, it overheated twice while still fairly young in life when I was on family trips as a kid, way before rebuild.
I took in on a camping trip and it tried to overheat at 30mph with just light camping gear and 200lbs of dogs in the bed a year ago (no trailer). Transmission shop blew out the radiator and cooler to help airflow, hoping to resolve the issue.

Just got home from a trip to Oregon today and over the Siskiyou mountains at 40 mph (traffic), towing the 32' trailer, it tried to overheat. I pulled over twice to allow it to cool before we had a major blowout on the TT ( another story). After that, it threatened overheat at 60 mph, no overdrive, on slight uphill at high temperatures on I5. By high temperatures, I mean 105 plus. Yeah, I know it was hot, but this was never normal years ago. We have seen some hot desert days in this truck with the 32' trailer in tow and the only time we saw overheat was at 25-30 mph up long, steep hills when stuck behind a semi.

Do you guys have any opinions at all on this? Is this normal? Is there something I can do about it? I can understand it getting hot with a 8K pound TT in tow at low speeds up hills, but overheating when basically unloaded seems unusual to me, yet alone on relatively flat land at 55-60 mph.

One more question: What about towing in OD while on flat land? At 60 mph today, I noticed it was still a little hotter than normal, so I put it back in OD and it cooled down to the half way point, or "normal".

Thanks everyone,
Dan

 

Do you trust the factory temp gauge to be accurate? Would installing a dedicated ATF temp gauge into one of the ports on the transmission give a better reading of the internal temperatures?

 

Ah, yes, forgot to mention that I plan to add a dedicated gauge, as the factory one only tells if it's hot or not, and who knows how accurate it really is. Good point. Any time any gauge shows something is hot on the dash, I automatically assume it's past where it should be, as most gauges are just mechanical idiot lights that tell you too late, at least in my experience.

I was just hoping to find someone who maybe had the same/similar trouble and find if they did anything that solved it. I'd like to avoid the issue again next time we take the rig out of state. The gauge is on my short list, however.

Thanks,
Dan

 

I had a similar lack of faith in a factory oil pressure sensor, assumed very low OP was simply a bad sensor. As it turns out the OP was well below spec, oddly enough the sensor in perfect working condition.

I ended up replacing the engine but now running a dedicated OP gauge along with the factory sensor to keep the cluster happy (2005 E-350 w/5.4)

I sincerely hope your situation is nothing more than a faulty sensor!

 

I know! It is very accurate. It just isn't really useful.

It will move from cold to the middle of normal when the trans heats up to 50°F. It will move to the yellow at 230°F. I think it will move to the red at 260°F, but my memory is a bit fuzzy on this number.

 

Mark,
Not trying to high jack his thread, but what is a "normal" operating temp for the 4r100 ? And what temp would you start getting concerned about it ? I've got the 4r100 in my 99 Expedition with the 5.4L, and sometimes wonder if I should be concerned about the temp when I'm towing. I have an SCTx4 plugged into the OBD2 port that I usually use to monitor other things, but when towing (in the neighborhood of 5500 lbs), I keep an eye on the trans temp. It has gotten to 230f a few times in stop and go traffic, but typically hangs in the 200-210 range while cruising at 65mph. I usually use OD when I'm above 60mph because the trans will actually run cooler. For reference, the radiator was replaced with a 3 row unit, new water pump installed, and new fan clutch installed about 15,000 miles ago. It also has an aftermarket Hayden cooler.

 

You can run up to 220°F all day long with no problems. You can go up to 250°F for up to a half hour at a time.