I have a 2005 F150 Lariat 5.4L. I am at least the second owner. It came with some mods when I bought it. Cold air, Edge Programmer, rims and tires. Since buying the truck it has had an issue with the trans overheating (Edge says upwards of 270 F at times). Sometimes towing wave runner's, sometimes not. A couple times it got hot enough to tell me transmission malfunction on my dash. It also has a shudder, which I always just said it was a shudder in the trans, but after reading on here its probably the torque converter. It would shudder typically going 44 mph and if I let off or push harder on the gas it goes away.
This has been going on for a while, until last week. I has going up a steep canyon road and the trans started to get hot, had smoke coming out the back and then it seemed like it came out of gear. Each gear was like neutral. I lost fluid all over the freeway and luckily made it to the shoulder.
I had the truck towed home and a few days later dropped the transmission pan, no chunks of metal, just the very fine metal power/sludge. Put a new filter on it and put it all back together. Filled it up with Merc V and ran it through the gears. Then tried to go forward and back. Worked great. Loaded up my tools to go for a test drive and that's when it started... lost all the new fluid out of the inspection hole on the dome. So we shut it off and its been sitting since Monday.
So from what I have read, it could be a have some bad seals or a cracked torque converter. What I really want to correct is the overheating issue. And of course leaking all my fluid out.

 

Your in for a transmission rebuild.
270 degrees is way to hot to many times and likely has burned the front pump seal out.
They will not take that kind of temperatures.
The overheating likely is a front pump gone bad.
Normally the running temperature is below 150 with a locked converter and no substantial load.
Load temps depend on the load weight, how long out of lock and how hard the pull is..
The shudder likely is a bad ignition coil and/or maybe the faulty transmission.
Good luck..

 

That's what I was guessing, as far as a rebuild. One shop I talked to said there are some design flaws with that transmission and that he has done a bunch if them. He puts some mods on therequest to help prevent it from doing the same thing. Has anyone done a rebuild with mods to keep it from overheating in the future?
When I was digging into the problem the other day I took the 'in' hose off my trans cooler and turned the truck on. It seemed to pump fluid through pretty good. And we put an air compressor on the cooler and it would seem that there are no obstructuons.
Once rebuilt I wonder if I should do an aftermarket cooler or will the stock one be okay. I've looked at doing a stacked find cooler, one with a fan one without.
There are times when it will overheat under normal driving conditions but more so when I'm pulling my trailer or off road driving, (typically very slow in 4wheel).