I have learned a lot about my 1993 7.3IDI with the E4OD. Some of that learning was from manuals, some from letting a hackjob "mechanic" touch my rig and having to redo days worth of crummy work, and some from this forum. A lot of people dump on the E4OD and so far I have not had mine go out on me even though I could have sworn it was on its last leg. Here are a few things I have learned about the trans. First of all - the factory cooler was small and weak (fixing some line leaks the barbs broke off it) and keeping the trans from over heating is important so that got fixed early. And a gauge - so I know how it is doing. Tire size matters - I had tested and tuned and debugged for hours. I replaced and tested and tuned some more to get the trans to stop "lugging out" and I did not like where its shift points were. I had a planned 3k mile trip so I put stock tires on the truck and it all fchanged! The TC lockup stopped coming in and out randomly, shift points were pleasing and it was no longer lugging out or shifting at weird times. I attribute this to the speed sensor being off with the larger tire size. I also went with a thinner tire for less rolling resistance to squeeze out a bit more MPG and I dont like the look of fat tires anyways. IP vs FIPL vs Fuel Screw - this is a longer one but what it boils down to is that I was adjusting adjusting my foot on the pedal to accommodate the condition of the engine - which made the trans act "poorly". -_- So the IP had the fuel screw turned way up to the point of having to back off the throttle A LOT. I was told "well its really tricky to get to and adjust properly" which is a crock and a half if I have ever heard it. I had so much fuel dumping through that I was adjusting my driving habits to keep from sooting up the entire highway getting on. The whole "Prius repellent" joke is a lame one but what is worse is the transmission thinking --oh its cool we are only at half throttle we can stay here in this gear all day-- but the amount of fuel pumping through is saying "lets roll coal up this half mile stretch of I35 and show everyone how senseless we are!" Shift points being less than ideal, having to pop the OD button to shift down, not being able to get to full highway speed without trans temp breaking 1000*F at 55mph all got old and annoying. I towed with the truck like that twice and it was very nerve wracking. I suppose it was nice having people stay WAYYY back from me but it needed changed. I slowly turned the fuel screw down little at a time until I am happy with the view out the tail pipe and everything is acting as it should. So after reading and having done all of the checks that are typically advised with transmission weirdness, and it being all "set up properly" on the transmission and related sensor end - it was non transmission issues which made it seem like I was looking at a pricey rebuild/replace. These are just a couple of the non-transmission related problems I have dealt with over the years that seemed to make the transmission act up, what about all of you??