I have a 1995 F-150 2wd with the 4.9L and E4OD. I was told by the previous owner that they had the transmission rebuilt. I have no paperwork of it but the case looks very clean and there are some other signs that the transmission was out at some point. Ever since I got it, the truck has had a long 1-2 shift and it drops way more RPM then I think it should. It will shift from 1-2 at about 3000 RPM and drop to around 1500 RPM. If I’m accelerating with less than about 1/4 throttle it will sometimes shift fine though. Something very strange I’ve noticed is when I take off and floor it, if I manually put it into second right before it would shift on its own, it shifts almost flawlessly and doesn’t take long like it usually does between gears. RPM still drops a little more than I think it should but not as bad. Something else I noticed is that the torque converter rarely ever unlocks which seems mostly responsible for all of this, the truck chugs a lot because of this. I usually have to quickly mash and let go of the throttle to get it to unlock and even then it will only stay like that for a few seconds even under heavy load. The truck also tried to stall very often when I put it in reverse or manual first at a stoplight, I did some research and it sounds like they had a heavy duty torque converter installed and that’s the reason for most of this but I could be wrong. Lastly and possibly the strangest out of all of these symptoms, if it’s below 50 degrees Fahrenheit outside and the truck has sat overnight, it will shift absolutely flawlessly and the torque converter locks and unlocks perfectly keeping the truck in the power, but only does this until the trans heats up which usually lasts about 30 seconds to a minute and a half depending on the outside temperature.

Sorry about this extremely long post, this whole scenario with my transmission has had be baffled for a long time. I know nothing about transmissions so if anyone has some input on what may be happening or honestly any theories and info at all, I would love to hear it.

 

What codes are stored in the PCM? Here's how you can read them: www.troublecodes.net/ford

 

My overdrive light doesn’t flash and I don’t have any warning lights on the dash, I’ve ran tests through the OBD1 port before and there were no codes at all besides a code for an insufficient idle RPM during the test or something like that.

 

You should check now and see what codes are stored in the PCM. Without codes, I predict you won't be able to fix this without spending a boatload of money.

 

Check your coolant temp sensors, the truck may have more than one. One is for the guage/light and the other one is for the PCM. If the one for the PCM is faulty it could be telling the PCM that the engine is hot and the PCM will engage the converter on top of the 1-2 shift to help with heat generation.

Not sure the specs for your vehicles sensors, I think cold should be around 30 ohms and hot around 8 ohms, may wanna double check that.

 

Sorry for the super late reply, ran another test and still no codes came up for the transmission. I messed with the truck while driving a bit, and I've noticed that the truck just flat out doesn't want to unlock the torque converter. It's fine when it's cold for the first minute or so of driving because I believe it's programmed not to lock while it's cold, but once it warms up it goes into lockup and pretty much stays there. If I manually shift it into second and mash the gas up a steep hill, it does unlock but usually not for very long. I'd say the longest it has stayed unlocked was less than 10 seconds, I think that's mostly responsible for the chugging I've experienced. And once it starts chugging, instead of it unlocking it will just downshift and unlock for about half a second once in that gear and then immediately lock back up. I'm thinking it's an issue with the torque converter now, but some feedback would be helpful.

 

Is it possible that you are expecting way to much out of your truck? You got a 4.9 and an automatic. It's only going to do so much.

I am probably wrong, but 1st gear there is no lock up, all the other gears have some sort of lock up. That lockup is determined by the computer. I suspect when the transmission shifts from 1-2, that the lockup converter is also engaged which would cause even a larger drop in RPM. There are only 4 gears in this transmission and they are spaced to get the truck moving and keep the engine at a decent RPM down the freeway. Certainly not like the newer transmission where you have at least double the amount of gears for the computer to choose.

I think you are fine, but I have a 95 5.8L, not the 4.9.

 

We had a 94 F150 in the shop last week that the converter was always on in drive and would stall the engine at stops, it turned out to be a bad PCM. We paid 700.00 for a used PCM for this thing because they are hard to get and apparently cannot be rebuilt.

 

All forward gears have lockup, not some sort of lockup. That includes first gear, though first gear will only lock with the throttle above 75% open.

Back to the original poster: Does the converter unlock in manual 1? There is a hydraulic circuit that should force the converter to unlock when in manual 1.

 

My Tweecer does not show a lockup schedule for 1st gear for my Ford. That does not mean there is not one. Could be that it cannot access that.