Hi Y'all. I've got a 95 f150 with a 5.8 and the E4OD. She's my papa's old truck and my current pain in the butt.

I starting having problems a couple weeks ago where the transmission would shift in a very weird but consistent way. It was originally very sporadically it would do this, but now its a constant.

The truck starts in 1st, will hold it until 3200 rpm / 20ish mph, shift to 2nd and occasionally go between 2nd and 1st until 30mph when it shifts into overdrive and lugs at about 1000 rpm. Its a fairly consistent pattern. It doesn't matter how much gas I give it above 30mph, the best it can do is come out of OD and into 3rd for about 4 seconds and then back into OD, or just shift into 1st. I can force shifting from 1st to 2nd if i take my foot completely off the gas and then it slams into 2nd. If I row through the gears with the column shift, it works normally until I reach Drive. The truck does has 290,000 miles on it, but the engine itself is still going incredibly strong. I can take a video of it if that would help diagnosing it.

I have replaced the IAC, MLPS, redone all the vacuum lines, the EEC 2 years ago, and the vss. There are no codes thrown, despite the computer reading my smog delete correctly, and the TPS is reading correct voltage and resistance. I might have a little bit of hesitation when accelerating, but with Oklahoma roads and not wanting to punch it with a transmission ready to money shift itself, It might not actually be there.

I really have no clue what it could be at this point and any ideas or reasoning would be greatly appreciated. Thanks.

 

Welcome to FTE.

You want to hear from @Mark Kovalsky


How are you checking for stored codes? And what codes are you getting, you should at least be getting a system pass code. Is it OBD or OBDII? I like the Innova 3145 for OBD, they’re cheap and buy it on Amazon.

Fluid full - checked in park, warmed up and idling? When was the last time it was serviced, ie. fluid change?

Is the O/D light flashing on the shift column? Does it make any difference if you turn OD off, will it turn off?


Once the above is checked, I’d want to drop the fluid and pan and see what you find in the bottom of the pan / filter.


Hopefully mark will see this and chime in. First thing he will ask for is codes..

 

Its an OBD1, and I use the Innova too. I get the regular system pass (111) and code 311 which is the smog delete when doing KOER. There are no stored codes or given codes with KOEO.

The O/D button does nothing to change the shifting, it still will have a mind of its own. However when the problem was intermittent, the O/D button did work like it was supposed to when the tranny wasn't having a mind of its own.

The last time I did the fluid was about a year ago. My papa never serviced the transmission so that was its first change... It did have some metal shavings on the magnet in the pan. The fluid is full

 

Did you replace the IAC and MLPS before or after it started acting up? Were they genuine Ford parts?

 

The IAC was a while before it started acting up, the MLPS was after. Both were Motorcraft.

I don't believe that the IAC would be able to cause the shifting though, and the truck idles perfectly fine.

 

Were there any codes prior to changing the TRS / MLPS? What made you suspect that?

I don’t have a lot of faith in after market replacement parts, possible it is defective out of the box.

 

The IAC could most definitely cause your shifting problems. The IAC went bad in my '94 F-150 with your same engine and transmission and it shifted and jerked terrible and I also had a very fast idle and my check engine light was on. If you hadn't used a Motorcraft IAC I would definitely be advising you to get a Motorcraft IAC. I'm not saying your Motorcraft couldn''t be bad. I don't know what to say now.

 

Have you tested the speed signal?

 

Good thinking, I forgot to mention that.

As well as any changes in your lights, LED bulbs? Google: OBS LED third brake light, they interfere with the E4OD.


I would also drain and check the fluid pan and magnet again (after a year) and previously finding metal in it, before I went any further.

 

You can test the raw VSS signal with an oscilloscope. I suggest connecting it under the hood and running the wires into the cab so you can monitor the signal while you drive. eBay has cheap o-scope for about $40.

 

I haven’t used an oscilloscope in over 30 yrs. Especially have not used one with a fluke meter, or a new style.

Maybe you could do a ‘ How to tutorial’ someday. What it can be used for on this gen of truck, and what we’re looking at.

 

I paid $5500 to have a Jasper rebuild installed.
FYI

 

Another area I’ll add for trouble shooting, even if no codes present is to check all the electrical connections.

The TRS / MLPS connection and the solenoid body connections (I have seen pins corrode and break, and dirty electrical connections make intermittent electrical issues on various machines). Either one can cause shifting issues, and have been documented here.

Check the solenoid connection for fluid as well. There is a small heat deflector on the RH side of the transmission, remove it for easier access.

I doubt this an issue in this case, but check the filter, make sure it hasn’t dropped and it is sucking air.


I wouldn't jump to conclusions yet on replacing - the issue could be electrical and it may follow to a new trans.

A note for the OP: if it comes to replacing / rebuilding, you can rebuild it yourself.


We should make up an E4OD check list for trouble shooting and make it a sticky.. trying to remember everything each time is a bit of a pain. A flow chart would be good.

 

For the TRS, the truck was running weird and the TRS voltage was really bad. The MLPS was doing this weird thing where I had to pull up on the column for the truck to start, also it was shifting hard. That got fixed with the new one

I replaced the VSS. It didnt help at all. The speedo works perfectly, and if I unplug the VSS, nothing changes with how the truck shifts.

I did replace the 3rd brake light about 2 years ago. I replaced it with a LED one because regular bulbs kept melting the plastic. I didnt install the resistor because I was lazy. Do you know what resistance it needs so I can splice a resistor in the wiring and see if that works?

I'll check the pan later, Im in college right now and next week is finals week. I really don't want to risk being left stranded on my 10 hour drive back home because the only thing holding my tranny together was metal shavings and dirty fluid.

Also I apologize for the late response, my life has been really busy.

 

Thanks for the suggestion. I'll definitely check the pins, I didnt even think about the solenoid connection. I'll check on it once I get back home and check all the filters and whatnot at the same time and get back to y'all . Im just praying that its not a rebuild.

Ive seen some really old posts that have sort of a checklist, but most of them have links that are broken now. An E4OD checklist/thread would be the greatest thing since sliced bread for anyone who comes across it.