Alright.
I've been posting on the big six forum about ECU failures due to age and how those failures effect how our trucks run.
I'm here because I have had my transmission rebuilt and it still slams into reverse. I have repaired my ECU (via the below link) and I know that it still isn't working correctly (EGR valve functions when the engine is cold and not up to temperature).

If all of you go back and re-read the posts in this thread,, there was somone (rwdfan) who said that their tranny was having problems and their fix was to replace the ECU.

Here is rwdfan's quote:"I think it is worth mentioning that my truck had shifted hard occasionally since I bought it at 123k miles, at 152k miles it had been doing it more frequently and I had began having some erratic fuel pump operation that I traced back to the engine computer. Upon replacement of the engine computer, I found my transmission shifted like a new unit. Just a thought if any other issues start to pop up. My engine computer was rather affordable, under 100$ I believe, and this was a remanufactured unit from Oreillys."

The fact of the matter is that the E4OD transmission is completely COMPUTER CONTROLLED, so you'd better have an ECU that works correctly !!!!!!

You probably want to read this and do some checking of your ECU.
Thus far it seems like everyone assumes that the ECU's never go bad or have any problems.
Click on this link.
A9x ECM's (and same years ECM's) Failures Due to Age

I'm here because:
1. I have had my transmission rebuilt and it still slams into reverse.
2. I have repaired my ECU (via the above link) and I know that it still isn't working correctly.
3. I just wanted to see how many folks found that a bad ECU was making their E4OD's shift badly.

In a nutshell, if the ECU is bad, the transmission will not function correctly !!!

Think about it !!!!

Good Luck,

Bob

 

1992 f150 e40d hell and back. I bought truck had tranny rebuilt would drive good then, hard shifts between 1-2, then hard shifts at operating temp. Would drive no prop first 5-10 miles. After 3 times sending back my tranny I was on my own.
1.replaced speed sensor
2.got all vacuum leaks fixed now above 20lbs and each time help a litlle for a little while but always went back to hard shifts.
Then i read a post from Bluegrass which led me to here.
Go to Fuel Injection Technical Library
code 634
Transmission Manual Lever Position Sensor circuit out of self test.

riding smooth now!!!! FINALLY I have combed this site and joined just to say thank you to Bluegrass whom ever you are, thank you. A tranny was really a stretch for my skill level and my wife was "I told you so" every night I was working on it. FINALLY she can go back inside and STHU!!
Thank you Again. hope this helps

 

have a 97ford f350...e4od...just had rebuilt in may...have had back to shop 4 times for shifting hard and torgue converter breaking...it will shift fine for a bit then back to shifting so hard it broke dash off truck...have just replaced the pcm...still same thing...put programmer on it and the line pressure jumps to 128 then shifts hard as hell...tranny guy cant help...so can someone tell me why a new rebuilt tranny will shift like that

 

I know exactly what it is it isn't the trans its your rear end over time the crush sleeve gets worn down and it needs replaced my dad had the same problem don't go fooling with the trans I know that's what it is trust me the guy that owned the truck before my dad had the trans rebuilt by jasper only to find out that's what it was it is very common in these trucks you can try to shim it or replace it

 

I have an E40D as well. I have 199k on odo, the speedo jumps a bit and it downshifts hard and randomly when I use cruise control. What do you suggest I do? Disconnect battery and try to reset? It also will do it sometimes even without cruise control on. Any ideas?

 

You can always try unhooking the battery overnight.
Check codes, clear them.
If speedo is jumpy, it's either the cluster, speed sensor, or wiring.
Trans shifting hard could be speed sensor, mlps, ecu, wiring, maybe a shift solenoid.

These trucks are known for shifting hard. My truck had 25k on it, and shifted hard. I remember driving it when it had 10k on it, and it shifted hard. It's the erratic shifting you need to be worried about.

Keep reading buddy. Add a location to your profile. Once you reach 25 posts, you can add a signature.

 

Disconnecting the battery won't reset anything except for the stored codes. These will reset as soon as the problem happens again.

The thing to do is to troubleshoot why the speedo jumps. Once that is fixed the trans will be fine again.

 

why do these thread live on? someone needs to take this out back behind the barn and put it out of it's misery.

 

Haha
I do wish that admin would lock some of these older topics, and build threads.
But whenever a thread gets brought back from the grave, it means that a new guy has used the search feature... Which doesn't happen very often. I can appreciate the due diligence.

 

I have this same problem .. The guy who replaced my trans couldn't tell me what it was ..so the truck set for awhile .. I got under yesterday and the wire harness to the solenoid block ..because he didn't put the clips back on the frame and trans that hold the harness in place ..and I believe it took a while to come lose because the harness was laying on the front drive shaft and when I used 4x4 it would work it self out a little .. Could a bad connection to the solenoid cause hard shift ..and since it set exposed for awhile cause it to be bad and or not be clean and have a bad connection

 

A bad connection will cause harsh shifts.

 

Started the hard shift problem about a month ago. Tried all the suggestions I could find online. Finally broke down and took her to the trans. shop. Pump burnt up and over heated the trans. The fix? A re-manufactured transmission, and $2000 later it shifts better than I have ever felt it shift in the 6 yrs. I have owned it. It's a lot of money to put in an old truck but it cheaper than buying another used truck and finding out it has issues too. Good luck to all of you having shift problems. I hope you have better out come than I did.

 

I've had this truck since 25k miles, and it's always shifted hard. I changed fluid at 50k, and it got much better. Now that cold weather hit, it shifts very harshly again. But it warms up, it shifts fine.
I am curious if the there is a trans temp sensor and if it would cause hard shifts.

I'm really getting fed up with this thing, and I'm wworried it's going to break itself. I've swapped computers, changed fluid and filter, and checked codes, and I'm tired of this.

No, it doesn't have 160k on it, only 60k. It's been in my family since new, and no one can remember it ever shifting correctly. It will be getting a 4r70 if it doesn't get figured out.

 

I am finding it useful. Would you rather I start a new thread about the same problem? I would like the OP to report if there was a solution.

 

There wasn't a solution... that's the problem.
The op started this thread 6 years ago, and it probably still shifts hard.
There are 500 threads about terrible shifting, and none of them have a solution, and a few just replaced the trans to "fix" the issue.