Shops, Barns, Varmints, and Trucks

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1991 E4OD

Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Shops, Barns, Varmints, and Trucks
Forum Description: anything you want to talk about except politics
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=207853
Printed Date: 19 Aug 2025 at 12:08pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: 1991 E4OD

Posted By: Lars(wi)
Subject: 1991 E4OD
Date Posted: 18 Aug 2025 at 4:38pm

In my F-350 started shifting funky the past couple days. Friday it slammed into 2nd, and 3rd a couple times, but 3rd into 4th, and 4th into OD was smooth. Now today, around town, when in 2nd and 3rd, occasionally the rpm’s would jump up a few hundred, then drop back down, then ground speed would increase. ATF is at full, always properly checked, nice and pink/red on towel, does not smell burnt. 133,000 miles on the truck, no knowledge on past maintenance history since purchased this past October. I have put just over 4,000mi on it.

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I tried to follow the science, but it was not there. I then followed the money, and that’s where I found the science.

Replies:

Posted By: LouSWPA
Date Posted: 18 Aug 2025 at 4:58pm

I would start by replacing fluid and filter, even though it does not smell/look bad

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I am still confident of this;
I will see the goodness of the Lord in the land of the living.
Wait for the Lord;
be strong and take heart and wait for the Lord. Ps 27

Posted By: ScottNC
Date Posted: 18 Aug 2025 at 6:58pm

Must be something in the air. I got a 1991 F150 that did the exact same thing Saturday and Monday. Haven't had time to dig into it yet.

Posted By: steve(ill)
Date Posted: 18 Aug 2025 at 8:52pm

The "E" in the spec mean ELECTRONIC SHIFT.... Several INPUTS and then SOLENOIDS engage the trans with oil pressure... you can have a bad INPUT SIGNAL... or a BAD SOLENOID or wire Harness...

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Erratic Shifting Behavior

With the E4OD transmission, electrical problems are often the main culprit behind erratic shifting behavior. It’s often due to faulty sensors readings. Wrong readings from a faulty tachometer (which measures RPM), throttle position sensor and vehicle speed sensor can cause the transmission control module to shift gears at the wrong time.

Some E4OD transmissions had issues with the analog range sensors, especially the ones built before 1995 as the poor weather-proofing allowed water to enter the connector and cause electrical problems.

Delayed or No Shifts

Poor cooling and vibration may damage the shift solenoids, and lead to their failure. If this happens, the automatic transmission fluid will not be routed through the valve body properly to engage the right gear.

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Like them all, but love the "B"s.

Posted By: fjdrill
Date Posted: 19 Aug 2025 at 5:03am

Pull the pigtail where it goes into the tranny. If wet replace coil pack. Also, it has speed sensors on top. (same as cam speed) if replace do both with Motorcraft brand. If getting a flash on gear shift and hard shifting probably torque converter coming apart inside and turbines getting locked w/debris. Also. have seen filter drop out/down. replace w/Motorcraft and install with retainer clips added. you can buy the retainers, or I just made them out of thin sheet metal-they are just clips that keep the filter from falling down.