Just purchased a 1991 F350 with a 7.3l and an E4OD, 410 axle with 30,000 miles on it. Local Emergency Vehicle, hence the low milage.

I was told the tranny is no good, but I am pretty sure the problem is the Engine Tachometer Sending Unit as the Tach in the cab acts sporatically. Torque Converter locks up unexpectantly, truck starts in 3rd gear and won't shift down on take-off.

What are some of the other things to watch out for on the E4OD?

 

Quite a bit unfortunately. The E4OD isn't a very good transmission. Here are a couple of threads with some good info in them:

https://www.ford-trucks.com/forums/s...d.php?t=292701

https://www.ford-trucks.com/forums/s...d.php?t=381773

I agree that your problem does sound like the engine speed sensor.

 

Thanks,

I will follow up on the links.

My Dad been running the E4OD for almost 400,000 km (250,000 miles) in his 92 F250. I agree with you though the E4OD is not meant for heavy towing. The only time my Dad got in trouble was when he once started pulling a heavy trailer loaded with firewood and burned out his torque converter. He had the usual problems along the way like the tach sender, but keeps the truck lightly loaded most of the time.

 

The tach, VSS (vehicle speed sensor) and the FIPL/TPS must all be working flawlessly or set to correct specs, the trans will do wierd stuff otherwise.

I would suggest:
Check all the trans electrical connections especially the one on the right side with the tin cover, remove the tin heat shield, remove the solenoid connector by pushing on the center tab and pulling up on the wire harness. To install push down until a click is heard. Always reinstall the tin heat shield.

What your looking for is bent, corroded, missing pins etc.........

 

Thanks,

I see you have gone down this road before.

I have replaced the tach. sensor because it was bad. Seeing that my new problem is the the truck won't shift down when the pedal is fully applied I will replace the TPS next. VSS looks steady, I will change it last if need be.

But before I spent any more mula I will check the wiring as you suggested, sounds like a good thing to do.

 

Well,

Finally dropped the oil pan on the tranny last weekend on my new 91 F350 with 30,000 miles on it.

Didn't take long to figure out what is wrong. The solenoid (SS1/SS2) body was damaged.

After asking some questions found out that one of the employees of the past owner had put a dent in the tranny pan which cracked the solenoid circuit board and completely severed the electical connector. Rather than fix it, they just put on a new tranny pan and they ran the truck in Limp Mode for six month before selling it. There was a small amount of fine metal on the magnet in the pan probably from slipping 3rd gear while they were running in limp mode. Third gear is holding fine under full engine torque at 2,100 rpm so I thing the tranny itself is still ok given that it only has 30,000 miles on it.

Buying a new solenoid body today ($CDN 575) and installing it on the weekend.

By the time you count up what I have spent on the sensors, gaskets, oil, etc.. this will be a $1000 repair just in parts.

Also noted the tach jump from 60 to 0 and back once so I replaced the tach sender VSS as well.

Can't wait to get this Tranny out of Limp Mode.

 

All good now.


The problems were due to the damage to the solenoid body. Bought a solenoid body ($504 CDN) and installed last Friday.

Boys if you ever put a dent in your tranny pan there is a good chance you will damage the solenoid body, don't just chance the pan like the guys did I bought this truck from.