I have a 1996 Ford F-250 with a 7.3L Powerstroke Diesel motor. It has an E4OD transmission.

I'm having this problem where the transmission will go in and out of gear while I'm driving. I'll be driving normally, when all of a sudden, it will act like it's in neutral, and when I press down on the accelerator, it will just rev. But then it will go back into gear, and then back out, and then back in, and so on. Usually it will stay in gear for two to five seconds, and then pop out of gear for two to five seconds. It will also shift at incorrect speeds, making the engine rev very high before a shift, or sometimes putting the engine into really low RPMs after a shift. Also, many times the motor will either quit or act like it's going to quit for a split second, but usually not when it's doing the tranny thing.

I tried changing the speed sensor because I had heard that E4ODs are often finnicky about the speed sensors. I changed it, even though the speedometer was getting accurate speed readings, except it would many times gently drift from about 10 mph faster than I was going to my actual speed when I was traveling at high speeds in the overdrive gear (usually about 70 mph).

The new speed sensor seemed to help the problem, but not cure it. And now when I get into the overdrive speed, the speedometer will violently bounce around. This does not seem to affect the transmission function. I went through about three seperate speed sensors, but all of the new ones make the speedo bounce, but the old one works the speedo just the same as before I changed it.

I've been putting BorgWarner speed sensors in it. The sensor goes into the top of the rear differential.

I really need to fix this problem, so any help would be greatly appreciated. If you need any more information or pictures or clarification or anything to help me solve my problem, I would be more than happy to furnish it.

Thanks in advance for any help!

 

I'm going to clean out the differential some time this week if I can get off of work at a reasonable hour. If not, I'll do it this weekend. I'll post if that fixes it, but I am not holding my breath.

 

Don`t know. Maybe a bad throttle position sensor? Best idea may be to check it for trouble codes. You would need an OBD2 code reader for that.
Maybe post on the Power Stroke page in the Diesel section for more opinions?

 

Last time I had it checked, the test came up clean, but the guy at Advance said that he couldn't get transmission codes. I don't know what that is about, but how do I get transmission related trouble codes?

 

Any OBD2 code reader should read the trans codes, if there are any. Maybe take it to a trans shop and get them to check.

 

I read something somewhere else on this site about grounding out a wire going to the self test input and being able to read the check engine light blinking. Should I try that?

 

No, that is for OBD1 systems only, yours is the later OBD2 system and does not have that option. The diagnostic port for your truck should be, I think, beside the ash tray whereas the older system had it under the hood on the drivers side inner fender.
One option would be to buy a code reader so that you could check any current or future trans or engine codes yourself.
The guys on the Power Stroke page could advise on the best one to buy.

 

This issue is now resolved. I had been busy, so I didn't get around to it until now. The speed sensors that Advance Auto Parts were not functioning properly with my truck. They were Borg Warner sensors. I ordered a sensor of a different brand from a different source on the internet, and it functions just fine. The truck operates normally now. Thanks for all the help, guys. I appreciate your responses and advice.

The reason I didn't get around to it until now, by the way, is I emptied fluid from the rear axle, and noticed that the differential cover was nearly rusted through, and there was no gasket or seal left. For these reasons, I ordered a new cover with a gasket, but I didn't get around to ordering it until last week, and it came yesterday. Now it's all back together and running well.


Edit: Also, I found out through research on the internet that many OBDII readers are not compatible with Ford diesels and you need special software in many cases in order for the code reader to communicate properly with the vehicle's computer. This explains my difficulty at with the reader at Advance Auto Parts.

 

Great news guys! I got my issue fixed and wanted to pass this along. My 1996 F250 7.5l 460, had an erratic speedometer, stalling at low speeds or when coming to a stop and the occasional shifting problems. After three months of research and pain staking effort to figure out the problem, I came to this conclusion. At low speeds, 1-3 miles per hour, the signal from the psom (programmable speed/odomter module) to the PCM was telling my speed limiter that was traveling at a high speed, (say 180 mph). At this speed, the limiter shuts off power to the fuel injectors and causes the truck to stall. All other times, the speedometer was just erractic and bouncing, and truck would run fine at normal speeds.
So I replaced the PSOM unit with a $50 dollar speedo from the junkyard and my truck is finally normal! SO HAPPY! My truck is gas, but replaced with a diesel speedo from same model year! Hope this helps, because I know that this is a common problem. There is bad solder point on the rear, and they cause bad connection. My chip fell completly off and you cant get those put back together. REPLACE YOUR PSOM UNIT AND YOUR TRUCK WILL BE FINE!

 

I know this post is old but I just found it and can't wait to pull my speedometer and check the PSOM. The stalling and erratic speedometer issue has driven me crazy but I got very familiar with the electronics on my truck! Thanks for posting.

 

I had the same problem with my 95 E250 trans
was the instrument cluster
wouldn't send correct signal the the computer
been through 2 of em

 

Which brand and part number sensor did you end up using?

 

i was wondering the brand name of sensor that workec instead of borg warner one and did ur other sensir work good until over 80 km an hr then act up and my cruise aint working either since i changed vss sensor and instrument cluster thanks

 

What brand of sensor did you get and what web site im having this same problem

 

I ended up putting one from wrecker yard oem one to verify the new one I brought wasn't compatible with speedo unit and yes it fixed the problem with the one from the wrecker yard the one I had brought was from Napa brand that didn't work