E40D Problem
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New User
Joined: Dec 2006
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From: Northwest Georgia
E40D Problem
I drove my '90 F250 7.3L Diesel about 4 miles, left it running and stopped to talk to a friend, about 10 minutes, I left to come back home and the transmission starting going nuts, kept turning off the OD switch (which I had lit up) and the Tach would lose RPM's and lose speed, I could rehit the OD switch and it would run fine for a few minutes and do it again, I did this all the way home. I checked the fluid level, which was fine ( I just changed fluid and filter a week ago). I couldn't see any wires undone. Any help would be appreciated.
Chuck
Chuck
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Joined: Oct 2005
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From: West Palm Beach, Florida
Check your VSS vehicle speed sensor on the rear axle. It plugs into the top of the differential on the front. It tells your tranny how fast you're going so your tranny can manage itself (E4OD stands for electronic 4 speed overdrive - lots of electronic sensor inputs so tranny can be electronically controlled to match engine speed with ground speed.) There are other sensors, too. The flashing OD light and the harder shifts are a result of the tranny not being sure what is going on so it goes into "Limp Mode" to hopefully be able to get you home and at the same time alert you to the fact that there is a problem so you can fix it and then the tranny will be happy again and stay normal because it is getting all the information it needs to run properly.
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From: Northwest Georgia
The wire appeared to be normal, I unplugged it and cleaned it, put it back on, but it's still doing the same thing. I'll get my speed up to about 40 mph and the OD light will turn off, then the Tach gauge fluxes back and forth and I lose speed. If I re-engage the OD switch it begins to run normal until it again shuts off the OD light. Do you think maybe the sensor itself is bad?
Post Fiend
Joined: Nov 2004
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From: Manitoba
What is the truck a 4x4 or 2x4 did you get the right filter....... did the neck seal come out of the hole with the old filter..... Can you get the code it is setting..... go to azone and get them to read the code.
If the tach is not operating perfectly check the wires by the sensor on the oil filler..... The tach and VSS are esential to the correct operation of the trans, any problems with those 2 sensors the tran will go into Limp Mode.... 2nd and reverse only. Continued use if the vehicle in LM will burn up the trans.
If the tach is not operating perfectly check the wires by the sensor on the oil filler..... The tach and VSS are esential to the correct operation of the trans, any problems with those 2 sensors the tran will go into Limp Mode.... 2nd and reverse only. Continued use if the vehicle in LM will burn up the trans.
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Joined: Nov 2004
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When your tach acts up (fluctuating) it sends a signal to the trans controller to go into limp mode (changes the pressure from the pump). Do not run for any lenght of time. Look at changing out your tack sensor (by the oil filler neck).
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From: Northwest Georgia
It's a 2 wheel drive, the trans filter I bought was the correct one, the gasket was reusable and fit perfectly, and the tach only acts up when the OD switch turns off, once it's reactivated it works fine. I spent 3 hours checking all wires and connections, cleaned and resecured them, so I know it's not a connection that is loose or broken. I can only wonder, does the VSS operate off of the differential oil and if it were low could it cause the VSS to malfunction?
Junior User
Joined: Jan 2007
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From: Mooresville, NC
Not to hijack your thread here, but was just wandering myself, my od light flashes from time to time and shifts hard when it does but my tach works fine when it happens.
I took out the vss sensor and cleaned it, put it back in, also changed diff fluid at the same time but still have the same problem, could the sensor actually be bad?
I took out the vss sensor and cleaned it, put it back in, also changed diff fluid at the same time but still have the same problem, could the sensor actually be bad?
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Senior User
Joined: Nov 2004
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Did you check all the connections on the solenoid pac ? But if it only act up when you use the o/d switch you may have a problem with the switch/wiring.
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Post Fiend
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From: Manitoba
Bigblack
Normaly if your going to all that trouble best to just replace it first time......new style do not have the bare metal for the fileings to attach to (if any). Did you need the additive in the gear oil for the LS axle.
Post a signature of your truck info please.
Normaly if your going to all that trouble best to just replace it first time......new style do not have the bare metal for the fileings to attach to (if any). Did you need the additive in the gear oil for the LS axle.
Post a signature of your truck info please.
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From: Northwest Georgia
I checked and cleaned all the connections on the Solenoid, I also removed the switch for the OD and tested it, checked out fine. I plan to replace the VSS as soon as I can get down the International Dealer this week. I also checked the fluid level in the axle and it checks out fine. As soon as I replace the VSS I'll post the findings. Thanks again.
Chuck
1990 F250 SC 7.3L non turbo w E40D
Chuck
1990 F250 SC 7.3L non turbo w E40D
Junior User
Joined: Jan 2007
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From: Mooresville, NC
You are right PLC7.3 I should have went ahead and replaced the vss sensor but thought cleaning it would help, guess not so it looks like I am planning on replacing it this coming week, I am assuming I can get this from Ford?
The diff lube I used was a synthetic blend designed for the LS rear, made by Valvoline.
I actually tried to put in a signature for my truck but could not find a place to add it, I just went back and looked at all my settings and profile but no luck.
By the way it is a 1993 F250 4X4 ext cab with 7.3 non turbo and E40D tranny w/ 3.53 gears.
Rob
The diff lube I used was a synthetic blend designed for the LS rear, made by Valvoline.
I actually tried to put in a signature for my truck but could not find a place to add it, I just went back and looked at all my settings and profile but no luck.
By the way it is a 1993 F250 4X4 ext cab with 7.3 non turbo and E40D tranny w/ 3.53 gears.
Rob
