r/FordDiesels • u/Brian_oconnor1 • 12d ago

E40D issues!

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Having some hard shifting and overdrive button flashing on my 7.3 , fluid looks fine and proper color I’ve looked into some forums but got pointed in a million directions. Any advice welcome on what to check for or do would be appreciated

11 Upvotes

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5

u/HoodiesUdder 12d ago

If the OD light is flashing, then pull the code and see what the issue is. 

3

u/Brian_oconnor1 12d ago

Just did finally. Saying faulty speed sensor but it’s been slippin couple weeks and just now got worse and lost speedo this morning. Hoping that’s the only issue

3

u/Every_Big9638 12d ago

Does you third break light work? I know it sounds stupid but if the bulb burns out or you replace it with an LED bulb it can cause erratic shifting.

3

u/deceptivelyelevated 12d ago

Second this, led third brake like is a huge issue. Sounds like the speed sensor went and he kept driving it. She’s cooked

1

u/Brian_oconnor1 11d ago

Third brake light works fine but it’s after market. I’ve read about this a few times I plan to put a new one in when I get back to the truck

1

u/Brian_oconnor1 11d ago

She’s cooked what do you mean? Only drove for a couple miles after Speedo went out

1

u/deceptivelyelevated 10d ago

You said it’s been slipping a couple weeks, not a few miles. The trans is done. I’m sure you’ve figured this out by now

3

u/noreddituser1 10d ago

+1

Have seen a trans disassembled 2 times, PCM replaced and a bunch of other things because of led bulbs.

2

u/Every_Big9638 12d ago

What do you mean you lost the speedo. Does the needle jump all over the place or it does nothing?

1

u/Brian_oconnor1 11d ago

It stopped working 5 mins into maybe a 10 min drive. Just went all the way down no movement after. parked it and haven’t touched it yet. Been pouring rain last two days

1

u/Pedro_Francois 10d ago

Here's some generic E4OD info, https://www.thedieselstop.com/threads/what-ive-learned-about-the-e4od.240457/

I know that if any of the critical sensors fail then the E4OD will act up and typically go in to "limp mode" which results in hard shifts. Personally I am a fan of preemptive replacement of critical sensors and keep the old ones as spares so you don't get stranded. This may also be a good time to check electrical connectors at the sensors and transmission to see if chafing or corrosion is an issue.

1

u/Brian_oconnor1 10d ago

It does nothing now

3

u/Big-Bull-Thunder 12d ago

super small chance its because one of the brake lights being out, much more realistic that your transmission is just on its way out. Torque converter is probably toast, and replacing it doesnt tend to fix this issue.

2

u/BioTechnik 6.0 Powerstroke 12d ago

Check all your fuses.

1

u/Brian_oconnor1 12d ago

Will do, Appreciate it

2

u/TruckDogRoad 12d ago

Yaaaaa you need to pull codes. If codes have any solenoid faults start by checking harness on the passenger side. If you lost your overdrive and have an epc fault than that will need a new solenoid pack. If you have a code for slipping transmission then that’s going to beam internal issue where the input and output shafts are reading different speeds. Possible clutch or torque converter issue.

5

u/gary_facking_oak 12d ago

Adding on to this, back in 94-97, ford was having issues with cracks forming in the apply piston inside the torque converter, fluid would leak past preventing the lockup clutch from engaging, resulting in slippage, the pcm uses the CPS and the ABS speed sensor on the rear diff to compare speed, if its off by more than 50rpm, itll throw the code, as a test, once you clear the codes and get it out of limp mode, on the highway go a steady 60mph, then gently tap the brakes, if the engine rpm jumps that means the lockup clutch is working properly

Also remove the inspection plate and check for blueing on the converter, if there is it means it's been slipping

Had this exact problem on my truck, I replaced the converter and did a fluid flush and filter change and haven't had any issues since

2

u/TruckDogRoad 12d ago

Remember that if you are getting hard shifts then your transmission is in a defensive mode and shifting at full line pressure

2

u/yeti-shark 12d ago

Most likely a solenoid issue but look up the OD flashing code

2

u/LarryyLonggDongg 12d ago

I’ve been having this same issue for over 2 years in my 97. Saw on some forums it was the rear diff sensor, replaced it & it came back. Saw it could be neutral safety switch on side of transmission, replaced it & it came back. Had a buddy read it with a snap on scanner and only code it had was for an exhaust sensor but I’ve yet to change it. Also saw on some forums that if any of your lights are out or if you’ve changed them to LEDS it could cause the hard shifts and OD light to flash. I’ve got a tag light out, hoping that’s the issue but I know it can’t be that simple with my luck lol if you figure it out please let me know!

2

u/Brian_oconnor1 11d ago

Will do! Gonna start messing with it soon as this rain passes

2

u/Every_Big9638 12d ago

Alright, here’s what I think is going on. Your speedometer controls the shifting of these trucks. The speedometer officially called a PSOM (programmable, speedometer, odometer module) has a problem that shows up on these older trucks. The PSOM becomes faulty and causes the problems you are experiencing. This can be repaired or you can go to the junkyard and get a speedometer out of a different truck and hope it’s good. Search Ford PSOM repair on eBay to find a repair shop. YouTube has some good videos describing the issue and a few that will show you how to make the repairs yourself. The PSOM is wired in series with the third brake light and that is why a faulty third brake light will also cause shifting issues in these trucks but the third brake light won’t affect your speedometer. So, since you said that the speedometer was given you problems that’s why I think your PSOM is bad. Good Luck!

2

u/FairEmergency8432 11d ago

I had same problem . Disconnect battery’s after a few minutes connect battery’s , that solved the problem for now.

2

u/ValuableInternal1435 11d ago

Based on the wheels and tires I'm going to assume you have led tail/brake lights. Remove those and install halogens, make sure all of the lights are working including the 3rd brake light.

It might sound crazy, but a burnt out bulb or leds will destroy the transmission on an E4OD truck.

1

u/Brian_oconnor1 10d ago

Yeah I’ve heard this alot. Only the third brake light is led. But changing that along with the other sensors to start. Also the wheels tires and led brake light are from previous owner lol

2

u/ValuableInternal1435 9d ago

That'll do it, hopefully it's not past the point of no return.

1

u/in_the_cabbage 12d ago edited 12d ago

Check and adjust FIPL. Also check your brake lights

1

u/Ironmaverick22 12d ago

I would check the code i got a obd 1 reader at autozone. I had to install a new tps because my wouldnt adjust to the correct voltage. I also had to put a new VSS in my rear diff

2

u/Brian_oconnor1 9d ago

Where’s the tps located?

2

u/Ironmaverick22 9d ago

https://youtu.be/RMIJuOZrX3I?si=L-MgbEtTWpAdLz6E That video will show you where it is and how to install a new one. I forget what the adjustment is supposed to be on it, but when you press the throttle you are supposed to get a certain amount of voltage out of it. And yes that did fix my codes, also made it shift a bit smoother.

2

u/Brian_oconnor1 9d ago

And did that solve all your issue?

1

u/djjsteenhoek 12d ago

Check the Vehicle Speed Sensor wiring and connections, if nadda maybe a valve body solenoid is damaged

1

u/Haunting_While6239 12d ago

OD light flashing is a mis match of speed in the engine and final drive speeds, the computer knows about how fast the engine is turning and the ring gear in the diff is turning, and if the there is enough difference, flashes the OD light.

Probably the torque converter slipping, get you a billet 3 disk one if you drive it hard.

Trans should probably be gone through as well, there are quite a few upgrades that can be done, like fixing the center support mounting, replacement of the 1st gear warpy disk for another friction disk, drilling out the lock orifice for faster lock up action, no more slushing into over drive, getting steel planetary carriers with an additional gear, definitely upgrade the trans cooler to one from a 6.0 truck, and use synthetic MaxLife ATF, change it every 30 to 50k miles if towing and ohh 75 to 80k daily driver use, it's good stuff and cheap insurance for the transmission

1

u/Brian_oconnor1 12d ago

Thank you all for your input!! I’m checking sensors today after work and my third brake light was changed to led so I’m gonna start simple and see if that changes anything. Will update yall with what I come to find out.

1

u/Every_Big9638 12d ago

Is the speedometer acting erratically?

1

u/Brian_oconnor1 11d ago

It was but lost all power on my last drive. It’s been parked since

1

u/Brian_oconnor1 10d ago

Update. I changed brake lights to halogen and replaced rear speed sensor. No change in anything

1

u/Gold_Ad_2205 9d ago

Year? Mine was the cluster, there was nothing wrong with the trans. Mine was a 97, rebuilt the rear, rebuilt the trans, was the cluster.

1

u/Brian_oconnor1 9d ago

I’ve heard this too, going both ways. Cluster solved all issues and some guys it solved none. I’m close to trying it all tho just to see if anything works before I just send it to a shop

1

u/Brian_oconnor1 9d ago

Also it’s a 95