EO40 shifting issues - Diesel Forum

Lciambotti · 10-27-2006, 08:35 AM

Here is my problem. When I start out in the morning, the transmission shifts fine for the first time it goes through the gears. However, sometimes it doesn't exactly make it to overdrive (like its half in, half out) so the RPM's are higher than normal. After that first time through the gears, it misses the 2-3 shift and goes right into drive. And shifts into overdrive just fine. Any thoughts? I read a thread about putting seafoam into the trans. to clean it out, but I never heard of seafoam.

Thanks For The Help!!!

1991 F350 7.3L EO40 118K miles. [img]/ubbthreads/images/graemlins/shrug.gif[/img]

cdnsarguy · 10-27-2006, 09:20 AM

Before doing any liquid repairs......... do your speedo and tach work flawlessly. The trans is an E4OD......

Lciambotti · 10-27-2006, 09:37 AM

They apppear to. I've changed the gear in the trans to accomodate the tire size (285X16). According to my wife who was following me,(and the radar gun where I work at) I am only off by 2 mph. I forgot to mention this was happening with my last transmission, and it finally went bad. The replacement is a used Jasper rebuild. I did not flush or change any lines. FIPL has been changed three times, speed sensor changed.
Thanks
Leon

Snotzalot · 10-27-2006, 09:57 AM

It could merely be bad plugs/wire connections on the trans, remove them all, clean and see if that helps.

Mr_Roboto · 10-27-2006, 10:27 AM

I would recommend that you replace the tach sensor. It is one of the parts that can cause trans malfunctions if it is not working properly.

"Replace the tach sender on the oil fill housing a big 1" nut with 2 wires. Ford only part Engine RPM sensor E5TZ-17B384-A about $50."

cdnsarguy · 10-27-2006, 10:51 PM

[ QUOTE ]
FIPL has been changed three times,

[/ QUOTE ]

OK but was it set to specs after the change.....

munn · 10-27-2006, 11:47 PM

Could the half in half out you are experiencing when cold be an unlocked TC? I don't think it will lock up until the trans is warm.

Lciambotti · 10-31-2006, 09:02 AM

Not sure about the torque convertor. It came with the used Jasper tranny I bought. The FIPL was suppose to be set to specs, but I didn't check it myself. I should probably check it.

cdnsarguy · 10-31-2006, 02:09 PM

When trans is cold the TOT will not let the trans upshift until the ATF is at a certain temp. Mine in winter -35*F can take 6 miles at highway speeds before final upshift.

TOT.. Transmision Operating Temperature.. sensor(diode)

merdock69 · 10-31-2006, 10:41 PM

Have you pulled codes from the PCM? Sounds like the tach sensor...

Lciambotti · 11-01-2006, 02:31 PM

According to the dealership that read the codes, he said it is a 2nd 3rd shift error. He didn't mention about the tach sensor.

Mr_Roboto · 11-01-2006, 03:17 PM

There may not even be a code for a faulty tach sensor.

Look at your sensors, the E4OD will NOT shift properly if one of the sensors is bad or out of range.

There have been numerous times that transmissions have been replaced only to have the new shifts as poorly as the old and fail, due to a faulty sensor.

Lciambotti · 11-01-2006, 05:07 PM

Heck,
I might as well replace the tach sensor, I've replaced everything else. Would a faulty tach sensor that is causing the trans to miss 3rd, eventually cause it to go bad? After awhile, it wouldn't shift at all.

merdock69 · 11-02-2006, 09:22 AM

I'd also try dropping the accumulator boday and putting a shift kit in. It could be as simple as the body being gummed up. But, 2 - 3 shift relies on the intermediate clutch pack, and if that is burned up you would smell it in the fluid. Also, if the tach sensor is bad it could be give "random" signals making the transmission skip around in its shift algorithm. If the fluid smells fine then my rule of thumb is test electronics. It could be the shift solenoid pack as well, if it is the wrong one, then you will start out in 2 in 1 and 2 and in 4 in OD. Sometime people put the wrong solenoid packs in for their year, and the connector doesn't seat properly. The solenoid pack both initiates the shifts and controls the line pressure in the transmission. They are only $3x.00 from a transmission shop (I bought mine from DACCO detroit). I also got into ever connector under my hood and truck and filled them each with di-electric grease to improve continuity and ensure that I was experience signal loss from corrossion.

Kevin 007 · 07-07-2009, 08:59 PM

Can anyone tell me where the TOT sensor (diode) is located. Is it in the valve body?
Im almost certain that mine is shot. won't shift by itself when its cold but works well after its warmed up, and when cold, it goes straight into overdrive when I manually engage drive...skips third

. Im gonna have to sort this out quickly because every morning its either a screaming engine in second or lugging in overdrive.