4r55e help please

[pjm]

Ok, I've spent hours reading and can't the specific answer to a question I have: would a red band epc in a 4r55e prevent shift into OD?

History: The transmission is about 3 years old with less than 50K on it. I had the flex plate frag on me so purchased a new one from Ford. Already had the sonnax spacer so reused that. The torque converter and bell housing were scratched up but looked servicable so I reused them.

While down, I pulled the pan for a filter change and then realized I should go ahead with a shift kit, ford epc fix and flexplate fix, and new epc. Installed transgo shift kit, ford epc blowoff fix, and ford flexplate fix.

There is a reputable transmission shop in town where I've had work done and who i trust. I went to them for an epc and they sold me the one with the red bands. I double-checked and called them back after reading all the posts with issues with red band epc replacing a green band oem one. They swore up and down that this was an upgrade and one they would install in a 96 if they were doing the work. I've also noticed that some websites that sell these say they will work in a 96.

I have a P0761 error and now have the pan down. OD light was not blinking. No bare wires on wiring harness. Continuity test passed, have continuity from solenoid plug to bulkhead connector. Pins are in good shape. Solenoid C clicks with a 9v battery applied to terminals. OHM test is within spec at 29.

The truck shifted normally with exception of one 2-3 flare that did not recur. I did a full throttle test from standing start and it shifted well, just didn't shift into OD.

Any thoughts here? Sounds like I'm ordering a green band epc but would like something more definite first as that's a $200-300 part.

Thanks much.

 

[pjm]

Update, and additional questions

Back together, checked and re-torqued valve body. Filled with fluid.
On test drive, shifted normally through 3rd. Can't get OD for the life of me. Took out on freeway and transmission never shifter into OD. Played with the OD on/off - no difference in rpm. Also torque converter never locked up.

Eventually got check engine gain, no flashing OD light. And error was p0761 referring to OD shift solenoid.

I will check/adjust the bands just to cover all the remaining bases that I'm aware of, but have a sneaking suspicion that's not going to do it.

So... I'm ordering the green epc now and plan on driving without OD until I get it and install it. Any chance I'm going to hurt anything?

In the meantime, what are the chances the torque converter was damaged enough by the flexplate failure to cause damage to the OD function only?

Best place to buy a reman torque converter if I have to?

I'll post updates as I figure them out. thanks.

 

[Fordzilla80]

According to my books, P0761 refers to Shift Solenoid C. What is making you think it's the EPC solenoid?

 

[pjm]

Think it's the EPC (or at least need to remove that as a possibility) because of all the posts on the forum that say you can't run a red band epc in a 1996 4R55E valve body. Even though some places on line and a trusted transmission shop locally said it's an update for that application.
There are a number of posts here that indicate people have had a lot of problems trying to run the red band, including no overdrive, and other shifting problems.
Several people reported that when they swapped out the red band epc for the oem green band, shifting returned to normal and everything was fine.
So I intend to swap the red epc out for the green one that I ordered and see if the problems are still there.
The major problem I'm experiencing is no OD, and some erratic shifting through the other gears.
I ohm checked all the solenoids during the shift kit install. I'll also click test the od solenoid and check for continuity through the harness when I drop the pan to swap the epc's.

 

[pjm]

Update

Ok, so have been driving around without OD. No flashing OD light. Only the one trouble code for SS3.
So today had some time and did some more diagnostics, while I'm waiting for my green epc from 700800 Transmission.
Adjusted the bands. I was able to get to the 120 in/lb on both bands, so that tells me neither one is broken. Set per specs at 2.0 turns back for OD, 2.5 turns back for intermediate.
Started checking sensors. VSS sensor checked out good at 225 ohms. Within spec of 190-250 per my manual.
Then pulled the bulkhead connector and checked ohms for each solenoid at the connector.
Specs are shift solenoids should be between 22-48 ohms. TCC between 9-16 and EPC between 3.1-5.7.
SS1=21.4, SS2=28.9, SS3=28.7, TCC=11.4. EPC=6.0.
SS 1 is slightly under spec, EPC is slightly over. I actually have been experiencing a somewhat slow reverse on occasion and wonder if this could be the culprit (meaning low reading on SS1).
The shift solenoids all appear to be on the lower end of specs - is this an indication of wear or just normal manufacturing variance? Does it make any sense to swap out the shift solenoids for fresh ones? How about the TCC?

Going for a drive now to see if adjusting the bands had any effect. If not, will check out TPS and MAF (and clean MAF) to remove those as possibilities. Oh yeah, my brake switch works because I have brake lights, and I'm running stock incandescents, not LEDs.

Hoping install of the green band epc will clear up everything when i get it, but want to throw in any shift solenoids I need at same time the next time the pan is down.

Final question - is anyone having problems with 700800 trasmission parts? My part was supposed to be here several days ago and every time I've called to get status I get referred to someone else who isn't there or told to call back.

 

[pjm]

Green epc in, better shifts but still no OD

There was a shipping mixup at 800700 Tran, finally got my green band epc.
Just finished installing. While I was in there I swapped out the filter also.
Gave SS3 a click test and clearly heard it engaging.
Took for a test drive. I was experiencing slow reverse and some flare on the 2-3 shift. These seem to be completely gone. Reverse is right now and upshifts are crisp and quick.
So add my voice to the others that you can't use a red band epc in 1996 4R55e. Anyone need a red band epc in good shape for cheap?

But... still no OD. Has not thrown a code yet.
I'm unsure of my next steps but I think I need to get a pressure gauge and start working through line pressure and stall tests.
I have a sinking feeling that maybe the torque converter that I thought I could reuse was somehow damaged internally when the flex plate let go.

Appreciate any insight anyone has on this. I'll also troll through the site some more to see what I can find.

PO761 is back. Unsure if I should stay focused on valve body and install a new shift solenoid or move to line pressure tests. Guess I'll do both.

 

[pjm]

Separator plate question

After some more thought, I remembered I replaced the separator plate with a bonded plate that I was told was the one to use (again by my local trans shop). However, since I have a 96 with a 4r55e, they never came with a bonded gasket plate, they always came with separate gaskets (based on what I've read here).
I've ordered the correct plate and gaskets from Ford directly from the numbers listed on the TSB.

I think the difference between the two plates is that one has a hole where the other one doesn't but I forget which is which.

Could this be causing my no OD, TC lockup problem?

I'll know for sure in a few more days when I get the parts and swap in, I'll post another update then. When I have the VB down I'll go through all the retainers, bores and checkballs to ensure it's absolutely correct.

 

[pjm]

Resolution

Took half a day yesterday, pulled the valve body back out, went through everything.
I found two mistakes, even though I was careful and took my time the first time through.
1. I had one checkball in the wrong spot
2. There were two small pieces of gasket material that I somehow missed after cleaning the gasket off the valve body. I went over the valve body several times with a powerful light and thought I had everything, but missed a couple.

When I had it off, I checked all the solenoids, click test and ohm test, they all passed.
I also checked all retainers to make sure none were missing or in the wrong place. They were fine.
I checked the Ford epc fix and the shift kit I installed. They were fine.

I put on the new separator plate that I knew was correct, with new reverse servo gasket.

Just got back from test drive, now have lockup and OD - finally! No codes.

What I learned:
1. A 1996 with a 4R55e MUST use a green band epc. Even though there are web sites that say the red band is an upgrade, Even though transmission shops will tell you it's an upgrade - Don't use the red band epc in a 96!
2. Separator plates are not interchangeable either. There is a difference between the bonded gasket plate for the 5r55e and the one for the 4R55e that takes separate gaskets. I've read elsewhere that this alone can cause problems with lockup and OD.
3. You can't be too careful or meticulous when working a valve body. Take your time, triple check everything and make sure it's immaculate before you put it back in.

Finally - thanks again for all the fine info on this forum. It took me more hours than I want to admit, but I finally figured it out with all the great reference info here, and saved myself hundreds of dollars in the process.