4R70W questions

[540milotalon]

I have a 1996 Ranger, 2 wheel straight cab, long bed.
I swapped in a 1999 5.0/4R70W from a Mountaineer, the donor had 183K and looked original, it was totaled and prior to the idiot wrecking it, it was actually owned by a little ole lady. I have put 70K+on my build and now 1st gear is SLIPPING. Of course I am assuming it now has 250K on a daily driver work truck, complete with tool boxes and ladder rack.

I am pulling the tranny this week to totally rebuild and am wondering since I have to use a ‘98 and newer ECM because it would not shift into drive/OD because of the EPC while it is down, should I replace the newer EPC with a ‘92-‘97 one? I have a ‘96 ECM and they are actually an over the counter part here locally and the ‘98 and later are not, should I need a replacement.

Are there any other problems I am overlooking?

 

[JoshT]

What are you calling an EDC? Did you mean EPC?

Exactly what parts are you using now? Looks like a 99 drivetrain, but you've got me confused on the ECM.

'96 transmission electronics, and wiring harness are going to be different from the '99 stuff. To be P&P you'll need to use the matching later parts, otherwise you'll have to modify (or replace) the transmission electronics and wiring to match the ECM you are using.

If you know that you hafve transmission issues on a high mileage transmission, I'd get it rebuilt and see what happens before you go borrowing other problems.

 

[540milotalon]

Ok,
Fixed the typo "EPC" but I'm not sure you read the entire post? I am rebuilding it and I know,
1. It is not easy getting a '98 and newer ECM over the counter and if I do it has to have PATS removed in order to work in the '96 Ranger. So,
It's not "plug and play."

2. '96 Explorer/Mountaineer ECM will work except for shifting into D/OD.

My question is, if I install a '96 EPC so I can use the '96 ECM, are there any other problems?

I also wonder if I change the EPC for a '96, would I still be able to use the current one in a pinch?

 

[JoshT]

I read it, and I answered best able from what was asked. Did you proof read it before posting it? Probably would have been a much more understandable post if you had.

My response still applies once you understand what you are asking about.

1) you are jumping the gun assuming that you need a new ecm.

2) No the 96 ecm will not just work "except for shifting into d/od."

By plug and play I'm referring to the EMC working with the engine and transmission electronics and wiring harness. The '99 engine and transmission harness and electronics are not compatible with 96 ECU, and it goes well beyond just the EPC on the transmission.

Many engine sensors are different between 96 and 99, and are not cross compatible. Wire harness is different and not cross compatible. Those are just broad picture differences. Making the transmission work with the earlier ECU would be the easy part, to make the engine work you are looking at a swap of the entire engine harness and many/most sensors. Potentially fuel system modifications as well.

The EPC itself may work interchangably with both ECUs, but the harness inside the transmission is different. There were a few variations during the years, and IIRC a big change was around 1998. The internal harness could be swapped to work with the EPC, but you'd also need to address the other internal electronics that changed along with the harness and EPC. If you changeed, you'll have to repin and possibly replace the external harness connector to the ECU to match. It's not a simple matter of just swap to the earlier EPC.

The later EPCs and other transmission electronics were an upgrade over the earlier stuff, even just between 96 to 99 models. It's common for earlier models to upgrade to the later internal electronics (and transmission as a unit) and make the necessary modification to match. Going the other direction would be a downgrade

Good luck, maybe someone else will come along to hold your hand through it. I'm certainly not in the frame of mind to do that right now.

 

[540milotalon]

I have driven this combination 70,000 plus miles already. I had, just short of total zero ability finding someone to remove PATS from the ‘99 Donor Mountaineer ECM. I finally found a vendor. No one I called, no so called “Speed Shop” would or could do it. I found one after months. Truck sat because it would not run in drive. I tried using the 1996 ECM because of PATS in the donor Mountaineer.

The truck will start, ran great but will not shift into drive/OD with a 1996 ECM. I probably have a thread from 4-5 years ago on this and other sites, and I finally figured out that Ford had changed the EPC. Transmission shops said I needed a rebuild then.

I’m sure Ford was constantly changing things in those days but on this particular set up, the EPC appears to be the only thing different. They plug in with same configuration.

Sorry I ticked you off, sorry about the original typo, and your experience is probably correct, but this one is as described.