Early Bronco 4R70W conversion rebuild Part 1

[partsloco]

I picked up this transmission free off craigslist. It came out of a 3.8 liter V6 2000 mustang so it should fit a 302 351W bell housing pattern. I'm not sure if I'm going to rebuild this transmission and get an electronic transmission controller or just take out the wide ratio gear set and put them in my AOD. My kid was distracting me so I keep repeating myself. Let me know what you guys would do?

https://www.youtube.com/watch?v=fGAPyLEX-yE

 

[pcf_mark]

I would rebuild the 4R70W any day - it has a variety of upgrades beyond the gear set (larger drums with more plates).

But you can usually buy a perfectly good one in working order for $200 which is cheaper than the parts to rebuild it.

 

[Broncobowsher]

4R70W all the way. The clutched lockup convertor alone is worth it. Part throttle driving it is almost like a gear splitter as it locks up.

 

[partsloco]

That's kind of what I was thinking. Even if I bought a fully rebuilt one I would still have to take it completely apart to get the dana 20 adapter in it. I already have the rebuild tools from my last AOD transmission rebuild. I would also like to rebuild using Alto red clutches and bands. Kind of bummed my Holley HP ECU does not support transmission control. The more expensive dominator does. I'm not opposed to going factory ford. I think the explorer EEC-V is the only factory ford 5.0 that had a 4R70W. I have a 351W but have thought about swaping a complete explorer EDIS setup in there. I thought about putting a Explorer EEC-V ECU on it but I run TFI and the explorer was EDIS. I wondering if the 351W MAF ECU with e4od control would be able to control the 4R70W. Might be just simpler to get a bauman controller. What are you using to control the 4R70W?

 

[partsloco]

I think the 1995-1996 ford F150 5.0 4R70W is the only factory setup that might be able to work. Here are a few of the things I'm looking for in a factory ECU setup because I have a 351W.

• 4R70W control
• MASS (Maf)
• TFI distributor

 

[garberz]

I used the factory Explorer PCM, I had it flashed by EFIguy. Winters shifter with a momentary switch to control the OD function. 5.0, trans and harness are out of a 96' Explorer 4wd.

Mark

 

[partsloco]

Are you running EDIS or TFI? I know the explorer 5.0 is EDIS.

 

[Broncos n' VWs]

My vote is that you rebuild the 4R70W. I love my 4R and like Broncobowsher stated, the converter lockup is one of the crown jewels of the 4R70W. Quickshift controller and go!

 

[EFI Guy]

Correct, the Explorer route is internal EDIS. Is there a reason that you want to retain TFI? EDIS is far superior to TFI. The only reason I can think of is that you don't like the front dress?

 

[partsloco]

I agree with you about EDIS.

I wrote this article about 5 years ago.

http://www.fintechcommunications.com/funstuff/

I have a 351W and would have to get the 50oz explorer pulley machined to 28oz. If this was a 302 it would be a no brainer.

The only reason I'm thinking factory ECU is for ease and being able to forget about it. I love Holley and Megasquirt EFI but some times it can be annoying. I would actually love having EEC-V because of OBDII. I could hook up my lablet and get some real time info.

 

[pcf_mark]

EFI Guy is the best source if you want to keep it Ford.

I use MicroSquirt from DIY Autotune to control my 4R70W. Cost about $325 for the unit plus the wiring pigtail then you need to take the old sensors / switches pigtails from the Ford harness and solder them to make your own. It took me a day to get it wired up and set up. I download a basic trans tune that was really conservative and it has been great. I can adjust everything from shift timing, shift firmness even converter lock up rpm very easily.

 

[partsloco]

I was looking at that microsquirt trans controller. I have built a few megasquirts. Actually I think a 1994-1995 mustang 5.0 would work also. It was the new body style mustang with the 5.0. It uses EEC-V(obdII), TFI, MAF, AODE trans controller. going the Holley dominator route is going to cost about 2K.

 

[partsloco]

Hey EFI Guy, your running a dana 20 correct? I heard the explorer transfer case was to wide for the bronco.

 

[garberz]

Hey EFI Guy, your running a dana 20 correct? I heard the explorer transfer case was to wide for the bronco.

The Explorer transfer case doesn't have a low range.

Mark

 

[pcf_mark]

Microsquirt is the cheapest way to control a 4R70W but it needs TPS and RPM signal so include that in either plan. I have Megasquirt II v 3.57 running my '95 5.0 in the same truck. Using the CANBUS feature of MSII I was able to get TPS, engine temp (to manage shifts when cold) and rpm by a two wire hook up between the two computers.

 

[partsloco]

When I looked at the microsquirt trans controller I was thinking CAN bus also. The CAN bus protocol that Holley uses is proprietary with very little documentation. I guess I can throw my MSII 3.57 back on but I really like Holley's software and real time display. For factory setup I think my only option is 95-96 F150 5.0. I guess I could always go the explorer route and make another EDIS trigger wheel.

 

[EFI Guy]

I "think" you could make the SN95 PCM work. But, IIRC there was a difference in the solenoids (1 ohm vs. 10 ohm) for the TCC. You would need to use solenoids that match the SN95 PCM.

But I wouldn't run a 351 with that PCM without a tune because it's 100% load based spark tables and the extra displacement would skew them. Shift points would probably need tweaking as well because of the different ratio. It's probably doable but to do it right would probably cost more than going the Explorer route.

I don't know much about the EEC-IV truck computers of 96-97, but I'm pretty sure the EEC-V's only support E4OD for the PCM controlled autos. I could be wrong, I've just never seen one.

If you already have the MS stuff then that might be the cheapest option. I'd still be tempted to run EDIS with the MS if I went that route.

 

[partsloco]

I think my closest match is a 95-96 5.0 F150. These came factory with 4R70W, MASS, TFI. I don't mind getting some tuning. At least programming could be done via OBD2. I like the idea of OBD2 so I could hook up my tablet and get real time engine info.

 

[pcf_mark]

EDIS is awesome!

With MS you get wide tuning capability you would not have with Ford parts but I have heard the Holley tuning suite is really nice. MS uses TunerStudio which is basic but works well w/o a lot of clutter. Adding a dashboard for real time reading is a separate project but can be done using Rasberry Pi option.

 

[Tiko433]

From what I read ......
the cross member needs to be moved and a Adapter is needed for a D20 Is this right ?