4R70W Upgrades for towing - Request for assistance. | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

4R70W Upgrades for towing - Request for assistance.

Fredness

Elite Explorer
Joined
June 2, 2000
Messages
712
Reaction score
64
City, State
Tejas!
Year, Model & Trim Level
'05 Sport Trac Adrenalin
Patient: 2000 EB 5.0L AWD - Flashing O/D - 134,000 miles - CoPart Salvage Title $600
[Fixing issues BEFORE it gets driveline swapped into a 2005 Sport Trac.]

Indications:
Flashing O/D light
Clean, unburned fluid
No unexpected debris in pan, no plug
"Firm" shifts (as expected in "limp-home" mode)

Codes:
P0401: Insufficient EGR Flow
P0174: Lean Bank 2
P1746: Electronic Pressure Control (EPC) Solenoid A - Open Circuit
P1270: Excessive Engine RPM/Vehicle Speed [Hmm...]

Expected Use:
Pri: Towing a 5,000lb (loaded) camper in varying "Lower 48" conditions.
Sec: Escape the undead horde.

Looks like the EPC has failed, or the Internal Molded Lead-Frame is bad. My plan is (as always) to do this once:
New EPC, verify/replace TCC, 1/2 Solenoids
New Internal Molded Lead-Frame
New filter
Add drain plug to pan

"While I'm in there...":
Considering the J-MOD and SONNAX Zip-Kit, or Fairbanks Trans kit, but the search data show 15yo threads with info on early (Pre-'98) trans.
Looking for some up to date/modern "Sauce" on the 2000 4R70w (Original "Warranty Claim" sticker on the pan - so post-TSB?).
Thx

20210430_104152.jpg


20210430_110027.jpg


20210430_111903.jpg
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Ordered NEW Solenoids and the Internal Molded Lead-Frame for starters.
I'll do the fix while waiting for updates.
 






Plan to be into it for a few hours, half under it and half on the bench. Replace all solenoids, accumulators, and do the Sonnax upgrades. Find the 4R70W pages on Sonnax, and read those carefully. Almost everything they make is worth the time and money. But they do have a later VB upgrade that is about $75 which is very good, but it replaces the PR valve I believe, meaning don't install both that kit, and the higher pressure regulator spring and other PR valve, those come in the Zip Kit. Those can't be used together, both raising the main pressure. I got that from Sonnax by phone a couple of years ago, while researching that newest upgrade part, and other high end hard parts.

The VB you work on out of the vehicle, which is when you might do the Jerry's Mod. Also inspect the springs in the 1/2 and 2/3 accumulators, those sometimes are found broken.

If you were to be taking the 4R apart, I'd suggest upgrading the forward drum(about $200), but only as a rebuild. They also have a much stronger direct drum kit, but skip that, it's a $600 upgrade best for high powered trucks.

Be sure the EPC fits fairly snugly, they can vibrate and create excess wear in the case bore, which is a leak.
 






No rebuild (I hope).
Is the Sonnax VB upgrade $75 in addition to the Sonnax ZipKit?
I'll take a deeper dive on their page.
Having done a couple 5R55E's, an A4LD and a couple 6R80's, I'm sold on the Sonnax stuff...
 






That "$75" upgrade is called a line booster kit, here it is on Amazon; Amazon.com: Line Booster Kit: Automotive
Note the prices vary greatly, there it's $60. Hunt around, on Rock Auto also, as they now carry several Sonnax items.

That's the last VB item they developed, and it's a more complicated valve upgrade. It doesn't simply raise pressure, it has a unique valve design which varies the pressure by throttle input(description says on Sonnax). Read about that one, it is a bit higher than most VB items they have, and it's not part of the Zip Kit. That one is better than the part in the Zip Kit for the same valve location. So I've got those and plan to leave out the small items that overlap that line booster kit. Those would conflict.

I hope to get my hands on a 6R80 some day, possibly for my 98 project.
 






Double check the separator plate for cracks in this area.
D92EF566-8E41-400C-96AE-22E2A4693E32.jpeg
 






Is that a 2001+?
Sonnax has a patch for that too!
 






Ditto, I bought that small retrofit cover for the later VB's, I have an 03 V6 trans that's like that, no cover on the smaller area.
 






The best way I’ve found is installing a Superior “Tuff Plate” no drilling or tapping plus its much thicker than OEM. If you end up pulling the unit and are going to replace forward drum stay clear with stuff made in China.
Brad
 






The best way I’ve found is installing a Superior “Tuff Plate” no drilling or tapping plus its much thicker than OEM. If you end up pulling the unit and are going to replace forward drum stay clear with stuff made in China.
Brad

Funny Brad, I bought that Tuff plate also, it is much thicker. That's two ways to fix that same 2001+ defective decision to do away with the little cover plate.

I also have the two available forward drums, both by Sonnax. The lesser one evidently is defective, the grooves aren't deep enough for full contact by the bottom pressure plate. I prefer the black one anyway, for $30 or so more, it holds another extra clutch set(8 versus 6 stock). Don't ask me about the direct drum kit, I have those two also.
 






Might replace the snap ring for OD servo that breaks.
 






Do you mean the large one that holds it in? I think the Zip kit has the new seals and small upgrade seals for the servo piston itself.
 






Yes, the large one that holds it in the ear will break off of and get in the valve body and you’ll lose overdrive.
Brad
 






Any update on this: j-mod hole pattern
Or how it relates to the 2000 4R70W?
Is installing a car VB still this answer?
 






That is an old thread, I took notes on what I had learned from a well known 4R builder, but I'm not sure where they are now. I wouldn't be as worried as back then about using a truck VB. That applied to aftermarket shift kits, so the Jerry's Mod is not the same thing. I would be conservative on the hole sizes, by the instructions you can know what each hole affects. So you can decide which shifts you do want firmer and which you may be happy with what they are now etc.
 












That's a good chart for determining the area change for a certain larger hole size.
 






From Superior regarding their "Supertuff" 4R70W 4R75 Ford Valve Body Plate Kit K092/K0192:
"If you use the .092 it gives you a firmer 1-2 shift. If you want a factory shift use the K0-192"

So the 2000 can use the "Supertuff" plate.
The K092 has a .092” 1-2 Feed Hole (hence the name?) for firmer shifts.
The "NEW" K0192 "Supertuff" plate has the "smaller .073″ 1-2 feed hole and works as a stock replacement on the later model 4R75’s that came with a smaller 1-2 feed hole, and factory accumulator springs."

I'm going to go K0192 plate and drilling the holes noted in the J-Mod with the sizes stipulated by Sonnax.
 






Very good. Do you have the J-Mod instructions, the picture of the plate and hole names with sizes? That's needed, and that's where I began to see how many people varied with their choices of hole sizes. Some people didn't change their stock accumulator springs, some used certain OEM springs named by color, and a few used certain recommended OEM springs, all of that for the 1/2 and 2/3 springs. That's where I got frustrated with trying to figure out which holes would be best, the springs have a definite impact on the shifts. I would very much prefer to use the two springs that are recommended, and still barely easy to come by, on eBay etc.

The hole sizes needed will vary if you go with different springs than those, either what's stock in it, or some odd color some people liked. Most of the J-Mod examples you find will be cars, mid 90's Thunderbird's or Mark VIII's. That's why I decided to choose conservative hole sizes, and then readjust after driving it.
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





I do: https://www.crownvic.net/tech/4R70Wnotes.pdf
No hole names though - you have to bounce back and forth from the text.

Updates: There was no yellow "Plunger" in the pan, filter was reasonably clean suggesting service on the trans in the past.
 






Back
Top