With the good - there is always bad. Looks like my transmission is TOAST

[MuscleJunkie]

So I think my transmission is toast.... I think - maybe someone here can tell me different?

So as everyone might know I just finished a major upgrade on my 5.0 AWD 2000 Limited Explorer which consisted of:

• Powerdyne Supercharger with Bosch BOV​
• 1" Intake Spacer​
• 90MM MAF​
• GT500 Injectors​
• 75MM Throttle Body (kept stock TPS)​
• 80MM Intake Elbow​
• Electric Cooling Fan (Contour) and controller​
• New Motor Mounts​
• MSD Coils and new wires​
• EGR Delete​
• Already have headers installed​
• Saleen Borla Cat Back​
• Walboro 255LPH Fuel Pump​
• Custom Tune (only fuel mapping - no transmission settings changed)​

So when I received the car back - as expected during shake down things started to pop up. Keep in mind before the upgrade - everything was working perfectly.

• With overdrive engaged, 4th to 3rd downshift was different (not normal)
  • Engine would rev up then slam down into third
    • manually turning off overdrive - transmission shifted as expected
  • It was suggested this was related to tuning - that turned out to not be the case.
• Heater Core started leaking
• After a couple hundred miles - intermittent (which started to happen every time) chirping that sounded similar to belt squeal or camshaft syncro going bad
  • Determined that noise was related to blown off PCV valve on back of intake
    • This was resulting in vac leak.
      • Apparently the stock PCV valve is not a one way valve and boost was causing it to blow off
    • Replaced with Motorcraft EV-127-A for Thunderbird I think turbocoupe which is a one way valve and this problem is fully solved.
      • After PCV was replaced - chirping was gone but now transmission is all screwed up
        • When starting off sometimes it starts off in 2nd instead of 1st. This happens mostly after running awhile
        • When the transmission is low 190s or 180s - seems to shift closer to normal but higher temps it really gets worse
          • Slips out of gears when under heavy throttle intermittently.
          • If driving really easy - less likely to see any slips except when starting out doesn't want to be in 1st when temps are hot.
        • Fluid doesn't smell burnt - doesn't look bad
        • Trans runs in the 200 range during normal driving now (outside temp 65 to 70)
        • There is a trans cooler (i have stock trailer tow package and 3.73)
        • Coolant is running during driving 180s to 190's during normal driving. Will go to 200 or so under heavy driving.

So either the trans was screwed up somehow from the vac leak and what is was doing during this time or perhaps something else. I've seen some old posts that trans issues could be related to changing the throttle body and TPS? Do not think it is tuning related as tuner said didn't touch transmission settings.

When vehicle is at a stop after driving - coming to a stop there is a swishing noise coming from the unit that I can hear. When I put it into neutral or drive - it goes away.

Anything I could be checking here that could save this 200k transmission or is it a goner?

If it is dead - obviously I am going to need a new unit. Suggestions? I really need something that is going to be bulletproof - performance OEM drivability (like if in 2000 Ford made an SVT level Explorer) that can handle the power I have now and will be adding in the future.

If I can answer anything else - just ask

Thanks in advance for any help or suggestion. Feeling frustrated.

 

[C420sailor]

Those numbers are high for normal driving. Makes me think things are slipping, generating heat. Fluid may not be burnt yet, but it may be on its way there.

How much power is that engine putting out? Introducing a blown, high HP engine to a high mileage trans generally isn’t the greatest idea.

Also, OD OFF flashing? Codes?

 

[MuscleJunkie]

Those numbers are high for normal driving. Makes me think things are slipping, generating heat. Fluid may not be burnt yet, but it may be on its way there.

How much power is that engine putting out? Introducing a blown, high HP engine to a high mileage trans generally isn’t the greatest idea.

Also, OD OFF flashing? Codes?

On my 2000 5.0 AWD now putting out somewhere at 250 rwhp and 306 rwtq on a 2wd dyno with shaft removed. This was with a faulty IAT sensor and I suspect at the time a possible vacuum leak at the PCV valve since we did not know the stock one in the truck was not a one-way valve. In that scenario it was pushing about 6.33 pounds of boost at 4.9k RPM. Probably some boost was being lost during that Dyno run. Haven’t had a chance to Dyno it with that corrected but I’ve been told probably to expect more. Before we discovered the PCV valve had completely blown out of the intake attempted another Dyno run and saw additional 1.5 pounds to 2 lbs of boost was lost at same RPM

Transmission light is not blinking and no codes thrown.

 

[C420sailor]

Wonder if that IAT is creating problems. It’s combined with the MAF, and in many vehicles a bad MAF can cause transmission shifting issues.

 

[MuscleJunkie]

Wonder if that IAT is creating problems. It’s combined with the MAF, and in many vehicles a bad MAF can cause transmission shifting issues.

I’m not using the IAT in the maf. We have a separate IAT mounted in the charge tube of the supercharger. It is the one from the lightning and it’s working fine now. The one that we had before that was included with the supercharger kit was not working correctly. Have no idea what it was or where it came from to be honest. I think it was a part that the previous owner had picked up but the history on that was lacking.

 

[MAS Tequila]

Just had my trans rebuilt a couple of months ago.

It was running at 170-180 degrees, now it sits between 130-135, at the same time the coolant is 190.

Butter that toast.

 

[MuscleJunkie]

So it seems that the possible consensus here is I’m going to need to replace the transmission. Really need some advice on the best route to go with this because I want to get the best thing possible for what my truck is today and what it will be tomorrow with my continued upgrade project.

 

[Josh P]

I know the 4R70W can be built to handle insane amounts of power, if it was my car I'd be happier with the 6R80

 

[MuscleJunkie]

So transmission is now tore apart.

Still waiting for some more specific information but apparently the over drive band is toast. At least that’s one of the things that I heard so far this early. Anything interesting or apparent from these pictures???

 

[Mbrooks420]

The overdrive portion of the 4r70e is the weakest link. I wouldn’t bother with a trans model swap, the 4r70w isn’t a terribly complicated transmission, and there is a solid upgrade market for it. Rebuild it right and it’ll hold up to whatever power you’ll make with a factory 5.0 block.

 

[MuscleJunkie]

The overdrive portion of the 4r70e is the weakest link. I wouldn’t bother with a trans model swap, the 4r70w isn’t a terribly complicated transmission, and there is a solid upgrade market for it. Rebuild it right and it’ll hold up to whatever power you’ll make with a factory 5.0 block.

Is it possible to give a list of upgrades to add to this transmission that would achieve this? I want to compare this to what the builder is going to suggest. Thank you

 

[410Fortune]

What is the condition of the fluid in the awd t case? Good time to check

Trans temp should not reach 200 so easily

A built 4r70w will serve you well that one was on its way out

 

[MuscleJunkie]

The condition of the fluid was not too bad. Builder told me that the overdrive band was toast and thinks it had a hydraulic leak whatever that means. The photos I posted above were of my unit torn down. This is a list of things that they gave me so far. Since transmissions are not my expertise hoping somebody can give me some ideas of what they have put down so far and what I need to change or upgrade.

 

[410Fortune]

What about the shift solenoids? I would replace those too..

11.99 a qt for
Mercon v!! Ouch

superior shift kit 0$?? What is that?

Is he doing any valve body updates?

Also I would make sure they clean out the coolers and lines while it is apart

 

[MuscleJunkie]

What about the shift solenoids? I would replace those too..

11.99 a qt for
Mercon v!! Ouch

superior shift kit 0$?? What is that?

Is he doing any valve body updates?

Also I would make sure they clean out the coolers and lines while it is apart

He didn’t have the pricing for the ones that are marked in 0.

I’ll ask about the other items.

This is what I sent him in response to that list initially.

Anyway one of the questions I have out of the line items is which of these are upgraded ones to deal with the things we discussed with as of my goals for this rebuild? And which items are stock items. One thing that's very important as I do not want any foreign or Chinese stuff used if it's something that's a stock replacement. I copied this from my social media post regarding my goals for the rebuild so we all have it here.

What practical upgrades would you recommend to this transmission to handle all the addition power I have today and more that I might have in the future? Keep in mind, i’m looking for OEM performance drivability and reliability in this rebuild. What would Ford have done differently with this specific transmission at the factory if they had built it for a ~350 - 400hp and 400-500 ft lb torque Supercharged performance version of the 2000 Explorer 5.0 V8 instead of a 215hp and 288 ft lb torque stock Explorer 5.0 V8?? I’m not looking for a transmission that will break my neck at every shift and it should be and feel like it was built at the factory for those power levels.

His response

THIS IS HOW I WOULD BUILD IT FOR YOUR PLANS THOSE ARE ALL UPDATED STOCK PARTS OTHER THEN THE BAND AND SHIFT KIT THAT IS MORE PERFORMANCE, IF YOU WOULD LIKE TO UPGRADED TO MORE BEEFY SONNAX PARTS THEY WOULD BE A LITTLE OVER 1000 EXTRA DOLLAR FOR PARTS ALONE AND DONT HAVE A ETA ON THOSE PARTS AT THIS POINT ATTACTCH IS A LINK TO THE WEBSITE FOR THE SONAX PARTS THAT ARE AVALIBLE FOR YOUR TRANSMISSION BUT WOULD BE OVER KILL FOR WHAT YOUR DOING WITH THIS CAR Ford 4R70W Transmission

 

[CDW6212R]

I just found this thread, I'm sorry to hear you need a rebuild on the trans.

Don't buy anything yet, I see a few things there I wouldn't buy or pay so much for.

Sonnax has a really nice forward drum I would buy for any 4R needing solid reliability. I have one of them among my many new parts to build some 4R's for my projects. Buy that dark colored Sonnax forward drum, not the lesser one that's silver and may be $25 less. I paid $185 from Summit, and the lesser one was about $155, and may be defectively designed.

Sonnax has a sweet direct drum kit, upgrade, but it's $625ish or more. That fixes the main weak link of the direct drum and the small stub shaft(they have one part that replaces those). I have that too for my big power project.

I'm not sure I would use a Kevlar OD band, I've been told by a trusted 4R builder to stick with a good high carbon OD band, a top brand etc. The OD/4th gear should never see WOT, that is a weak link you can't fix, you will run out of speed in 3rd gear, so gear it to match the 1/4 mile or your goals.

A nice replacement TC should be much less than $375 etc, and a high stall aftermarket is what you will end up needing. Those will be $750 etc, but you don't necessarily need that until you get closer to the final power level.

I'd do the J'Mod, no other shift kit, plus all Sonnax VB items. Those items should cost about $200, my guess on the last time I priced them.

I suggest rebuilding that one to a nice level, minus the $650 Sonnax direct drum kit, normal TC, and live with that until you get closer to the end. I personally am leaning to the 6R80, and that will be a sweet gear ratio spread for these trucks. But the cost I project at at least $4k, that should be considered, and everything planned before committing to that.

 

[MuscleJunkie]

Thanks Don - I brought up these points to him and sent him these items and waiting for input.

 

[donalds]

 

[CDW6212R]

I suggest Amsoil ATF, their Signature fluid is better than almost everything else. I just bought another two gallons for doing my latest 98.

The VB modifications are a primary need for most automatics, and over time the 4R now has several valuable Sonnax upgrade items. Note they have a Zipkit for the VB, that is very good but it doesn't include one item they developed after that kit came out. The kit has been out for about 20 years, and that one other part is less than ten years old I think. That "new" item is about $65 minimum, Summit was where I got the last one. So it's the most expensive VB upgrade they have, and it goes in the main PV port etc. There is a part in their Zipkit that is for that location, that should not be used if the newer design item is used.

The J'Mod will have the biggest effect on shifting, and a new member here just suggested following the common recommended hole sizes. The member owns several 90's Thunderbird's, which is the popular 4R70W platform that the J'Mod is done to and discussed a lot. That member evidently works on transmissions at his job, so he is familiar with the J'Mod process. I'd do that immediately with any Explorer 4R70W now, it seems like a win win project for anyone.

 

[C420sailor]

Just be wary of differences in separator plates. My 4R70W in my ‘99 has a plate that is quite different than the one discussed in the JMod. Some holes were the same, some already enlarged, some didn’t even exist. I think truck transmissions may have been shipped with a diff plate, just suspicion though.

I left my plate alone and just did the accumulator spring business and it shifts NICE. Snappy as **** at WOT.