96 5.0 explorer 2wd 4r70w transmission swap to 2002 4r70w from 3.8 v6 mustang

[C420sailor]

^^^ everything is now suspect

Servos looked good?

 

[TelMinz]

^^^ everything is now suspect

Servos looked good?

I haven’t looked at the servos yet, I will check them tomorrow. But I was thinking today about the TCC solenoid and how the resistance of my original one is different from the new one. I think the older style was like 1-3 ohms and the new ones I think are 10 ohms. How does the computer handle the new solenoid being a different value? I think I’m going to try swapping the electronics tomorrow and see if that fixes it along with putting in the old valve body. I looked at the valve body from the old transmission tonight, everything works on it so I guess I’ll have to use it. It does have some kind of shift kit tho, so hopefully that isn’t an issue. I noticed the 2-3 backout valve doesn’t have a spring like the other one did. The tail is solid and the spot where the little plate usually goes to hold the spring is it’s held in with a kind of clip and the valve doesn’t move much because of how it’s made. Not sure if I should swap it out for the one out of the bad valve body, but I’m going to risk it and leave it in.

 

[Mbrooks420]

I’d probably buy a rebuilt valve body for the specific trans thats in it before trying to Frankenstein new and old parts from two different transmissions. The last thing you want to do is smoke a “rebuilt” transmission because you skimped on some relatively low dollar parts.

 

[TelMinz]

So along with the TCC solenoid being different, the valve body is a new design. The transmission is a 2002, so several of the passages were moved on the valve body, such as the 2-3 backout valve having been connected to the EPC, but was moved to the number 2 shift solenoid. An overdrive servo regulator was added, along with several other changes.

I feel like it was a mistake putting in a 2002 transmission, I don’t think the computer knew how to handle the changes with the valve body or electronics. Hopefully I haven’t burnt this transmission up, or my computer. But it drove fine for 3 or 4 days, then stopped, so it seems like something may have gotten broken.

I’m going to use the valve body I have, I don’t have time to wait for a new valve body. Although at this point I doubt using a 2002 valve body would work so im not even sure which one I should buy. And they aren’t “relatively inexpensive” either, $200+ isn’t exactly cheap. It’s not like I can buy all three flavors and try them out, and I’ve already spent way over my budget on this thing. Are they even interchangeable? I’ll look at the cases before I swap them over, but none of the literature I’ve found says the cases were changed. I don’t see how it would be an issue if I check it over and clean it good and everything lines up like it should. Worse thing that can happen is that I’m still in the same spot as I was yesterday. Besides, I’m pretty sure this trans is going to have to be removed anyways at this point, so might as well go for a Hail Mary.

 

[CDW6212R]

Did you replace the range sensor with a new 96 model part? The pre-98 PCM requires the older DTRS(the range sensor), it is analog and the 98+ are digital. Don't reuse the old pre-98 DTRS, those were all defective(bad seal around the perimeter).

So if not done yet, change the DTRS to a new one made for your 96 Explorer PCM. The wiring at the trans needs to be rearranged, remind us did you do that already? The 98+ models use a different wiring harness inside, plus the solenoids, I don't think any of them can be swapped from early(pre-98) to later 4R's, or the other way either.

So in general, if you install a pre-98 range sensor, and rewire the vehicle connector at the trans, then it should work fine if the 2002 trans was built right.

 

[TelMinz]

Yes, the wiring harness is correct. And I just verified the pinning was correct before I pinned it back to original.

The dtrs is new. No issues showed in the scanner as far as it recognizing what gear it is supposed to be in.

 

[CDW6212R]

Okay good, then it's a 1996 DTRS, not the 2002 part? At that point, I'd suspect the solenoids or the VB itself, it sounds like the builder didn't fully check or test all of the parts for movement.

The VB parts that you discovered not moving freely, are they by chance among those which Sonnax replaces with one of their many small kits? They have a half dozen or so part kits for various VB items, some for improved performance, and some due to old age wear issues.

 

[TelMinz]

Okay good, then it's a 1996 DTRS, not the 2002 part? At that point, I'd suspect the solenoids or the VB itself, it sounds like the builder didn't fully check or test all of the parts for movement.

The VB parts that you discovered not moving freely, are they by chance among those which Sonnax replaces with one of their many small kits? They have a half dozen or so part kits for various VB items, some for improved performance, and some due to old age wear issues.

Yes, there is a kit for the one valve that is stuck. The other one is free now, but a kit is made for it as well. It doesn’t matter tho, I will not use it knowing that it is redesigned for 02+. I don’t think it is a good idea to put in a 4r70w later than an 01 in a pre 98. It just isn’t the same as far as the valve body goes.

 

[CDW6212R]

Don't use the 96 VB, what are you thinking. Keep the 2002 4R intact. If it has an issue you can fix, work on that. As others said, a rebuilt trans is an unknown, you are betting on it being done right. You can start over or try to work with what you have. The 4R trans is a very reliable unit, it's hard to screw up unless an idiot worked on it, or it was seriously damaged prior(commonly called burned up).

 

[Mbrooks420]

So along with the TCC solenoid being different, the valve body is a new design. The transmission is a 2002, so several of the passages were moved on the valve body, such as the 2-3 backout valve having been connected to the EPC, but was moved to the number 2 shift solenoid. An overdrive servo regulator was added, along with several other changes.

I feel like it was a mistake putting in a 2002 transmission, I don’t think the computer knew how to handle the changes with the valve body or electronics. Hopefully I haven’t burnt this transmission up, or my computer. But it drove fine for 3 or 4 days, then stopped, so it seems like something may have gotten broken.

I’m going to use the valve body I have, I don’t have time to wait for a new valve body. Although at this point I doubt using a 2002 valve body would work so im not even sure which one I should buy. And they aren’t “relatively inexpensive” either, $200+ isn’t exactly cheap. It’s not like I can buy all three flavors and try them out, and I’ve already spent way over my budget on this thing. Are they even interchangeable? I’ll look at the cases before I swap them over, but none of the literature I’ve found says the cases were changed. I don’t see how it would be an issue if I check it over and clean it good and everything lines up like it should. Worse thing that can happen is that I’m still in the same spot as I was yesterday. Besides, I’m pretty sure this trans is going to have to be removed anyways at this point, so might as well go for a Hail Mary.

$200 isn’t relatively cheap? Price an actual new transmission, and that’ll change.

 

[TelMinz]

Update: I changed the valve body out for the original one, swapped the electronics back, re-repined the harness, I also pulled the over drive servo, it looked good and had good engagement with the band. No changes tho, I still get a 3-4 neutral. So the valve body didn’t make a difference, neither did changing the electronics. I guess I’ll have to dig around in the service manual and try and see how I can test the computer to see if it was damaged by the new TCC solenoid or something else.


I found this information out on an article about the 4r70w - “If you manage to get through gears 1, 2, and 3, a transmission that fails to make overdrive (fourth gear) is not an electrical issue. If your AODE/4R70W experiences no 3-4 upshift, it is a sticking 3-4 shift valve, overdrive servo issue, or a failed overdrive band. Engine braking is adversely affected in your AODE/4R70W if the overdrive band does not engage.”

So I can rule out the electronics, and since I’ve changed the valve body i know it isn’t the valves. So it’s either the servo or the band. I looked at the servo and it seemed ok, but I’m going to check it again. If it’s the band then I don’t know what could of caused it, the sonnax troubleshooting diagram didn’t list OD band failure as symptoms the stuck valves I found. I’m wondering if the band may have failed somehow and managed to stick up those valves I found?

On a positive note, the engagement of the gears that do work has improved with the old valve body being installed. They just feel firmer which is a good thing I think. I’m just hoping the old valve body isnt the cause of the low coolant flow issue I had with the old transmission.

 

[CDW6212R]

Those choices can all be possible from the rebuild, not trying to damn the builder, just suggesting the trans isn't inherently defective or weak. The OD band is always a big weak link, the prior owner may have noticed a slipping or thought it was time to get rid of it. Also the OD band is possibly a Kevlar band, which is a poor choice unless the line pressure is increased. The Kevlar requires more pressure to hold the drum, to not slip; yes it will last longer, but only if it isn't slipping. So the line pressure may not be high enough for the OD band, and it's too late to correct it if it was slipping before. The OD servo you can replace if you think it may be leaking etc.

 

[TelMinz]

Those choices can all be possible from the rebuild, not trying to damn the builder, just suggesting the trans isn't inherently defective or weak. The OD band is always a big weak link, the prior owner may have noticed a slipping or thought it was time to get rid of it. Also the OD band is possibly a Kevlar band, which is a poor choice unless the line pressure is increased. The Kevlar requires more pressure to hold the drum, to not slip; yes it will last longer, but only if it isn't slipping. So the line pressure may not be high enough for the OD band, and it's too late to correct it if it was slipping before. The OD servo you can replace if you think it may be leaking etc.

I swapped the OD servo and no change. This Kevlar belt you mention sounds like it very well could of been the issue. Thank you

 

[TelMinz]

So I think I figured out that it’s either the direct clutch or direct drum. The truck never actually shifts to 3rd, the computer calls but it doesn’t shift, then when 4th is commanded it neutrals. Looking around online at others with these same issues and they all found a problem with the direct clutch parts.

The low cooler flow issue has returned, so now at least I know that’s in the valve body.

So I’m just going to get a new valve body for my old transmission, put it in and then rebuild the new “rebuilt” transmission myself. This is the second supposedly rebuilt transmission that has been installed in this truck, but that’s just my luck. Maybe if I do it it will work right this time!