96 Explorer 4.0L 2WD - 4R55E saga. Help needed!

[bdkdave]

Hi Guys -
Thanks for all the GREAT information here. I'm going to ask for a little more, and hopefully help others at the same time.

The truck: My sister's 1996 Explorer 4.0L 2WD with 168k. Tranny was flushed and filled at 100k and never any issues until:

The "incident": My neice backed out into traffic, freaked, and dropped the truck into drive while still rolling backward. Truck lost 1st, but would move fine in manual 2 and then D once up to speed.

Took the truck to trusted repairman who had the problem pegged before we got there. Tranny was dropped, problem was as expected: overrunning / one-way clutch was broken, and a busted drum. Tranny was clean inside, no metal other than broken part. Part failed due to break rather than heating / burning. Parts replaced:

1) Torque Converter (at our request - better safe than sorry)
2) Drum
3) Overrunning / one-way clutch
4) Overhaul kit
5) Fluid and filter

Picked up truck and things seemed perfect. Started home (50 mile trip) and my sister pulled over a little before halfway back home. She said the truck just didn't feel right - it was revving too much. We switched cars, and I found the truck had lost overdrive. O/D light was flashing, and I limped it the rest of the way home....

(continued next post)

 

[bdkdave]

The saga continues... (part 2)

Get the truck home and hook up my OBDII reader to the laptop and pull codes. I get the following report:


AutoTap Diagnostic - Version 3.00
Date: 7/13/2006 8:27:56 PM
Hardware Serial: XXXXXXXX

Check Engine Light: ON

Confirmed Diagnostic Trouble Codes:
Code: Description:
P0751 Shift Solenoid A Performance or Stuck Off
P0733 Gear 3 Incorrect Ratio
P0734 Gear 4 Incorrect Ratio
P1701 Reverse Engagement Error

Possible Diagnostic Trouble Codes:
Code: Description:
P0751 Shift Solenoid A Performance or Stuck Off

Truck seemed to take a long time (5 seconds) between moving shift lever from P to R and the actual "clunk" of the tranny engaging into reverse. Also, driving in D the truck would sometimes overrev / race instead of shifting from 2 - 3.

Checked fluid levels (fine) and electrical plug connections to tranny, all fine as well. Returned truck to mechanic who vowed to straighten out... no worries.

During return trip, I kept the laptop and OBDII reader running to watch the shift solenoids being commanded and actual gears. Also monitored tranny temp so as not to overheat as I limped it along.

Truck shifted into O/D fine the first 2 lights, but then refused to return to O/D even though the computer was requesting 4th (O/D).

Pulled codes at the repair shop and have the same 3 as above.

Once I return home this evening, I'll post more detailed info (screenshots, etc) when I have access to the diagnostic laptop.

(continued next post)

 

[bdkdave]

The saga continues... (part 3)

Mechanic sent this a bit later:

"Ok its down to a 50 million dollar question , I replaced the solenoid , it does the exact same thing . I had XXXXX put it on the machine and it tells him 2 things , incorrect gear ratio , and 3rd shift solenoid , and a ground fault code . I'm going to pull it out this weekend and go over the insides . he thinks its a computer related problem not telling it to shift because it shifter perfect several times ,, then not ,, then correct . I will let you know what the insides tell me sometime this weekend . The band adjustment helped but it still seams lazy in reverse . The line pressure checks out not he high normal side so that's not it . I will touch base with you shortly ,, the problem is there , I just have to find it ."

Shortly thereafter this came through:

"I have learned volumes about ford overdrives this week . I have learned that the 3rd design A4ld and the 44 and 55 series that followed have a reverse apply solenoid . This was incorporated to aid in positive reverse engagement because earlier versions had a soft apply leading to roller clutch failure . This valve was incorporated to correct the problem but later proved to aid in the problem as it sticks . It dumps pressure and causes a multitude of false computer codes including reverse engagement and incorrect gear ratio . I have someone that will help me check out the valve body Friday and hopefully we are getting close to a solution . XXXXXX can check the ground fault code we got with XXXXXX's scanner . I just wanted to touch base with you . I'm learning every part intimately so far ,, we will fix it ,, may require dynamite ,, but we will fix it "

And finally this one:

"I'm in need of the proper Ohms readings for the solenoids . the EPC solenoid in particular . Reverse has very low pressure and with a 4th gear issue the manual is telling me to check the EPC ( Electronic Pressure Control ) solenoid . "

I researched and found (thanks ExplorerForum!) that the shift solenoids should ohm out between 26 - 40 Ohms, which he verified. Also noting that the EPC can't be truly tested simply by an ohm reading. While constructing my reply, I received this, the latest:

" I drove it this morning and had all 4 gears but very soft shifts like it had . It dropped 2nd and 4th gear after 5 miles . It starts off in low and I believe its shifting into 3rd skipping 2n and 4th plus ,, with the soft reverse shift it points toward the EPC solenoid malfunction or cpu failure . It didn't store a 3rd gear shift solenoid failure code this time either with the new solenoid . As a matter of fact with the od light flashing on and off while driving ,, it stored no codes at all but doesn't have 2 of the forward gears . I am almost positive it has low line pressure making reverse sluggish , that can be caused by either something in the EPC circuit ,, solenoid , hydraulic EPC mechanical circuit or CPU . I believe we are close as one of the EPC / CPU symptoms is a loss of 2nd and 4th with a lazy reverse . I need to finish an overdrive for a GMC today so I will wait to hear from you before I do any more on the explorer . Thanks"


We had been leaning toward a possibly faulty PCM (what numbers / info do I need to match to properly exchange a PCM from a donor vehicle?), but this really leads me to think it's EPC related.

Can someone help point me in the right direction? I'm glad I've got a tech who is openly sharing information other than "it's not fixed yet."

My deepest thanks to all who've read this far!!

David

 

[1karkrazyguy]

My 96 4.0 XLT 2wd doing same thing

Hey Dave, please let me know what turns up with your trannie. I have 115,000 miles on mine. I am having the same problems with my trannie as you are, on my 4r55e. Clean fluid. Not burned. No parts/shavings in the pan.

I had my transmission guy, Gaby at Jul's transmission in L.A., Ca. who is very good and does a lot of work on Jags, Mercedes, BMW's and just about any other trannie, pull the codes after I got the CEL and the blinking OD light while on the freeway. It was P0756, shift solenoid B not working. Dropped the pan, no damage mechanically. We replaced the solenoid SSB, cleared the code and did the FORD valve body seperator plate upgrade listed here on the Forums, cleared the code.

Same problem again; shift flare/soft shift 1/2 and 3/4 with having to lift up off the accelerator pedal to have to shift 1/2 and same code came up again after a few miles of driving.

Next I replaced the EPC solenoid and the other 3 shift solenoids, upgraded the bracket on the 4 solenoids on one side and again after clearing the code, after driving, I seem to have the same 1/2 shift problem again, though the trannie shifts better in the later gears UNTIL the check engine light came on and the OD light starts flashing.

The funny thing is that this time when I shut the engine off when I got it home and then restarted the truck a few minutes later to move it, the CEL light had GONE OFF. First time it has done that..... This is definitely an electrical problem, not a mechanical problem. We are not driving the truck at all until we diagnose the problem, to prevent mechanical damage to the trannie.

Gaby also thinks it is a bad Powertrain Control Module as well. The next step is to go through the wiring harness with a multi-meter, starting at the transmission.

I ordered through AutoZone a replacement PCM.

Let me know what you find out and I will let you know what I find out as well. We are also going to check the Throttle Position Sensor and the Vehicle speed sensor.

Any help here from any of the members here would be appreciated.

Thanks, Nick.

 

[Wrench]

1karkrazyguy - When you turn the ignition switch off it will reset the PCM which cancels the flashing OD light till the next time it sees the fault. The trouble code is still stored in memory till removed by a scanner, so don't rule out a hydraulic/mechanical problem.

 

[1karkrazyguy]

Thanks for the heads up Wrench. Next week I will go through the electric harness on the transmission and the truck.

Any other updates David from your trannie mechanic on what your problem was?

Thanks. Nick

 

[Glacier991]

The fact that it has this problem once warm suggests a hydraulic leak somewhere. Since everything worked before the mishap, I am doubting there is anything wrong in the shift solenoids. Depending on age the EPC could be an issue, but again I doubt it. Did he do the FORD upgrade with a new separator plate? If this wasn't a rebuild it almost sounds like a blown gasket. Might check the torque on the VB as well. Yet.... the code strongly suggest one of three things (one of which he has ruled out) a) a bad solenoid (nope) b) A wiring harness problem (these can turn up in rebuilds when a harness gets stretched, pinched etc, and: c) a pcm issue. Of these three the harness issue seems most likely.

WOW, I just reread that and I sure rambled. It was kind of stream of consciousness. I'd recheck the vb torques and carefully inspect the internal harness. They can get brittle with age.

Let me know how it goes.

I admire his openness. I think he is mistaken in his statement there is a reverse solenoid in the A4LD etc. There IS a reverse engagement valve in the VB though. Sluggish R in these trannies is legendary, and sometimes things can effect a change in that problem, but not the same thing works for everyone. Me ? I'm patient and stay off the gas until I have reverse.

While the PCM can be an issue, the sequence here makes me doubt a bad PCM input.

ps. If he has access to a NGS tester, tell him to run pinpoint test J.

 

[bdkdave]

Glacier - Thanks much for your input. I was hoping my thread would catch your watchful eye, but didn't want to beg you to come and look

As of this writing, nothing has changed with the situation. I think we're both looking for some direction at this point. I'm a fairly good wrench with the "simple" stuff, but have never made the dive into a transmission, so I'm actually educating myself as I go along.

I don't believe that he has access to the NGS tester. I've been watching a Rotunda NGS unit on eBay, and it's not gone over $400 which puts it out of my range for a one-time application - lol. Someone should rent those things out - they'd make a killing!

Anyway, I do consider myself lucky that he's openly sharing information, so I'm trying to be understanding during the lulls, and use the time to dig for more information to bring to the table.

And Glacier - you didn't ramble NEAR as much as I did - 4 posts from the start!

Would hooking up a pressure gauge help with the troubleshooting at this point? Also, I'll be asking about the separator plate when I speak to him this evening.

Again, many thanks for your time and help!
David

 

[bdkdave]

Just off the phone with the tech, and the internal harness tests good on each wire from plug to plug. He thinks maybe the 3rd shift solenoid wasn't plugged in well the first time, as now he no longer gets any codes related to the 3rd gear shift solenoid.

He does, however, still get the reverse engagement code. The trans shifts fine for a mile or two, then seems to shift from 1st to 3rd, with no 2nd or OD. This, per his book/manual, is a symptom of the EPC failing.

With nearly 170k on the tranny, I'm tempted to believe perhaps the EPC could be the issue.

I've been quoted a price of $114 + tax from APD for the replacement part, and at this point, I'm almost ready to eat the cost just for piece of mind, both now AND down the road when it might fail anyway.

Suggestions / directions greatly appreciated!
David

 

[1karkrazyguy]

Epc

Hi David,

As I told you before, as the Explorer Forum suggested here, I did the FORD valve body plate upgrade and I did replace the EPC solenoid and all the other shift solenoids EXCEPT the TCC solenoid and I still have the same problem as you have with the incorrect shifting of the transmission and I have 115,000 miles on my trannie. We have stopped driving the truck as we do not want to damage the internal mechanicals of the tranmission until we figure out the electrical problems causing the trannie to shift like this.

Apparently from what I have read and what Gaby has told me, these 4R55E and the 5R55E transmissions are all computer controlled and the PCM sets the shift points based on the driver, driving conditions and a range of factors from the inputs sent by various sensors on the engine and the trannie. There is a failure mode hard programmed in the PCM, where the tranmission can limp back to a repair shop to be diagnosed and serviced when a component fails, so that greater damage is not caused. That is the reason one stops driving the vehicle when the CEL comes on and the OD light starts flashing, which indicates a hard part failure in the trannie. People continue to drive the vehicles with these lights flashing and compund the problems with the trannie, going beyond the original failed component.

But when dealing with any computer system that accepts data and gives a result, one must remember that if one is inputing corrupted data: "Gigo" "garbage in, garbage out" is the end result. So that is the bad wiring, bad sensor issues related to the PCM and/or the PCM itself.

Again my transmission repair guy, Gaby, at Jul's Transmission in L.A., who is really really good and works on and rebuilds only automatic and manual transmissions for Fords, Chevy's, Jags, BMW's, Chryslers, Mercedes, for all years etc., thinks it is definitely an electrical problem somewhere in the transmission wiring harness or in the main vehicle wiring harness. Again he thinks it is a PCM related failure, but we will go through all the wiring just to make sure. I just bought on eBay a factory issued 1996 Ford Explorer electrical circuit/diagnosis manual.

I have seen some very very weird electrical problems on this truck, my sister's 96 Explorer. Last year it was a problem with the windshield wipers, power windows and the headlights not working all at the same time. It was intermittent and it drove me crazy. Ford dealer could not figure it out.

The problem turned out to be a moisture/water leak from the front engine/firewall in the interior of the car, accumulating on the driver's side footwell and soaking the padding and carpet there pretty badly. I sealed the water leak in the firewall where some aftermarket alarm wires had been run through, dried out the carpet and the interior under the dash and that solved the problem after all the moisture was dried out inside the truck. At one point the humdity inside the truck was at 90% by the dash. The water from the leak was causing some sort of short with the GEM and the ACCY relay under the dash above the driver's footwell.... No problem since then.

I am sure this problem is going to be something weird related to how Ford designed the circuit and then routed wiring for various items. I see in the HAYNES electrical diagrams that the transmission wiring runs through the GEM module and the ACCY relay.....

I will let you know what we find out.

 

[Glacier991]

Great input, thanks.

 

[bdkdave]

another thing checked...

Found a couple of posts mentioning a problem with the bracket that holds the EPC solenoid cracking and allowing the solenoid to shift enough to effect its' ability to correctly control pressures within the tranny.

Tech was already aware of this, and had inspected the bracket carefully. No cracks, and the solenoid is firmly in place as it should be....

Oh well - it was a possibility!

Posted in the Sale/Trade/Want forum hoping to find an EPC solenoid I can use to test with. At least like to put in a different one to see if it has any effect on the current issues, and if it does, I'll then have no problem in buying a new one. However, it's a lot of money to dump to buy a new one with no idea if it'll even help the problem.

Anyone have a spare EPC solenoid for a 1996 4R55E that they'd like to sell / loan / rent?

Thanks for all the help so far - you guys are great!

 

[1karkrazyguy]

Hi David,

Took my 96 Explorer today to my trannie guy and we put a NGS tester on the transmission and tested the trannie while driving and while it was on the hoist, activating the solenoids one by one. We also checked the PCM and it checked out OK and the continuitie on the trannnie wiring harness connector at the outside of the transmission body that plugs into the vehicle wiring harness. Everything checked out. We still got the same DTC code, P0756 which is a SS2 failure and that SS2 has already been replaced. There is no evidence of a mechanical failure of the transmission components at this point. Evidence is starting to point towards a hydraulic problem, though we are not finished ruling out all electrical issues.

After replacing all soleniods except for the TCC solenoid, (5 solenoids) and upgrading to the new style solenoid bracket, and checking the electrical harness and the PCM and after having updated the plate on the valve body with the FORD TSB posted here on the forum, with all new gaskets, and putting in a new VSS and a TPS, the conclusion we are arriving at is a worn valve body. But it could still be the internal wiring harness at the solenoids and we will check the transmission ground cable too. Bad grounds cause many problems too. We will test that Monday as well. I also bought a used 96 Ford Explorer Factory Wiring Manual on eBay to trace all the wiring from the trannie external plug/connector, through the body wiring harness to the PCM.

We will pressure test the trannie on Monday and I will update you then. The trannie rebuild book you can buy for $15 on eBay, is pretty detailed in the listing of fluid pressures, DTC codes and what they represent, other engine sensor componets that when they fail or go bad, read out certain DTC codes and the stall test for the transmission and the actual rebuild of the transmission and a step by step diagnosis of trannie problems. You should take a look through one of those.

We're still thinking rebuilt valve body for my trannie, but will explore that option after we finish going through all the other electrical issues.

Some of the DTC codes you originally list in your posting as problems, P0733. P0734 are listed in the repair book as a component failure or a blockage in the hydraulic circuit or a failure. Again problem could be in an old worn valve body.

As for reverse, there is a servo piston at the right rear of the trannie when you drop the oil pan, off the valve body, inside the case close to the exhaust. We replaced the 2 o-rings on that servo to firm up reverse. There are 2 other servos on the right side of the trannie case, by the exhaust, that are covered by a heat shield that are accessible with out dropping the pan. Easily serviced. There seals can get cooked by the exhaust pipe nearby.

My local Ford dealer hasn't a clue as to what is wrong with my trannie... All they want to do is sell me a rebuild. That does not solve an electrical problem if there is one, which would just burn up the new trannie... We do not think it is a PCM problem at this point... Thanks Ford....

 

[1karkrazyguy]

Hi David and Glacier991,

UPDATE: 11-5-06

Not to ramble but:

Quick thing David, did you replace the 2 bands in the transmission when you rebuilt it? Certainly sounds like a mechanical problem still. I'd follow the diagnosis info in the ATSG book and get access to a FORD factory NGS scanner tool to correctly read out all the OBD II DTC codes. This tool trumps all the after market scan tools, including the ones from SNAP-ON and MAC Tools...

The only OBD II code scanner that read all the DTC codes correctly on my Ford 4R55E transmission is the FORD NGS tester. I finally know what is wrong with my 96 Explorer transmission.

If you live in Southern California, Jul's Transmission in Hollywood on Hyperion, 1-323-666-1955, Gaby the mechanic, is honest and good and diligent. Rare thing these days AND HELPFUL FIGURING OUT MY PROBLEM.

Before we used the FORD NGS tester on my Explorer a 2nd time, we used my transmission repair guys SNAP-ON tester and a MAC tools tester and the only code we got was P0756, SSB failure, shift solenoid 2. So Gaby thought it had to be an electrical problem, not a mechanical problem as we had checked the solenoids and ALL THE ELECTRICAL CONNECTIONS AND CIRCUITS TO THE PCM and the wiring harness inside the pan to the solenoids. He swore up and down it was an electrical problem. He was wrong. And this is a guy who owns and runs a transmission shop that rebuilds transmissions only of all kinds and types. The problem was that his buddy who owned the FORD NGS tester did not tell Gaby about the P0732 DTC code when it came up.... Unfortunately the person who owned the FORD NGS code scanner/tool, was NOT a transmission guy... If he had told Gaby the P0732 code, Gaby would have known immediately that it was a mechanical problem, not an electrical problem.

When we used the Ford NGS tester, it read out P0732 AND P0756 DTC codes after driving. P0732 is an incorrect gear ratio and means a mechanical failure in the transmission and P0756 is SSB or shift solenoid 2 not working itself or a problem in the valve body. My transmission repair guy was pissed that he had not used the FORD NGS tester first.

P0732 is a mechanical failure in the transmission. We dropped the valve body and looking up into the case, sure enough band 2 was broken. So we are going to do a complete rebuild now with Borg Warner clutch pack and new FORD factory Turbine Sensor and CalTrans rebuild trannie kit. I already replaced all the solenoids and did the valve body plate upgrade.

End of problems with my transmission.

The ATSG manual is very very accurate for diagnosing the problems with these transmissions.

What are very inaccurate are the OBD II aftermarket code scanners. Get access to a place that has the FORD NGS OBD II code scanner.

The Ford NGS tester can activate all the solenoids individually WHILE THE TRANNIE IS IN THE TRUCK and can test the PCM as well.

Good luck. I just spent 3 weeks fooling around with this problem, but IMHO that was because we thought it was an electrical/valve body problem based on an incomplete DTC code read out from aftermarket scanners that only gave us 1 of the DTC codes, P0756, but not the P0732, mechanical failure. FORD NGS code scanner all the way and an honest transmission mechanic/shop...

To all people with Ford Explorer transmission problems, read the posts on this Forum board from Glacier991, get the ATSG service manual for this transmission, READ IT and follow what it says for diagnosis, testing and what the DTC codes mean, (http://www.atsgmiami.com/), get access to a FORD NGS scanner tool and get the OBD II DTC codes read out from your PCM for the transmission problems you are having, check the ATF fluid in your trannie when it is hot and on flat ground, state the mileage on your truck and when the fluid/filter was last changed, check whether there are any leaks from the trannie or in the radiator fluid.

The OBD II DTC codes when read out by only by a FORD NGS scanner, are very specific and tell exactly what is wrong with these trannies, IMHO. You must have a transmission person that WORKS ON A LOT OF FORD TRANNIES interpet these codes correctly, as there are OTHER SENSORS ON THE FORD TRUCKS ENGINES, THAT AFFECT HOW YOUR TRANSMISSION RUNS AND SHIFTS!!!!

 

[1karkrazyguy]

FINALLY FIXED! This 4r55e transmission now shifts so smoothly it is ridiculous with it's upshifts and downshifts and lack of noise. Anyone rebuilding has to replace hard parts on these trannie's. The FORD oem hard parts just don't wear well at all from what I saw replaced. And if you don't replace the hard parts that need it IMHO, you're just asking for trouble a short period down the road. Especially if you tow or go off roading....

Just got my 96 Explorer 4.0 XLT 2wd back with the rebuilt transmission. I had Gaby at Jul's Transmission in Hollywood, Ca. go through the whole thing and replace everything internally of the hard parts that needed it.

Originally we were getting OBDII DTC of P0756, which is SSB (performance solenoid shift solenoid 2 not working, hydraulic circuit not working) and then we got DTC code P0732, (incorrect gear ratio) which indicates a mechanical problem in the transmission. The intermediate band had broken at the end of the band at one of the case mounting points.

Now with the rebuilt/repaired transmission, none of these codes are there and the transmission works perfectly.

Besides installing the standard rebuild kit with all new bands, seals, servos, and high heat BorgWarner clutchs, I had installed a remanufactured torque convertor, new pump, 2 new drums, new front and rear planetary gear sets, and replaced any and all hard parts that were worn or questionable, new FORD oem turbine sensor, plus the valve body we had already rebuilt with all new solenoids, new upgraded FORD seperator plate listed here on the Forum, etc.

Smooth shifting now as my buddy's Lexus. Amazing. Like a hot knife through 'butter'....

The amount of wear and then the slop in the FORD oem hard parts, especially in both sets of planetary gears was unreal and on the pump and the drums.

This is how a trannie should be rebuilt, the way Gaby at Jul's Transmission did it; soft parts and hard parts, plus it was very very reasonable. These trannie's in the 2wd VERSION are easy to pull out, rebuild and re-install. Compared to the the way AAMCO or some other large transmission repair shops do their rebuilds, re-using the old worn hard parts from your trannie that should be replaced. I know because my 94 Explorer trannie died on me last year in the middle of nowhere and I had no choice but to go to the local AAMCO shop.

They were very very expensive compared to Gaby.

AAMCO used the standard rebuild kit, but that was it; re-used many of the old hard parts and when they were finished, they had a serious attitude problem with trying to scare you that you should have bought their $3500+ rebuild, and that their $2400 rebuild wouldn't last as long....

I told them for the price I was forced to pay AAMCO in the middle of nowhere, there should be all new hard parts internally and a rebuilt valve body, or a new transmission from the FORD dealer!

I then told this AAMCO shop I would report them to the State of California Bureau of Automotive Repair who regulates them and all of a sudden the shop manager got realllllllly nice and offered me an extra free 1 year extended warranty, for a total of 2 years/24,000 miles instead of 1 year/12,000 miles and then did a free oil/filter change with synthetic oil, changed the lube of the rear differential and had the truck washed/waxed and the engine steam cleaned. Weasels. I guess they got a little worried I was from the state.

I got a call 2 days later from that AAMCO shop owner, asking if everything was OK and another call a week later from AAMCO corporate headquarters asking the same thing...

That's why I don't recommend AAMCO.

But I do high recommend that when you do rebuild your 4r55e, replace ALL the hard parts as I did AND the turbine sensor using a FORD OEM part and upgrade your valve body and plate. It makes alllll the difference in the world. And use Mobil1 Synthetic ATF...

Good luck.

 

[Glacier991]

Thanks you for sharing. I have long maintained that a quality rebuild of the A4/4R/5R requires hard parts to be replaced too...and not just a soft parts rebuild. Thank you for illustrating that point.

 

[1karkrazyguy]

You're welcome and thanks for all the insight and help initially.

I wonder what bkDave ended up doing?

 

[bdkdave]

bdkDave is currently awaiting a shipment of parts from an oh-so-helpful member of this very forum.... (Thanks Brad!)

He hopes that the EPC solenoid he's getting will aid in troubleshooting his current issues which are still yet to be resolved.

He also promises to keep everyone informed, and the thread properly updated as he progresses... knowledge is power!

Thanks as always,
bdkDave (in 3rd person)

 

[toy720]

David We are over the bug I read through this but did not see where the seperator plate and new gaskets were done? Also another thing that can totally screw these trannies up is the dtr not sure if it would cause all these problems but can produce alot of unwanted symptoms if failing or mis aligned.these are just my thoughts and i hope the solenoids are helpful.
keep us posted
Brad

 

[bdkdave]

Update!! Another chapter (this really is a SAGA):

Received the parts from Brad (insert another plug for what a nice guy he is!) and delivered to mechanic. He installed the EPC solenoid, and it seemed to work fine until the truck and trans heated up, then it started the same problems. Mechanic says he's suspicious of the used part (EPC solenoid) that's not known to be 100%, so he's arranged to borrow one from a friend that is known to be in 100% working order.

Mechanic installed borrowed "known good" EPC solenoid, truck drives fine, until it heats up, then exhibits same behavior. Mechanic returns borrowed solenoid to his friend who know reports the donor truck is having the same problem as my sisters. Mechanic claims that her truck destroyed his friend's donor EPC solenoid, so it must be something electrical. Advises he wants to pull it in the shop "one more time" to look over the trans for anything electrical he might have missed.

-------------------------

So - my question is: Is it possible for my sister's truck to have fried this other guy's EPC solenoid? If so, wouldn't the ECM be showing some different codes, and/or the mechanic should've seen some strange readings when he tested the wiring harness, as he assured me he did.

I'm REALLY tempted to suggest that my sister ask for half the funds back, and tackle this project myself.

Thanks for all those who've stuck around this long!

karkrazy - congrats on your fix!