Tranny gurus - Can You Diagnose My Problem?

[GJarrett]

Already tried search but if the answer is somewhere in all the hits, I missed it.

I've already tried plan "A" at the tranny shop and they are stumped, and the owner has a lot of experience, so this isn't an easy one. I wonder if any other Explorer owner has had the exact same tranny problem so I can tell him where to look next instead of guessing by replacing expen$ive parts until we find the right one.

'99 SOHC w/ the 5R55E tranny, 94,000 miles. After driving awhile, if I go fast enough to strain the tranny a little and make it start searching and downshifting in and out of O/D, or drive up and down hills etc, after it has to slip engagement enough times and search for gears, it gives up and decides not to do it anymore. I lose O/D and also in the lower gears it will slip and the torque converter will not lock up.

I can then pull over, turn the key off one time, restart, and it works again, until it decides to start doing the same thing later on. If the tranny itself was going out and needing a rebuild, it would not lock right back up after a simple restart, right ?

The OBDII code it throws is 0741, torque converter engagement problem (which doesn't help because I already know that).

The tranny shop pulled my pan and inspected my tranny. There are NO part pieces in the pan or any evidence whatsoever of a failing tranny. Based upon that fact and that a simple restart temporarily fixes the problem and makes it go away, the possibility of an electrical problem was discussed, and my shift solenoid was tested. It tested good but that didn't mean anything because it was cold and my problem doesn't crop up until I have driven many miles so it may be a problem that won't show until hot.

We took a chance and replaced my shift solenoid two days ago. It worked yesterday but today on my way to work it happened again. I stopped and restarted and drove another 20 miles without it reoccuring.

So I still have the problem. Has anyone else experienced this, and what did the problem end up being? There's all sorts of possibilities with sensors, etc; and it would be nice to have an idea where to look next. Or can the actual tranny truly be going out without leaving evidence in the pan? Can this simply be another total rebuild about to occur and I am catching it before it does the very same thing that all the rest of our worthless Explorer trannies do?

And I'll ask another possibility that AgExplorer may not like, but I have to ask. About 6,000 miles ago I switched to fully synthetic tranny fluid for the first time. Could my fluid be too slick? I know that's a dumb question but hey, I'm stumped.

[aldive]

Originally posted by GJarrett
And I'll ask another possibility that AgExplorer may not like, but I have to ask. About 6,000 miles ago I switched to fully synthetic tranny fluid for the first time. Could my fluid be too slick? I know that's a dumb question but hey, I'm stumped.

Sorry you are experiencing troubles and I have no clue as to your problem, however, I seriously doubt it the synthetic ATF. I have been running fulkl synthetic ATF for about 50k miles and have had no troubles,

Have you bt chance monitored the tranny temp?

[Jason_25]

Originally posted by GJarrett
I lose O/D and also in the lower gears it will slip and the torque converter will not lock up.

Does the o/d on/off light flash when this happens? I beleive what you are describing here is "failsafe mode". This happens when the computer detects any sort of tranny fault, and it gives you enough time to "limp" to the dealer for service. Mine did the exact same thing at 93K miles. When I reached highway speed it would begin to "hunt", and eventually the CEL and o/d on/off light would begin to flash. I don't know the code the tranny produced, but the CEL code was for the TPS. My mechanic explained to me that when the TPS goes bad it sends funny signals to the tranny causing to to trip fault codes. So to make a long story short I bought a new $19 TPS from autozone, installed it, and reset the computer and voila problem solved. I'm at 97K right now with no recurring symptoms.

Just thought you might try replacing something that's 19 bucks before you replaced something that's 2000 bucks.

Good luck with your problem.

[Alec]

I agree that the TPS could be causing problems. I also agree that the computer is going into safe mode. Though it is possible the computer could have something wrong, it's more likely the torque converter is going. Even if the rest of the tranny looks perfect, it can still be the tq conv. Unfortunately, the only way to tell is to drop the tranny and take the tq conv out, sorry. Also, did the shop inspect inside the planetary gearsets? Probably not, as you have to disassemble to be able to. I'm sorry to say Gerald, but your symptoms sound like mine a few weeks before it failed.

[addkev]

I have a tranny problem that the dealer can only guess at is caused by the fact that the PSOM wasn't recalibrated when I went to a larger size tire. My truck runs like a champ cool, once it warms up it will search for 2nd gear. If I dog it, it shifts normal if I am just cruising then I notice the problem. Now to add to the confusion, if I disconnect the battery over night it will take 3-4 days for it to start doing it again.

[AgExplorer]

The synthetic fluid is not the problem. If it was the torque converter, I would think that there would have been a ton of metal shavings in the pan when the shop removed it. At least, mine did that.

I'd have to go with the TPS first. If that doesn't solve it, you may have to get things up to operating temp and have the tranny shop run the diagnostics again.

[addkev]

What exactly is the TPS?

[AgExplorer]

TPS = Throttle Position Sensor

[JDraper]

addkev, that's kinda strange. I am running 31's and never recalibrated my speedo, and I have never had my tranny act strange. (Knock on wood!!) I can't tell the difference in it's shifting patterns at all. The truck came stock with 235-75/15's on it. I have the 5R55E tranny too. I wonder if it has something to do with fluid pressure, because running larger tires will put more stress on the drivetrain.

[addkev]

I dunno either. Truck still runs really good and my problem is only the shift from 1st to 2nd. No indication from either the CEL or O/D flashing. And I have every intention of driving from Florida to California next month.

Something I have wondered was if it has anything to do with me having 3.55 gearing and alot of you guys have 3.73 and 4.10's, and that putting more of a load on the tranny. But again, I dunno.

[GJarrett]

Yes, I forgot to add that when it starts failing the O/D light starts flashing.

I figured there was no way the synthetic could have been the problem but posed the question to take away another possibility.

I don't know if a TPS code was in the OBDII; as far as I know he pulled the 0741 code up and maybe he didn't look for more codes in memory. I will surely try the $19 part first to see if that fixes it.

AgExplorer PM'd me with a great idea. If the TPS doesn't fix it, I'll send a 4 oz. sample of the fluid in for analysis and let the lab tell me what kind of stuff is floating around in the fluid. That may help pinpoint something.

aldive, I don't have a temp gauge for the tranny so I haven't done that.

I also do believe that if the TC or any other part was going out, there would be something in the pan, even if it was just a little. Also this started on the way to Moab and I have made it another 4,000 miles. If it was going I would think it would already have gone.

Time to head to AutoZone and pray to the Great Healer and see if He will do a little time as the Great Mechanic and let me get out of this for $19 more bucks.

About the tires, the very first question the tranny guys asked me was how long I had those big tires on it. I explained that it had been two years or so but I had the computer recalibrated the same week I replaced the tires so that wasn't the problem.

[addkev]

I just looked the TPS up and it seems really easy to troubleshoot you should be completely able to diagnose it with a multimeter(Haynes page 6-14), and won't autozone run OBD-II codes for free? I am pretty sure they do, that way you can look to see if you had any other codes in memory.

[JDraper]

Originally posted by addkev
.

Something I have wondered was if it has anything to do with me having 3.55 gearing and alot of you guys have 3.73 and 4.10's, and that putting more of a load on the tranny. But again, I dunno.

I'm running 3.55's too, and I have quite a bit of extra weight on the vehicle (skid plates, brush guard, etc..), so I doubt it's the gearing.

[Alec]

My TC was almost totally grenaded, and there weren't any parts from it in the pan, they all stayed in the TC.

[Keach]

Gerald, I'm experiencing the same thing now. Its hunting gears and flashing O/D light. Let me know what you find out!

[GJarrett]

Keach! You still do exist! Just curious, how many miles are on yours?

TPS wasn't it, which sort of makes since, it wasn't throwing a TPS error code. I had it put on the superduper Ford $100k analysis machine and it is coming back to the same thing; a failing TC.

So now I am faced with the choice of paying $600-$700 to replace the TC only; or while the tranny is removed why not just do a total rebuild for another $grand so I can sleep well and not worry if anything else goes out next year.

Unfortunately I cannot afford a rebuild and I may have to take a gamble and just replace the TC and hope the rest of the tranny is good for a long time. D@m#. This is an extremely difficult decision in the first place, and having my pocketbook force me to take a gamble I'm not in the mood to take makes it worse. If I have to pay labor to have them replace the TC I'd really prefer that while they're doing it to just do the whole thing while they are at it.

And I haven't had it fixed yet. There is an outside chance that replacing the TC won't fix it. This is worse than Vegas, and the stakes and odds aren't any better either.

[Jason_25]

It's possible to replace the TC yourself right? As far as I know, it can be done at home with a little bit of help.

Is the 600-700 dollar quote from Ford? You may want to check with some private tranny shops in your area if you're sure you can't do it yourself.

[GJarrett]

Ford = $750. Local Tranny shop = $600. Local shop says the TC is approx. $200 and the rest is labor @ $50/hr. If a tranny shop charges 8hrs labor to replace it, I am fairly certain that I don't want to try to do the job myself (with no autotranny rebuild experience and no air or power tools while I am laying on my back on an apartment parking lot under my Explorer that isn't lifted up on a rack).

[aldive]

I reckon that you don't have an extended warranty? Sorry.

[offroader_69_me]

Originally posted by GJarrett
Ford = $750. Local Tranny shop = $600. Local shop says the TC is approx. $200 and the rest is labor @ $50/hr. If a tranny shop charges 8hrs labor to replace it, I am fairly certain that I don't want to try to do the job myself (with no autotranny rebuild experience and no air or power tools while I am laying on my back on an apartment parking lot under my Explorer that isn't lifted up on a rack).

damn sounds to me like thats WAY WAY high for labor 8 or 9 hours to R&R the tranny thats nuts! sounds like it is tiem for a road trip out here and I can change it at my shop or time to find some locals that dont mind getting dirty and pull that bad boy at home! THe tc is really easy swap after you get the tranny out!