Servo O-Ring Mod A Permanent Fix For 5R55? | Ford Explorer Forums - Serious Explorations

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August 2, 2011
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Greenville, SC
City, State
Greenville, SC
Year, Model & Trim Level
2000 Explorer Limited 5.0
I have a 2004 Eddie Bauer 2WD Explorer with a 4.6L V8. It has 206k on the clock. It has been a joy to drive and I've taken it on a lot of long, long road trips. I've also been pretty careful on the maintenance. There is one problem that is common with this vehicle, that I was afraid I would have, that I am now having. That is the tranny. This couldn't have happened at a worse time.

The day before I took off to take a friend to NY and recover some property from a storage unit, the transmission began acting-up. The computer starting throwing error codes. It had a difficult time shifting out of 1st Gear and OD was deactivated. The codes are P1744, which is related to the torque converter. I have P0745 solenoid error, and P0731, 2, 3, 4, gear ratio errors.

I have problems shifting out of 1st Gear, but when it does shift, it is still smooth. 2, 3, and 4 are OK, shifting at normal RPM range and shifting smoothly. Eventually, it will get to where I can't shift out of 1st unless I turn it off and turn it back on. Then it will work again unless I stop 3 times. I guess this thing doesn't like "stop-and-go" driving any more than I do.

Before this, the transmission never had any problems that I'm aware of. I've only had it since August, 2016.

The behaviour sounds pretty consistent with the problems I have read about related to a servo bore issue where a steel rod wears-out the hole (s) in the aluminum transfer case. This apparently causes various behavioural issues and error codes related to the aforementioned gear shifting, torque converter, and solenoid.

If I replace the original servos with new ones made by AJ1E, will that be a permenant fix, or will it buy me time? Even buying time might be worth doing if it buys enough time. I've read a little about this, but I want to read testimonials before I pull the trigger.

To anyone who has done this repair, how long can I expect it lo last?


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I have not done the fix, but I researched it a lot when trying to diagnose my own transmission problems. Mine is related to the line pressure relief valve in the pump, not the servo bores. But when I was reading up about the AJ1E fix, I saw a lot more positives than negatives. The company claims multiple customers have put over 100,000 miles on the servo fix with no issues. About the only negative I could find was a single youtube video claiming the person had to install the servos with smaller o rings because the supplied ones were too thick to fit in the bores.

I say do it. There's no telling how long it will last, but it does seem to me like it's a perfectly acceptable fix that will more than likely last the rest of the life of the vehicle, given you already have 200k+ miles on it. $200 and an hour or so of install time, versus swapping the entire transmission out or having the case machined for new bore sleeves.

It's well worth it IMO. If it doesn't work you're only out $200. If it does, you've saved a few thousand.

I just ordered the AJ1E kit for my “new to me” 2002 Explorer. Mine is the 4.6 with 4wd, and I got a code reporting P0775 Pressure Control Solenoid B. The folks at AJ1E shipped the servos really quickly and I got them in a couple of days (today in fact.).

Sadly my problem is that the band adjustment locknut is really stuck and there’s not much room to work with tools to break it free, so I’m going to take the Explorer and kit to a mechanic to have the work done. But the kit comes with replacement O-rings, so if it lasts me 50K miles and I can re-ring again, I’m actually far ahead than spending thousands on a rebuilt transmission.

That said, I agree with Wakeboardrb and think you should give it a go also. Not a lot of money to spend, and with a 2wd Explorer, you’ll have more access than I did to adjust the bands and

Did you use a box wrench or a socket on those hard to turn lock nuts? What about using a penetrating oil spray on the lock nuts?

I used liquid wrench to penetrate the lock nuts, but it was still pretty darned hard to break free. I used a socket (had no room to use a box end wrench) and even then, I was running the risk of rounding off the lock nut.

I have 246K miles on my Explorer, and am not sure if this is the original or rebuilt transmission. But in either case, it’s not been apart in a while, so I guess it’s to be expected that the bolts are pretty well stuck. I’m going to drop it off at a transmission shop in the morning and see if they can do the job for me...

I am out of work right now, so I can only afford to gamble if I know I'm going to win. I was illegally evicted recently, so I'm "camping" at my parents' place, which is uncomfortable for both me and them. My dad is insisting that I need to take it to a shop and eat a $2.5k bill for a rebuild.

I don't have money for a rebuild and I don't have any expectation of receiving handouts. I also am not excited about selling the vehicle as-is. The engine is in good shape. the interiour is in good shape and no leather is torn. Both the heat and air work great. I stilly don't expect anyone would be willing to pay me enough money to replace it with any working vehicle. I want to get another First Gen Explorer, preferably with 4x4.

I've called a few transmission shops and they are all adamant that they don't want to install the AJ1E servo kit and most only want to fix the servos as part of a rebuild. One shop offered to give me a free diagnosis, but I don't know how involved that diagnosis is. I don't know if it includes checking the fluid. Another shop wants $75-ish for diag. and that included pulling the pan and checking the solenoid pack. He says it sounds to him like that could be bad. All of the shops I've called want to drill-out the servo bores and install a brass sleeve in the IM and OD servos.

If there's anyone on here here who is confident they can fix the '04, and wants to trade "Even-Steven" for a 91-94 4-door Explorer (preferably Eddie Bauer, preferably 4x4), let's talk. I don't know if that's a good deal or not. I just need to get moving.

Thanks for the link. I called most of the places in my area that are on that site, but they are all insistent that they want to bore and sleeve the servos. If you pull the tranny, you might as well re-build it, even if it is not failing. One shop insisted that if the servos are bad, other things (like clutches) are bad as well. I got a few different opinions from a few different people. some really turned me off, because they seemed to indicate they want me to shut my mouth and open my wallet. Others seemed to not be like that. Either way, if I take it to a shop, I'm out a lot of money.

Honestly, I think I could change a solenoid pack if I had to. It's right there when you drop the pan. It's going to be a lot of work, but I'd rather buy a solenoid pack and valve body gasket and do the work myself than pay out my @$$ for someone else to do it.

I haven't really done much tranny work before, but I've done extensive work on engines. I'm pretty sure I can figure it out. I just need to see if I can diagnose it myself.

If you've done engine work in the past, you can do tranny work. I never touched a transmission in my life until I bought my mountaineer. And then the servos had issues, leading to a broken band, and the adjuster laying in the pan. $800, and about 10 hours of actual labor (cleaning and removal took up most of that), and now it shifts like it should.

I should mention, I had the AJ1E servos, and they did fix my issues. Before that I had replaced the solenoid pack, but no dice. After the servos, it still had a sloppy shift from 2nd to 3rd, and that's where I got greedy and adjusted my bands... And broke them obviously. This is just my experience though, not all trannies are created equal.

For a rebuild though, you need a lot of time, a lot of space, and a good assortment of tools. But when it's done, you've got a solid tranny that should last you quite some time.

I'm sure I have the mechanical aptitude to do a re-build, but shop space and tools will be a limiting factor. I'm looking for a space to do the servo replacement, hoping that's all I need to do.

If I can suggest anything for that, I would say don't cut corners. I did mine without removing the y-pipe, it was such a pain to get the snap rings out. Also use lots of degreaser, probably a good bit of grime up there. Other than that, watch all the videos and it'll go easy.


After clearing the computer's memory, I went and got AutoZone to read codes again. At first, I shifted into D and took-off, using under normal acceleration, it behaved the same way as before, waiting to shift until almost 3k RPM's and giving error codes. At one point in the drive, The car turned off and I had to shift to neutral and start it up. I think that caused it to give a B1676 code. In the past, the car would stall if the cruise was set below a certain speed, but this was very infrequent. I probably need to get a new ECM, too.

I managed to drive around by shifting manually from 2 to 3. If I skipped 1, I didn't get any issues from the computer. I also turned-off O/D, so I was only using 2,3, and 4, and shifting manually. I did experience the transmission slipping out of gear when my foot wasn't on the accelerator, but it never slipped when my foot was on the pedal. What's happening. I'm afraid to drive it much before I get it fixed because I don't want to make things worse.

None of the shops I have called or visited are willing to install the AJ1E servo kit. One claimed it's because he can't warranty that kind of stuff. I guess that makes sense. I think I could do it myself, but I need to find a place where I can do the work.

I talked to one guy who I think wasn't being honest. He told me that the P0745 was a torque converter code, when I know it's a solenoid code and have seen two different diagnostic computers describe it as a solenoid code. He also told me that it was skipping 1st and 2nd and starting in 3rd. I know for certain that I was starting in 2nd because I shifted manually from 2nd to 3rd and switched to D to activate 4th. I know it's a crappy economy and everyone wants to sell a $2.5k job, but some people are really turning me off.

The internal hard wear parts(clutches and frictions) can go for ages, but the solenoids and various rubber parts are the biggest weak links. Rebuilds should always replace all of those items. But most issues come from VB functioning, and that's got nothing to do with frictions/steels(and the subsequent $2500 rebuild).

I suggest both doing what you can do, and finding a shop which will rebuild it if that doesn't fix it adequately. The parts you can do without a rebuild, have to be done anyway, and those are most likely the problem.

Actual bore wear is becoming more common, and the solenoids seem to create more of that when they get older. Meaning it seems wise to replace solenoids and accumulators etc, before there is a problem, at certain mileage intervals. I;ve been told it'd be smart to change the EPC solenoid on the early electronic models, every 60-100k miles, to reduce bore wear from the solenoids wearing themselves, and accelerating the case/VB wear.

So your trans case may be hurt already, and not every shop will identify that. But the solenoids still need to go, do that and adjust the bands, do the accumulators etc. Use best fluid and a Lubegard additive, and see how it does. That'd be the best first step.

Great conversation going on here.

I had the same symptoms of a servo bore issue (slipping from 2nd to 3rd) and ordered the AJ1E servos, installed and still had the same issues. I will say that the owner of the company, Andrew Wanie, was more than helpful in troubleshooting the problem with me. I will give him 5 stars for customer support and standing by his product.

The continued problem after the servo switch indicated that there was something more to this. I dropped the pan, solenoid and valve body to find bits of metal on the gasket where the overdrive gears live...

So... Knowing that this could easily be a 3K job at a tranny shop, I decided to do it myself and dropped the tranny. Reading a ton of threads here and watching Hiram Gutierrez's videos on YouTube gave me the confidence that I would be able to do it.

Turned out that my overdrive planetary and sun gears were chewed up. So I'm in the process of ordering new ones. I also have the Superior kit and a deluxe rebuild kit that I will install once everything is in.

So what I'm trying to say is check for all possible issues before assuming the AJ1Es will fix the problem. I still intend to put mine back in after the rebuild. Good luck!

Oh and if anyone on here has any experience with rebuild kits send me a pm. I have a few questions.

I guess the first thing I'm gonna do before I fly into a project and gamble, is check the fluid. I hate sealed tranny's.

I wanted to get a look at the fluid before I pull the trigger on a bunch of parts. I don't know how much of a diagnosis I can make just by looking at fluid. Today, I removed the drain plug and had a look at the fluid. I was expecting the fluid to be very dark and maybe even burnt. That wasn't the case at all. It smelled a little bit unpleasant, but it was still oily and very clean. It was a little darker than new Mercon V from the bottle, but not significantly. It didn't look dirty and I didn't see any visible metallic particles. I don't know if particles from failing clutches or dears would make it past the filter. I've never messed with an automatic before. I'm pretty sure I have the mechanical aptitude for it, but it is still new for me. I replaced the fluid that drained out and reinstalled the drain plug.

If there are no mechanical parts failing, I am in the mood to buy that AJ1E servo kit and a solenoid pack.

Is there any way I can determine at home if the pressure is being properly maintained or regulated by the pump? From what I've read, that pump malfunctioning can cause the kind of issue I'm having, and even if the rest of the tranny is OK, you still have to tear it down to replace that pump.

If there are no mechanical parts failing, I am in the mood to buy that AJ1E servo kit and a solenoid pack.

If you do decide to go the AJ1E Servo route, drop me a PM. I bought it a couple of weeks ago and ended up having the transmission completely rebuilt. I have the servos, clips, and lubricant that I can sell you at a good deal.

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