5R55S Transmission woes

[abuzar1]

I have an 06 Explorer with 120k miles. It started to shift weird where it would rev up really high and then shift. It has transmission codes for solenoid pressure on multiple solenoids. So I ordered a used solenoid pack and replaced it along with new fluid. However I made a mistake, I used Supertech ATF (Not Mercon V) by accident and I still was getting solenoid codes.

Now the car would not go into gear at all unless I revved it really high. Also the solenoid codes were still there but it didn't say solenoid pressure this time. It just said solenoid defective. I figured solenoid might be defective so I sent it back and got another unit. I also did 3 drain and fills with Valvoline MaxLife ATF which is compatible with Mercon LV.

Now I have no more check engine lights or transmission codes. HOWEVER the transmission wont go into gear unless I give it a little bit of gas, like it's low on pressure. I would say its low on fluid however I used the ford method of unbolting the center screw when the transmission was warmed up to correct the level.

In fact I took it for a drive it would require only a little bit of gas to get going, but then when I brought it home I undid the center screw in the drain plug about 2.5 quarts of fluid came out indicating it was overfilled. Since then the transmission shifts even worse requiring a lot of revs to get going. There are no error codes.


Do you guys think this is due to the Supertech or Maxlife atf? Or maybe a failing transmission fluid pump?

 

[gdgiordano]

Personally I would have someone just flush it all and refill with the perscribed mercon V. A lot of people on here hate flushing out of fear it could damage something. Up to you but I would just have someone do it.

 

[abuzar1]

So I got the transmission flushed and it's exactly the same. It revs really high in first before shifting and it will not go into overdrive. The code is for P0775. So far I have done these things to try and fix it. Got the fluid flushed, changed the filter, changed the solenoid pack, adjusted the overdrive band, as well as got the replacement servos with the orings. None of that fixed it. Can I fix this transmission or should I just buy a used one for 800 bucks and replace it.

Will a transmission from a 2006 Mercury Mountaineer 4x4 V8 fit my 4.0 2WD explorer?

 

[abuzar1]

I have a 2006 Explorer 4.0 RWD. It revs really high in first before shifting and it will not go into overdrive. The code is for P0775. So far I have done these things to try and fix it.

1. Got the fluid changed plus the filter
2. Changed the solenoid pack
3. Replaced the servo pistons with the aftermarket ones with the rubber orings. Also adjusted the overdrive band. I had this done by a local mechanic working out of his house because I didnt have time to do it myself.

Is there anyway to mess up the replacement of the servos? I asked the mechanic and he said he adjusted the bands and they didn't seem broken when he adjusted them. Can anything be done to save the trans or should I give up and replace it with a used unit?

 

[gdgiordano]

So I got the transmission flushed and it's exactly the same. It revs really high in first before shifting and it will not go into overdrive. The code is for P0775. So far I have done these things to try and fix it. Got the fluid flushed, changed the filter, changed the solenoid pack, adjusted the overdrive band, as well as got the replacement servos with the orings. None of that fixed it. Can I fix this transmission or should I just buy a used one for 800 bucks and replace it.

Will a transmission from a 2006 Mercury Mountaineer 4x4 V8 fit my 4.0 2WD explorer?

Hm I am at loss, however the tranny from the v8 will not work with your 4L sohc. It’s a different type.

 

[BrooklynBay]

Both of your threads were merged together. How do you know if the used solenoid block is any better than your old one? Did you check the internal wiring harness or the bulkhead connector for damage?

 

[08EddieCA]

I have an 08 V6 EX with 140K on the odo now. I had my trans 5R55s rebuilt about a year ago. I had similar issues. I also tried a pan drop and fluid/filter change. I didn't flush it out. Nothing worked. I do agree with BrooklanBay that it's a good idea to check the wiring harness. If your EX is subject to heat/cold cycles of the seasons, I can imagine that your connectors could be brittle. Before the rebuild I did repair some wiring that had exposed wire due to cracks in the insulation. The main problem with my transmission was the servo bores primarily (wouldn't go into reverse without a serious hesitation and very loud bang sound), worn clutch packs, solenoid pack, a broken spider gear, a new sun gear (?) and a related sprag(?). (I know little about transmission internals). Stuck with Mercon V. I've been lucky with my rebuild. I had my core rebuilt. The job took a bit longer since they didn't simply swap one from the shelf but it worked out in the end. Good luck.

EDIT: If you buy a used trans, I would see if it's possible to have the servo bores addressed before you install the used trans. I'm not sure what is involved with that procedure. My $0.02.

 

[Explorer_PL]

Not sure why you used Mercon LV at some point.
Sounds like the servo bores are not holding pressure, but electronics might be at fault as well.
I would not buy a used tranny, you just don't know anything about it. It can be worse that yours.
I bought a rebuilt unit from Street Smart transmissions for $1800 incl shipping. Almost 2 years and no issues.

 

[08EddieCA]

Not sure why you used Mercon LV at some point.
Sounds like the servo bores are not holding pressure, but electronics might be at fault as well.
I would not buy a used tranny, you just don't know anything about it. It can be worse that yours.
I bought a rebuilt unit from Street Smart transmissions for $1800 incl shipping. Almost 2 years and no issues.

I agree...

EDIT: I paid roughly the same amount for my rebuild.

 

[Blackexplorer06]

Your trans did well. rebuild time. They are weak and can fail before 100,000 miles.

 

[gdgiordano]

I really do wonder if someone would come out with a kit or alternative to these tranny’s. They really are terrible. I think people would pay for something more robust.

 

[08EddieCA]

I completely agree. I don't know what hard parts typically fail with exception of the servo bores. Some rebuild kit's claim to be upgrades. My opinion is the maintenance schedule set by Ford was part the demise of these tranny's. If maintenance was set at 60K I can only imagine there would be less issues however I can't account for the servo bore issue.

 

[Blackexplorer06]

Even with regular fluid changes the servo bores will wear. My trans came out for the first time at around 90,000 miles. Then again at 120,000 miles. The second time I opted for a full rebuild. Trans case completely empty and cleaned. All new parts with the sonnax kit.
Shifts better than new. $3000.

 

[gdgiordano]

Even with regular fluid changes the servo bores will wear. My trans came out for the first time at around 90,000 miles. Then again at 120,000 miles. The second time I opted for a full rebuild. Trans case completely empty and cleaned. All new parts with the sonnax kit.
Shifts better than new. $3000.

How many miles on your rebuild?

 

[Blackexplorer06]

So far 23,000 miles. The sonnax kit firms the shifts up a little.

 

[abuzar1]

The seller was a transmission shop that claims to test each solenoid block before they send them out. The first solenoid block didn’t work so I thought maybe it’s an issue with the used solenoid block then they sent me a second one. I just figured the chances of two different solenoid blocks both claimed to be tested not working would mean the issue is elsewhere.

I used the LV fluid because according to Castrols website it was compatible and I thought hey full synthetic sounds good. I didn’t find out till later it was not.

I mean at 1800 bucks for a rebuilt transmission plus the labor to get it changed makes me feel like I should just part it out. Sigh. It’s such a nice clean SUV hate to go down that path

 

[abuzar1]

I’ll check the wiring though, I’ll do a search if someone’s done it before and follow their instructions.

 

[Mitchs07explorer]

I'm at 115k mi right now, I had my tranny rebuilt at 80k mi due to work servo bores and random shift flares between 2nd and 3rd gear. I had been in 3 different transmission shops before it was rebuilt but what drove me most insane is when these places were looking at my transmission no one could find anything wrong. I finally pulled the trigger after fears of being stranded in the mountains kept popping into my head. I had an assumably trusted tranny shop do the work, the owner called me before starting to reassemble to let me know he could find nothing wrong upon visual inspection. Not what I wanted to hear but oh well I'm already committed to the rebuild.

After rebuild it ran like a Swiss clock, clearly the servo bores were worn because my shuddering shifts were gone and no consistent 2nd to 3rd shift flare. Then I got to about 90k mi and 2nd to 3rd shift flare turned up I took it back to them and they tightened my bands. Another week went by and it did the same damn thing so they changed out solenoids and fluid and things were great again. But after another 5k mi that same damn flare would show up but only intermittently and you can never predict when it will happen. The flare seems to be more common in the summer than in the winter for whatever reason. Now I've finally given up on trying to chase it after a $2700 rebuild and multiple trips in over 3 years worth of warranty I'm sure they were glad to see me go lol. Anyway I finally gave up on trying to make it 100% perfect. Recently I came across a thread here posted in 2006 that has some helpful info in regards the 5r55 trannys. I'm going to get a drain, filter and fill done probably every year for as long as I own the vehicle. That might keep the shift flare at bay. Here's the 12 year old thread if anyone is interested, it applies to the older 5r55's but is still applicable and has good info.
The 5R55E and the infamous 2-3 shift flare issue

 

[100%forddriveway]

I knew about Explorer tranny issues prior to buying our 2010 4.6 a few years ago at 80k miles. it is now 130k w no probs. I used research at carcomplaints.com to help w my decision to buy. Data clearly shows that in 2009 Ford had a design change that eliminated the issue. Find out what that change was and I suspect you will find how to fix the root cause of problem.

 

[94Eddie]

I knew about Explorer tranny issues prior to buying our 2010 4.6 a few years ago at 80k miles. it is now 130k w no probs. I used research at carcomplaints.com to help w my decision to buy. Data clearly shows that in 2009 Ford had a design change that eliminated the issue. Find out what that change was and I suspect you will find how to fix the root cause of problem

Buying the 2010 V8 model got you into the 6R80 transmission and not the 5R55. The 6R80 is just a better, more reliable, transmission all around. For me moving from a 3rd gen to a 4th gen, getting a 2010 V8 model was a requirement. Oh, and that it wasn't a vehicle that spent time in the Rust Belt.