10R80 3-4 shift went into neutral

[TXGTPig]

This is interesting.

My first thought was that I doubt it broke an "end cap" and destroyed the short block from going into neutral and hitting the limiter. The stock tune, assuming the tuner didn't totally screw it up, hits a soft limiter (throttle) then hard limiter (spark cut) well below the point where engine damage should happen. More on this later...

The 3-4 shift is accomplished by releasing clutch E and applying clutch F. On the shift, if both are applied at the same time, it's called "tie up", and if both are released at the same time, it's called "flare". In almost every shift, there is a time period called the "Torque Transfer Phase", where both the oncoming and offgoing clutches are partially engaged. The torque phase ramping up of the oncoming clutch, F in this case, and ramping down of the offgoing clutch, E in this case, is tightly specified and controlled in the calibration. I'm not saying the tuner didn't mess this up but this part of the transmission tune is complicated, and most don't understand how it works. Furthermore, you can make some pretty drastic changes to these values and it still won't generally cause noticable flare or tie-up, plus there really isn't much incentive to tune these values. As such, most tuners don't dare mess with it for fear of messing it up. I really doubt this is a tune issue...but it never ceases to surprise me how bad some aftermarket tunes are so I wouldn't 100% rule it out.

The engine damage part got me thinking. The rev limiter can only work if engine power is what is causing the rpm to increase. In something like a manual trans, downshifting to too low of a gear can cause over-rev'ing and the rev limiter can't do anything about it. Well, it just so happens that if you release both E and F clutches on the 3-4 shift (typically a flare state), it doesn't go to neutral; it goes to 2nd. So if E releases and F is slow to engage, it goes from 3rd to 2nd gear. Based on this and the nature of the rev limiter, it sounds more like it's a slow engaging F clutch.

It's a known issue that some of these solenoids stick. I've experienced flares that occur only at mid torque levels, theorizing that at higher torques or WOT, the higher electrical current applied to the solenoid overcomes the sticky part. Or maybe its the dreaded CDF drum bushing....I don't know enough about the specific symptoms of this one to say if it's a possibility.

So I don't believe the "over rev" caused the engine failure. However I wanted to give all information for both scenarios. I only had the car for right under 2K miles when event one happened. When I took delivery of the car, I did notice some things that led me to believe it was probably run hard and put up wet from the previous owner(s). Also, when the shop got in there, they said it was a clean engine; however, there did appear to be some rod fatigue, and they do not believe it was a tune issue.

So the reason I say it went into "neutral" is because that's how it felt. I've experienced shifting into a lower gear while getting on it, and this was not the same. There was no "engine brake" applied when it happened. The car just stopped accelerating; however, it continued to rev.

I do plan to have it looked at. There is a shop near me that builds the 10R80's and has a popular following. I did pull the codes, however the only stored code is for the active shutters. I'm absolutely baffled by the whole ordeal. I'm somewhat superstitious, so needless to say, I'm not going to be giving it any kind of throttle at that particular underpass any more...lol. Also, thanks for the explanation, that's greatly appreciated.

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[Robottrainer]

I've got a strange one, and I can't find anything on it. I picked up a '21 GT A10 car with 37K miles on it. I believe I'm the third owner. It is stock, minus a CAI, h-pipe and tune. Shortly after acquiring the car, I was doing a U-turn under an overpass. As I come to the end of the U-turn, I see my opportunity to merge into traffic. However, it's going to require some throttle. I'm doing maybe 10mph. Car is in S and I'm letting the ecu/tcu do the shifting for me. I mat it to the floor, WOT. Car shifts into 2nd, shifts into 3rd, then when it "shifts" into 4th, it's like it goes into neutral. It bounces off the limiter a couple of times, and then I hear a bang, a lot of shaking, and well...cylinder one end cap let loose. This all happened within maybe 1-2 seconds. I didn't even have time to process WTF was going on. When it did this, I looked down at the dashboard, and it showed 3rd gear. Needless to say, a new short block was in the future.

So let's fast forward, new short block, break-in, now I'm at about 1,000 miles. Only mods are CAI, H-pipe, catted LTH, and tune from my local shop that did the work. I kid you not. The exact location and the same scenario as above. However, this time I only gave it 1/2 throttle. Goes to "shift" into 4th and it's neutral. This time, however, since it's shifting at 5,500ish, I have time to process and let off the throttle before it bounces off the limiter. RPM' come down, I apply enough throttle to maintain the current speed, and all is fine. Again, when it happened, I looked at the dashboard, and it was showing 3rd.

Previously I had an '18 GT MT82, so I'm new to the A10, but not the S550. When I first got the car, I thought..."hmmm, this shifts strangely." However, after researching, I found it was normal and nothing to be alarmed about. I did read that a lot of the A10 transmissions came underfilled, and thought that might be some of the quirkiness. I checked the level, and it seemed low, so I bought the Motorcraft ULV and a filter to do a drain and fill. However, event one happened, and I didn't get to do it. I did have them change it when they replaced the short block, and the quirkiness has gone away. I'm not sure if it's the new fluid and filter, or the fact that the car sat without a battery for almost 2 months.

With all this, I've run it through the gears under WOT with no issues at all before the first event and the second event. I'm racking my brain as to what this could be. I don't believe it's the tune, as the first event was with one tuner (who is highly recommended and liked around here) and the second happened with the tune from my local shop. I've used this shop in the past and have plenty of faith in them. Any thoughts and suggestions would be greatly appreciated. I hope this all makes sense.

I have a 2021. I had an issue with the 3 to 4 and 4 to 5 shift flairing. Only in sport, sport plus, and track. That told me it's shift strategy. I had it reflashed several times. Ford either isnt interested in fixing it or they dont give a crap.

I had to take matters in my hands and reprogram the trans. Now it shifts great! It doesn't hold a higher gear when coasting down and lugging. It down shifts in steps on coast down so it's in the right gear to accelerate.

 

[TXGTPig]

I had to take matters in my hands and reprogram the trans. Now it shifts great! It doesn't hold a higher gear when coasting down and lugging. It down shifts in steps on coast down so it's in the right gear to accelerate.

Where can I find the re-program procedure?

 

[Robottrainer]

Where can I find the re-program procedure?

It's not for the faint of heart. Either you would need either PCMtech or HP tuners software/hardware as well as a special USB to Obd2 port cable.

It took me months to learn from others where to address it and then it just fixed my issue. Probably not totally optimized but it's good enough for me.

Someone like wengerd, who knows the tuning intimately could be your best bet. They can tune the entire program to optimize the entire strategy.

 

[Rolls]

The tuning school released a gen 3 training guide recently and will be releasing a PCMTEC specific one towards the end of the year. Over 100 hours of video content.

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