Transmission shudder

[22Platinum]

Use Sport or Tow Haul mode, but just drive normally ... in my opinion one that far more accurately represents when someone would shift if the vehicle was a standard transmission

I agree with this assertion, however..

...pretend your truck had 3 pedals. Would you seriously have already shifted to overdrive at 40mph?

Yes I absolutely would, and I'm elated to see when Ford does it too! Its even a mild game for me to see how low I can convince the truck to hold 10th.. 47-48mph is certainly achievable. Fuel mileage is through the roof at that moment if you can just stay easy on the pedal. Makes for a nice Sunday drive.

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[Snakebitten]

OK, I will absolutely admit that I use 93 exclusively, AND I will sacrifice fuel mileage over lots of things.

I dread low RPM near-lugging(?) of the drivetrain. I want happy truck.
Happy truck, happy owner.

 

[flynavy]

Time to spark this thread again. My 21 had a shudder for a long time, so I dumped some shudder fix in it, and it instantly went away. It eventually came back, so I did my own pan drop and changed fluid/filter, again it went away. It came back relatively quick, within 1000 miles so I knew its no longer a fluid issue but a torque converter issue.

At 59,930 ish miles I brought it in under warranty. The torque converter was found to be blue from overheating and replaced, along with a few clutch plates that were slipping. Seemed to drive well and I was happy.

I'm now 300 miles deep from that repair and the shudder is back, just as bad as before! I'm at my wits end, now over 60k, really don't want to dump the truck and is the first time I've ever committed to keeping a truck this long.

Any ideas?

 

[Bluegrass]

Transmission learning:
The TCM program is equipped to adjust to Trans Wear and changes over time.
(Not) to how any driver modulates the Gas pedal and stores that as information.
.
Vibration:
Noted often in 8, 9 & 10 gears under light Throttle loading.
Trans Valve Body valves used for those Gears can Oscillate in their bores and vary the fluid pressure to the Clutch packs and output drive.
As a result, you feel vibration as a >Resonance condition< that comes and goes with speed ranges and throttle loading.
.
There can always be other sources of vibration but carefully see what and when it begins and stops.
Next Gen knows about this. Ask them.
Good luck.

 

[flynavy]

Transmission learning:
The TCM program is equipped to adjust to Trans Wear and changes over time.
(Not) to how any driver modulates the Gas pedal and stores that as information.
.
Vibration:
Noted often in 8, 9 & 10 gears under light Throttle loading.
Trans Valve Body valves used for those Gears can Oscillate in their bores and vary the fluid pressure to the Clutch packs and output drive.
As a result, you feel vibration as a >Resonance condition< that comes and goes with speed ranges and throttle loading.
.
There can always be other sources of vibration but carefully see what and when it begins and stops.
Next Gen knows about this. Ask them.
Good luck.

Helpful, thanks! Any chance you can clarify why I might have this shudder and oscillation still after a brand new TC install? Just trying to be informed before I head back to the dealer. I did some light tests on the highway today and it’s just as bad if not worse shudder wise.

 

[Davidwnuc]

Helpful, thanks! Any chance you can clarify why I might have this shudder and oscillation still after a brand new TC install? Just trying to be informed before I head back to the dealer. I did some light tests on the highway today and it’s just as bad if not worse shudder wise.

Because the torque converter change doesnt fix the valve body issue described in his post.

link to next gen diesel. Good description /explanation in the valve body section

https://nextgendiesel.com/collections/10r80-transmissions-transmission-parts

 

[Bluegrass]

Helpful, thanks! Any chance you can clarify why I might have this shudder and oscillation still after a brand new TC install? Just trying to be informed before I head back to the dealer. I did some light tests on the highway today and it’s just as bad if not worse shudder wise.

.
I already described it under the VIBRATION HEADING.
Read it again.
Good luck.

 

[flynavy]

.
I already described it under the VIBRATION HEADING.
Read it again.
Good luck.

I have read it, I’m trying to understand how that information relates to the torque converter. I’ll look elsewhere!

 

[Bluegrass]

It doesn't.
They are two different independent actions.
The vibration is described for Valve Body action reflected in the output side toward the drive line, NOT up front at the Converter.
Good luck.

 

[flynavy]

It doesn't.
They are two different independent actions.
The vibration is described for Valve Body action reflected in the output side toward the drive line, NOT up front at the Converter.
Good luck.

Got it. I understand this. That explains the vibrations, what about the shudder with light throttle tip in? That’s typically from a failing TC right? My next step was to check if they filled fluid to correct level. I can’t see it being related but I’ve seen a few people change plugs and cure a shudder as well.

 

[Bluegrass]

Light tIp in is when you would most feel it.
Pressure fluxuations may not be felt under heavier loading when driveline clearances are all taken up under higher load.

 

[flynavy]

Light tIp in is when you would most feel it.
Pressure fluxuations may not be felt under heavier loading when driveline clearances are all taken up under higher load.

Reading through this thread some more, a few have mentioned the shudder going away for a few hundred miles after the adaptive tables were reset. My TC was replaced, and those tables were reset, which could perhaps explain why it was "smooth" for the first 300 miles or so.

I'm going to experiment and reset the tables myself tomorrow on forscan and see if the shudder goes away. If it does, would you say that rules out a mechanical problem and now its narrowed down to the software level?

 

[flynavy]

Reset the tables, shudder immediately present. So that theory is out the window. Dealer is aware my issue is back, I'm in a weird spot since now I'm over 60,000 miles but this warranty fix was applied before that happened, so I should be covered in theory, we'll see.

I also ordered new plugs, probably needed anyways and figured it can't hurt. My biggest fear is the tranny has a issue and won't present itself until later.

 

[jafo]

I don't see this mentioned in this thread, but I had
tsb 25-2383 done back in September. I thought the issue was resolved at first, but that's not the case. Issue persist. Prior to this I had left my truck with the dealership to replace the hybrid torque convert. While i had a 2025 XLT Powerboost loaner I never experience this issue. I put over 800 miles on that loaner.

I have about 11k miles left on my 100k extended warranty and hope they can find a resolution to this.

 

[bjl95mustang]

I had an odd shutter on the highway at 80 when I would feather in the throttle. No codes for every day driving and the missfire count looked fine. I got on it hard a few times with the right conditions and I was finally able to get the coil to show a fault and flash the cel.

Replaced the #1 coil that caused the cel flash and all was good after that.

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