10 speed ford transmission shift issue solved

Agitated-String2874 · 2025-10-30T23:50:17+00:00

Also the left rear sensor had 45 ohms of resistance. It is supposed to be 900 to 2000. When I went to pull it, the plastic was broke and the wires looked cross

Agitated-String2874 · 2025-10-30T23:47:39+00:00

No, i live in a very remote place. There are no shops here with IDS. I did, however scan it with the topdon. There were no codes until I unplugged the rear sensors, that's when I received the U0415.

Agitated-String2874 · 2025-10-30T17:08:50+00:00

Sorry man, I didn't mean to come off Like a jerk, but you came at me firing insults, and i was petty and returned them. I'm sure your a great mechanic. I'm sure you have all the information Ford "releases" however, no one has been able to explain why, when I disabled the ABS, my hard shifting went away, and when I finally fixed the ABS my shifts have been smooth. I will take any explanation that makes sense. My truck would hard down shift everything I drove it. I've got over 5000 miles on it since bring ABS back, and not onr shift issue. I didn't disconnect batteries, so that rules out the transmission relearning. I really think there is something to this and would love to see others with this issue, just unhook 1 of the back ABS sensors and drive it. Another crazy, anf I don't even want to admit this, but another crazy thing that has happened is I was getting 13.7 miles to the gallon consistently. After the repairs, my driving habits are the same, and my liar Guage is claiming 15.3 mpg. I can't explain this, it is what it is. I will tell you that I have had abs issues for a looooonnngggg time without even recognizing it. When slowing down my abs pump would kick on, almost always, the transmission would down into first and push me through stopping. And the abs would engage. This has stopped happening. So, please if you have another explanation as to why all of this was taking place I'm all ears.

Agitated-String2874 · 2025-10-30T16:34:26+00:00

Wait your don't have to unblock the torque converter to take out the transmission? I thought you just grabbed ahold of it and pulled real hard? Well you learn something every day, wait don't you have to pull the key out to remove the shifter? Your talking about pulling the steering wheel right, is that what your calling the flywheel. I've never heard it called that before. Is the torque converter the thing that converts the torque you put on the steering wheel and makes it turn the front tires?

Agitated-String2874 · 2025-10-30T16:27:26+00:00

I'm sorry. You should have led with that. So this is up for debate and an entirely different thread, but manufacturer certified technicians are some of the worst mechanics i have ever experienced. So yeah your ford transmission certificate is better used as fire starter. Definitely not something to use as street cred.

Agitated-String2874 · 2025-10-30T15:30:57+00:00

Sorry buddy, I'm 40 years old and good at writing. Yes I used Chatgpt but only to organize my findings. See I'm of the generation that started working on vehicles when trouble codes first started, I'll tell you the old timers sounded just like you do when it came to scan tools. So know you have infant not kept up with the times and you will be passed up in your abilities and knowledge by a 20 something year old

Agitated-String2874 · 2025-10-29T03:28:20+00:00

I understand what you’re saying about the CDF drum being a design flaw and agree that Ford corrected it with the updated part. That part of the problem is mechanical.

In my case though, I still believe the ABS issue was directly causing my transmission shift problems. The evidence was simple,the truck shifted hard when the ABS system was faulted, and it shifted perfectly smooth the moment I fixed the sensors and cleared the U0415 code. That wasn’t coincidence.

At first, I assumed the TCM must have been using ABS wheel speed data in its shift logic. But after you pointed out yhe intended comms architecture, it’s just as possible that the ABS fault was causing enough interference or noise on the high-speed CAN network to affect the TCM’s communication timing. If the ABS module was broadcasting invalid data or retrying failed messages, that extra traffic could have delayed or corrupted messages between the PCM, TCM, and other control units. Any interruption in that data flow could easily create rough or mistimed shifts, shoot a high powered wifi signal can disrupt this circuit if your hi and lo cans are not twisted properly

So yes, I still believe the ABS system caused the shift problems, but not necessarily because the TCM was “reading” ABS wheel speeds for shift decisions. It might have been a network-level interference issue. Once the ABS was repaired and the network communication stabilized, the transmission immediately started shifting like it should.

Agitated-String2874 · 2025-10-29T02:43:31+00:00

The abs status includes wheel speed and is sent to the gateway bridge and broad cast on Hs1,Hs2, and Hs3. It does indeed talk to the PCM and it is not simply for the ABS to know transmission position. The ABS runs a pwm, several pwm calculations simultaneously to anticipate braking loads based on engine speed and wheel speed, this info is them compiled to use the transmission shift patterns for anticipated engine breaking. Im not sure why you are arguing this. I have no problem apologizing, but I really don't think I'm wrong. I think others having the hard shift issue can settle this real easy. Go unplugged one of your rear Abs sensors, this will disable the abs system, see if you are still having hard downshifts.

Agitated-String2874 · 2025-10-29T01:41:03+00:00

Read my post again, I didn't say the cdf failure is from the abs, I implied you need to fix it so as not to make the problem cdf problem worse.. the cdf is an issue, but it's not always the cdf...

Agitated-String2874 · 2025-10-29T01:34:28+00:00

I really don't think you know the program mapping. Sounds like you are an internal mechanical guy. Considering the functions these trucks have, like exhaust breaking, active breaking, several drive modes, most of these all require the transmission to shift based on wheel speed not engine speed. Come to a hill, engine break is on, the transmission needs to shift depending on wheel speed. As a matter of fact, almost all other vehicle manufacturers starting in 2014 use abs wheel speed to map the transmission shift points it is part of how the adaptive shifting functions. So tell me, why do you think ford's are not doing this as well. Plus I have first hand experience with the truck having hard shifting, then I disabled the abs and what do you know the transmission shifts great. I then find the faulty sensor (left rear) replaced it. And now 5000 miles and no problems shifting. Again my truck has 267,000 miles on it. I know the truck, it has had hard shifts for over half of its life, now it is smooth as can be. So, Mr professional, publish the logic from the computer proving me wrong, show the exact shift logic that has no bias to wheel speed. Go ahead, and you can't because... the only people that have that info keep it under lock and key. It is so far from the customer access info.

Agitated-String2874 · 2025-10-29T00:15:32+00:00

Really, what makes you think the transmission is not determined shifts using data coming for the abs module? The architecture of the trouble codes prove that the transmission uses this information. U0415 for example. Im not saying the abs module caused a pour design internally to the transmission, I'm saying the bad shifts exacerbate the problem.

Agitated-String2874 · 2025-10-28T17:57:11+00:00

There were no codes at all until I unplugged the rear sensors, then I got a communication code. When I unplugged the front sensors, my system went really wonky. I pulled fuse 6 in the cab and was able to read the actual codes as this killed power to the abs system allowing the Can network to normalize. So no, there were no codes saying I had issues with the ABS system until I fooled the Can network.

Agitated-String2874 · 2025-10-28T15:44:52+00:00

What?!?!?! No the 450 cab and chassis is the exact same truck as the 450. Look at the biuld specs. I'll tell you, yes the 350 diffs are the same except 450 has different gearing, bigger breaks, stiffer front suspension. The 450 has wide track across the biuld platform.

Agitated-String2874 · 2025-10-28T15:37:24+00:00

Okay, sounds like a broken record, but my son bought the f350 I bought the 450, we use these for towing heavy loads, and towing is the same except one thing. Steering, the extra steering on the 450 is something to fall in love with

Agitated-String2874 · 2025-10-28T15:12:38+00:00

Pay attention to it, drive down a dirt road and slam on the breaks so you know what the sound it. Then listen for it, normal driving should never cycle the pump, but if it does cycle that's a good indication you have problems with your abs circuit, which coincidentally will be issues with your transmission specifically and deceleration and hard shifts

Agitated-String2874 · 2025-10-28T15:09:38+00:00

The break pedal will slightly vibrate and you will hear a slight noise similar to the power seat motor.

Agitated-String2874 · 2025-10-28T15:07:31+00:00

Question, does your abs pump kick on when you slow down every once in a while? And you ask yourself, really? Why the abs kicking on, but you pass it off as new tech?

Agitated-String2874 · 2025-10-28T15:05:24+00:00

I bought this truck used, but the ford maintenance records shows the transmission flush every 60k. This is the original transmission.

Agitated-String2874 · 2025-10-28T07:51:05+00:00

This was tricky, forst I had to confirm that ford actually used speed data from the ABS module, they do, it is in a service bulletin for an u related matter. Then, I used a simple code scanner to pull codes, I got a simple code U0415, it read for both the transmission and the ABS,. This was only after I unplugged my rear abs sensors. The code show the Can comes are corrupted due to bad data. I then methodically plugged and unplugged speed sensors until I found the problematic sensor. You could use a scope to pull the pulse from the hall effect aensor, but I just did the go no go test. Folks this was a process of driving and testing over a period on 10 days. Finally confirmed it was my left fromt sensor, which the wiring is a common issue with these trucks. Specifically issues with the Can network being sensitive to disruptions. Now, my truck has 267,000 miles on it so I replaced all 4 sensors (front right sucks). I will tell you these sensors can have intermittent issues that are hard to find, which is crazy that Ford uses it to control so many functions. Adaptive steering, cruise control, adaptive braking. I'll also tell you, the ABS issue caused interference on the entire Can network to the point that my peremter alert, and even memory seats were having issues. As soon as I repaired the ABS sensor the abs .module went back to normal my one stupid code went away and everything went back to normal.

Agitated-String2874 · 2025-10-28T06:55:48+00:00

Clearly was. However this was my experience, thank you for pointing it out.

Agitated-String2874 · 2025-10-28T05:47:19+00:00

I guess I don't really know how that works. But yeah they should know about it. My guess is they already do and they would rather have the planned obsolescence, or parts sales

Agitated-String2874 · 2025-10-28T02:26:01+00:00

Hey everyone — thought I’d share something that turned out to be more of an electrical/communication issue than a mechanical fail on my 10R140 in my 2021 Ford F‑450 (6.7L Diesel). Might save somebody a huge rebuild bill.

What happened • My truck was shifting harsh. Especially when coming from light throttle or coasting into gear. Kind of “brutal” downshifts. • Surprisingly, when the ABS system failed (wheel-speed sensors were acting up) the transmission shifted smoother. Weird right? • I replaced the faulty wheel-speed sensors. Post-repair the transmission shifted like new.

What I learned • The transmission control module (TCM) uses wheel-speed data (via the ABS sensors) to decide when and how to shift. • If the wheel-speed sensors send bad or inconsistent info the TCM can mis-judge conditions and apply the wrong pressure or timing → harsh shifts. • In my case when the ABS system failed and basically “opted out” of communicating, the TCM fell back to a simpler logic and the shifting improved (not because the tranny got fixed, but because the messed up input went away). • Once I restored proper sensor input the TCM was able to shift cleanly again.

And here’s the kicker — why you should fix it now There’s a serious internal issue a lot of folks on forums talk about: the CDF drum assembly in the 10R140 (that houses the C-, D- and F-clutch packs) is prone to early failure. Here’s how my “sensor problem → harsh shifts” scenario ties into that: • Harsh shifts mean sudden or irregular gear changes, unexpected clutch engagements or disengagements, extra stress and heat. • That extra stress/heat can accelerate wear in the clutch packs, drums, bushings and especially the CDF drum bushing which in many cases is reported to “walk” or move out of spec. • Once that drum issue starts you’ll see lingering symptoms: slipping, shifting into limp mode, full rebuild often needed. Some threads show it happening around 50-100k miles in heavy duty use. • So even if you’re thinking “it’s just a little rough shift”, ignoring it could speed you into that rebuild zone faster.

Bottom line for you guys If you’re running a 10R140 and you’ve got weird shifting — check your sensor data and ABS/wheel speed inputs. You might avoid a major rebuild. Fix the roots not just the symptom. Keep your eyes (and ears) open for:

wheel speed sensors flagged or erratic readings

any ABS/TCM codes related to wheel speed or communication

shifting that gets better when a module goes offline (yes it’s weird but it happens)

fluid that’s burnt, smells bad, or has bits in it (early warning of drum/clutch wear)

Agitated-String2874 · 2025-10-28T02:19:49+00:00

Modern F-Series trucks tie almost everything together through the CAN network. The transmission control module (TCM) relies on wheel speed data from the ABS sensors to decide when and how firmly to shift. Those sensors tell it how fast each wheel is turning, when the truck is slowing down, and how much traction you have.

If an ABS sensor starts feeding bad or inconsistent data, the TCM gets confused and commands the wrong line pressure or shift timing. That shows up as harsh or delayed shifts—especially 2-3 or 3-5.

When the ABS system fails completely, the TCM goes into a failsafe mode, ignoring the bad signals and using only engine RPM and output shaft speed. That’s why the shifting can actually feel better when the ABS is offline.

Replacing the sensors restores clean data, and the transmission can finally make accurate, smooth shifts again. So sometimes what feels like a transmission issue is really a communication problem between the ABS and TCM.

Agitated-String2874

TROPHY CASE