2019 SE (automatic) - transmission - Return of the Shuddering

About a year ago I started experiencing a worrisome issue with my Fiesta's transmission system: as I was accelerating at low speeds, in the moments my Fiesta was shifting gears (I believe between the 1st and 2nd), the car would often shake and shudder and make a rattling sound. It was especially bad after driving in a high gear first, say on the highway, then coming back down to a slow speed. In the moment of speeding back up, the shuddering would be awful and was getting worse and worse over several weeks...

I took it to a transmission specialist who said, yes, the transmission system and clutch were fairly busted/worn out. I got them replaced at a cost of over $2000.

Now, less than a year later, the exact same issue has returned. Clearly, there is some other underlying issue.

I've started reading about much discussion and issues, even lawsuits and news stories, surrounding Ford's DPS6 system and the TCM controlling it. Ford had a Customer Service Program for the TCMs on some earlier models, and was even reimbursing people for earlier transmission repairs, because it was so common. Shuddering and trouble shifting gears has been cited as a common symptom of the issue.
https://www.fordtransmissionproblems.com/fords-transmission-problem
https://www.freep.com/story/money/c...-focus-transmission-lawsuit-dps-6/2506025001/
https://fordauthority.com/2023/07/ford-focus-fiesta-owners-get-new-one-time-tcm-replacement/

I'm just worried, because consulting with Ford Customer Service and my local dealership, searching by VIN, shows no open recalls or CSPs for my 2019 vehicle. I called to see if there is an adjusted warranty, but there is not... These links above seem mostly to do with earlier models.

Has anyone else experienced this issue or have an educated guess of what's going on? Does shuddering indicate that the parts themselves will need to be replaced again?

I'm thinking my next step is to take it to the dealership and zero in on a possible TCM issue, diagnose and see if there's maybe a CSP that isn't coming up in the search online (the warranty person said there might be, the car would need to be at the officially looked at first). If there isn't a CSP, and TCM repair ends up being too costly, perhaps I try a service like this: https://www.upfix.com/product-category/repair-return/tcm-repair/?make=FORD

Or, could it be something else entirely?

I really can't afford another big repair is all (and really I don't think I should have paid for the first big repair either, if in the end it was something more fundamental like the TCM and not a standard transmission failure). Seems unfair to be constantly paying to repair or replace the transmission and clutch if the car just chews them up...

Love my Fiesta otherwise!

This may be a Zombie thread, but due to my experiences with Both DSP6 and the Ford 5-speed Manual - I can attest to both designs having flaws dealing with how the clutches of one, tend to fail and the syncros of the other - tends to follow suit and also fail in epic ways.

The DSP6 being a novel (per Ford's Entry into this) design is also prone to self destruct in having the need to be replaced due to the wear and tear of the clutches that serve to move the forks of the odd and even gearing's and the inability of their synchronizers to hold the gears to the shafts ...

You'll notice there is something like a watch factory going on inside the transmission too. The actuators use the watch-type of gearing to reduce the stepper motion into a more pressure applying force to move the gears - so the zzzz-it, zzzz-ip and zzzz-at the actuators do - apply and moves the transmission gears in increments by using those multiplier gears - not as smooth as manual clutch to plate as per a humans senses to feel the tug and grab and move the foot to affect the pressure on that clutch place. But having lacking that touch - the TCM works using the ECM's control inputs thru the speed sensors as well as engine RPM and several other tricks of; fuel to air ratios, the Cam advancement as load feedback as part of it's tool box because of the level of pressure-by the application of the multiplier gearing to reduce the steps into a gradual slope of pressure - they do most of the job without causing excessive wear - in most environments.

There is also a Limited Slip Differential that offers a level of complexity and a means to a working out solution to a problem of gear mesh and slipping that having the LSD (Limited Slip Differential) become a necessity in order for this type of system to work. The LSD can apply a type of slip to reduce the overall racing and overshoot the gears would otherwise do without the use of a synchronizer - the teeth of the gears and their pressure applied to the SPLINES of the shafts they are on - being they rotate at less speed (torque notwithstanding but speed in distance traveled) than the whirling of outer gear teeth - the slipping on engagement and and disengagement off the shafts - the gears of the shaft can apply and engage because one side is always moving as you drive - letting the other gears on the opposite shaft then let the TCM rev the motor up and down quickly enough to make the meshing window easier for engaging the gears. Yes, the LSD can help in providing that window.

So what do you do when the transmission grabs? It's a sign of type of an overhaul is needed - the contaminates in the media in the transmission is wearing out the parts to a point that the ability of the TCM to adapt to the changes is too excessive - it's out of tolerance. You'll see why as you deal with how others you work with treat their vehicles versus the ones they use for work - there is a dichotomy present in everyday life.

The above photo is from a YT user thinking they had worn a differential bearing - however due to the overall wear of the transmission. Following the owners manual - the lack of fluid changes that let the transmission wear evenly; comes at a cost. Being? Of now the lack of changes for the fluid then lets those suspended particles wear down all components involved which will add a level of slop that now goes beyond tolerance and so you have the "grabbing" issue. This is not just about the moving parts but in the video - it is also shown as a part of the transmission housing CASTING that can limit the service life and require a replacement - so by driving habits as well as the level of torque applied, can drastically shorten the service life of the transmission. Be sure to look for the Magnet the transmission (any of them) comes with. The level of particle suspension in the fluid being ferrous metals - can be attracted to the magnet and stay, but its also the non-ferrous metals and materials used (brass as well as other media like; coatings and aluminum of the casing itself) that add to the contaminate suspended in the fluid - increasing wear.

You can review the troubleshooting this user did by viewing it here.

• Be sure to watch the related search videos too - they can provide more insight to how the mess is created and the steps needed to fix them. It - may make you reconsider how hard you drive and what you do to purchase a new vehicle and the trade offs in choices that you have to make.

Why do I mention LSD?

• - it's not because it's a lifesaver or any means to add years of life you can enjoy your car with while you're jammin' to your tunes and the engines under WOT while you buzz thru "Orange" lights on your way to work.

Far from it, it's to remember that it and the media, and the suspension of all those metal shavings are mixed into the mess. So the understanding of how such a Differential can save a transmission is not what is being discussed here. However but by observation, why some vehicles do better and have a longer service life than others - simply due to the variables present - one mostly being the driver and the way its' driven, with the secondary effects being the precision and quality of the components used along with the combination of those components used can extend the life of the cart (before the Horse) well beyond the typical service life.