My nearly new (3600 miles) 2020 S560 is at the dealer having the transmission and torque converter replaced. Upshifting, it worked perfectly. Downshifting, especially from 3 to 2, it felt like someone (other than the driver) jammed on the brakes. I am convinced that many folks would have lived with it. However, this is my third W222, and this new car has not performed nearly as well as the 2015 S550 & 2018 S560, with respect to transmission downshifts. So, I complained, the dealer did all sorts of software updates and adjustments, but finally asked MB for a decision and the dealer was “instructed” to replace the transmission and the torque converter. I’ll let you know how the surgery goes.

Yikes, sorry to hear. It's tough to have major surgery on a new car!

Wow, did they give you loaner? How long do they say it's gonna take? My 2018 S560 is a little jumpy on the downshifts mainly the 2 to 3 and the 4 to 3 but I just live with it, like you said upshifts are fine. I never complained about it I figured they would just tell me it's normal like everything else.

Funny, I have had 2 times when I was coasting in my 2016 S550e and the downshift was so so hard that I thought someone behind me had rear ended me. It hasn't happened in a while, but next visit I am going to voice this concern as I still have warranty left. Anybody else ever had this happen?

I have a feeling that a new trans and TC are not going to fix the issue. This seems to be a long running software problem with the W222 chassis that most dealers don't know how to properly address.

My car had a new torque converter installed by the previous owner at 25k miles to try to resolve the same issue. The dealership told me that the owner returned a couple more times and that the software updates that they were trying were not resolving the issue, so he just left it the way it was. I still notice the rougher downshifts all the time. When I have some extra time on my hands, I'm going to take my car to the dealership along with a copy of the 1st post from this thread and make sure that they get it resolved properly.

https://mbworld.org/forums/s-class-w...ting-w222.html

BTW, after you get the new trans and if it feels better initially, just give it some time to see if the same issue comes back as it may also have something to do with the adaptive logic. But if I were you, I'd be taking the much less drastic approach first before swapping in a new trans and TC.

I am afraid to say that I also think that a new transmission is not going to resolve the issue. It sounds to be (I went through this battle with MB for over a year), and it sounds to be a combination of DESIGN and SOFTWARE issue. So, even the new transmission is going to have these inherent issues in it. The only way to fix it is if you end up with an experienced mechanic at your local MB dealer who knows how it fix it.

As you know, I have started a long thread and was the OP on the thread referenced below. I changed 3 dealers until I finally found one of the mechanics at a MB dealer who knows exactly how to fix it. It's all in my post below. Also make sure you politely pass the service advisor and directly talk with the mechanic and see if he even knows about this issue!. Interview him!, yes!... that's what I did 3 times until i finally met one who clearly assured me that he knows exactly how to fix it. It is a combination of following a recall issued by Mercedes as well as some experience that whoever is doing the work on your car needs to have when the manual shifting adaptation is happening. It needs TWO mechanics, fully aware of the issue, one driving the car, and another actively while driving for over an hour trying to find the best and most accurate shifting adaptation ratios/values and enter it into your car. I heard that each car will have it's own values (kind of depends on the actual wear and age of the transmission). Apparently, a fresh new transmission doesn't ever come with perfect values either which his why we have seen people with this issue even during the first few thousands of miles. See my thread below on how i finally fixed this issue. If your transmission has not been replaced yet, I would strongly suggest you ask them to stop immediately and don't let them do the work and mess with the car, and instead find a dealer who knows how to repeat the work in the thread below. Note: this is not a new software installation only... it also includes manual shift adaptation while car is being driven and values are to be found while driving the car in specific conditions... Also, my mechanic did enter different values for cold, warm and hot transmission temperatures... it is more like coding but using a software they already have..... I know 3 others who tried to follow the steps in that thread and it worked, but many others were not lucky to convince their dealer that this is the way to go.

https://mbworld.org/forums/s-class-w...ting-w222.html

They gave me a brand new (30 miles) GLE350. They said “a few days.”

I am skeptical myself, but I am going through the steps MB is laying out. If they want to replace the transmission and torque converter, who am I to argue? If it doesn’t get fixed 100%, I going to go lemon law on them and order a 2022 W223. What amazes me, is HOW something like this can happen. The 9G-Tronic has a great track record. It was flawless in my 2018 S560, so WHAT changed?

What year is your car?

I agree with you... I would say that it could be something that nearly 50% if all S-classes are experiencing (must be a design issue!!!!). Out of those 50% cars on the road today, I would say that probably 5% of those people are able to catch the issue and at same time be willing to go to the dealer.... most people think that it is normal!. My mechanic mentioned to me that at least over 50% of the S-class cars that he tested for other issues were found to also have this issue while he was doing a test drive.... but only few people have complained about it.... It is really a serious design issue (someone needs to be fired )

I had the software update done on my 2016 S550 coupe and it made a significant improvement in the D5 to D4 downshifts. I only can feel a minor rough downshift occasionally when the car is cold, otherwise OK. Good luck!

Hate to hear that on such a new vehicle. I thought the rough downshift only affected 2014 to 2017.

My 2015 had very rough downshifts mainly from 5 to 4 which i complained about every time i took the car in. The software update posted in the other thread helped but did not entirely eliminate the issue. I just live with it now.

Keep in mind that I have mentioned couple of times that it is not just the software update. Software update will help for the first few days but then the same problem will come back even if at lower rate. What they need to do is exactly written in the thread (software update + manual shift adaptation while car is being driven). See the thread for the details. They also need to do the adaptation at multiple temps (cold engine, warm engine, hot engine). Software update only is not going to fix it at all (i tried that too in the beginning and it did not work). Unfortunately not all dealers have a mechanic who knows how to do it manually.

Does having this done do away with the adaptations where the car learns your driving style? I think that would be a huge bonus if it did.

No, that is the point of manual adaptation. I am not a mechanic, but my understanding from him is the the new software will only impact those values that the car will re-write and learn anyway after sometime which is why it is useless..... The manual adaptation they did is different from those values assigned by the system that learns your driving style. I think it is more related to the gears ratios.

Again, this is the 9G-Tronic transmission which has been around for years now. It is used in most every passenger vehicle MB produces. I had it in my 2918 S560 and it was perfect. I currently have it in my 2019 SL450 and 2019 E450 Wagon and it is perfect. WHY, all of a sudden, does MB forget how to produce a transmission that works properly—AND, in one of their premier models? Is it better in the new W223, or will the issues persist in that S Class as well? This is just NUTS!

I am glad I read this thread, I thought that I was crazy when this happened a few times, seriously was like I was rear ended, if I hadn't been on a freeway offramp with nobody behind me i would have jumped out and tried to stop someone behind me.

I am making appointment next week

It would appear that you are right.

Was informed that my car was ready, that the transmission and torque converter were both replaced, (as noted on the invoice) but the SA actually apologized, saying that the issue was STILL present. I picked the car up and it’s as if nothing had been done to it. If anything, I’d say the problem is worse! I was told that MB says it is a “software issue,” that they are “working on an update,” and would have one soon. Of course, I consider this BS, as HOW long has this been going on?

I phoned MBUSA yesterday and opened a case. I’m supposed to receive a call back within 24 hours. As someone who has bought or leased SIXTEEN, brand new, higher end MB’s, I plan on really coming down on them. This is just INSANE! How they could let these cars out of the factory, KNOWING of this issue, is just incredible. To be continued.................

@Streamliner
Oh man... i tell you, I really had 99% confidence that this would happen.... that's the reason I suggested you call them and ask them to not mess with the car... they worked on the car and re-assembled everything together, and at that point, I would rather have the original factory assembly structure because I know that replacing the transmission won't help at all (it is a DESIGN + SOFTWARE) issue.
The fact they told you (MB says it is a “software issue,” that they are “working on an update,” and would have one soon) means that whoever is doing service there, has no idea how to fix this issue!.. I told u i had to ask they take it to 3 other dealership locations until i found a mechanic who knows how to fix it.... THERE IS A SOLUTION ... i guarantee you, there is already a solution, but it only needs someone knowledgeable enough to do the service.... I will try to find the name of the mechanic who did the service on my car, but he works at MB in the east coast. remember, it is NOT a software issue, it is a design+software issue, and for that, there would need to be lots of manual adjustments for the gear ratios while car is being driven... almost like re-doing the engineering work from scratch and overwrite the car original values... in my case, my car drives like buttery smooth since service was done (1 year now, prefect shifting on all gears at all temperatures including cold start).

To be honest, if enough people would support (and are aware of this issue) you could easily sue MB for such an issue. (it is in ALL models from 2014-2021).... also, knowing that the W223 has same transmission design, I guarantee you it would do the same!.

Based on a previous post(s) it would appear that you have the seven speed transmission. Just wondering how applicable your experience is to the newer 9 speeds.

I agree, but even the dealer is getting lots of complaints about the same exact issue for the newer 9 speeds transmissions. Keep in mind that the way car companies do product development, is to build further on the previous design, so if there is an inherent issue that they have not been able to address, it will appear again unless they find a solution for it.

It sounds like it was a pretty full redesign not just a delta of a couple of gears. https://www.greencarcongress.com/201...-9gtronic.html. What could be in common is the control methodology which could be subject to similar variations as the seven speed.

" In this direct control system, the hydraulic gearshifting element is directly linked to the electromagnetic valve. The hydraulic control slides now only have one third of their original diameter. This means that control of the six shift elements (three multi-disc clutches and three multi-disc brakes) can be much faster and more efficient."

The downside to this change could be less force margin on the control valves making them more sensitive to friction.

It is threads like this one that make me take the position that if a car is working well, drive it into the ground, warranty or not.

BTW the 7-speed in my 2015 S600 is working just fine.........

This thread started by Streamliner is both shocking and sad. I am not sure what year MB released the 9G-Tronic system with the hydrodynamic torque converter, but there is clearly a combination of basic design issues plus software issues. The V-8 AMG's use a 9 speed with an MCT shift system that uses a wet clutch start with dry clutch shifting. The AMG transmission case is magnesium rather than aluminum. After a software updates the AMG 9 speeds work great and do not exhibit the downshift issues described above. It is amazing that MB is making MCT's that shift smoother than a hydrodynamic torque converter. An easy fix would be to get an S63 rather than an S560.

How long did your car shift smoothly? Just trying to get a sense of what changed. Clearly it is not the transmission mechanicals given that replacing the transmission and torque converter did not cure it.