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The transmission is killing this car for me. I mostly love the car and have put on 4000 miles. However, even in comfort the transmission will clunk so hard my passenger is thrown forward on the 1-2 or 2-1 shift, or it will fail to shift down to 1 and stay in 2 with a very slow spool up. I have also seen the hard clunk in other driving such as a 4-3 shift after a throttle relax in normal street driving. There is no excuse for this kind of performance, as other dual clutch transmissions are far better. It's going into the dealer, but multiple reviews mention hard shifting (I now know just how hard), making me wonder if it's just a bad design. Anyone else seeing this? Any advice?
The transmission is killing this car for me. I mostly love the car and have put on 4000 miles. However, even in comfort the transmission will clunk so hard my passenger is thrown forward on the 1-2 or 2-1 shift, or it will fail to shift down to 1 and stay in 2 with a very slow spool up. I have also seen the hard clunk in other driving such as a 4-3 shift after a throttle relax in normal street driving. There is no excuse for this kind of performance, as other dual clutch transmissions are far better. It's going into the dealer, but multiple reviews mention hard shifting (I now know just how hard), making me wonder if it's just a bad design. Anyone else seeing this? Any advice?
What's the date of production? Make sure you talk to the dealer about software update.
Some folks did complain about that but they never come back to update us. Mine does not exhibit any of this in any mode.
The 2-1 not happening is because you're not coming to a complete stop in my experience. This is probably to make stop and go traffic smoother but if you're anything like me you will coast to a right turn and keep going if it's clear without coming to a complete stop - it will stay in second and be super lethargic because of being in second.
I don't have a heap of complaints about the transmission after it's warmed up. Sometimes 1-2 shift feels like it grabs partially and then slips creating a jerkiness if you aren't really feathering the throttle pedal. But again this seems to go away once warmed up.
I would have to agree with @alexasa above. I'm about to hit 4500 miles on mine. This transmission isn't perfect by any means, however most of the jerkiness that I've experienced is only when the transmission is cold. Once it warms up it does a better job at smoothly transitioning gears. I do a lot of highway cruising for my commutes, so most of my driving so far has been in Comfort mode. When I drive the car in S or S+ the transmission's downshifts and upshifts are much more aggressive and "jerky" if you're coming to a standstill in traffic which is what you come to expect from those modes, because they're meant to be driven hard.
The transmission is not a dual clutch transmission just so you know. It's what they call a multi clutch transmission. It's a planetary gearbox with a single startup clutch instead of a torque converter. The next gear isn't pre-selected as it is in a dual clutch. The next gear ratio is selected like in a regular automatic transmission by applying clutches and brakes inside of the transmission. That is still smooth normally, though.
The thing is, the MCT was designed specifically for the V8s. It had never been used with the 4 cylinder before, so it looks like AMG has some issues making it adapt properly to the smaller engine. I love this transmission in my 2019 C63S coupe. It's one of the best parts of the car. Yes, it does take some throttle modulation on my part to make it drive smoothly at low speeds, but that's part of the fun, because it's engaging. Just like a manual transmission, it takes deliberate inputs and I actually drive it in manual mode at least 90% of the time.
Mine used to insist on downshifting to first gear whenever I came to a stop. That was very jerky. Eventually it adapted to my city driving and now stays in 2nd gear until I have come to a full stop. I can hold it in 2nd gear even in manual mode. The difference is with the torquey V8 it has enough oomph to get going again in 2nd gear. The 4 banger in the new C43 despite electric turbo just doesn't have the pull down low like the V8s do.
There have been several reports that the transmission in the C43 isn't quite right. One reviewer said AMG is planning a software update to fix it. Not sure where that stands.
Last edited by superswiss; 09-28-2023 at 11:37 AM.
Really appreciate all the feedback and guidance on this! My production date is 11/22, so thinking it is a bit early and hoping the dealer can update or smooth it out. Agreed that manual shifting really helps! I am aware it's not a dual clutch but appreciate the explanation of operation, and it makes a lot of sense that the trans being moved from a V8 will have some growing (shrinking?) pains adapting to a four. I do believe my unit already adapted as reported and often stays in 2nd even at full stop. The real challenge is the unpredictably. Again, thanks to all! I will report back next month after service.
Really appreciate all the feedback and guidance on this! My production date is 11/22.
My C43 has a build date of 06/23, I don't have the issues you've described here.
There is a slight surge if I manually shift from 2-1 at low speed (below 15mph). I wouldn't describe it as jerky through, rather you feel the engine RPM rising to match the vehicle speed. Its exactly the same as I've experienced in any AMG with a dual clutch gearbox, I think it's just a matter of the inertia in the gearbox/engine/drive train, nothing to do with the MCT.
At higher speeds no jerkiness going 2nd to 1st, never any from 1st to 2nd either. Is there a way to check the software version of gearbox control unit? Happy to check if my car has a different version to you as this may hold some answers.
PFL205.064 with M276.823 (Oil pump solenoid defeated)
Originally Posted by AMPERAGE
My C43 has a build date of 06/23, I don't have the issues you've described here.
There is a slight surge if I manually shift from 2-1 at low speed (below 15mph). I wouldn't describe it as jerky through, rather you feel the engine RPM rising to match the vehicle speed. Its exactly the same as I've experienced in any AMG with a dual clutch gearbox, I think it's just a matter of the inertia in the gearbox/engine/drive train, nothing to do with the MCT.
At higher speeds no jerkiness going 2nd to 1st, never any from 1st to 2nd either. Is there a way to check the software version of gearbox control unit? Happy to check if my car has a different version to you as this may hold some answers.
To check the version of the gearbox, unless your scanner (that is advanced enough or designed for MB vehicles tells you), the best way is to check through Xentry DIAG but since OP mentioned their vehicle is a relatively early production model, it might be lacking the necessary updates that mitigates this problem which your vehicle already has.
As a person prone to motion sickness, I’m really fed up with the jerkiness switching between low gears. I brought it to the service dept and above is the service log.
So they found a bulletin, updated the software and did some adaption - now the jerkiness is gone.
I hope this is helpful for anyone who has been experiencing the same.
As a person prone to motion sickness, I’m really fed up with the jerkiness switching between low gears. I brought it to the service dept and above is the service log.
So they found a bulletin, updated the software and did some adaption - now the jerkiness is gone.
I hope this is helpful for anyone who has been experiencing the same.
They say software is unavailable... lol
You had adaptation reset - which is a good thing and should help.
Thanks to alexwang for sourcing this update and to all others in helping with this issue. Please note however, the update (XENTRY Tips) is a slightly different number: L127.60-P-076554. The Tip image is below. It confirms hard 1-2 shift, jerky shifting and jolting. It also describes a procedure to mitigate the symptoms until the SW is released. What a great relief to have Mercedes acknowledge and address it! Thanks also to Mercedes of Bend, Oregon for their assistance.
Thanks for the update. What is not really clear to me is why some have it and some don't since the software update is not out yet.
It could be the way we drove when it was new perhaps, maybe a game of chance?
Or perhaps the later produced models have this incorporated already but not yet available as a separate update? We can only speculate.
It sounds like from the description the issue is the adaptation algorithm not having sufficient data, so having the issue or not comes down to how one drives. I guess under certain conditions the algorithm isn't collecting sufficient data, so it ends up shifting in a jerky manner. It's kinda laughable that this issue was already known during the press event when the car was revealed and it's October now and still no software update. I just watched RBR's review of the new GLC 63 SE and he commented that the transmission is now laggy in this latest incarnation of the hybrid powertrain. Not something that the 9-speed MCT had issues with in the V8 models. The instant upshifts in manual mode is something I particularly like about this transmission and even the slightest delay would be annoying to me. Sounds like they still haven't quite sorted it out in conjunction with the M139 engine.
Last edited by superswiss; 10-18-2023 at 05:41 PM.
My 2023 C43 is 3 months old and my 4th MB since 2011… This trans is totally unacceptable. At times, makes the car seem unsafe! So unlike MB, just really disappointed. Also, the stop/start feature can be a little scary. Nothing like my other MBs. Overall, not what I’d expect from a $75k+ vehicle.
The transmission is killing this car for me. I mostly love the car and have put on 4000 miles. However, even in comfort the transmission will clunk so hard my passenger is thrown forward on the 1-2 or 2-1 shift, or it will fail to shift down to 1 and stay in 2 with a very slow spool up. I have also seen the hard clunk in other driving such as a 4-3 shift after a throttle relax in normal street driving. There is no excuse for this kind of performance, as other dual clutch transmissions are far better. It's going into the dealer, but multiple reviews mention hard shifting (I now know just how hard), making me wonder if it's just a bad design. Anyone else seeing this? Any advice?
Normal for MB transmissions since at least the 7G. MB doesn’t know what they are doing when it comes to transmission engineering and manufacturing.
Options are live with it or dump the car for something with a real transmission - a ZF8HP.
Normal for MB transmissions since at least the 7G. MB doesn’t know what they are doing when it comes to transmission engineering and manufacturing.
Options are live with it or dump the car for something with a real transmission - a ZF8HP.
I don’t have any of the described trans issues and I own the w205 7 mct and 9 mct version. This is not the character of the trans. If that were true then i’d be having the same problem as well. I think this is a quality issue just like the steering issues mercedes are having
I don’t have any of the described trans issues and I own the w205 7 mct and 9 mct version. This is not the character of the trans. If that were true then i’d be having the same problem as well. I think this is a quality issue just like the steering issues mercedes are having
Yeah, he just likes to use a broad brush and label everything MB garbage. The ZF8 is a torque converter automatic. The new C43 as well as the 63 models before it with 7 speed or 9 speed have a clutch where there would be a torque converter with the ZF8. Different animal of a transmission. The ZF8 is nice in a commuter car, but that's about it. Porsche makes the PDK very smooth, but that also makes it boring.
Yeah, he just likes to use a broad brush and label everything MB garbage. The ZF8 is a torque converter automatic. The new C43 as well as the 63 models before it with 7 speed or 9 speed have a clutch where there would be a torque converter with the ZF8. Different animal of a transmission. The ZF8 is nice in a commuter car, but that's about it. Porsche makes the PDK very smooth, but that also makes it boring.
100% I have the dual clutch amg gtr and the shifts is really fast and smooth but I like the 7 mct and 9 mct better for every day as it’s just rough and brutal/violent it is on the shifts. All my friends that drive dct lambos and 911 commented on how violent the mct shifts when driving hard. Suits the character of the car very well. I know owners of the 7 mct and 9 mct having rough shifting problems in auto but that’s not every c class and it doesn’t make it a trash transmission. I like it far better to the zf8 speed as the zf are more suited towards luxury cars like the s63 and 7 series M
100% I have the dual clutch amg gtr and the shifts is really fast and smooth but I like the 7 mct and 9 mct better for every day as it’s just rough and brutal/violent it is on the shifts. All my friends that drive dct lambos and 911 commented on how violent the mct shifts when driving hard. Suits the character of the car very well. I know owners of the 7 mct and 9 mct having rough shifting problems in auto but that’s not every c class and it doesn’t make it a trash transmission. I like it far better to the zf8 speed as the zf are more suited towards luxury cars like the s63 and 7 series M
Yes, AMG deliberately engineered some violence into the MCT. I agree, it does suit the car and you can choose how you want it based on the drive mode. Sport+ gives pretty violent kicks in the back during a power upshift, but Comfort, Sport and Race shift quick and smooth. The kick in the back is fun once in a while, but if I'm going for hard drive I prefer Race mode. Getting kicked in the back gets tiring quickly on a long canyon run. The DCT in the GT is indeed just a bit too civilized for my taste as well, even in the BS. Shifts very fast, but w/o any drama. Great on the track, but a bit boring on the road. None of this makes any of these transmissions bad, just different, and if one prefers Buick style shifting, well there are other cars for that. Having said that, it does look like AMG is having some trouble getting the MCT properly mated to the M139. Not all that surprising as the M139 has so far been paired with a transverse transaxle DCT, and the MCT was specifically designed for the V8.
Last edited by superswiss; 11-04-2023 at 08:17 PM.
Hi dhspencer71. There is a factory bulletin as discussed earlier in this thread that cleans the valves and reprograms the shifts. I had this performed and it actually totally smoothed the low speed shifting character of the transmission. As has been reported here, some cars have no problem, and now mine has joined those ranks. It's no guarantee, as we are waiting for a software upgrade which is on the works, but at least for me it delivered excellent results!
PFL205.064 with M276.823 (Oil pump solenoid defeated)
Originally Posted by Venturep
Hi dhspencer71. There is a factory bulletin as discussed earlier in this thread that cleans the valves and reprograms the shifts. I had this performed and it actually totally smoothed the low speed shifting character of the transmission. As has been reported here, some cars have no problem, and now mine has joined those ranks. It's no guarantee, as we are waiting for a software upgrade which is on the works, but at least for me it delivered excellent results!
That is wonderful news, glad MB finally fixed it and you are enjoying a transmission with no more problems.
09-28-2023, 06:29 AM
