Harsh shift in low gear?
 

Hi C43ers,
I have my C43 since April this year. tranny seems problematic on this car...Rocking back and forth is always bugging me I dont even want to talk about it. I would like to check with C43ers about another issue.
Do you guys experience really hard shift from gear 2 to gear 1 in sport+ mode?
It is so hard like someone is pulling you from the back. Also in comfort mode it downshift hard from gear 3 to gear 2. Any similar experience? Is it normal?

The rocking back and forth is just how you modulate your foot. You're coming to a stop and the car is shifting down from 2 to 1. But as it shifts to 1st gear, you are giving it gas while its jerking forward from the downshift causing the rocking back and forth issue. I've only had the jerking happen once and I learned to modualte my foot better and hasn't happened in 6+ months.

I definitely know it's not about how you modulate your foot. The car has a major issue when it comes down to the jerking back and forward that numerous drivers have cited. I have experienced it in comfort as well, and at least once a week as of late when I'm driving in a more spirited fashion. I spoke to my service rep about it and he acknowledged that it was something he's heard of and is unfortunately just a part of the vehicle. Unless they implement a software update where it does a better job of preemptively hunting for the right gear, it's here to stay.

hmmm, thats weird. The only time I've notice the jerking was in Sport+. Might be because I only drive in Sport+ and never in comfort :naughty:

Ill keep an eye out and see if i can replicate it in comfort as well.

Can you try lower you speed from higher gear. Then when it auto shift to gear one, apply some extent of gas before coming to a full stop. In my experience, only baby foot or full throttle can avoid rocking back and forth. I somehow agree with you that the rocking back and forth is associate with the jerky transmission and sometimes rough road condition. I always drive carefully in Sport plus trying to avoid rocking, but still it happens from time to time. Another thing...does anyone experinece rought downshift from gear 2 to gear1 in comfort mode???

I found in sport+ and automatic mode, the car is harsh. Put it into Manual mode and when you come to a stop leave it in second gear (don't downshift to one). Downshift to one once you come to complete stop and you will not have this issue.

I'm sure Mercedes can adjust the programming on the transmission if enough people complain, but to me its not a big issue.

Unless you're manually down shifting or in S+, 1st gear should almost never engage on its own. Depending on your speed at 2>1 downshift, it can be quite jarring because of the combination of gearing and high torque. Otherwise, assuming this is happening in comfort and no other driver intervention is taking place, it might be worth a dealer visit for their opinion.

I have exact problem as the OP. On Eco mode, my 2018 c43 jerks when slowly coming to stop from 3rd to 2nd. On sports+ it's even more harsher from 2nd to 1st.

I try to counter it like the other poster said to modulate with your foot on gas pedal. Seems better and you learn to not jerk you car.

I want to say Munis posted something on this somewhat recently I just can't find it. Basically there's no middle ground for the throttle it's either all in or not. The way I think of it is like driving a stick, you never really hang out in 1st gear unless you're at a dead stop. Believe it to be intended behavior.

This happens on the 7spd on the C450 as well. But after 3.5 years of owning this vehicle, I realized that I only get the jerky shifting during spirited driving if I am trying to accelerate through uneven roads/surfaces. Somehow the car has problems deciding on which gear to hang onto when it's battling for traction with the 4matic.

That's my theory anywho

S+ mode is not meant for low speed cruising in the city but if you want to make loud exhaust noises, you just have to get used to the jerkiness.

This is a good post. Welcome to the world of dual clutch transmissions. One of the reasons why I went with the C43 over another S5 is that Audi went away from their (excellent and probably perfect) DSG and replaced it with a torque convertor.

c43 has a tq converter, no dual clutch

Lol I wonder what will happen when he finds out!

So I am one of the first to discuss the issue with the 7G Sport transmission and found that MB does not have the knowledge to assist without AMG letting them know what to do including tuning the transmission.

That being said, I drove the C43 and did not notice the issue of jerking in 1-2 or 2-1 but I am sure that since it's a 9G transmission that the 2 other gears are smaller and as such, it will be more sensitive in those gears if you are not pushing your foot down hard enough for spirited driving. This is what Sport+ is used and made for. Not for every day driving in traffic or on road streets. That being said, the 9G is very smooth but you must keep in mind that you should not be in Sport+ when the transmission is cold. Keep it in Comfort until you see the temperature in white and not blue.

I don't think there is anything wrong with the 9G transmission but I could be wrong.

Im sorry but learn how to drive the car. There is nothing wrong with the tranny and it is after all a sports car that you're driving in Sports+. Now I know its not super comparable, but driving my mom's Aston Martin Vantage takes effort and modulating of your foot even in comfort mode and if you're not paying attention it can be very jerky at low speeds; however at high speeds and for spirited driving it is an absolute pleasure. If you want a car that is muted and meant for low speed everyday driving then switch to a Lexus sedan, or even the regular C300 as this car seems to not be for you orrrr maybe don't be in Sports+ at low speeds because thats not whats its meant for. Nor should you be engaging 1st gear all that much.

It has been one and a half year since I started this thread. My C43 has been fully refunded by MBUSA due to jerky shifting in low gears. Not sure if it is the same extent of jerkiness as you guys but I can even hear a clunk sound when it is down shifting at 3 to 2 to 1. Now I am driving a C63S Coupe. I would say it is much smoother in every modes. However, in S+ you still have to pay some attention with the throttle when cursing in low speed especial on rough roads because the throttle is very sensitive and the rough surface will affect the position of your foot on the throttle. 50% of the time I am driving in city with sport+ mode, and during my 9 months ownership of C63S, it never experience rocking back and forth like C43 does. Maybe I am comparing apple to orange but my point is, even if it is normal for C43, you have other option out there which is more powerful in performance but does not rock back and forth.

If you've been "fully refunded" (I'm not sure what that actually means, but I'll follow a literal line of thinking) something else was wrong with your car. No one else here is getting MB to admit fault in a manner of fully refunding a purchase.

Yea can you elaborate on "fully refunded"? What does that even mean? Ive heard of warranties and manufacturers fixing a problem which they have identified as theirs, but Ive never heard of ANY car company that would even come close to giving you a full refund on a car that you've driven for almost 2 years...

I bought the C43 back in Apr 2017 and experience the rocking back and forth and harsh low gear downshift since day1. I tried to live with it and adjust may way of driving to accommodate the "special character" of my C43. Not until one day, I test-drove a new 2018 C43, I definitely can feel the difference. It was shifting way smoother than mine, so I determine to bring this issue to dealership. Lead technician admitted my car's behavior was not normal, but with multiple attempts in four months they could not fix it. I ended up contacted mbusa and they agreed to buyback and refund what I paid for when I purchase the car.
From what I was told, dealer reset the tranny adaptation, replace valve body, this and that, and even the transmission itself but harsh shift still persist.

He most likely lives in the USA and as per the terms in the Lemon Act, he can get a refund whereas in Canada the car companies screw us and fix, fix, fix it over and over again.