Hey guys! I just purchased a 2020 GLC 63 a few weeks back, and love it...with one pretty large exception. The transmission...

It doesn't matter what mode I'm in (C, S, S+) shifting between 1st and 2nd, and 2nd and 3rd is incredibly jerky (not always, but about 60% of the time?), and sometimes delayed so long that the car seems to rock back and forth a little, which is embarrassing in a car at this price point. I've sifted through previous posts regarding this issue, and saw a few people blame it on "driver error", but my previous 3 cars all had more power, and buttery smooth transmissions. Is this something that Mercedes has found a fix for? It's gotten so bad that it's all but ruined my confidence in pulling out into traffic, which makes me sad.

Just wondering if anyone's had the same issue and come up with a solution, or can relay what Mercedes has told them regarding our transmissions. Thanks guys!

 

My 2019 is fine. My initial Stage 2 tune made the "jerkiness" in S+, 1st gear go away but then either my Ethanol or my TCU made it worse but it is just sensitive to how smooth you are on the throttle.

 

Have you done a "transmission reset"? You may have to do a search for it, but there is supposedly a way to reset the transmission fairly easily. That said, it has gotten mixed reviews, so it may not fix your issue 100%, but some have claimed it works. I only had the issue in my GLC43 when the trans was cold or when I was in Sport+ mode...other than that, it was pretty smooth. Dealer is the next step, but probably won't have much luck there. Finally, I think Renntech or one of the other aftermarket companies may have a transmission mapping that might help...but you obviously would pay for it and could void that portion of your warranty. Good luck, I know the first time I encountered it, I was like WTF, was like a bucking bronco.

 

Thanks for the advice! Yeah I reached out to the service manager here, and he said he's received numerous complaints for the same reason, and there is no fix. It's considered a "characteristic" of the transmission...crazy...we'll see if things improve with time/mileage.

 

So there are several threads across the different subforms going into some of the details to be aware of. I'm guessing your previous cars all had traditional automatic transmissions with torque converters. Most of the AMG 63 models don't use a torque converter and instead use a wet clutch. The entire transmission uses a total of 7 clutches to do all the shifting, starting and stopping. That's why AMG calls it a multi-clutch transmission. This is done specifically for a more direct feel and a much better response. The downside is that any rocking from the drivetrain gets generally transferred to the rest of the car. Anybody who has driven manual transmissions in their previous life will be very familiar with this. If this is your first transmission with a clutch, then you gonna have to become familiar with it. The transmission will also adapt to your driving style and get better over time. To me, the transmission is a major selling point of AMG. I loathe torque converters. They just numb the driving experience, but yes, they make for a smooth driving at slow speeds. If that's what you are seeking then this may not be the right car for you.

 

I think most of us get used to it and subconsciously learn to drive it where it is not an issue. In S/S+ it doesn't do it at all in my car, but most of the time I'm just mashing it anyways. I'd give it a few months and then report back or go with a TCU tune.

 

Exactly....

That's why mine always expects a Launch Control/Race Start whenever it moves...lol...It thinks it is always at the track...

 

So this is actually a theory I have. I've come to the conclusion that the transmission can't really adapt to different driving styles at once. Meaning it can't be smooth on one hand for moderate driving, but also sporty and crisp for somebody who drives more aggressively. At least to an extent. I think it gets further confused if you use S+ for normal driving and also for dynamic driving. In the end it can't know how you really wanna drive if you are not consistent.

Therefore I'm very specific as to when I use which mode and when I let the transmission shift automatically vs. shifting myself manually. I pretty much stay in C for city, around town driving and longer distance highway cruising and keep the transmission in automatic mode, but as soon as I change out of C for more dynamic driving, for example I have setup my Individual mode for spirited highway driving, I switch the transmission to M. My Individual mode automatically puts the transmission in M, and whenever I use S+ or Race (don't really use Sport) then I immediately put the transmission in M.

Doing that I've noticed that my transmission adapted to my casual city/town and long distance highway driving, and I'm not poisoning it with my dynamic driving style, because whenever I drive dynamically then I shift myself. For me, the automatic mode of the transmission is a convenience feature for mundane driving situations, but when I actually go for proper driving then I don't want the transmission to decide for me. While the shift programs are very good, the transmission still can't read my mind and ends up being reactive sometimes which I don't like. Having driven manual transmissions for almost 20 years, it is in my nature to manually shift and make sure the car is in the right gear at all times. I don't need a computer to decide that for me.

 

I get it, mine stays in S+ or Individual with everything S+ but suspension in comfort since I am lowered and that helps sooth it out some.

Manual shift can be fun, I even added the carbon fiber extensions but AUTO can't be beat on the dragstrip, but I could see where manual would be good on twisties.

 

I'm not an expert, but my experience with a 20 GLE580 was also frought with shifting issues. I could never come to a smooth gradual stop w/o the eco/start system jerking the whole car. I was told it was because of the new quasi-hybrid system, or whatever. I finally traded the 580 for a 21 GLC43 Coupe and could not be happier in terms of both shifting and handling. Not quite as quick off the line as the 580, but the average driver never fully utilizes more power than the 385 HP of the 43, unless at the track. YMMV. I'm happy.