Chrisk03

Yeah, 2 separate issues seem to be intertwined in the conversation. I think it breaks down like this

1. Overall un-smooth transmission shifting in various scenarios. (Not necessarily topic of the title of the thread, but people are adding experiences, which is fine.).

2. Topic of thread, where there is jerking or more like bucking bronco action of the vehicle when accelerating after slowing (for turn) or near stop.

#2 was my scenario and I was in Sport+, which is when I believe this transmission action happens. So, I was slowing down and coming to a right turn and after the turn, I got back on the throttle with kind of a pu$$y foot, to be honest. . The 43 bucked back and forth like a mad man and I was like WTF. I let up on the pedal because there was a car a little ways in front of me, but it seemed to still buck, so I quickly hit the Up paddle and all calmed down. I tried to re-create at the next turn and couldn’t, but I wasn’t exactly sure what caused it, so was probably not re-creating correctly.

After doing a little research here, I kind of knew exactly what was going on. The throttle/pedal is damn sensitive in Sport+. If you drive in that mode, little inputs will do certain things like downshift to lower gear or take off to the next gear. Sport+ really is a mode for no half-a$$ing it or being indecisive. It makes sense, especially after thinking back to my time at AMG Academy. There wasn’t an instructor there that didn’t tell me to thrash the doo doo out of the vehicles if/when in Sport+. “They can handle it” was a common refrain....they are right. So, if in Sport+, thrash your GLC.

That said, there are times and in other modes where the transmission can be a bit un-smooth or indecisive in its function. I found it mostly before the transmission warms up and perhaps the way it learns driving style has an effect. It’s not really a bother to me if/when it happens and I don’t think on my vehicle it’s as bad as say MBenz or MJ experiences. Overall, for me, still enjoy the vehicle. YMMV...

GeraldG

We are experiencing the same, dangerous jolting/bucking of our 2019 model (purchased January 2019) when coming out of a turn at low speed while in Sport+. A visit and test ride at the dealership was not able to reproduce the issue, and no codes/alerts, etc were evident when they looked over the vehicle's engine. They did "flush the valves" but that had no impact on remediating the issue as I experienced the jolting two days later while in Sport+. I decided to capture the incident on video. The video shows the car in Sport+ mode operating normally until making a right turn, at which point when the accelerator pedal is pressed to increase speed the car begins bucking/jerking violently to the point where I have to remove my foot from the accelerator to avoid losing complete control of the car. Obviously this is unacceptable performance for any car, much less a $65k Mercedes.

I forwarded the video to the dealership yesterday and I am awaiting their feedback, but judging from the other posts in this forum the issue has never been remediated beyond "adjust your driving style".

We bought the AMG GLC 43 based on a number of factors, one of which was the impressive acceleration and sound of Sport+ mode. Apart from this issue the vehicle has performed generally well and is fun to drive. It's a stunner too in all black with night package. However this Sport+ issue is dangerous, and had I known this in advance I would have opted for a different vehicle.

I will update this thread once I have a chance to discuss with dealer.

osidepunker

You won't want to hear this, but I blame your driving style. You said the following, "We bought the AMG GLC 43 based on a number of factors, one of which was the impressive acceleration and sound of Sport+ mode." Well, if you are in S+ mode and make a right turn, then mash that accelerator. You won't have any bucking, you'll only have "impressive acceleration and sound of Sport+ mode"

Now, if you think that taking a corner at full throttle is too much, then right before the corner, move it down to S mode. You can give it partial throttle with no bucking. I am constantly switching drive modes to suite the situation. Thats what they're for. There's only one way to use S+ at low speeds, gas on or gas off. At freeway speeds or on mountain roads, S+ works fine. For full throttle drag launches it works fine. But they didn't design that mode for partial throttle at slow speeds.

I agree the software mapping for S+ could be improved. But imo its not worth the hassle of fighting with Mercedes. I would rather adjust my driving style to the car and enjoy driving it.

GeraldG

Driving style is not at fault (owners manual clearly states the accelerator pedal position influences how the automatic transmission shifts gear; :little throttle = early upshifts, more throttle =:late upshifts, No mention in manual to avoid this style of pedal management when in Sport+. In my video it is clear there is no upshifting going on. However I get your point - driving style can be a remedy to the issue, However, imo that would be a weak position for MB to advocate for given the car's price tag and the AMG (lite) badge they affix to the car. Again, apart from this issue the car is awesome, but I bought it to drive in Sport+, not to make manual adjustments while I take a corner in situations where slamming the pedal is not wise due to traffic conditions.

osidepunker

If you say so. Suite yourself man. Some fights aren't worth fighting. I drive the sht out of my car switching drive modes as I see fit and the car performs phenomenally for me. I could care less about a jerking issue I never experience because I never drive it like that.

But I understand. You want the car to be "perfect". Have fun seeking perfection. Meanwhile, I'll be enjoying my car

rjaffrey

No one has commented for a few months but I am getting the same thing as described here. It's clearly a fault of the cars NOT driving style. I have a 19 GLC 63s. My particular issue happens from a stop when turning right in any mode C, S, S+ at anything other than very mild throttle. I took our local MB shop foreman out this morning and he reproduced the same jerkying/bucking/loss of power that happens EVERY TIME the car is in that situation. This is not normal, we should not have to adjust our driving style, this should absolutely be fixed. He witnessed it but was hesitant to say if that was normal or not.

Any updates from anyone on a fix? Doesn't seem to be one which is a shame because in every other respect I love this car and look forward to driving it everyday!

Will report back here if this does somehow get fixed.

thanks

ray

Chrisk03

Did they (or you) perform an adaptive transmission reset? I would somewhat agree with you that if this bucking/jerking is happening in ALL modes, you probably have an issue. It only happened in Sport+ for me and really depended on what I DID with the throttle...quick shift of the paddles or stomp on the throttle fixed any issue for me. I believe there is also a trans update available that is posted over in the AMG C-class Forum, if you want to try there. Perhaps someone posted a TSB or Work Order # you can take to your dealer. Good luck!

PS. Nice stable of cars you got there...

rjaffrey

thanks Chris, actually they were my past cars, i have deleted them.
Will check out the other forum and hopefully, this is something they can fix with a transmission update..

Chrisk03

You can try the throttle reset yourself, if you want...Google it. That resets the ECU/Throttle memory of what your car has learned since you have driven it. The actual transmission update is apparently some software update MB has for this complaint.

ParadigmDawg

Pretty sure on the GLC you just disconnect the battery for 10 minutes and it resets.

rjaffrey

Update:

So I heard back from the dealership yesterday, they basically said this was happening because my rear tires were worn. I told them that this has been happening since I bought the vehicle on 26th Sept 2019. So the date is 6th Nov, essentially I have driven the car 2700 miles in that time and the tires (Pirelli) which were brand new at that time, are down to 3/32 showing even wear so not out of alignment. How is that even possible? So there are two issues here, the jerking motion when turning right which happened from Day 1. and the fact that my rear tires only lasted 2700 miles!

Has anyone else experienced this dramatic tire wearing?

Before anyone asks my driving style is moderate to aggressive. In previous cars: M3 Competition my tires lasted 18,000 miles before needing to be changed. My E63s about 10K, my E55AMG about 6K to 7K.
I generally drive in C mode in the mornings due to traffic, weekends I drive in S+, a couple of days ago I started playing with Individual settings where my new favorite is S+ Driving mode, with Sports Handling mode engaged, but I barely have a day of driving on that mode mostly on highway.
I'm bewildered at this point on the tire life. I understand that we have AMG's and its to be expected, I'm ok with 6K or 7K tire changes, but am shocked at under 3K.
I have also never used launch control much less heard tires spinning.

So I'm left with the problem not being solved and the extra cost of having to replace tires so quickly and at this rate will be changing rear tires 8 times a year!

Any thoughts?

ParadigmDawg

Interesting. I drive like a bat out of hell, always in S+ or individual with everything in S+ but the suspension which is in Comfort so the ride isn't so harsh since mine is lowered so much. I have done 20 launch starts or more and a zillion 0-60 runs with the tires spinning.

My tires are pretty shot at almost 10,000 miles and this is with the camber being way off, to the point you can visibly see it, secondary to the lowering.

I only have some jerking if my drivetrail isn't up to temp and I am in S+.

For reference, my GLE63S got 8,000-9,000 between tire changes.

Something seems off with yours.

Chrisk03

rj - sorry, that sounds like complete BS. Tire wear wouldn't likely cause that, IMO. Further, no way your tires should be that low with less than 3k miles unless you are burning rubber constantly. Check your owners manual packet for the tire warranty and push the dealer for replacement tires as defective. Then when you still feel the jerking after the new tires, you can call them out.

If not, I'd try a more accommodating dealer if you have another close and probably call MB customer service and put in a ticket/complaint.

Just my .02...Good luck!

johnz1954

IMO, I don,t think the tires are "defective". I think something is screwed up in the suspension geometry of that vehicle. My GLC43 never had the jerky acceleration problem and I got rid of it with 33k on the original tires. Of course, those tires rode like rocks.

Chrisk03

What tires did you have? Sounds like run flats?

I had summer performance tires (Conti's) and they were fine at 7100 miles, although the fronts were wearing a bit on the outside due to suspension geometry.

Either way, under 3k miles for tires going bad is crazy UNLESS he's driving like a mad man. Also, highly doubt it has anything to do with the trans...as what he describes with respect to jerking happened on my 43...with new tires and with miles on them.

GuyWithABenz

Ever driven a manual transmission? Let out the clutch too fast in 1st? Or try to creep with clutch out? The car will bounce against the gears and bendy parts back and forth. Only fast cure is push the clutch in or creep in 2nd. I’m sure the motor is also bouncing off the motor mounts (not good). I have had this happen in my glc43 while in 1st and sport+. Yes, grabbing the paddle to 2nd or 3rd when lifting helps. I think this transmission was made to imitate a dual clutch setup. And/or aggressive lockup helps emission/mileage and lower track use wear. This GLC transmission is always annoying at slow speed on USA roads.

ParadigmDawg

The 43 still uses a Torque Converter

The 43: SPEEDSHIFT TCT 9-speed

The 63s:SPEEDSHIFT MCT 9-speed

FastE

I have a ‘17 C43 and am waiting on my GLC43.

1) Mercedes went very aggressive to a super tight first gear. Crazy short.
2) Throttle response is also extreme in SPORT+

I personally believe it is a blend of these two issues is causing it in all of these cars. I don’t think anything is wrong.

mash it.

Don

Have experienced bogging down in my 2019 GLC 63 on moderate acceleration from both right and left turns from a stop in multiple drive modes. It's disturbing and dangerous. Have experimented extensively with changing drive modes and modulating throttle inputs. Have not yet found a reliable solution. It seems worse when the engine/tranny is cold, but still occurs when all is warmed. Sport ESP mode seems to help, but does not eliminate the issue.

Have owned numerous high performance vehicles over the years . Tire wear seems normal for such a vehicle. But bogging down on mild to moderate acceleration out of a turn from a stop is not normal. And it is dangerous. Something is definitely amiss.

In for one year service in two days. Have alerted my service advisory to the problem. But it seems like an endemic issue with the 63 and the MCT. Was planning to upgrade to the 2020 model but will wait for this issue to settle. Otherwise love the vehicle.

kennys2003

When you bog down when turning, are you noticing the traction control light activate some of the time? When i was running the wrong size rear tire, i clearly had bogging issues in a straight line or when coming out of a corner due to the traction control/differential trying to figure out what is going on, due to the tire size difference. I had it happen even without the traction control light coming on, you could feel the car yawing from side to side as the rear differential 'slipped' or freaked out. This felt like the car was bogging down to some degree.

Put the right tires on and the car drives awesome. Unless it's extreme tire wear, I doubt thats the problem.

Toughen

Yes happened in comfort mode, 1 to 2 or 2 to 1.
In slow traffic speed. When upshift, it feels like the trany is missing clutch. When slow down slowly, it feels like the car is using gear to slow the car down not the breaks.... This new 9 speed trany is not good at all...

miamiml63amg

I have been driving my 2019 GLC 63 for 3 weeks now and i can tell the trany is the worst part of this capable SUV. All issues reported here i am experiencing as well. MB AMG does not know or is unwilling to tune this transmission for comfort driving in my personal opinion unless the 9 speed hardware just does not allow for smoother shifting. The 7 speed in my wife 2014 ML63 is a bit better but still plenty of hard shifts. Looks like the S63 AMG have the same transmission so may be if anyone have tried that one can tell us if this 9 speed can be smooth in comfort mode ?

Don

Yes, the tranny is rough and seems to get confused at low speeds when acceleration is variable. Most of us here have agreed we can live with that as a trade-off for the overall fantastic performance of the AMG '63.

But the issue I (and apparently others here) find inexcusable as well as dangerous s the propensity of the GLC 63 to bog down by drastically reducing engine power when accelerating even moderately from a stop into a left or right turn. It's not a shifting problem because it happens in manual shift mode. Flashing yellow lights in the instrument panel indicate traction control is kicking in.

This makes no sense. My tires are good and properly inflated. This has been a problem from day one and persists after 10,00 miles. It seems to be more of a problem when the engine (and tires?) are cold. I've resorted to operating in ESP sport mode which seems to help. But something is not right. Dealer has not been able to find find anything wrong. Just living with this for now.

Stepny Vlk

Hi guys have the same from day 62 (i bought a test car with 6000km) in my glc43 2016 have now 45000km.
Did you guys happen to have the radar option?
On m my when i dissable the radar(distance control) and lane assist it seems to be far less present...
i think the presave peddestrian protection is interveining. And the sport plus drives from 1 gear insted of 2nd on comfort and as stated not realy great for creeping.
Have the same engin gearbox in my 2015 gle 450 coupe and never had this issue despite having the radar aswell.

Ruderegime

Maybe a proper alignment will help with the traction control kicking in?