Cosworth2000

I can do this for fun. :-) It will happen easier if your tranny is not 70 degree warm. The trannies normal running temperature is 73 C Degree.

If you push your foot down and the trannie is warm, it will not do that unless you push and raise your foot to fast before it changes gears.

MBzW205

Solution: Take your foot off the gas, shift to 2nd or put the car in neutral..

In Texas we call this "The Bull"

Lol I had experienced this also but was familiar with the this happening before from my previous sports cars that I owned that were manual transmission. I'm surprised that drivers actually think this is an issue with the transmission and not their foot. It's a short gear, it will happen in any vehicle.

Radcap

Perhaps let the engine/transmission break in a bit before overreacting. I have just a bit over 5000k on mine and it perfect, no issues in any mode, I did not use s+ until I had 3500k on it.

Big Goober

I've had the bucking happen once. Not a good feeling when traffic may be bearing down in you. Easily overcome with the paddle.

I've also noticed that in S+, my transmission doesn't shift to 1st at a stop in every situation until moving forward again.

cenzo86

Im thinking the same thing here. 1st gear is short and this car has power. That bucking happens when your foot slide on and off the gas pedal if you get a little over zealous from a stop.

gabe.m

Car stopped. Step on the gas. Car accelerates really fast for a split second. Your foot stays behind the gas pedal, due to a thing called "inertia". Gas pedal responds very fast, resulting in really fast deceleration of the car, together with the pedal. Your foot, which is moving forward at this point, presses the pedal again, and the cycle repeats a few times.

It can happen with a truck too, in the first gear, due to gear ratios.

This happens when/if you are trying to accelerate smoothly (why the hell would you do that?) in sport+. This is not a Toyota!

Anyways, keep your foot firmly on the gas pedal and it won't happen.

Jimmy C43

I'm glad this thread got bumped as I had not seen it previously but am experiencing the same issue

Something very similar happens in mine as well in Sport+ but I just figured it was me not being used to the vehicle

I've only had the car for 5 days, took delivery last Friday so just at the very beginning of learning about it. I have not even experimented with paddle shifting yet, still getting familiar with driving my new car

When in Sport+ mode driving between 1-10 miles an hour there is a lot of bucking and jerking around, especially when I'm unsure of exactly what it is I'm doing as far as acceleration/deceleration (navigating an intersection for instance, where I'm gauging/merging with other traffic)

Another example is driving through a gas station parking lot looking for which pump to use and travelling at 5 mph

Now that I've found this thread, I'll pay more attention the next few days and report back

I do think some of it is driver related (as another poster mentioned), these cars do have a lot of power and seem to have very close/tight ratios in the low gears

Big Goober

I haven't had the issue of the transmission jerking while not at a stop, but as mentioned in my thread, I think I have isolated the issue coming out of a stop to the car not shifting into 1st gear. I will be getting some other stuff done soon and will be asking service about this.

Big Goober

Thanks for the laugh!

1Gunner

I was aware of this thread and so far in 2,000 kms it has happened only once to me.

While turning left at a busy intersection. Car still moving but a brief moment of hesitation judging how fast oncoming traffic was coming... do I go.. should I wait... I decide hesitantly, ok go and the bucking started. I backed out and smoothly applied gas. It was an eye opener...

In S+ the throttle pedal mapping is very sensitive (overly sensitive?) to any movement.

emanisem

Do you guys get that feeling that the engine runs smoother (less back and forth) as soon as the oil temperature hits +50 to 60 degrees C?

1Gunner

Yes probably it does, but that certainly wasn't the case when I experienced it. It was 45 minutes into a drive, so engine and all fluids were at operating temps for some time.

g8rgrl

The outdoor temperature here is always 23-29 C, 75-85F. My car gets above 60C not long after I start driving. I've had it buck after an hour of driving. It also does not like speed bumps....3 or 4 speed bumps in a row in a residential neighborhood, with the slowing and then giving gas and the transmission going between 1st and 2nd gear does not work well with this transmission.

emanisem

I haven't experienced this whole rocking back and forth thingy yet then...but then again I've had my car for little more than a month!

1Gunner

Me to, and it did it started to do it again last night while at an intersection.... Consider yourself lucky. It's only a matter of time.
Only does this in Sport + from a stand still or slight coasting from 1st gear.

emanisem

oh that explains it then, i normally drive on C mode.

darkh0rse

Anyone had this resolved? I'm having this issue but in a GLC43. Sport+ will occasionally produce hard rocking/shaking. This has occurred from a complete stop and from a near stop (rolling up to a light and accelerating).

This is not be mistaken with a hard shift. I have driven a GLA45 almost exclusively in Sport+ for the past year and never had this happen or even anything remotely like this. I also used to own a Macan Turbo which I drove in sport+ and never once had this type of bucking occur. This is not a characteristic and is downright dangerous when it happens as it forces you to either jolt around (picture mechanical bull) or decelerate and switch into comfort before being able to resume acceleration.

I'm taking my car into the dealership later this week but if someone has had this looked into and had any kind of resolution then please chime in.

Thank you.

NathanC43

I am sure dealer would want you to replicate the issue in front of them for them to determine the root cause. Just share with you the way I have found to make the issue occurs. From a full stop, accelerate hard and release the gas all in a sudden before it shifts to gear 2; then re-engage the gas again right away. (like giving it a hesitation during acceleration). 80% chance you can see your car rocking back and forth. Please share with us when you got an resolution on this issue. It has been bugging me since day1...

tmoneyC450amg

Not sure if you guys have noticed this one: at times there is also a moment of dead pedal when you try to accelerate after decelerating. I've had this problem occur near intersections and when attempting lane changes and its just as scary because you can stomp on the gas and for 1/2 of a second, there is completely no response. A lot can happen in that 1/2 second.

cenzo86

yup
I find when coming to a hard stop, and then flooring it, it feels like the engine is dead. No power, no noise, no building boost, just flat for a second, followed by a more gradual power delivery than usual. It's a bit disconcerting, and probably a safety nanny for the trannie.

tmoneyC450amg

I'm hoping after my AMR tune on Wednesday this dead throttle and rocking might go away

Biggreenogg

Like other posters, I noticed the behavior once or twice driving in S+ just after I got the car. I assume I adapted my throttle mashing fairly quickly because for the next five months I didn't notice the behavior. Also none In the month since my eurocharged tune.

triggerhappy

This has happened to me but only when I am in sports+ mode and travelling slowly through the neighbourhood. It is interesting that when you are just cruising in sports+ mode that it would drop it down to first. I was always taught when driving a manual car to never put the gear into first when slowing down unless you come to a complete stop. I suspect that the transmission has trouble dealing with the low speed in first gear and if you do something unexpected (i.e. accelerate when it thinks you are slowing to a complete stop) it puts it on a bad footing.


Do I think this is a major issue, not really as it only occurs in low speeds and only when you are trying to baby the throttle, not like you would be taking a corner at 10-15 kms per hour and gently accelerate after apex


An easy way to recreate this is change from comfort to sport+ when you are rolling along or starting to accelerate at an intersection. Happen to me a couple of times when I wanted to impress some ladies walking down the street and wanted to pop the exhaust...Serves me for being an idiot...Talk about embarrassing!

DameMD

I don't think mercedes-AMG made the sport+ mode to do lazy driving i.e. stop-and-go where you actually need 1st gear unless you are at a complete stop. I mean the gearing is already short, and sport+ makes it shift faster and keeps the revs high. I only use sport+ when I really want to let loose with my right foot as I know the shifting is already jerky. Since, I too experienced the jerky 2-1 slow down, I try not to keep decelerating and accelerating at very low speeds where I know the transmission is trying to hunt for 1st gear. I still use Sport+ 90% of the time in the city but I watch my RPMS and gearing now, and I haven't had the jerkiness since I changed my driving habits.

Twowheelsgood

That was my impression after a test drive trying out all the modes. The throttle tip in with Sport+ is very aggressive. Fun, but not for trolling around town.