tqb

Just purchased new 2013 SL550 in October. It now has 600 miles on it. I absolutely love the car but have a minor concern. I have payed attention to the transmission shifting points. When accelerating the only way I know the transmission shifts is the tachometer readings. Just as smooth as silk. Here's where I have a bit of an issue. When decelerating to close to a stop I can feel a noticeable downshift from second to first. You can feel some of these downshifts more at times than others. Definately do not need to look at the tach to determine if the car is in first gear when slowing down at any time. The downshifts from all other gears are barely perceptible. Has anyone else noticed this?

jmrscuderia

I'm sorry to here that, I haven't herd of any issue with this transmission but I will keep a close eye on mine to see if does the same. I'll talk to a MB mechanic that I know and get back to you.

Daytona-flyer

I've noticed it on occasion. It's not a big downshift, I'd guess the revs go up to 2500 or so.

Florida Joe

I have noticed the same. I have 1,200 miles and am noticing it now where I didn't previously.

I can't tell if it has always been there or I am just more cognizant of it.

red308

I had a 2004 SL500 that was the first year for the 7 speed trannie. I vaguely remember a symptom similar to what you are describing. Never did anything about it and it never caused any other problems.

Question: are you sure it is shifting all the way down to first gear? Or is it shifting into second gear. I think if you are in the normal (Comfort) setting it may be shifting only down into second gear.

Also, this may be that the engine control computer is learning the way you drive and may be making adjustments. This may account for why it seems like the symptom only appeared recently.

Dudereeno

Dear TQB, I've been driving my 2013 SL550 for two months now with no such problem. HOWEVER, the 2005 I owned previously had a transmission failure within three months of new with similar symptoms. this is a different transmission, but I'd watch it carefully. My wife and I were out of town visiting relatives and I was playing around with the paddles for manual shifting. It froze in first gear and it wouldn't shift out. They had to replace the transmission. Mercedes has a program for this sort of thing and they reimbursed hotel costs, meals etc., but we quickly rid ourselves of the car. It felt like a lemon after a major failure like that within just a few months of buying it.

F456 V12

Are you in Sport mode or Economy?

Sport mode shifts to 1st gear and blips the throttle a bit, not like my Ferrari, but just a bit you can notice. Economy shifts the car into 2nd gear and starts from 2nd as well.

MB

tqb

I have to admit I was not aware of the car only downshifting to second in comfort mode. That being said I normally drive in comfort mode but have tried sport mode to see if I could tell a difference. I could not. I have noticed if I decelerate to a stop very slow I can not feel the downshift. And when I mean slow I mean slow. In normal road traffic if I came to a stop that slow I would have more to worry about than the transmission downshift. From what I understand I need to drive this car for a while to see if the adaptive transmission will improve this. At the end of the day my gut is this is how the transmission shifts and it is something I can live with. I will keep everyone posted. Thanks much for the constructive comments. I value your opinions.

Daytona-flyer

I've seen it in the economy mode.

However, I'll correct myself concerning the RPM. I wrote 2500 in my prior post. It's nowhere near that. It's just enough to feel the shift and it's effect on slowing down.

jjomaa

Noticing the exact same thing in my 13 sl63 I can feel it downshifting when im coming to a light never noticed it before. I have about 1000 miles on mine

Kind of strange

Daytona-flyer

It doesn't seem to happen all the time.

Tezer

I get it too,most of the time & I'm in econ mode

EuroDeliveryGuy

This discussion on downshifting leads me to ask: is anyone other than me putting their transmission into neutral as you approach a toll both or other gradual stopping situation? I've always done this with my stick-shift cars, and now with $4 gas ($8 in Europe) I'm doing it more often. To me it is an easy way to reduce gas consumption.

Also, if you free-wheel-it -- in neutral -- down a long decline for a mile or so, and then drop the transmission back into gear, can you do any damage to the transmission? I've tried this a few times and it seems to work perfectly, without any popping or sudden movements.

Thanks for your thoughts on this.

red308

Interesting question on whether to shift into neutral on gradual stops. The newest transmissions shift using software algorithms. So not sure if the following comment applies to the newest torque-converter automatic transmissions (as opposed to double-clutch manuals). But....

I have ready many times that putting torque-converter automatic transmissions into neutral does not actually save gas. Because the engine idles at a lower rpm when in gear than it does when in neutral. The articles say that idling at the lower rpm while in gear actually uses less gas.

Does the engine use more fuel just keeping the torque-converter spinning while in gear?? Don't know. I am just quoting the articles.

Are there any trannie experts out there?

Daytona-flyer

It may be of no consequence but coasting is not legal in some states.

Tell that to a guy driving a stick.

Ssgdk

Owner's manual says that shifting into neutral while driving could cause transmission damage.

Philip317

Be careful out there as the MB transmissions have a history of problems and in particular the 722.6 transmission. I bought an SL 350 new in 2004 and some real scary experiences. Power failure linked to sticking in gear nearly cost me my life. I sued MB and won and in the course of my case I introduced 3 other car owners with similar scary experiences. What annoyed me about al this is that MB have been aware sine approx 1996 that tg problem existed and have done sweet damn all to resolve it - they simply have denied it. In my case they attempte to interfere with one of my witnesses but it backfired and my witnes turned up and told the full story. How is that for an honourable marque such as MB. See my case history under SL 350 - R230. Be careful you drivers out there as this problem MB has hasn't gone away as can be seen in these forums and expect them to deny it- shocking considering that they are putting lives at risk. Keep an eye on my space as you will be seeing interesting developments in this area as I propose getting the European Commission to look into the cover up that is going on here.

sound 8

If you have a MCT gearbox, then that's how they are, in sport mode they blip
and you feel the change down, that's good because it brakes the car, I luv
it, when driving normally it changes smooth without jerks.
Mines an AMG.

PeterUbers

I have this too on my 2k14 e550 ...intermittent, usually when colder engine temp, 600 miles on my odo too...wouldn't worry about it yet

Philip317

Hi
Mine wasn't a blip, rather total loss of power, without warning. This wasn't a performance feature but a malfunction and which we identified in 3 other SLs

Be careful . This is a real problem and one MB know about but are not rectifying it. Other members on this web site have experienced this problem as well. Don't be fooled or conned into paying to have repaired as it is a MB liability

PeterUbers

I took my car in to get it checked by the stealership -- checked tranny fluid, software, reset the adaptations and car still does it.. mine is most pronounced 5th-->4th downshift, never really any other downshift or upshift, and much more prevalent when cold... and not always, only about 10% of the downshifts when simply moderately braking to come to a routine stop.
Dealership said this was normal tranny behavior, and from what I'm reading here on this website/forum .. seems intrinsic to the 7spd tranny...

it's very annoying

Philip317

Hi Peter
I take your point but remember as your car has shown up this kind of problem that what has happened to my friends and I are likely to happen to you also . It is simply a latent defect. What happens in my car is the car simply fails 'to take off' and there is total loss of power and can compromise you when you will least expect it. It happened to me as I was entering a roadway with a car coming and I was almost taken out. Not good for the blood pressure! My engineer says that this happens if you apply your accelerator sharply and it appears what can happen then is that selector , on occasions, ( ie intermittently) gets confused and the selector selects what is described as a false neutral but rather interestingly is that the only way you can get the car to function then is to turn off the engine and allow the system to 'reset'. You can't therefore apply manual mode without turning off the engine and this is what makes the whole problem a most serious issue. So be careful particularly when overtaking , entering motorways or making a quick getaway from the kerb as you could let yourself in for a serious drop
So be careful
Philip

PeterUbers

...more people with 2k14 E350's and 550's have pm-ed me with this issue as well...

PeterUbers

FYI --

Just had my transmission valve body replaced under warranty after fighting with MBUSA about my "rough shifting" -- now I have a much smoother shifting transmission. They also updated the software.

Had to involve MBUSA in NJ before the dealership would take me seriously.

PeterUbers

absolutely sounds like a nightmare issue to have on a very expensive car or any priced car, for that matter!

I hope MB does the right thing and looks for this issue in other cars on the conveyor belt...