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Sean***
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I don't mind that Mercedes thinks they know better and only provide the AMG 55 with one option for a tranny but at least in a AMG they could try to do like Porsche, Ferrari and many others and have a sport mode and manual mode that is much quicker on up and down shifts. I'd love to have a totally manual option and may even be willing to fork out the money to change my AMG over if there was a good option that worked and didn't require too much bastardizing the car to adapt a manual tranny but they pretty much make that impossible with the technology and way the cars are not really easy to modify other than a few performance arts that I have already added. I have talked to a few shops that have TCU options for other Mercs but the SLK doesn't have this option avaliable the from my searches all I can find is a company that will modify your transmission and torque convertor which may cause a lot of destruction to the rest of the drive train.
Has anyone ever found a solution that does work to increase how responsive and quick you can shirt in manual mode at least.
The car would be so much more fun to drive if the shifting was quicker. I find it too much to thik about when you have to mentally calculate your shifts so you hit the mark and dont get into the rev limiter when driving hard.
Would like to hear if anyone has found a good solution.
 

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Sell it and get a manual 350! :grin:

In all seriousness try resetting the transmissions adaptive learning. There are steps to do this located somewhere on this forum. Another option is to get a sprint booster which adjusts pedal response but also seems to have a perceived effect on the shifting speeds.

To be fair to MB the Porsche PDK is a godlike gearbox. The Ferrari F1 style gearbox is not so good at lower speeds pre-458 double clutch. Even then a Ferrari is in a different part of the car buying market than the SLK55 entirely.

It is like comparing a mid-2000s 1080p TV to a 2015 4k TV. You have to remember that your car is getting on for near ten years old and adjust your expectations appropriately.
 

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Administrator Founding Member since 2006
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Registered 2012 SLK55 AMG
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Transmission fluid change and engine remap certainly improved mine...nowhere near as good as other sport gearboxes on the market though.
 

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The speed of the shifts in my 7G, in all modes, has been a bit of a weak point in my SLK experience todate. I will give the 'remap' a try and see what I find. The Porsche PDK is indeed a great gearbox. I just drove a 2015 Carrera 4GTS for 5 days in southern France and was very impressed by the PDK gearbox. We have the 6 Speed MT in the 2013 Boxster-S, the wife likes a 'real' gearbox (her words), even thought I noted the PDK gives you a faster car. But it is her car so she got to select what gearbox it came with. Even our Cayenne-S with its 8 Speed Tiptronic, is also a fast shifter, you touch one of the up/down paddles and the RPMs almost instantly change. While in the SLK I notice a lag of perhaps just under 1 second. It is no real big deal in the SLK, you get use to it, and deal with it in your driving style, if in the Manual Mode. Does the AMG variant in the 55s shift better? I think they do label it as a 'Speed Shifter' or something like that? My next car will most likely not be for about two years, so I will see what MB is offering at that point, hopefully they will up the tranny performance a wee-bit. But as noted above, you are paying some big cash when you are in the 911, and up, world, so one should well expect some benefits.
 

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Premium Member 2005 SLK55 AMG
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Some people claim that it shifts faster if you use the gearstick instead of the buttons, but I wouldn't know as I either use auto (sport mode is best if you do that), or shift manually with the steering wheel buttons / paddles... and doing that, there's still the lag you talk about, even on the AMG (but, you do get used to it and adapt). :)
 

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Sean***
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Discussion Starter #7
True, but they have not improved it that much from what I read.
I have talked to several people including the guys at Kleemann that give a very logical explanation as to why the transmission is how it is, mostly to protect the rest of the drive train. The slip allows less strain on the drive train to to avoid wear and tear. Mercedes seems to more concerned with the fuel consumption, emissions and comfort than performance driving which is a bigger concern to most of the people who buy a SLK and I wanted a SLK over another Porsche for the driving comfort but then having a manual mode is almost a farce when you can't rely to engage when you are redlining the engine.
What would be nice but likely won't happen is if there were more after market bits available for the SLK 55. The SLK never hasn't been a track car really and any version such as the black is not all that different other than the fact the roof is fixed but Mercedes won't even sell you the other bits off that car which is annoying. One thing I always liked about Porsche was the way you can fit bits from one model and year 911 to another and there is a ton of after market and factory parts you can buy. One company does offer to modify the torque converter but I won't mention names because I found out later from someone that what they do will break other parts and get very expensive and it isn't cheap to have the modification done. I have tested 0-60 times and most consistant and fastest times I get are in sport mode letting the car do the shifting but I am going to change the fluid and try remapping after I get a few other bugs worked out. I suspect I am loosing about .5 sec in the transmission but will check boost and a few other thing before I delete the data that is saved. It would be a hard and messy job to try and do but I'd love to have an actual manual box even if an electronic one is easier to drive on a daily basis. Just would be nice to be able to not have computers always interfering in your driving. Was a lot worse before I put a Quaife diff in though especially after adding the super charger and other engine modifications.
Anyone have any experience with a larger throttle body with a super charger?
 

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I find all this rhetoric, which is all it is, about the 7-G amusing and not accurate.

The person who said he can determine the 7-G's timing between gear shifts is has spent too much time reading Harry Potter and lives in an imaginary world. The 7-G transmission is remarkably smooth, and the shifts are barely perceptible if at all. Remember an automatic transmission is deciding when to shift, and the 7-G handles this job exceedingly well. The problems comes in with manual shifting or using the paddles both of which are useless. It's doubtful that many drivers really know when to change gears even with a manual transmissions. Mercedes should eliminate this option along with the Sport mode.

I happen to have a BMW 135i with a DCT transmission. It too has the Sport mode and paddles which I never use simply because the transmission does a perfect job of deciding when to make gear changes. Machines always win over humans due to being so unemotional. BTW, this option was only $450, but it now only offered on the high buck M3/M4 for a huge sum of money. The Ones now have an 8-spd Steptronic likely similar to the Mercedes, and it does an excellent job too. Anyway, the only way I can really be sure what gear this transmission is in is a readout on the instruments.

After having driven both cars for enough miles to know that the performance of both units, I'd say that neither has a margin to claim superiority. Regarding the Porsche PDK, one might remember that the unit is a nearly $4,000 option in a car with a base price of $84,000! Oh yes and I have driven more Porsches than I care to admit to. Why do you think I drive an SLK and a 135i? The transmission doesn't work a bit better than the unit in my BMW, and I'd say it is just as good as the 7-G. Most of what goes around as great technology is mostly hype generated by the auto rags or hyperbole from the makers. If you really want to know how well your car performs, then run it against something or the quarter mile.
 

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Premium Member 2012 SLK350
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725 Posts
DSSG while I have to agree with some of what you say, if this car did not have a sport and manual mode, I think MB would sell very little of them or not at all. I would not have one. I want the manual mode for driving on curvy roads, like when I need to hold a gear in a corner or coming down a mountain grade.

The only time I seem to have a problem with this gear box is when I am in manual mode and I come to a stop, sometimes it goes to first on it own and sometimes it doesn't.

But overall, I like the manual mode and use it on twisty roads.
 

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Premium Member 2006 SLK55 AMG
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DSSG – I agree. It appears that the biggest issue people have with the 7-G is in manual mode. I have run my SLK55 in several autocross events and my best times have all been in “Sport” mode. The transmission software in Sport mode seems to always be in the correct gear for where ever I am on the track, with quick shifts at redline.
 
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