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Rough Shift Until Warm
My 2013 SLK-55 AMG has a "difficult" shift from 3rd to 4th until the operating temperatures become warm. The car hesitates as if it's "trying" to shift to 4th, and then shifts abruptly and somewhat hard into 4th. It does the same thing whether applying light throttle or heavy throttle. After the car warms up, the shift from 3rd to 4th is totally normal. The AMG has the performance package, and has 4,500 miles on it. It's typically being driven in "C" and all perimeters are in the typical default mode.

I don't remember this shift being problematic last winter, but then the car has few miles on it and my wife is the typical driver.

Any of you notice a similar situation with your AMG's?

Thanks!
 

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Can't speak for r172, but i always let my amg warm up and let the revs drop to 7500 before proceeding. In cold weather, yes, down the block after letting it warm up, it will do about the same. And I always drive in S anyway.
 

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Can't speak for r172, but i always let my amg warm up and let the revs drop to 7500 before proceeding. In cold weather, yes, down the block after letting it warm up, it will do about the same. And I always drive in S anyway.

Theats what I like to see - a man who warms up at the red line ....!!

Cheers
Sean
 

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you know what i meant! 750! LOL!!! Truth came out!
 

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Haven't experienced the problem you're describing, but then again, a "cold start" in San Diego describes different conditions then the rest of the country, particularly this winter.

I don't know when the last time was that your car has been serviced, but there is an open campaign out there called '2013110002 - Fuel System Update' that looks to have manifested in issues for a couple of other forum members.
 

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If it is under warranty i would have it checked by MB to check for error codes and maybe TCU update if available.
 

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Solution to cold start.......Move to San Diego:bannana: Ok, I'm a banana . I couldn't resist. The Chargers have had a few games on TV of late and when they show those panorama shots of the sail boats and the palms, it must be a beautiful site for folks that are living where you get 4 seasons.

Cars with low miles shouldn't have the problems with rough shift. In most auto trannies, the fluid should be doing all the work hydraulically and when the fluid has had thousands of thermal cycles from regular use it begins to break down. The compromise in shift performance is subtle in most cases. The tranny in the AMG is different because of the difference in engineering between conventional torque converters vs the compact wet startup clutch. Fluid integrity, however is still critical for proper operation.

I recently did a tranny service on the SLK 320 5 spd auto tranny with 35K mi. on it, the improvement was substantial. Mind that the initial MB service protocol on these trannies was "no service for lifetime on unit". Of course that had been amended several times. Along with the new tires I had installed, the driving quality changed noticeably after the service. A tranny service like that only changes approximately 50% of the fluid. If I were you, and the car is still under warranty, I would have them change the fluid first along with a TCU reset/update, and see if that fixes your problem.

May you shift fast and prosper
 

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Rough Shift Until Warm
My 2013 SLK-55 AMG has a "difficult" shift from 3rd to 4th until the operating temperatures become warm. The car hesitates as if it's "trying" to shift to 4th, and then shifts abruptly and somewhat hard into 4th. It does the same thing whether applying light throttle or heavy throttle. After the car warms up, the shift from 3rd to 4th is totally normal. The AMG has the performance package, and has 4,500 miles on it. It's typically being driven in "C" and all perimeters are in the typical default mode.

I don't remember this shift being problematic last winter, but then the car has few miles on it and my wife is the typical driver.

Any of you notice a similar situation with your AMG's?



Thanks!

I could be wrong, but I remember reading somewhere that cars with the PP have a complimentary gearbox service included after a few thousand miles.
 

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Discussion Starter #10
Well, the shift from 3rd to 4th gear appears to be worsening. How disappointing to spend so much on a vehicle only to have what appears to be a significant mechanical problem. One can always hope for a simple fix..... I've scheduled the car to be dropped off at the Houston Mercedes dealership Feb. 7th.

I'll let you know what they find.
 

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Hello,

I had a similar issue between second and first. I understand it happens because the Artificial Intelligence algorithm in the car learns from your driving (sometimes wrongly). There is a way to de-program the learning byaccesing the menu and pressing the accelerator (i found it on the web and will look again tonight and post it if i do). At the dealer initially they could not solve it and argued that the software was the same(obviously but not the learning...) until the AMG expert took the car, turned esp off, and drove the car for a while retraining the software. I would then reset the software and drive the car 'adequately' without forcing changes with the trottle for a couple of days... hope this helps..... BTW I know itsounds odd but even your washing machine today can have some AI software....
 

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Discussion Starter #13
Took the AMG to the Houston dealership and they told me there was a transmission computer control upgrade for my car. They installed the update and it shifts better. Still a tad "clunky" when it shifts to 4th (only when cold), but quickly disappears after a few miles.

I tried the "adaptive learning" reset (thanks for the link guys). That didn't seem to help, but I've also got a keyless (pushbutton) start so I'm always a little unsure that I'm working the switch right when doing the reset.
 
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