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So I've purchased this car back in August with 32k miles, vehicle ran strong with no issues. Around November the vehicle sat for a month, went to start her up and its first shift from 2nd to 3rd slipped really bad. Didn't think much of it so I kept driving, eventually I started to notice it was slipping from 1,2,3,4 and 5 about 200 to 500 RPMs depending on my throttle. I then decided to perform a full transmission flush since according to Mercedes records it never received one. The vehicle now has about 36k miles, purchased all the fluids, filter, gaskets, and bolts from Mercedes and performed the flush. Upon dropping the pan I noticed good amount of shavings on the two magnets, considering this pan has never been cracked open before I'm not sure if this was "normal" wear from the clutch or if I'm just super unlucky with this clutch wear (Attached images below). So, I proceeded with the flush and see if it at least helps. After completing I performed a TCU reset, put the car in sport and began the relearning process. The AMG drove a lot better but it still had a slight slip between 1,2 and sometimes 3. Drove it for a few days and performed the flush again without dropping the pan. The AMG now drives a lot better but not as great when I first purchased it. Still a slight slip between 2 and 3. On a hard pull the transmission shifts just fine, however I'm concerned if there's any underlying issues with the transmission that's preventing it from being nearly perfect.
According to Mercedes a ECU and TCU software upgrade is available, this'll be my next step and I'm hoping this'll resolve any issues. Also not to mention my CEL is on with P0171 (Bank 1 and 2 are lean), I don't think this has anything to do with the transmission as I'm sure its just a leaky vacuum hose as that seems to be common?
AMG currently has no mods besides ROW airboxes.
Since Mercedes will be doing the software upgrades I'm wondering if they'll be able to diagnose any underlying issues with the transmission (solenoids, valve body, etc) or if it's shifting as fast as it should be. Any thoughts or suggestions would be appreciated.
Last edited by C63AMGeez; Jan 4, 2019 at 06:37 AM.
I’m not a fan of flushing gearboxes as many of the guys on here will probably agree. I much prefer drain and refill cycles, it may cost more, but it’s a safer bet.
2010 C63 AMG RIP. 2021 Toyota Tacoma TRD Off Road, 2013 C63 coupe
The amount of build up on your magnets is not concerning in my opinion. I have flushed two torque converter 7g and one MCT 7g and saw a similar amount of build up.
As you dropped your oil pan, did the filter drop as well or did it stay clipped in?
The amount of build up on your magnets is not concerning in my opinion. I have flushed two torque converter 7g and one MCT 7g and saw a similar amount of build up.
As you dropped your oil pan, did the filter drop as well or did it stay clipped in?
It stayed clipped in. Has anyone performed a TCU upgrade from factory and noticed any difference?
mine had the same. I unplug the minus battery pole for about 10 minutes and after the transmission ecu begins to learn from new. after reset shifting is harsh, after 50 miles normal drivimc its much better.
I had this after ecu upgrade, after headers and cats.
Performing the flush ended up resolving the slip issues I was experiencing. I realize the MCTs like to slip on low rpms between 1-2. As they warm up to normal operating temp the shifts become more aggressive in M mode. Comfort mode will of course always slip to maintain smooth power delivery.
Some issues:
Transmission service involves following the factory procedure to drop the oil and replace the oil and filter.
Transmission flush involves hooking up an expensive external pump that is not called for in the MB procedure and as per the flush designation, pumping pressurized liquid through the transmission, in hopes of doing more good than bad.
The external machine is certainly not cheap. I think that the labor to do the oil replacement is much reduced. So this is something that benefits a shop. And when things go wrong, they will suggest another flush...
Then they will indicate that hey, flushing did not work, now get the transmission rebuilt...
As far as clutch material..
Clutch material would have no business being in the oil pan.
While this is a "wet clutch", what makes the clutch wet is not the transmission fluid. It makes sense because something so fragile as the internals of the 7 speed, would not survive clutch material running through it.
Also, if you look at the oil changing procedure of the MCT, there is no additional drain plug that you normally have for the torque converter, no additional quantity of oil to be drained from the clutch housing, as you normally have for the torque converter.
There is also no procedure that I've seen to replace the wet clutch liquid. Maybe it's replaced in one sealed unit.
I've read all promotional materials about the MCT and other than being multi clutch, there was not much explained.
I watched the Tassos video about the MCT, but no luck so far. Maybe I'll try to message him.
At the same time, I don't know of anybody here that required a clutch pack replacement in an MCT. Maybe someone will post now...
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