bullitt69

Did anyone ever have problems with their wet clutch on MCT C63s or on other AMG vehicles equipped with the MCT SpeedShift transmissions?

If yes what were the sypmtoms?

The reason I'm asking is that I'm experiencing the weirdest and hard to diagnose problem on my 2011 facelift C63.

The car is emitting a droning / groaning sound on low speeds with a minor resonance with can be felt in the pedal cluster, steering wheel and seats.

It feels that the source of the sound and resonance is somewhere between the center and front section of the car.

This sound is speed dependant and stays there even if you roll down a hill with the engine off in neutral.

List of what was replaced:
- front brake rotors and pads
- both front wheel hub and bearing assemblies
- driveshaft support and bearing
- gearbox and differential fluid

When the car really warms up it starts shuderring upon acceleration on low speeds.

I'm susppecting that it's the wet clutch, gearbox or driveshaft. It's deffinitely something that keeps on spinning with the engine off and the car rolling.

roadkillrob

So, as far as I know the 2012 was the facelift year and the 2012 was the first year C63 with the MCT - are your sure you have the MCT or maybe if not in the US, they may have called some of the facelift cars at 2011?

bullitt69

roadkillrob

Ah that makes sense, I have not heard of any real issues with the MCT unless heavily modded or supercharged and making a lot more power. What is mileage, last trans fluid change?

Also check your center driveshaft mount for play, have seen that before get a bit loose and cause noise vibration. Motor mounts are also a common failure point it seems that can cause some vibration and noise to be transmitted.

bullitt69

Diabolis

It's unlikely that it is the the wet clutch per se if that's the only symptom and you can feel / hear it when the engine is shut off and the gearbox in neutral. In light of the fact that you've had the wheel hubs, various mounts and driveshaft bearing replaced, the question I'd be asking is why the transmission and driveshaft mounts and driveshaft bearing needed to be replaced in the first place as they are not items that would normally fail at this time. It almost sounds like the transmission and driveshaft are misaligned or the driveshaft itself is warped, which could cause said vibration (even more noticeable now with a new, tighter bearing) and could result in premature driveshaft bearing failure.

bullitt69

Thanks for the idea, I'll have the protective shielding removed and the driveshaft visually inspected in motion with the car on the lift.

I had the engine mounts replaced on the recommendation of the tech who had the car inspected after the purchase.

By the way, I had the idea of misalligned engine mounts come to my mind and actually had the reseated again. It didn't help.

Another thing which puzzles me is that it feels as if something is restricting the movement of the car on overruns. I think my best option would be to initially replace both rear wheel bearings besides having the driveshaft inspected. I have a feeling that strange gearbox behaviour could be caused by something hindering the movement of the wheels and driveshaft, leading to gearbox overheating. Too bad we can't monitor gearbox fluid temperature on the instrument cluster of the C63.

Vladds

What's the wet clutch marinating in? It's not transmission fluid and you don't get to change it when you're changing the transmission fluid in MCT cars. The quantity of transmission fluid for MCT is exactly the 7 speedshift without torque converter contents.
How many wet clutches are there, is this a clutch pack? All remarks about the clutches that I've read are based on the single phrase that was put out at the press release, surely not enough to know what's going on with these. What engages them, a solenoid? What happens to the torque converter torque multiplication in the 7 speedshift, it's out the window for the MCT cars ?

BLKROKT

Amr_c63

I'm having some issues now that its freezing temps outside , the engagement is slow and also it tends to slip from time to time . I have 52k on the clock and I don't think the trans service was done yet from the previous owner. Once the car is warmed up it behaves normal. I have a question though has anyone done the fluid swap and noticed an improvement ?

bullitt69

Update:

I had a mechanic check whether the driveshaft had been assembled back together correctly during the driveshaft support bearing replacement procedure. And what do you think - it wasn't. The marks on the two parts didn't match.

They reassebled it they way it should be and my problem didn't go away.

My last 2 bets are the wet clutch or something in the gearbox.

The problem is so weird, it feels as if you're driving over very rough asphalt when the road is perfectly even.

zcct04

Have you ruled out wheels and tires?

bullitt69

bullitt69

Just to update:

I had the wet clutch (torque converter replaced) and it it did absolutely nothing to solve my problem.

The car drives absoutely fine and with minimum noises from the drivetrain after being parked for the night in an underground parking lot. As soon as it heats up it strats emmitting the groaning sound along with the vibration I explained above as well a power loss and a laggy throttle reaction. It almost feels like the infamous transmission limp mode. The area I live in is rather cold now with temperatures below freezing but I can spend an hour in traffic jams, so the car can really heat up.

Also I get the same groaning/ vibration immediately after I start moving on my car which has been parked on an outdoor parking lot near my office for the enitire day.

I'm trying to figure out whether the power loss and the groaning sound is somehow connected, but I'm nearly out of ideas. It's such a problem that the car doesn't throw out any related codes.

Celicasaur

I get this random vibration at times, when the car is very cold and coming to a stop on my journey to work....the cold slippage also seems like it's becoming somewhat normal for older cars..i think it's just general right of passage until it inevitably fails

Once warmed up though, I don\t have any issues with sounds,vibration or engagement. Safe to say i'll be making a thread or posting in this one within the next 12 to 18 months.

Did you have the clutch discs replaced too though?

bullitt69

I had the entire wet startup clutch unit replaced, the clutch discs are inside this unit. There are more friction discs inside the transmission though which are resposible for separate gears.

Vladds

Does that wet clutch drum have a drain plug ?

bullitt69

Mahoo2

Hi

Did you manage to resolve your issue. I’m having similar problems but no mechanic can find out whats causing it.

kuti63

Hello vBulletin
i have the same problem. were you able to solve the problem?
I would be happy for a feedback.

kuti63

Hello
i have the same problem. were you able to solve the problem?
I would be happy for a feedback.

eightysixtuned

the MCT should not make any "groaning" noises. It is a wet clutch system thus should be fairly silent unless it is broken internally which is rather rare. if the MCT is not being correctly engaged it'll work as it is disengaged and will not move the vehicle. In most cases, the transmission clutch plates will wear out well before an MCT clutch system wears out assuming it isn't a freak occurrence of failure.

not having a code within SDS is something i'd like to see as it is almost impossible. the factory engine computer and TCU calculate "requested torque" and "actual torque" along with "engine speed", "transmission speed", "output/driveshaft speed", and wheel speed. if any of those are out of specification you'll fault.

bullitt69

Yes, I solved the problem back then - it was an overheating issue.

The following procedures were done:
- front bumper was removed and ALL radiators were surface cleaned with disassembly. There was loads of dirt and road debris in between the radiators. The secondary oil radiator (by the wheel) was clogged as hell.
- all fans were checked for proper operation
- the AC radiator was replaced. I heavily damaged it's fins when pressure washing the car myself which was preventing proper airflow
- the coolant was replaced

Many problems on these cars come from overheating apparently, as the engine is too big for the w204 engine bay.

Now I annually have my radiators cleaned and frequently change all fluids.