2018 c63 transmission problem
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Joined: Aug 2024
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From: Long Island N.Y.
2018 C63 sedan
2018 c63 transmission problem
Hi All hoping someone can save my day here. I have a 2018 C63 original owner. Car is stock and always had its maintenance. I’ll be honest I run the car hard but after all isn’t it meant to be. Terrible car to launch it either blows the tires off with no traction control or does weird things like shift to soon then downshift again when just a ordinary launch off the brake with traction control on. Launch control is just plain slow. I’ve learned to roll race only as this car gets spanked out of the hole. Lately I noticed a weird shift 2-3 and 3-4. It’s sloppy. Almost feels like it’s on the rev limiter or hitting traction control but it isn’t. Instead of a quick pop to shift as it’s always done it’s more of a flutter and car really falls on its face when it happens. It was sporadic but I’m now noticing 1/4 or 1/2 throttle it does it almost everytime. If I nail it from 55 or better it shifts as it should. And it’s mostly 2-3 but noticing it’s happening now 3-4. It’s a problem and it’s embarrassing because it’s prevalent and it falls down bad enough to lose races. Anyone else have this issue. No lights coming on. I’m told possibly a TCM or valve body issue. My local dealership says nothings wrong. They won’t take a test drive with me driving and evidently whoever test drives the car just doesn’t care or is oblivious. Thanks in advance for any help.
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Joined: Nov 2018
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From: San Francisco Bay Area
2019 C63CS
Thinking out loud here. I'm assuming the dealership has at least hooked it up to read any codes to see if the TCM is reporting excessive clutch slippage. If not, you may wanna do that. Hard driving is fine, but you may need to increase the maintenance frequency if you hammer the transmission. There's hard driving and then there's racing and launching it. You seem to be doing the latter mostly. Launching is very hard on the clutches and the drivetrain in general, and leads to premature wear. Just going with regular maintenance may not be enough. How often do you change the transmission fluid and have they checked if there are any metal shavings in the fluid?
The PFL is harder to hook up as the traction control is more brute force than anything, and the sedan is undertired with its relatively skinny tires compared to the coupe. AMGs are not really made for Drag Racing, which I'm guessing is what you are doing. You'll kill the clutches. Race Start has its roots in F1 essentially. It's meant for a fast start at the beginning of a race around a circuit, not straight line launch after launch. It's simulating what F1 drivers do manually with the clutch paddle on the steering wheel. A controlled dropping of the clutch at the beginning of a race for the fastest start and finding the balance between wheel slip and traction. It works better in the C63S FL with the 9-stage traction control as you can dial in how much wheel slip you want to allow.
So, you may wanna start with reading out all the codes and change the fluid, and checking the condition of the fluid. Look for metal shavings and signs of clutch burn.
The PFL is harder to hook up as the traction control is more brute force than anything, and the sedan is undertired with its relatively skinny tires compared to the coupe. AMGs are not really made for Drag Racing, which I'm guessing is what you are doing. You'll kill the clutches. Race Start has its roots in F1 essentially. It's meant for a fast start at the beginning of a race around a circuit, not straight line launch after launch. It's simulating what F1 drivers do manually with the clutch paddle on the steering wheel. A controlled dropping of the clutch at the beginning of a race for the fastest start and finding the balance between wheel slip and traction. It works better in the C63S FL with the 9-stage traction control as you can dial in how much wheel slip you want to allow.
So, you may wanna start with reading out all the codes and change the fluid, and checking the condition of the fluid. Look for metal shavings and signs of clutch burn.
Last edited by superswiss; Aug 13, 2024 at 06:58 PM.
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Joined: Aug 2024
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From: Long Island N.Y.
2018 C63 sedan
Thanks for the input. I wouldn’t say I’m drag racing the car. I have tried a few times but realized early on the car doesn’t like to come out of the hole. I’ve used the launch control 2 times and It felt hard on the car and still wasn’t good from a start. I changed the tranny fluid at 55,000 miles. Suggested by dealership. They did check the car for codes and tell me there’s no issue. I run the car hard but mostly from a roll. I’ve done a few burnouts just because it’s so hard to resist. All and all I would say I beat it that bad. But all that being said I have a def issue going on and it’s taking the enjoyment out of driving the car so I need to find resolve. I’m told at dealership they won’t even rebuild it they just get another one and install. Any idea of cost for a tranny or if in fact it is rebuildsble?
Out Of Control!!
Joined: Nov 2018
Posts: 11,468
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From: San Francisco Bay Area
2019 C63CS
Don't know the cost of a new tranny, but yeah a dealership won't do a rebuild. You'll have to find a transmission shop. This transmission is easy to rebuild. It all comes apart and pretty much everything can be replaced. Won't be cheap as it is engine out, but all doable. You can even find rebuild videos on YouTube of the general 7G with the torque converter. At its core it's the same planetary gearbox. Just has a startup clutch instead of a torque converter.
Last edited by superswiss; Aug 13, 2024 at 09:08 PM.
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From: Australia
⏱️ 700HP Facelift converted C63 S Coupe with Drexler 3.06 plated LSD
Hi All hoping someone can save my day here. I have a 2018 C63 original owner. Car is stock and always had its maintenance. I’ll be honest I run the car hard but after all isn’t it meant to be. Terrible car to launch it either blows the tires off with no traction control or does weird things like shift to soon then downshift again when just a ordinary launch off the brake with traction control on. Launch control is just plain slow. I’ve learned to roll race only as this car gets spanked out of the hole. Lately I noticed a weird shift 2-3 and 3-4. It’s sloppy. Almost feels like it’s on the rev limiter or hitting traction control but it isn’t. Instead of a quick pop to shift as it’s always done it’s more of a flutter and car really falls on its face when it happens. It was sporadic but I’m now noticing 1/4 or 1/2 throttle it does it almost everytime. If I nail it from 55 or better it shifts as it should. And it’s mostly 2-3 but noticing it’s happening now 3-4. It’s a problem and it’s embarrassing because it’s prevalent and it falls down bad enough to lose races. Anyone else have this issue. No lights coming on. I’m told possibly a TCM or valve body issue. My local dealership says nothings wrong. They won’t take a test drive with me driving and evidently whoever test drives the car just doesn’t care or is oblivious. Thanks in advance for any help.
Last edited by Jimmy_c63s; Aug 14, 2024 at 05:19 AM.
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My C63 S had an issue that sounds similar when shifting from 3 to 4, but only when on the track. It turned out to be that the transmission fluid was foaming. The fix was to add an anti-foaming agent. The AMG country specialist said he'd seen the same issue with some E-class cars in the winter.
What was happening was that a pump would pick up some foam/air'd fluid and the pressure would be low for an extended time during the shift process (we're talking milliseconds, here). That would slow the shifting so the revs would hit the limiter and fuel limiting would ensue. The net effect was that WOT would be .4 G acceleration, then suddenly about .2 G deceleration for a fraction of a second when the limiter cut in, then back to acceleration when the sift finally occurred (about 300 msec late). Very evident in track data-capture and by "seat of pants" meter. Also good for unsettling the car if you're in a corner.
Just a thought, but I wonder whether you've checked the transmission fluid level to ensure it's not low.
What was happening was that a pump would pick up some foam/air'd fluid and the pressure would be low for an extended time during the shift process (we're talking milliseconds, here). That would slow the shifting so the revs would hit the limiter and fuel limiting would ensue. The net effect was that WOT would be .4 G acceleration, then suddenly about .2 G deceleration for a fraction of a second when the limiter cut in, then back to acceleration when the sift finally occurred (about 300 msec late). Very evident in track data-capture and by "seat of pants" meter. Also good for unsettling the car if you're in a corner.
Just a thought, but I wonder whether you've checked the transmission fluid level to ensure it's not low.
Thread Starter
Newbie
Joined: Aug 2024
Posts: 3
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From: Long Island N.Y.
2018 C63 sedan
Hey thanks for the input. I will certainly look into checking the fluid. I’m guessing I have to take it somewhere to do that as I don’t see a way to check fluid. Looking into it now. Thanks for the tip.
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C63s
If shop did tranny fluid then have them check level because it will be a headache for you. Checking level is the same work as a fluid refresh because unless trans fluid was overfilled you will have to add more anyway
If you did it yourself then you get the car level (level while lifted, not level as in parked on flat ground) and let there be a rapid drip of fluid coming out while trans fluid is exactly 113°F or 45°C. Put the drain plug in at that moment.
If you did it yourself then you get the car level (level while lifted, not level as in parked on flat ground) and let there be a rapid drip of fluid coming out while trans fluid is exactly 113°F or 45°C. Put the drain plug in at that moment.
Last edited by '1663s; Aug 18, 2024 at 01:40 PM.
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