Has anyone else experienced the revs climb and then fall back down similar to a slipping transmission when applying full throttle from lower rpm in high gear? Sometimes if I stay in 4th or 5th and punch it at lower rpm the revs will climb and then fall a little and continue climbing and I'm sure I'm not losing traction. I have a dinan tune if that makes a difference

 

Your transmission is toast.

 

I find it hard to believe when many people are at higher power levels and my car is only at 18k miles. Maybe it's normal?

 

It sounds like the clutch packs have gone bad. is the car stock?

 

Sounds like your clutch pack is done. Time to see the Dinan warranty in action.

 

Okay, I'm going to take a video and see if everyone here thinks it's extreme enough to warrant talking to dinan about it. It's only a slight raise and decline of revs right now but it is bothering me and I don't want it to get worse.

I also read a post where the transmission valve body needs to be replaced, but that was on older cars. I have an MY17 coupe.

My issue is not as extreme as this:
https://youtu.be/8g5nwiby5rI

 

It is possible that it will get progressively worse over time.

 

Is it your first dual clutch gearbox car?

 

You seem to have a erroneous idea that a C63 has a dual clutch transmission.
It is a regular 7 speed auto transmission with the main change of putting a multi plate clutch pack in place of the fluid coupling.
NOT a dual clutch box.
The MB GT cars (GTS etc.) have a dual clutch gearbox.

 

Coming from a 2016 GTS, i assumed it was the same in my C63S. having said that, a multi plate clutch gives the same sensation when driving. hence, why i asked. it can be very deceiving to drive and can feel like slippage(like a valve body on a traditional automatic. thank you for setting me straight lol

 

 

There is a link to a YouTube video in the bottom of post #6.

As for the issue at hand, I'd suspect that the valve body is having an issue and not the clutch packs going bad. It seems to be fine at lower speeds, but the clutch just doesn't want to or can't engage in the higher gears. It's more like its kicking into random neutral and not slipping. If the clutch packs were toast, you'd also expect similar behavior (albeit not as bad) at lower speed in lower gears as well.

 

Did you find solution for this?

 

Did you end up getting the transmission valve body replaced? Did it fix the issue?

 

Do you find it does it in sport/race modes too, or just comfort?

I have noticed this behavior a few times, but not sure its slippage in a bad sense. I started noticing it long enough ago, and have done enough WOT pulls with no issues since, that I think the trans would have failed by now if it had actually been converter slipping. Fenerally once a torque converter starts slipping, it will get worse quickly and show up most under WOT.

Is it possible its the TCU programming is just making the torque converter flash up to ease stress on trans under high load?

 

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My car has been recently modded and my tuner told me that my clutches would not need to be rebuilt until I was closer to 800 crank hp
However, he has seen some modded cars have to do it sooner with less HP but they were 1/4 mile cars doing hard launches over and over.

I run my car in 1/2 mile events and recently competed in an event with my new mods and did 8 runs with no tranny problems...but then again 1/2 mile doesn't require as hard of a launch. I usually either put the traction control in "Sport" or turn it OFF and pedal through tire slippage to get her rolling.

I also have not experienced any slippage like the OP but then again my car is recently tuned and modded.

BUT there must be a reason that Weistec offers a clutch rebuild for our trannies??? Just my 2 cents!

 

My car has been tuned for about 8 months and I have done more launches and hard pulls then I can count. From that experience in everything I've read on different forums, I haven't seen anyone complain about proven transmission slippage or wearing it out with basic mods.



I think that has a lot to do with the fact that they sell big horsepower Turbo upgrades and figured that a lot of their customers may be looking for peace of mind with extreme builds. That does not necessarily indicate to me that it is something A lightly or moderately modified car would need.

 

Oh I agree 100% that is Weistec's intent with that clutch rebuild. They do offer turbo upgrades capable of pushing our cars to 900hp or greater. So why not offer this clutch rebuild for those type cars?

In my post I tried to convey that you should only have a possible problem with your tranny if your making big power...the OP said he was tuned but that doesn't tell me anything about how much power or TQ he is pushing or how the tune is delivered. So I was trying to make a general statement...guess I may have needed to word it differently???

 

Following as well. I notice what I thought was slip at first (it might be), but only under partial throttle. No issues on WOT or when doing pulls/driving hard.

If transmission valve body replacement is the fix, does anyone have the part #?

 

Have someone find out what causing this? Valvebody? Clutchpack?

Regards Mattias