armaggedon

Hey guys, new to the forum.

So I have a question and am interested in seeing if anyone else here has experienced the same things I have with their vehicles. There seems to be a terrible clutch/driveline shudder when launching in 1st gear. I mean typical sort of parking lot launching that is very low speed and non-aggressive. I've been contacting dealers to see if they've encountered the issue but none seem to have, and if they have, they aren't telling me about it.

Has anyone else experienced this or am I just a lone wolf?

HalfMoon

I am no expert here, but depending on the amount of vibration, what you're describing almost sounds like this is your first direct injected car and you are hearing/feeling the Dual Mass Flywheel.

When I first experienced this on the Audi and VW cars I thought something was wrong.

I've yet to drive a 7 speed C7 yet, so I cannot be certain... but others have talked a little about it here.

JoesC5

I've never driven a car with a dual mass flywheel, but I understand there were problems with them in the C4's. GM then built the C5's and C6's with a regular flywheel.

My understanding is that the reason GM went with the dual mass flywheel for the C7 was to dampen vibrations when in V4 mode.

HalfMoon

Yeah, there's a spring in the flywheel that acts as a buffer of sorts. In the German cars I have experience with them they remove the NVH under normal driving and idle, but when taking off normally from a stop there's noise that exaggerates the bit of vibration that is there as well, sometimes raising concern, even if you're used to driving them. Everyone has told me after I let them drive it that it is completely normal.

Very weird for a guy that is used the LSx motor cars for sure. Now I want to go find a manual C7 to drive to hear it before mine gets built.

gr814u2c

From my experience, some Corvettes will do this depending on the type of way you modulate the clutch. I wouldn't be alarmed.

armaggedon

Thanks for the replies guys.

This is my first direct injected car and first dual mass flywheel car but I don't really consider myself to be inexperienced with manual vehicles. The reason the shudder is alarming is because it's bad enough that it vibrates the car to the extent that not giving it enough gas and almost stalling it does. Enough to chatter teeth.

Granted, me modulating the clutch hasn't changed from previous vehicles I've driven. It just seems like there's something more to it. Idk.

Big Dan 427

It could be possible someone heated the disc before you got it, just like on a brake rotor it may now have a "hot spot." Could have been during dealer prep or even the car carrier riding the crap out of it while loading/unloading. Just a thought, could even be a defective disc.

gr814u2c

Are you launching with just the clutch or a combo of clutch and gas?

bdspell

hi do a search under clutch shudder on the c6 forum lots of info there ,my take on a c6 is that the engage point is higher off the floor and it's a learning thing even though your a experienced manual driver

ldepalma

Also, my C6 brand new did the same thing without dual flywheel and it was a MY 13. My C7 sometimes does it as well. Working as designed, I guess???

armaggedon

I'm launching with a combo. Just for ***** and gigs, I went out and kept the revs around 1200 while launching and if i modulate the clutch just right, I can keep it shaking for as long as i want to. It's not destructive to the clutch, at least it wouldn't be in any other car.

gr814u2c

You are finding a driveline resonance. All manual transmission cars have this at some RPM. Try keeping the RPMs below 1000 for normal driving around launching, it should help keep the shutter down.

HalfMoon

Armaggedon: When in doubt, swing by your dealer and talk to the service manager to get a second hands-on opinion.

armaggedon

Alright thanks for all the help guys.

-CM-

This happens to me, but I just chalked it up to being rusty with a clutch. For me, the reverse gear is a lot easier to modulate. I am still not completely proficient with 1st gear yet, even after 2350 mikes. But at least I don't stall the car any more.

pietro c7

Bingo.....on another note,clutch is taller then you think.....doesn't stall easy.

xp800

My C7 M7 has the shudder you describe. May be more noticeable when cold, and also when engaging at low revs on lazy engagement/accel. Wasn't too worried since I've not been hard on it, and the comments here make it seem it's the norm.

HalfMoon

Actually, thinking back, my C6 gave me fits for the first week with taking off in 1st gear. I then followed a thread here about removing or replacing the over-center spring on the pedal and it cleared up for me. I drove the car the rest of the 2.5 years and 14k miles w/o the spring and never had an issue. However, removing the spring makes the pedal much harder to press, so some people bought the C5 spring which was a medium ground between the C6 spring and nothing.

That spring made judging where the engagement point was a guessing game and a very inconsistent pedal feel which made smooth launches under normal driving a pain.

jwbert

My C5 had this problem bad, but then the previous owner
was a young kid who I'm pretty sure beat the snot out of the car
before I got it, based on this and some other evidence of abuse.

Bill B 1

It's been close to 30 years since I put in any time on a clutch and I haven't noticed anything like what you describe on my C7.