[speedyink1]

So since day one my car has exhibited a small vibration from what feels like the back half of the car. (2023 SS M6)

Now, strangely enough this vibration only happens in a specific scenario, which is as follows:

Only happens on deceleration between about 90km/h and 120km/h. It seems to be more pronounced in 6th gear, although you can feel it very slightly in 5th.

Goes away as soon as you push on the accelerator in the slightest, and at lower then 90km/h and at any speeds including... much higher then 120km/h it's smooth as butter.

I've told the dealer about it but haven't got around to bringing it in yet due to being super busy at work. But I'm gonna get some time where I can actually take it in on a week day. When I do, It'd be nice to be armed with whatever info that may be out there.

Thanks!

[CalgaryZL1]

Drive shaft balance? Universal joint? Drive shaft Support?

[N Camarolina]

It it has to be something in the drivetrain, rather than the wheels or brake system.

Since you hear it in the rear, have them start by looking for loose fasteners/connections (drive shaft at either end, axel half shafts from rear diff to rear hub) or problems with the rear diff itself.

[superham]

I have the same issue. My car is MT and when I disengage the clutch or start to accelerate the vibration goes away. The dealer said it was likely the exhaust that was causing the issue (I have the NPP). I didn't push the issue but curious what you find.

[speedyink1]

Thanks guys, I'll keep those things in mind when I take it in.

Originally Posted by superham

I have the same issue. My car is MT and when I disengage the clutch or start to accelerate the vibration goes away. The dealer said it was likely the exhaust that was causing the issue (I have the NPP). I didn't push the issue but curious what you find.

Interesting, sounds similar. I think mine also goes away with the clutch pushed in. Does it do it at the same speed?
I also have NPP, interesting..


At least I can ask about the above things(Again, thanks guys). In my mind is does feel rear diff related.. it's just weird that it goes away at higher speeds. Past experiences tell me rear diff problems usually get worse as you go faster. Like, it's smooth as butter at anything past around 120km/h (and well past). Same thing about not being there with any sort of throttle applied.. It's the dangest thing. Oh well, we'll see what the dealer says, and I will ask them to check the fasteners/connectors etc.

[superham]

Mine does it at highway speeds. Not sure if it goes away after 75mph. Will need to check it out. Try changing the exhaust mode - tour, sport, track and see if the vibration changes.

I had my rear diff fluid changed and its still happening on my 2024 2SS

[speedyink1]

Funny, I also got my diff fluid changed. No difference.

I'll change it stealth or tour and see what happens. I've never had the exhaust set to a quiet mode, I made it not change with the mode selector. Somehow doubt it but hey, weirder things have happened!

[superham]

Nah. Go from tour to track.

I don’t even know what this car is like in stealth. I live in sport and launch on track.

[Kamero6]

Originally Posted by speedyink1

So since day one my car has exhibited a small vibration from what feels like the back half of the car. (2023 SS M6)

Now, strangely enough this vibration only happens in a specific scenario, which is as follows:

Only happens on deceleration between about 90km/h and 120km/h. It seems to be more pronounced in 6th gear, although you can feel it very slightly in 5th.

Goes away as soon as you push on the accelerator in the slightest, and at lower then 90km/h and at any speeds including... much higher then 120km/h it's smooth as butter.

I've told the dealer about it but haven't got around to bringing it in yet due to being super busy at work. But I'm gonna get some time where I can actually take it in on a week day. When I do, It'd be nice to be armed with whatever info that may be out there.

Thanks!

Had a very similar thing. It was the runflat goodyears. They flatspot overnight. In the morning going to work I felt it more than coming back in the afternoon.
Try using 30psi. After 15k miles it kinda smoothed out. But it drove me crazy.
You feel it more in the back because the rear is lighter.

Also under full acceleration sometimes the driveline vibrates or feels like it does.
I blame the rubber discs that are used in the driveshaft. Its the nature of those things. If you shock them (like the A10 does) they sometimes deform and vibrate until you release the load and they come back to the center.

[Kamero6]

Originally Posted by speedyink1

So since day one my car has exhibited a small vibration from what feels like the back half of the car. (2023 SS M6)

Now, strangely enough this vibration only happens in a specific scenario, which is as follows:

Only happens on deceleration between about 90km/h and 120km/h. It seems to be more pronounced in 6th gear, although you can feel it very slightly in 5th.

Goes away as soon as you push on the accelerator in the slightest, and at lower then 90km/h and at any speeds including... much higher then 120km/h it's smooth as butter.

I've told the dealer about it but haven't got around to bringing it in yet due to being super busy at work. But I'm gonna get some time where I can actually take it in on a week day. When I do, It'd be nice to be armed with whatever info that may be out there.

Thanks!

There's also a NVH app for the phone that uses the accelerometers to detect frequencies and can determine what is it. It is paid, and the only option besides the expensive pico machine.

[Ventmaster]

Gotta go with Kamaro6, tire imbalance is the first thing to check out IMHO. Remember- KISS!

[speedyink1]

I usually have mine at 35psi, is that too high?

Also, that app sounds interesting, what's it called?

Yes! Definitely small things first! I was going to do the diff fluid anyway, was my 5000km initial change

[Kamero6]

Originally Posted by speedyink1

I usually have mine at 35psi, is that too high?

Also, that app sounds interesting, what's it called?

Yes! Definitely small things first! I was going to do the diff fluid anyway, was my 5000km initial change

I run 32 in the front and 30 in the back. It helped.

[superham]

I've switched to all season continental dws' and still experience the vibration. also put on a new set of wheels recently. no change.

i have a strut tower brace which may be contributing to it but doubtful since its not RPM dependent but speed.