Mayor111

Hey guys,

Looking at a 2017 GS auto. My previous C7 was a 14 M7 so I never had a chance to experience any shudder issues. Can someone please explain what the A8 shudder feels like? Does your wheel shake like it does when you have low tire pressure? Does your shifter vibrate? Does it happen when the car is cold or after driving it and its warmed up?

Any details what I need to look out for when testing driving would be most appreciated. Thanks!

rmorin1249

Several describe it as though you are driving over rumble strips.

AmmoVet

There are threads on this. Start your search here: https://www.corvetteforum.com/forums...-tracking.html

Flame Red

rumble sticks is how it feels - except the road is smooth as silk!

kvozel

B-17/B-25 CC

Plus you can watch the tach “surge” up and down 50-200rpm while highest cruising.

yellow2007

If you've ever approached a toll booth and run over those strips they use to make sure you're awake.......that's it......

Emsand1

Agreed.....similar to mild rumble strips. I mostly felt it under mild driving conditions meaning light acceleration or slight deceleration. I never noticed a problem under hard acceleration.

jim spitzer

My 17 vert just started it again, It's going to the dealer this Thursday for a few things. one being the rumble strips, Only this time mine was a little different it was more like when in the old days you had a u-joint going out it was more the vibration. My car has 29.8k on the clock I've had it well Dec 2nd will be 3 years. The transmission has been re flashed 2 times, the fluid flushed 2 times, the TC replaced 1 time after that I felt like I was home free. Then last fri went to meet up with the wife for dinner and between 48 and 53 mph new paved road plus I just put on a new set of tires 2 weeks ago the vibration shows up, So I parked the car until I take it to the dealer.

The other thing I have is a bad rattle in the center dash that goes to the passenger door. And I think the rear speaker is going bad. my car is a 2lt so it has the extra bass speaker in the back. I do believe that there is a TSB on the door rattle

yellow2007

Check my thread "lubegard vs shudder round 1" I believe I have stumbled on a cure.

Tally Ho

I had the fluid change and flush done on my car after the usual shudder symptom. About a week later I noticed a vibration similar to what you might get with bad u-joints. I found out I had two bent wheels both on the left side. Since you're taking the car back to the dealer, have them check all of your wheels. My car is currently parked until my new forged wheels arrive. I did not want to prematurely wear out new tires.

Dif

Here's a very interesting thread worth reading.
I'm now a Happy Camper
https://www.corvetteforum.com/forums...round-1-a.html

pdiddy972

Feels about $4,000

RiCorvette

For you SoCal Folk; I've got 2 tubes of Shudder Fixx 2 oz. I don't need - $6 ea
Pick up in Buena Park or Lakewood

craigp40

Gents, in addition to describing the A8 transmission problems (I've seen a lot of info on that) can you guys also provide instructions on how to recreate the symptoms? I'm in the process of upgrading my C5 to a 2014 or 2015 C7 and would like to know what I need to do on the test drives to expose this stuff. Haven't been able to find this info in my searches.

yellow2007

It's not really something you can "recreate". It either happens or it doesn't. You can try leaving the AFM on and not use the paddles and see if it happens.

DeweyIsgod

That...and on the test drive, I'd set the cruise control at about 60mph on a flat road after the car is warmed up. If you see significant (>50-100) RPM fluctuation, be very cautious regardless of whether you feel a shudder.

Of course, you can just make the leap that a lot of us have made and realize it's a lot easier to just install the Range device to keep the AFM deactivated and not have to worry about it.

Dif

The problem with some of us, myself included is when using a Range unit or putting it in Manual V8, it still does not stop the shutter.
Barring any mechanical problem, the Trans Fluid is what's causing this problem preventing the TC Clutches not to grab and release smoothly.
This thread on Lubegard Transmission additive has present day info, including the successful results I now have after adding Lubegard to my A8 Trans.
https://www.corvetteforum.com/forums...round-1-a.html

Here's my experience:
I have 24,500+ miles on the Original 2016 A8 ATF Factory fluid.
Since new, I always had that slightly annoying rumble strip feeling in V4 and V8,.. more so in V4.
Other than that it worked fine up until a little while ago when going slow in V4, the "whole" car would shake and shudder when giving it light throttle.
It seemed to be having trouble disengaging smoothly from V4 mode before going into V8.

I put 250 miles on after adding a 2oz tube of Lubegard Instant Shudder Fixx with successful results within the first 20 miles.
Later, not to over fill the Fluid level, I Removed 10oz of Trans fluid and Added 10oz of Lubegard Platinum for longevity as suggested on the Lubegard website, then put on another 100 miles.
At that point if I wasn't paying attention trying to feel something happening in V4, I didn't notice it any more.
Another thing it helped improve is the shifting, it's much more precise and stronger, and acceleration improved because the TC clutches are no longer slipping when they should not be.
Last time I drove the car I put on another 165 miles and it's improved even more.
Whether it's a permanent fix, time will tell.
But the fact that the Fluid is/was the problem, and adding Lubegard, my A8 is actually running smoother and shifting better in V4 and V8 than it did new.