A8 symtoms
Thread Starter
Intermediate
Joined: Jul 2019
Posts: 49
Likes: 10
From: Near the Chesapeake
A8 symtoms
Purchased a new 2019 LT1 with A8 last summer. Have 1700 miles on it. First corvette-I'm a novice.
Based on reading the forums, just installed a range device and almost all of what I thought might be A8 symptoms went away.
I have the August 2019 edition of TSB18-NA-355 which states in part, "Diagnosis beyond customer compliant(sic) is not required.
What exactly are the symptoms I should be listening /looking for? Should I go ahead with the fluid change anyway?
Based on reading the forums, just installed a range device and almost all of what I thought might be A8 symptoms went away.
I have the August 2019 edition of TSB18-NA-355 which states in part, "Diagnosis beyond customer compliant(sic) is not required.
What exactly are the symptoms I should be listening /looking for? Should I go ahead with the fluid change anyway?
Pro
Joined: Feb 2019
Posts: 630
Likes: 384
From: Florida
I have a 2019 1LT I purchased about 1 year ago. I installed the Range Technologies AFM Disabler soon after purchase. Although my A8 showed no sign of any issues (shudder) I had the triple flush done as well. No questions asked. I expect no issues with the transmission. Highly recommend you get the fluid change as soon as you can. Never know when GM might change their mind. Look for a dealer that has techs who have experience with the process. The tech I got had done over 200 flushes and really knew what he was doing. Was done in 2 hours.
Last edited by ShadowGray19; Apr 18, 2020 at 08:54 AM.
Safety Car
Joined: Jan 2014
Posts: 4,496
Likes: 856
From: Walhalla South Carolina
I have a 17 GS and run the range device with no issues but had the fluid changed as a precaution and it changes much better. I thought the 19 had the new fluid from factory, could be wrong.
Pro
Joined: Feb 2019
Posts: 630
Likes: 384
From: Florida
Le Mans Master
Joined: Nov 2015
Posts: 7,382
Likes: 3,501
From: Lake Havasu City Arizona
Woops! I see the above poster stated the same thing. 
Check the build date of your car on the driver side door jamb. If it is 2/2019 or later you have the latest and greatest trany fluid. The 2019 models built before that didn't have the newest fluid.
If you have the newest fluid there could be some other issue.
Check the build date of your car on the driver side door jamb. If it is 2/2019 or later you have the latest and greatest trany fluid. The 2019 models built before that didn't have the newest fluid.
If you have the newest fluid there could be some other issue.
Last edited by joemessman; Apr 18, 2020 at 09:53 AM.
Drifting
Joined: Jun 2015
Posts: 1,858
Likes: 694
From: Lagrange KY
I had previously owned a C4, several C5’s and a C6, all automatics and all were 100% trouble free. So I did very little research before purchasing (used) my 2016 A8 base coupe. Was like new with only 4K miles. The only thing I noticed during my highway drive home was the approximately 150 rpm flux on the tach while cruising lazily down the freeway. There was no shutter, warble or anything and you wouldn’t even know it was occurring if you weren’t looking at the tach. Didn’t give it much thought until I started reading about the issues reported here on the forum. Started driving it exclusively in the manual (paddle shift) mode, then installed the Range device at about 4500 miles and never had another problem. The car was a dream to drive. Buttery smooth and performance like I’ve never experienced before. Recently sold it though (with about 9k miles) in anticipation of buying a new 2020 C8 ME or perhaps a 19 GS or Z06. Would NEVER drive another A8 Vette without that Range device and the new transmission fluid!
Last edited by Squeaky Wheel; Apr 18, 2020 at 01:48 PM.
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Race Director
Joined: Oct 2008
Posts: 16,671
Likes: 7,738
From: NJ
The last thing you want is to be provided with symptoms to a problem you may not have...
You would know if the car wascausing you off driving down the hwy. Trust me. Went through it with my Sierta A8 and my 16A8.. nothing like my August 2019 built Z06 A8.. what a blessing this trans is. When it has a suitable fluid.. morons took almost 4yrs to fix it. Shame on them. I got rid of my sierra because of it.
Pro
Joined: Jul 2012
Posts: 539
Likes: 86
From: Newington CT
If you have the "shutter" you'll know it! I had it on my 2016 base A8. In the beginning it felt like the trans was slipping but only mildly and it lasted for a second or so but it happened every 3-5 minutes. Three weeks later it felt like you hit the rumble strip but again only for a second and 5-10 minutes apart. I took it to the dealer for the triple flush which is a warrantee item. Before I got out of their lot I could feel the difference, the first to second gear shift also felt better. The tech said it could take up to 300 miles to achieve 100% normality. It mildly shuttered twice and inside of 50 miles I was good to go. My tech tells me that the shuttering started to appear when they went from the A6 to the A8 and didn't re formulate a new fluid for it. They thought they had it corrected with a second fluid formulation but that didn't work either. Formulation 3 was the winner. It comes in a black quart container. The overall problem with the fluid was a water absorption issue which #3 fixed.
Last edited by NoRuls; Apr 18, 2020 at 02:39 PM.
Racer
Joined: Jul 2018
Posts: 362
Likes: 222
From: Fate, TX
I have an ‘18 A8 GS with ~15k miles on it. No Range device, no fluid flush and no transmission issues. I may be lucky, but it seems to me that if it ain’t broke don’t worry about it. If I have any symptoms of the problem, I’ll get it addressed. In the mean time I’ll enjoy this car on the road.
Le Mans Master
Joined: Nov 2015
Posts: 7,382
Likes: 3,501
From: Lake Havasu City Arizona
Le Mans Master
Joined: Jun 2002
Posts: 6,433
Likes: 3,622
From: Commerce Texas
But, then, there thousands upon thousands of A8s that have had zero problems .... my next door neighbor has 70K plus on her '17 zero problems. Buddy in Arizona has bumping 80K in his.... took the car to Italy for a year and drove all over the continent - zero problems.
Neither run range device.
Neither run range device.
Cruising
Joined: Jul 2021
Posts: 10
Likes: 9
I haven't seen it mentioned above:
(Correct me if I'm wrong)
The C8 generation is a wet clutch transmission. Previous generations were not wet clutch. Their clutch was not internal to the transmission in the transmission fluid.
A wet clutch is enclosed inside of the transmission. They wear down and contaminate the transmission fluid. This in turn can cause problems with the solenoid valve body.
I know both transmission types do have internal wear, The wet clutch is an internal adder to the fluid contamination.
(Correct me if I'm wrong)
The C8 generation is a wet clutch transmission. Previous generations were not wet clutch. Their clutch was not internal to the transmission in the transmission fluid.
A wet clutch is enclosed inside of the transmission. They wear down and contaminate the transmission fluid. This in turn can cause problems with the solenoid valve body.
I know both transmission types do have internal wear, The wet clutch is an internal adder to the fluid contamination.
Last edited by Joeg_Ohio; Feb 24, 2024 at 07:05 AM.
Burning Brakes
Joined: Apr 2009
Posts: 864
Likes: 398
From: White
Purchased a new 2019 LT1 with A8 last summer. Have 1700 miles on it. First corvette-I'm a novice.
Based on reading the forums, just installed a range device and almost all of what I thought might be A8 symptoms went away.
I have the August 2019 edition of TSB18-NA-355 which states in part, "Diagnosis beyond customer compliant(sic) is not required.
What exactly are the symptoms I should be listening /looking for? Should I go ahead with the fluid change anyway?
Based on reading the forums, just installed a range device and almost all of what I thought might be A8 symptoms went away.
I have the August 2019 edition of TSB18-NA-355 which states in part, "Diagnosis beyond customer compliant(sic) is not required.
What exactly are the symptoms I should be listening /looking for? Should I go ahead with the fluid change anyway?
Drifting
Joined: Jun 2009
Posts: 1,301
Likes: 231
From: Queen Creek AZ
I haven't seen it mentioned above:
(Correct me if I'm wrong)
The C8 generation is a wet clutch transmission. Previous generations were not wet clutch. Their clutch was not internal to the transmission in the transmission fluid.
A wet clutch is enclosed inside of the transmission. They wear down and contaminate the transmission fluid. This in turn can cause problems with the solenoid valve body.
I know both transmission types do have internal wear, The wet clutch is an internal adder to the fluid contamination.
(Correct me if I'm wrong)
The C8 generation is a wet clutch transmission. Previous generations were not wet clutch. Their clutch was not internal to the transmission in the transmission fluid.
A wet clutch is enclosed inside of the transmission. They wear down and contaminate the transmission fluid. This in turn can cause problems with the solenoid valve body.
I know both transmission types do have internal wear, The wet clutch is an internal adder to the fluid contamination.
