A8 shudder, stutter, warble, rumble strips
Thread Starter
6th Gear
Joined: Nov 2016
Posts: 6
Likes: 2
A8 shudder, stutter, warble, rumble strips
My 2015 Stingray 3LT had been at the dealer since October 18. Got it back last night. They replaced the torque converter after a service engineer came to the dealership and drove it. Works fine now. Service Bulletin 5337F.
Melting Slicks
Joined: Aug 2010
Posts: 3,063
Likes: 82
From: Tumwater, WA
what specifically was the bulletin for? My dealership says they have replaced alot of torque converters. Did yours have the warble sound?
Last edited by S'vette; Nov 24, 2016 at 12:31 PM.
Heel & Toe
Joined: May 2019
Posts: 17
Likes: 3
From: Lake Worth, FL
I don’t know if the previous owner ever did the Service Bulletin and if not, I’m wondering if it would be covered under my GM extended warranty. Thanks for any insight!
I also found this bulletin which looks like it’s from December 2018 and has specific instructions for the tech:
https://www.midenginecorvetteforum.c...ission-shudder
Last edited by Steve Garrett; May 21, 2019 at 03:00 PM. Reason: Merged Posts
Pro
Joined: Aug 2018
Posts: 652
Likes: 156
From: Clarksville, TN
Burning Brakes
Joined: Apr 2018
Posts: 1,177
Likes: 499
I also found this bulletin which looks like it’s from December 2018 and has specific instructions for the tech:
https://www.midenginecorvetteforum.c...ission-shudder
https://www.midenginecorvetteforum.c...ission-shudder
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Heel & Toe
Joined: May 2019
Posts: 17
Likes: 3
From: Lake Worth, FL
The bulletin specifies two models of the A8 transmission (8L45 and 8L90). I’m not sure what years those apply to, but I know it does apply to my 2015 Z51. The OP on the site I linked to mentioned that “90% of users with A8s don’t have yeh issue...” which I suppose is good news. I’m going to check in with the dealership this week and see one this applies, specifically with my GM extended warranty.
Heel & Toe
Joined: May 2019
Posts: 17
Likes: 3
From: Lake Worth, FL
Quick update that I scheduled the service for tomorrow and upon calling in, they knew exactly what I was talking about. The SA told me that they used the replace the torque converter but were still getting a portion of those customers back with the issue.
They said that now they flush the system with a new formula of transmission fluid and that resolves the issue. This is the solution referenced in the Dec 18 service bulletin I linked to above. I was glad to hear that they recognized this issue immediately over the phone and have a solution.
I’ll report back after I pickup the car and drive it a few hundred miles.
FYI it’s Greenacres Chevrolet in Lake Worth, FL. My SA is Mike Fox.
They said that now they flush the system with a new formula of transmission fluid and that resolves the issue. This is the solution referenced in the Dec 18 service bulletin I linked to above. I was glad to hear that they recognized this issue immediately over the phone and have a solution.
I’ll report back after I pickup the car and drive it a few hundred miles.
FYI it’s Greenacres Chevrolet in Lake Worth, FL. My SA is Mike Fox.
Melting Slicks
Joined: Dec 2004
Posts: 3,248
Likes: 564
From: Margaritaville Daytona
Had mine done yesterday, so far the shudder is gone. New SB, same number as the one released in Jan 2019 is now dated March 2019 with no change to the process.
Last edited by AmmoVet; May 21, 2019 at 01:16 PM.
Race Director
Joined: Nov 2005
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From: Supporting the Corvette Community at Abel Chevrolet in Rio Vista, CA 707-374-6317 Ext.123
St. Jude Donor '08
We'd be happy to confirm the issue and proceed with the repairs if the shudder meets GM's criteria. The newest version of the bulletin requires a snap shot of the data showing the vibration is above a certain threshold. If it is, we're good to go.
With that being said, 80% of the vehicles we road test (Camaro, Corvette, Cadillac, Truck and SUV's) do not meet the minimum threshold to perform the flush. We literally see at least one vehicle per day for this "issue" so it's nothing new to us, but we have to be able to verify (with data) that it's severe enough to warrant repairs. Many of the people coming in have a slight shudder, but they read on the forums about it and more or less just want a free fluid flush.
If the vehicle is under bumper to bumper warranty, GM will pay us the 3/10ths of an hour diagnostic time even if we can't prove the level of shudder is above GM's limit. If the car is outside the 3/36 bumper to bumper, GM does not allow us to submit the diagnostic time if the car is not severe enough so that time is the customer's responsibility. If the shudder is excessive and we can obtain the snap shot, all costs are paid by GM and the customer is not responsible for anything.
With that being said, 80% of the vehicles we road test (Camaro, Corvette, Cadillac, Truck and SUV's) do not meet the minimum threshold to perform the flush. We literally see at least one vehicle per day for this "issue" so it's nothing new to us, but we have to be able to verify (with data) that it's severe enough to warrant repairs. Many of the people coming in have a slight shudder, but they read on the forums about it and more or less just want a free fluid flush.
If the vehicle is under bumper to bumper warranty, GM will pay us the 3/10ths of an hour diagnostic time even if we can't prove the level of shudder is above GM's limit. If the car is outside the 3/36 bumper to bumper, GM does not allow us to submit the diagnostic time if the car is not severe enough so that time is the customer's responsibility. If the shudder is excessive and we can obtain the snap shot, all costs are paid by GM and the customer is not responsible for anything.
Heel & Toe
Joined: May 2019
Posts: 17
Likes: 3
From: Lake Worth, FL
We'd be happy to confirm the issue and proceed with the repairs if the shudder meets GM's criteria. The newest version of the bulletin requires a snap shot of the data showing the vibration is above a certain threshold. If it is, we're good to go.
With that being said, 80% of the vehicles we road test (Camaro, Corvette, Cadillac, Truck and SUV's) do not meet the minimum threshold to perform the flush. We literally see at least one vehicle per day for this "issue" so it's nothing new to us, but we have to be able to verify (with data) that it's severe enough to warrant repairs. Many of the people coming in have a slight shudder, but they read on the forums about it and more or less just want a free fluid flush.
If the vehicle is under bumper to bumper warranty, GM will pay us the 3/10ths of an hour diagnostic time even if we can't prove the level of shudder is above GM's limit. If the car is outside the 3/36 bumper to bumper, GM does not allow us to submit the diagnostic time if the car is not severe enough so that time is the customer's responsibility. If the shudder is excessive and we can obtain the snap shot, all costs are paid by GM and the customer is not responsible for anything.
With that being said, 80% of the vehicles we road test (Camaro, Corvette, Cadillac, Truck and SUV's) do not meet the minimum threshold to perform the flush. We literally see at least one vehicle per day for this "issue" so it's nothing new to us, but we have to be able to verify (with data) that it's severe enough to warrant repairs. Many of the people coming in have a slight shudder, but they read on the forums about it and more or less just want a free fluid flush.
If the vehicle is under bumper to bumper warranty, GM will pay us the 3/10ths of an hour diagnostic time even if we can't prove the level of shudder is above GM's limit. If the car is outside the 3/36 bumper to bumper, GM does not allow us to submit the diagnostic time if the car is not severe enough so that time is the customer's responsibility. If the shudder is excessive and we can obtain the snap shot, all costs are paid by GM and the customer is not responsible for anything.
How long did the service take start to finish?
Last edited by Steve Garrett; May 21, 2019 at 03:02 PM. Reason: Merged Posts
Supporting Vendor
Joined: Aug 2007
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From: CT
http://gmauthority.com/blog/2019/04/...ission-defect/
GM Hit With Class-Action Lawsuit Over 8-Speed Transmission Defect
GM Hit With Class-Action Lawsuit Over 8-Speed Transmission Defect
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06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS LS3, short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake, catch-can, ported/polished TB, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS LS3, short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake, catch-can, ported/polished TB, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
Last edited by 06MonteSS; May 23, 2019 at 01:08 AM.
Heel & Toe
Joined: May 2019
Posts: 17
Likes: 3
From: Lake Worth, FL
http://gmauthority.com/blog/2019/04/...ission-defect/
GM Hit With Class-Action Lawsuit Over 8-Speed Transmission Defect
GM Hit With Class-Action Lawsuit Over 8-Speed Transmission Defect
Heel & Toe
Joined: May 2019
Posts: 17
Likes: 3
From: Lake Worth, FL
I am pleased to report that after the service on Wednesday, I’ve driven ~150 miles and it’s like a completely different car! Not only is the shudder problem gone, but my shifts in M mode are completely smooth as are general shifts in automatic. This is specifically evident in Touring mode where I had just assumed since getting the car that it was jerky in Touring mode all the time.
I’ve also noticed less of a lag in shifting between reverse and drive, and no shaking/shudder when switching between V4 and V8.
The service took a full day.
I’ve also noticed less of a lag in shifting between reverse and drive, and no shaking/shudder when switching between V4 and V8.
The service took a full day.
Burning Brakes
Joined: Oct 2001
Posts: 860
Likes: 40
From: Woodforest
I just bought a 2019 GS with the auto and have noticed that when it is in 4 cylinder mode, I get a shudder which happens about once every 30 seconds or so from the car. It is not severe, but it's enough to get my notice constantly. It also happens when it drops to V4 or up to V8. Doesn't happen in 8 cylinder mode. I really hate buying an expensive brand new car and having issues. Didn't have a single issue with my 2012 GS.