C7 transmission problem
Thread Starter
3rd Gear
Joined: Nov 2020
Posts: 3
Likes: 0
C7 transmission problem
I have a 2015 C7 with A8 tranny. 17,000 miles. Warranty expired 6 mo ago. Just noticed problem with a vibration and fluctuating rpm. I find many references to this being a well known problem with torque converter. As this is a known issue, any chance I may be able to get Chevrolet to cover the repair costs?
Burning Brakes
Joined: Jan 2006
Posts: 966
Likes: 343
From: Yazoo City Mississippi
I had an 04 Vert that had just gone out of warranty and only had about 18k miles on it. Fuel sending units went out. Took it to local Chevy Dealer. They fixed it and filed it as “Good will warranty” (I believe that’s what it was called). Call Your Service Manager and ask. Can’t hurt
Team Owner
Joined: Oct 2004
Posts: 25,583
Likes: 16,940
I'd suggest you move this to the C7 section of the forum.
Your problem was fairly common in all C7 models with A8 transmissions, but common in 2015s. Since your mileage is under the powertrain warranty limit, I take it you're past the five-year mark. If it's close to that anniversary date (within 6 months), you might get some "goodwill" help if you play things really nice with a very good dealer.
If you're not the first owner, a check of warranty repairs may reveal it had A8 problems in the past, and perhaps either got a torque converter replacement or was fully replaced. If so, your chances of getting help may be better.
Good luck!
Your problem was fairly common in all C7 models with A8 transmissions, but common in 2015s. Since your mileage is under the powertrain warranty limit, I take it you're past the five-year mark. If it's close to that anniversary date (within 6 months), you might get some "goodwill" help if you play things really nice with a very good dealer.
If you're not the first owner, a check of warranty repairs may reveal it had A8 problems in the past, and perhaps either got a torque converter replacement or was fully replaced. If so, your chances of getting help may be better.
Good luck!
Last edited by Foosh; Nov 7, 2020 at 12:34 PM.
Race Director
Joined: Nov 2004
Posts: 15,678
Likes: 1,097
From: birmingham Alabama
St. Jude Donor '09 and '13
I have a 2015 C7 with A8 tranny. 17,000 miles. Warranty expired 6 mo ago. Just noticed problem with a vibration and fluctuating rpm. I find many references to this being a well known problem with torque converter. As this is a known issue, any chance I may be able to get Chevrolet to cover the repair costs?
Safety Car
Joined: Mar 2014
Posts: 4,481
Likes: 668
From: Kilmarnock Va
I have a 2015 C7 with A8 tranny. 17,000 miles. Warranty expired 6 mo ago. Just noticed problem with a vibration and fluctuating rpm. I find many references to this being a well known problem with torque converter. As this is a known issue, any chance I may be able to get Chevrolet to cover the repair costs?
Race Director
Joined: Mar 2001
Posts: 19,898
Likes: 6,697
From: Bonneville Salt Flats
If you do an "advanced search" across the C7 section here at the Forum for A8 transmission problems you will find a gazillion threads addressing absolutely every quirk and possible solution(s)... for everything related to the A8! All the best, despite your current issue. 
Le Mans Master
Joined: Aug 2015
Posts: 8,243
Likes: 4,613
From: Southwest Florida
If you are still within the five year powertrain warranty call the service department to have the triple flush done as it’s covered under warranty. Corvette A8 Revised Shudder TSB 18NA355 dated April 2020 clearly states, “Diagnosis beyond the customer compliant is not required” in order to perform the triple flush.
Read this thread for more info; https://www.corvetteforum.com/forums...nny-flush.html
Read this thread for more info; https://www.corvetteforum.com/forums...nny-flush.html
Last edited by Maxie2U; Nov 7, 2020 at 11:04 PM.
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Thread Starter
3rd Gear
Joined: Nov 2020
Posts: 3
Likes: 0
Thanks for your replies. Unfortunately,my warranty expired this past April. Does the transmission flush usually resolve the issue? I had found other discussions that suggest the torque converter and possibly the whole transmission will occasionally need to be replaced. I won’t quibble much if I have to pay out of pocket for a flush but I would not be happy to have a major transmission rebuild at 17,000 miles.
Instructor
Joined: Aug 2015
Posts: 115
Likes: 31
A simple solution is to drive the A8 in manual mode all the time. This deletes the V4 mode which is causing the shudder problem. I enjoy driving my A8 in manual ... brings back the fun of driving a high performance sports car. Try it and see what you think ... it’s free!
Safety Car
Joined: Mar 2018
Posts: 4,754
Likes: 1,650
Thanks for your replies. Unfortunately,my warranty expired this past April. Does the transmission flush usually resolve the issue? I had found other discussions that suggest the torque converter and possibly the whole transmission will occasionally need to be replaced. I won’t quibble much if I have to pay out of pocket for a flush but I would not be happy to have a major transmission rebuild at 17,000 miles.
Last edited by MMD; Nov 8, 2020 at 09:36 AM.
Le Mans Master
Joined: Aug 2015
Posts: 8,243
Likes: 4,613
From: Southwest Florida
Thanks for your replies. Unfortunately,my warranty expired this past April. Does the transmission flush usually resolve the issue? I had found other discussions that suggest the torque converter and possibly the whole transmission will occasionally need to be replaced. I won’t quibble much if I have to pay out of pocket for a flush but I would not be happy to have a major transmission rebuild at 17,000 miles.
Given the fact a rebuilt transmission will cost a fortunate if it was me I would first try the triple flush knowing that money could be flushed if it doesn’t resolve the shutter.
Last edited by Maxie2U; Nov 8, 2020 at 12:26 PM.
Safety Car
Joined: Mar 2018
Posts: 4,754
Likes: 1,650
My report after having the triple flush is completely resolved the shutter. In my case I had the triple flush down after having a very mild shutter and it’s like a new transmission. It also eliminated the harsh gear change from 4th to 5th. It was so bad I would left off the gas when paddle shifting from 4th to 5th. Now I can’t even feel when it shifts through the gears and downshifts are extremely smooth.
Given the fact a rebuild transmission will cost a fortunate if it was me I would first try the triple flush knowing that money could be flushed if it doesn’t resolve the shutter.
Given the fact a rebuild transmission will cost a fortunate if it was me I would first try the triple flush knowing that money could be flushed if it doesn’t resolve the shutter.
Le Mans Master
Joined: Sep 2013
Posts: 7,137
Likes: 3,176
From: Kannapolis MA.
Correct me if I'm wrong.I believe the TC was done at the early stages of the A8'S Misery.Many reported their cars disassembled and to still have some report issue's.
Then out came the Secrete Sauce and Triple Flush.The tranny's and owners are Happy Again
I recently unplugged my range to drive for the first time in the cars life of 28k miles.She has the SSSSSHutter.Plugged in range.All fixed.
Who wants your drivetrain switching back and forth.No Thanks
Then out came the Secrete Sauce and Triple Flush.The tranny's and owners are Happy Again
I recently unplugged my range to drive for the first time in the cars life of 28k miles.She has the SSSSSHutter.Plugged in range.All fixed.
Who wants your drivetrain switching back and forth.No Thanks
8th Gear
Joined: Oct 2019
Posts: 8
Likes: 10
From: Freehold NJ
Sorry to hear more A8 issues.... I too have 2015 C7, 15K miles and 6 months out of drive tran warranty... never had any transmission problems until 3 weeks ago. While driving at 80 MPH, it suddenly de-accelerated and started to violently jerk and shutter. Then I could not drive more than 30 MPH. Got it to my Chevy dealer and after a few days I was told they found metal chunks in the transmission, the tranny had a total failure . Now the dealer is searching for a GM certified re-man A8...very difficult to find. Oh...not covered by warranty. GM made me a very small monetary offer to cover some cost...
Thread Starter
3rd Gear
Joined: Nov 2020
Posts: 3
Likes: 0
WPI
Sorry to hear about your tranny being trashed. That’s what I was afraid would happen to mine. The shudder I just recently noticed was very subtle at first. Could only really feel it when gentle cruising on the highway. I think it is there on city street driving but really difficult to feel. Have a feeling it had been going on longer but rarely have it on the road. Thought about just trading it in while the issue was minor rather than risk a failure like you had. After seeing the reports of the triple flush I decided to take it to dealer today. They were pretty clueless, as they have always been. I had to give them the reference numbers fir the service bulletins. Hope it works.
Sorry to hear about your tranny being trashed. That’s what I was afraid would happen to mine. The shudder I just recently noticed was very subtle at first. Could only really feel it when gentle cruising on the highway. I think it is there on city street driving but really difficult to feel. Have a feeling it had been going on longer but rarely have it on the road. Thought about just trading it in while the issue was minor rather than risk a failure like you had. After seeing the reports of the triple flush I decided to take it to dealer today. They were pretty clueless, as they have always been. I had to give them the reference numbers fir the service bulletins. Hope it works.
Team Owner
Joined: Sep 2010
Posts: 32,040
Likes: 4,610
Sorry to hear more A8 issues.... I too have 2015 C7, 15K miles and 6 months out of drive tran warranty... never had any transmission problems until 3 weeks ago. While driving at 80 MPH, it suddenly de-accelerated and started to violently jerk and shutter. Then I could not drive more than 30 MPH. Got it to my Chevy dealer and after a few days I was told they found metal chunks in the transmission, the tranny had a total failure . Now the dealer is searching for a GM certified re-man A8...very difficult to find. Oh...not covered by warranty. GM made me a very small monetary offer to cover some cost...
