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Old Sep 23, 2014 | 11:20 AM
  #1  
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Default Automatic transmission

2014 Vette, transmission in drive: whenever i have to slow down and then try to get back into the gas, the car lugs down so much that the car shutters. It's really bad on a hill. As long as I have the highway to myself all is ok. When I first got the car, it spark knocked as I tried to accelerate to get onto the highway, I had to mash the gas pedal to the floor and it then responded. Car has been at dealers for over a week, I have e-mail and phoned Chevrolet. Am I the only one with this problem?
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Old Sep 23, 2014 | 04:09 PM
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Sound like the infamous "stalling" problem that leads to blown engines.
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Old Sep 24, 2014 | 03:24 PM
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I had this problem once. Maybe about a week ago, any word from your dealer or GM??


Originally Posted by mainemic
2014 Vette, transmission in drive: whenever i have to slow down and then try to get back into the gas, the car lugs down so much that the car shutters. It's really bad on a hill. As long as I have the highway to myself all is ok. When I first got the car, it spark knocked as I tried to accelerate to get onto the highway, I had to mash the gas pedal to the floor and it then responded. Car has been at dealers for over a week, I have e-mail and phoned Chevrolet. Am I the only one with this problem?
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Old Sep 24, 2014 | 03:26 PM
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Originally Posted by johnnyr89
I had this problem once. Maybe about a week ago, any word from your dealer or GM??
There is a tech bulletin coming, might be related... for a drive audit to determine if replacement is needed...
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Old Sep 24, 2014 | 03:37 PM
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Originally Posted by TOVetteFan
There is a tech bulletin coming, might be related... for a drive audit to determine if replacement is needed...

Great! Mind attaching link when possible
Thanks!
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Old Sep 24, 2014 | 04:08 PM
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Originally Posted by TOVetteFan
There is a tech bulletin coming, might be related... for a drive audit to determine if replacement is needed...
Replacement of what?
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Old Sep 24, 2014 | 04:21 PM
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Originally Posted by WelderGuy
Replacement of what?
Well, uh, the transmission.
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Old Sep 24, 2014 | 04:24 PM
  #8  
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Originally Posted by johnnyr89
Great! Mind attaching link when possible
Thanks!

Service Bulletin
GM Bulletin No.:
Date:
14628
September 2014
SERVICE UPDATE
SUBJECT: Service Update for Inventory Vehicles Only
Drive Audit for Transmission Noise and Loss of Reverse
Vehicle Limited to 3rd and 4th Forward Gear
Expires October 31, 2015
MODELS: 2015 Chevrolet Corvette
Equipped with 8 Speed Automatic Transmission (M5U)
This service update involves vehicles in dealer inventory only and will expire October 31, 2015.
This bulletin provides a service procedure to perform a drive audit on all 2015 model year Corvette vehicles in inventory that are equipped with an 8 speed automatic transmission (M5U). A small number of transmissions may develop a crack in the triple clutch housing internal to the transmission, leading to noise, loss of reverse gear, and limiting the driver to 3rd and 4th forward gears. The drive audit must be completed before vehicle delivery (and in addition to normal pre-delivery inspection activities) to identify vehicles with the condition. If the condition is found, dealers are to replace the transmission under the existing exchange program, see PIP5200A for details.
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Old Sep 24, 2014 | 04:42 PM
  #9  
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Originally Posted by mainemic
2014 Vette, transmission in drive: whenever i have to slow down and then try to get back into the gas, the car lugs down so much that the car shutters. It's really bad on a hill. As long as I have the highway to myself all is ok. When I first got the car, it spark knocked as I tried to accelerate to get onto the highway, I had to mash the gas pedal to the floor and it then responded. Car has been at dealers for over a week, I have e-mail and phoned Chevrolet. Am I the only one with this problem?
I had the same issue with mine. The problem for me was the displacement on demand V4 / V8 crap. I have removed that by way of a tune and the problem is gone.
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Old Sep 24, 2014 | 04:59 PM
  #10  
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Originally Posted by TOVetteFan
Service Bulletin
GM Bulletin No.:
Date:
14628
September 2014
SERVICE UPDATE
SUBJECT: Service Update for Inventory Vehicles Only
Drive Audit for Transmission Noise and Loss of Reverse
Vehicle Limited to 3rd and 4th Forward Gear
Expires October 31, 2015
MODELS: 2015 Chevrolet Corvette
Equipped with 8 Speed Automatic Transmission (M5U)
This service update involves vehicles in dealer inventory only and will expire October 31, 2015.
This bulletin provides a service procedure to perform a drive audit on all 2015 model year Corvette vehicles in inventory that are equipped with an 8 speed automatic transmission (M5U). A small number of transmissions may develop a crack in the triple clutch housing internal to the transmission, leading to noise, loss of reverse gear, and limiting the driver to 3rd and 4th forward gears. The drive audit must be completed before vehicle delivery (and in addition to normal pre-delivery inspection activities) to identify vehicles with the condition. If the condition is found, dealers are to replace the transmission under the existing exchange program, see PIP5200A for details.
Reply
Old Sep 24, 2014 | 05:04 PM
  #11  
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Originally Posted by TOVetteFan
Service Bulletin
GM Bulletin No.:
Date:
14628
September 2014
SERVICE UPDATE
SUBJECT: Service Update for Inventory Vehicles Only
Drive Audit for Transmission Noise and Loss of Reverse
Vehicle Limited to 3rd and 4th Forward Gear
Expires October 31, 2015
MODELS: 2015 Chevrolet Corvette
Equipped with 8 Speed Automatic Transmission (M5U)
This service update involves vehicles in dealer inventory only and will expire October 31, 2015.
This bulletin provides a service procedure to perform a drive audit on all 2015 model year Corvette vehicles in inventory that are equipped with an 8 speed automatic transmission (M5U). A small number of transmissions may develop a crack in the triple clutch housing internal to the transmission, leading to noise, loss of reverse gear, and limiting the driver to 3rd and 4th forward gears. The drive audit must be completed before vehicle delivery (and in addition to normal pre-delivery inspection activities) to identify vehicles with the condition. If the condition is found, dealers are to replace the transmission under the existing exchange program, see PIP5200A for details.
Well, since only a small number of 2015 corvettes have been built with the A8, a small number of failures could still mean a major problem, percentage wise.
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Old Sep 24, 2014 | 05:41 PM
  #12  
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Originally Posted by TOVetteFan
Service Bulletin
GM Bulletin No.:
Date:
14628
September 2014
SERVICE UPDATE
SUBJECT: Service Update for Inventory Vehicles Only
Drive Audit for Transmission Noise and Loss of Reverse
Vehicle Limited to 3rd and 4th Forward Gear
Expires October 31, 2015
MODELS: 2015 Chevrolet Corvette
Equipped with 8 Speed Automatic Transmission (M5U)
This service update involves vehicles in dealer inventory only and will expire October 31, 2015.
This bulletin provides a service procedure to perform a drive audit on all 2015 model year Corvette vehicles in inventory that are equipped with an 8 speed automatic transmission (M5U). A small number of transmissions may develop a crack in the triple clutch housing internal to the transmission, leading to noise, loss of reverse gear, and limiting the driver to 3rd and 4th forward gears. The drive audit must be completed before vehicle delivery (and in addition to normal pre-delivery inspection activities) to identify vehicles with the condition. If the condition is found, dealers are to replace the transmission under the existing exchange program, see PIP5200A for details.
Sigh.
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Old Sep 24, 2014 | 05:55 PM
  #13  
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Just bought my 2014 and I have a similar problem but the cause of mine is the AFM/4-8 cylinder deactivation. I feel it when having gone slow for a while then attempting to accelerate it stumbles and vibrates. If you use paddles to sift (non AFM mode) it runs fine! I bought a tuner to deactivate this POS! GM should have done it like the manual transmissions!
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Old Sep 24, 2014 | 06:00 PM
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(apparently some people can't tell the difference between a 2014 and 2015 C7.....)
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Old Sep 24, 2014 | 06:07 PM
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apparently someone doesn't know what the first post was referring to!

2014 Vette, transmission in drive: whenever i have to slow down and then try to get back into the gas, the car lugs down so much that the car shutters. It's really bad on a hill. As long as I have the highway to myself all is ok. When I first got the car, it spark knocked as I tried to accelerate to get onto the highway, I had to mash the gas pedal to the floor and it then responded. Car has been at dealers for over a week, I have e-mail and phoned Chevrolet. Am I the only one with this problem?
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Old Sep 24, 2014 | 11:47 PM
  #16  
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Originally Posted by mainemic
2014 Vette, transmission in drive: whenever i have to slow down and then try to get back into the gas, the car lugs down so much that the car shutters. It's really bad on a hill. As long as I have the highway to myself all is ok. When I first got the car, it spark knocked as I tried to accelerate to get onto the highway, I had to mash the gas pedal to the floor and it then responded. Car has been at dealers for over a week, I have e-mail and phoned Chevrolet. Am I the only one with this problem?
mainemic,

Sorry about your transmission concerns. Although I understand your displeasure, it's great that you've proactively reached out to your dealer for an official diagnosis. Keep us in the loop and updated on your service visit. If necessary, I can contact the dealer's Customer Experience Managers if you have additional questions. We'll look forward to your updates .


William R.
Chevrolet Customer Care
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Old Sep 25, 2014 | 09:22 AM
  #17  
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Originally Posted by sstew
apparently someone doesn't know what the first post was referring to!

2014 Vette, transmission in drive: whenever i have to slow down and then try to get back into the gas, the car lugs down so much that the car shutters. It's really bad on a hill. As long as I have the highway to myself all is ok. When I first got the car, it spark knocked as I tried to accelerate to get onto the highway, I had to mash the gas pedal to the floor and it then responded. Car has been at dealers for over a week, I have e-mail and phoned Chevrolet. Am I the only one with this problem?
Yup, my bad, saw transmission, missed 2014... doh.... Good luck with the resolution..
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Old Sep 25, 2014 | 10:09 AM
  #18  
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8 to 4 on a Corvette? What was GM thinking? For what? An extra 2 MPG? Can't wait to see the A8 w/ 650 HP.
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Old Sep 25, 2014 | 10:36 AM
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Sounds like a rare issue, not widely known or discussed, that very few have experienced.
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Old Sep 25, 2014 | 10:59 AM
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When you read his thread you know he is in V4 mode and it has difficulty coming out occasionally and requires heavy throttle activation to hurry the action up. I hate it on mine and have as yet to get resolution from GM. They need to install programming tables from manual shift cars so we can choose this feature or not. These audits are a stall tactic they already know, but haven't decided how to proceed. Most dealer techs are to busy to be auditors and flat rate does not pay them enough.
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