A/8 transmission question
Race Director
Joined: Oct 1999
Posts: 17,709
Likes: 1,219
From: Phila PA, Bonita Springs FL
BS....
And a PS, who buys a vette, a performance car for V4 gas mileage?
I specifically bought my vette BECAUSE it has a V8!
Why would I want to drive a sports car in V4?
Burning Brakes
Joined: Mar 2010
Posts: 1,016
Likes: 250
No transmission/torque converter issues. Not sure why the cylinder deactivation has any correlation at all to those we have had torque converter or transmission issues with the A8.
From day one to today, I'm impressed with how seamless the cylinder deactivation is--other than the change in engine note (which I hear but haven't yet had a passenger notice), it's perfect!
Last edited by boxster99t; Feb 11, 2018 at 01:30 PM.
Safety Car
Joined: Aug 2012
Posts: 3,960
Likes: 1,106
When not in V4 mode the torque converter locks and stays locked under steady cruising and moderate acceleration; with V4 mode the clutch is constantly engaging and disengaging which greatly accelerates wear. The 8L90 was designed to fit within the same space as the earlier 6L series transmissions and part of the ability to fit this space was through using what GM called a "squashed" torque converter which reduces the amount of space available within the torque converter and given the way the A6 (6L80) and A8 (8L90) react to the V4 vibration reduction routine it appears the space available for a robust converter clutch was reduced.
Le Mans Master
Joined: Jan 2006
Posts: 6,800
Likes: 2,653
From: Down south in Dixie
I say buy it, and don't worry about it. I haven't seen, or read a thread that an A8 has blown up. Also, the problems of the earlier A8's have been taken care of. My '16 has been fine.
The good thing is it has a 5/50K warranty.
The good thing is it has a 5/50K warranty.
Team Owner
Joined: Sep 1999
Posts: 41,732
Likes: 1,718
From: Springfield MO
Absolutely no mods unless you consider a coat of wax as a mod.
Another friend of mine is on his 3rd C7 Z51 as the first two cars had bad transmissions. First car(2015) had the transmission take a dump with 4 miles on the clock while the salesman(Wes Milby) was driving it to the gas station to fill the tank while my friend was completing the paperwork. He refused to accept the car and GM had to install a new transmission in that car. The second car(2015) had the original transmission replace at 1,600 miles and when that second transmission started acting up at 3,000 miles, GM put him into a third new C7(2016).
Last edited by JoesC5; Feb 11, 2018 at 05:15 PM.
Le Mans Master
Joined: Dec 2015
Posts: 8,711
Likes: 203
From: here
This happened to friend of mine and no, the car was never abused. A new transmission was installed under warranty with no questions asked, by GM but it took 2.5 weeks. It was inconvenient as hell for my friend as it happened while he was 200 miles from home.
Absolutely no mods unless you consider a coat of wax as a mod.
Another friend of mine is on his 3rd C7 Z51 as the first two cars had bad transmissions. First car(2015) had the transmission take a dump with 4 miles on the clock while the salesman(Wes Milby) was driving it to the gas station to fill the tank while my friend was completing the paperwork. He refused to accept the car and GM had to install a new transmission in that car. The second car(2015) had the original transmission replace at 1,600 miles and when that second transmission started acting up at 3,000 miles, GM put him into a third new C7(2016).
Absolutely no mods unless you consider a coat of wax as a mod.
Another friend of mine is on his 3rd C7 Z51 as the first two cars had bad transmissions. First car(2015) had the transmission take a dump with 4 miles on the clock while the salesman(Wes Milby) was driving it to the gas station to fill the tank while my friend was completing the paperwork. He refused to accept the car and GM had to install a new transmission in that car. The second car(2015) had the original transmission replace at 1,600 miles and when that second transmission started acting up at 3,000 miles, GM put him into a third new C7(2016).
Heck if the corvette was not so buetifull it would not be on my short list, and on the flipside we often hear of the bad one's more then the good.
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,053
Likes: 194
From: So Cal
A/8 is the newer variant of the A/7 which was the trans used in the 15-17 models. Now my understanding is they did some modification to the A/7 to solve some of the problems with the converters and torque tube problems, as you well know.
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,053
Likes: 194
From: So Cal
simple converters letting go, torque tubes , causing problems, as well as in some cases engine main bearings letting go because of an alignment problem between the trans and engine..
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Safety Car
Joined: Aug 2012
Posts: 3,960
Likes: 1,106
The A8 was introduced to the Corvette with the Z06 and is also used in other models, it is better identified as the 8L90 (8 speed, longitudinal orientation,with the last two digits indicating a relative torque within the transmission family). It replaced the 6L80 which is commonly referred to as the A6. Both of these families also have lower torque members used in other GM vehicles.
On edit basic data available from GM here, see second page of PDF for transmissions: http://www.gmpowertrain.com/assets/d...ide_101917.pdf
There is no A7 unless you are referring to the Audi A7
On edit basic data available from GM here, see second page of PDF for transmissions: http://www.gmpowertrain.com/assets/d...ide_101917.pdf
There is no A7 unless you are referring to the Audi A7
Last edited by NSC5; Feb 11, 2018 at 07:35 PM.
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,053
Likes: 194
From: So Cal
The A8 was introduced to the Corvette with the Z06 and is also used in other models, it is better identified as the 8L90 (8 speed, longitudinal orientation,with the last two digits indicating a relative torque within the transmission family). It replaced the 6L80 which is commonly referred to as the A6. Both of these families also have lower torque members used in other GM vehicles.
There is no A7 unless you are referring to the Audi A7
There is no A7 unless you are referring to the Audi A7
Drifting
Joined: Dec 2003
Posts: 1,711
Likes: 90
From: Hillsdale NJ
Not to mention the fact that the warranty is worthless since GM can arbitrarily not honor it.
Burning Brakes
Joined: Dec 2016
Posts: 982
Likes: 151
Since its already on order, too late to recommend a 2014 a6. No such thing as a Chevy a7 transmission. I have a 2014. Since you will be the first owner put a range technology AFM delete that plugs into the odb port and I feel you should be ok. Then post back 3 years from now and let us know if you have any issues. GM will make repairs under warranty but not having your a car for a week or two can be depressing.