A8 Flush
Thread Starter
Drifting
Joined: Feb 2004
Posts: 1,905
Likes: 554
From: Scottsdale AZ
A8 Flush
Had the car in yesterday and the tech offered the triple flush, had zero problems, but said sure why not, warranty was paying for it. Says prep per bulletin #18-NA-355, triple flush and fill with DT-45096. This the most recent update for the famed shudder?
Advanced
Joined: Jul 2010
Posts: 83
Likes: 56
^^ Definitely a great dealer.
Shudder, according now to GM info is related to the ATF picking up moisture from the air, thus changing the friction properties. GM is mum about whether the moisture has changed/damaged the friction material in the tranny. The fluid retains the moisture even if the fluid gets warm so the moisture stays in the fluid. GM info has highest priority for new fluid changes in the southeast and south where it is the warmest and presumably more humid.
The new 'blue label' LV ATF HP supposedly has a different friction package that does not pick up water from the air.
(There is a vent on all trannys to deal with the expansion/contraction with the warm/cool cycles with driving. So there is some normal air exchange in and out of the tranny.)
I say all that which is already out there from GM because..... seems to me that for ALL A8's, it is just a matter of time for moisture pickup in the ATF and shudder to occur. I have done TWO flushes on my own a couple of months ago with Mobil LV ATF HP, only to find out the fluid I put in is gonna pick up moisture too. (Bummer!!!!) So, all I did was reset the A8 'moisture shudder timer'. And any of you out there with an 'old flush'; you will need a new one!
This time around, I will see how great my dealer is, and try for a dealer flush with the 'blue label' fluid under warranty. Hopefully it's even way better than blue label scotch!!!
Shudder, according now to GM info is related to the ATF picking up moisture from the air, thus changing the friction properties. GM is mum about whether the moisture has changed/damaged the friction material in the tranny. The fluid retains the moisture even if the fluid gets warm so the moisture stays in the fluid. GM info has highest priority for new fluid changes in the southeast and south where it is the warmest and presumably more humid.
The new 'blue label' LV ATF HP supposedly has a different friction package that does not pick up water from the air.
(There is a vent on all trannys to deal with the expansion/contraction with the warm/cool cycles with driving. So there is some normal air exchange in and out of the tranny.)
I say all that which is already out there from GM because..... seems to me that for ALL A8's, it is just a matter of time for moisture pickup in the ATF and shudder to occur. I have done TWO flushes on my own a couple of months ago with Mobil LV ATF HP, only to find out the fluid I put in is gonna pick up moisture too. (Bummer!!!!) So, all I did was reset the A8 'moisture shudder timer'. And any of you out there with an 'old flush'; you will need a new one!
This time around, I will see how great my dealer is, and try for a dealer flush with the 'blue label' fluid under warranty. Hopefully it's even way better than blue label scotch!!!
Last edited by kensredvette2; Jan 22, 2019 at 10:18 AM.
Le Mans Master
Joined: Aug 2015
Posts: 8,243
Likes: 4,615
From: Southwest Florida
^^ Definitely a great dealer.
Shudder, according now to GM info is related to the ATF picking up moisture from the air, thus changing the friction properties. GM is mum about whether the moisture has changed/damaged the friction material in the tranny. The fluid retains the moisture even if the fluid gets warm so the moisture stays in the fluid. GM info has highest priority for new fluid changes in the southeast and south where it is the warmest and presumably more humid.
The new 'blue label' LV ATF HP supposedly has a different friction package that does not pick up water from the air.
(There is a vent on all trannys to deal with the expansion/contraction with the warm/cool cycles with driving. So there is some normal air exchange in and out of the tranny.)
I say all that which is already out there from GM because..... seems to me that for ALL A8's, it is just a matter of time for moisture pickup in the ATF and shudder to occur. I have done TWO flushes on my own a couple of months ago with Mobil LV ATF HP, only to find out the fluid I put in is gonna pick up moisture too. (Bummer!!!!) So, all I did was reset the A8 'moisture shudder timer'. And any of you out there with an 'old flush'; you will need a new one!
This time around, I will see how great my dealer is, and try for a dealer flush with the 'blue label' fluid under warranty. Hopefully it's even way better than blue label scotch!!!
Shudder, according now to GM info is related to the ATF picking up moisture from the air, thus changing the friction properties. GM is mum about whether the moisture has changed/damaged the friction material in the tranny. The fluid retains the moisture even if the fluid gets warm so the moisture stays in the fluid. GM info has highest priority for new fluid changes in the southeast and south where it is the warmest and presumably more humid.
The new 'blue label' LV ATF HP supposedly has a different friction package that does not pick up water from the air.
(There is a vent on all trannys to deal with the expansion/contraction with the warm/cool cycles with driving. So there is some normal air exchange in and out of the tranny.)
I say all that which is already out there from GM because..... seems to me that for ALL A8's, it is just a matter of time for moisture pickup in the ATF and shudder to occur. I have done TWO flushes on my own a couple of months ago with Mobil LV ATF HP, only to find out the fluid I put in is gonna pick up moisture too. (Bummer!!!!) So, all I did was reset the A8 'moisture shudder timer'. And any of you out there with an 'old flush'; you will need a new one!
This time around, I will see how great my dealer is, and try for a dealer flush with the 'blue label' fluid under warranty. Hopefully it's even way better than blue label scotch!!!
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Heel & Toe
Joined: Jan 2019
Posts: 20
Likes: 11
From: California
https://forums.dealersedge.com/viewtopic.php?f=3&t=11352&start=10
Last edited by FreeFlyFreak; Jan 23, 2019 at 01:52 PM.
Heel & Toe
Joined: Jan 2019
Posts: 20
Likes: 11
From: California
https://www.repairprocedures.com/bulletins/document/18na355/5181942.html
Le Mans Master
Joined: Sep 1999
Posts: 7,810
Likes: 416
From: FL
Drifting
Joined: Apr 2011
Posts: 1,755
Likes: 198
From: Southington CT
I am the original owner of a 15. Received it 1st week of September 2014. Had zero problems with the A8. My warranty expired this year. I have talked with my tech (Paul Korner) and basically said if it's not broke don't fix it. I have about 13,000 miles on it. I am thinking that I should do the flush while it is still under warranty. This sound right?
Heel & Toe
Joined: Jan 2019
Posts: 20
Likes: 11
From: California
I am the original owner of a 15. Received it 1st week of September 2014. Had zero problems with the A8. My warranty expired this year. I have talked with my tech (Paul Korner) and basically said if it's not broke don't fix it. I have about 13,000 miles on it. I am thinking that I should do the flush while it is still under warranty. This sound right?
Mines a 2016 8300 miles no sign of shudder but it lived most of its life in the desert.
Im going to wait to do mine a while, at least a 6 months maybe more let the rush die down, let the techs get the new procedure down and the dealers get rid of old fluid that maybe used by mistake. It has a CPO warranty till 100k 2020 though so Im not pushed for time.
Plus I doubt they would cover mine under warranty because it doesn't display the shudder, dry fluid.
Hopefully they will eventually make it a recall vs a TSB.
I will have it in at the first hint of a shudder though.
Le Mans Master
Joined: Aug 2015
Posts: 8,243
Likes: 4,615
From: Southwest Florida
I found it various places, but the original source appears to be here, a dealer forum that quotes a GM document:
https://forums.dealersedge.com/viewt...11352&start=10
https://forums.dealersedge.com/viewt...11352&start=10
I wonder if GM will issue a recall on the old fluid instructing the dealer to replace it with the new non-moisture absorbing fluid? But it may be the cost of replacing fluid in all C7s could be more costly than their cost to replace the torque converter and/or the transmission on cars that continue to shutter even after a fluid flush/fluid replacement.
Even if GM does not intend to issue a recall it sounds like we should as a preventative measure have the moisture absorbing fluid replaced on our own dime.
Heel & Toe
Joined: Jan 2019
Posts: 20
Likes: 11
From: California
Thank you for sharing!
I wonder if GM will issue a recall on the old fluid instructing the dealer to replace it with the new non-moisture absorbing fluid? But it may be the cost of replacing fluid in all C7s could be more costly than their cost to replace the torque converter and/or the transmission on cars that continue to shutter even after a fluid flush/fluid replacement.
Even if GM does not intend to issue a recall it sounds like we should as a preventative measure have the moisture absorbing fluid replaced on our own dime.
For now Im biding my time
2016 8300 miles car was in the desert till I got it.
At the first hint of shudder I will take it in.
If not before, on my own dime.
There is a link for the TSB online now but its $15 to look at it, and its not a pdf so I cant download it.
I did take about 20 screen shots though.
Link to $15 TSB 18-na-355 is here if anyone is interested, I am sure it will be available for free soon enough, there are different procedures for different vehicles in the TSB:
https://www.repairprocedures.com/bulletins/document/18na355/5181942.html
Last edited by FreeFlyFreak; Jan 23, 2019 at 06:27 PM.
Pro
Joined: Oct 2016
Posts: 656
Likes: 247
From: Florida
Flush success!!!
EXCELLENT! Just got 2017 Stingray back from dealer after the new flush,transmission oil, and reprogram. 
The transmission is perfect. No shudder, no hard shifts. It didn’t run this well when I took delivery 38000 mi. ago. Could not be happier. Thank you GM. It’s about time.
18 na - - -
The transmission is perfect. No shudder, no hard shifts. It didn’t run this well when I took delivery 38000 mi. ago. Could not be happier. Thank you GM. It’s about time.18 na - - -
Last edited by Har-ray; Jan 23, 2019 at 07:06 PM.
Le Mans Master
Joined: Feb 2005
Posts: 6,902
Likes: 1,423
From: Any City USA
EXCELLENT! Just got 2017 Stingray back from dealer after the new flush,transmission oil, and reprogram. The transmission is perfect. No shudder, no hard shifts. It didn’t run this well when I took delivery 38000 mi. ago. Could not be happier. Thank you GM. It’s about time.
18 na - - -
The transmission is perfect. No shudder, no hard shifts. It didn’t run this well when I took delivery 38000 mi. ago. Could not be happier. Thank you GM. It’s about time.18 na - - -
Last edited by V Vette; Jan 23, 2019 at 07:09 PM.
Drifting
Joined: Jun 2000
Posts: 1,872
Likes: 294
From: St. Louis MO
^^ Definitely a great dealer.
Shudder, according now to GM info is related to the ATF picking up moisture from the air, thus changing the friction properties. GM is mum about whether the moisture has changed/damaged the friction material in the tranny. The fluid retains the moisture even if the fluid gets warm so the moisture stays in the fluid. GM info has highest priority for new fluid changes in the southeast and south where it is the warmest and presumably more humid.
The new 'blue label' LV ATF HP supposedly has a different friction package that does not pick up water from the air.
(There is a vent on all trannys to deal with the expansion/contraction with the warm/cool cycles with driving. So there is some normal air exchange in and out of the tranny.)
I say all that which is already out there from GM because..... seems to me that for ALL A8's, it is just a matter of time for moisture pickup in the ATF and shudder to occur. I have done TWO flushes on my own a couple of months ago with Mobil LV ATF HP, only to find out the fluid I put in is gonna pick up moisture too. (Bummer!!!!) So, all I did was reset the A8 'moisture shudder timer'. And any of you out there with an 'old flush'; you will need a new one!
This time around, I will see how great my dealer is, and try for a dealer flush with the 'blue label' fluid under warranty. Hopefully it's even way better than blue label scotch!!!
Shudder, according now to GM info is related to the ATF picking up moisture from the air, thus changing the friction properties. GM is mum about whether the moisture has changed/damaged the friction material in the tranny. The fluid retains the moisture even if the fluid gets warm so the moisture stays in the fluid. GM info has highest priority for new fluid changes in the southeast and south where it is the warmest and presumably more humid.
The new 'blue label' LV ATF HP supposedly has a different friction package that does not pick up water from the air.
(There is a vent on all trannys to deal with the expansion/contraction with the warm/cool cycles with driving. So there is some normal air exchange in and out of the tranny.)
I say all that which is already out there from GM because..... seems to me that for ALL A8's, it is just a matter of time for moisture pickup in the ATF and shudder to occur. I have done TWO flushes on my own a couple of months ago with Mobil LV ATF HP, only to find out the fluid I put in is gonna pick up moisture too. (Bummer!!!!) So, all I did was reset the A8 'moisture shudder timer'. And any of you out there with an 'old flush'; you will need a new one!
This time around, I will see how great my dealer is, and try for a dealer flush with the 'blue label' fluid under warranty. Hopefully it's even way better than blue label scotch!!!