Latest on A8 Shudder problems
Burning Brakes
Joined: Sep 2015
Posts: 1,174
Likes: 824
From: Dallas Texas
Like you said, whatever fluid i have now must be better than what was in there, and with the triple flush it should be nice fresh fluid throughout 
In the pdf on post #18 of this thread it mentions revisions to the tsb starting in Dec. From what i recall they mentioned it being better for the environment not having 3 flushes worth of fluid to dispose of. So if the new process is only 1 fluid change i may be happier having done this older tsb version anyway.
If a newer fluid comes out i'm sure i could take it back in for a single flush tsb. I'm still happy to have gotten everything cleaned out of it with the triple flush for now
In the pdf on post #18 of this thread it mentions revisions to the tsb starting in Dec. From what i recall they mentioned it being better for the environment not having 3 flushes worth of fluid to dispose of. So if the new process is only 1 fluid change i may be happier having done this older tsb version anyway.
If a newer fluid comes out i'm sure i could take it back in for a single flush tsb. I'm still happy to have gotten everything cleaned out of it with the triple flush for now
Last edited by 555ctsv; Jan 16, 2019 at 01:54 PM.
Melting Slicks
Joined: Jan 2013
Posts: 2,576
Likes: 237
From: Murphy NC
My dealer did it the first time at 40K miles. No charge to me.
At 60K I replaced my fluid.
Fluid and filter is under 150.00.
You can do it yourself in about two hours. If you have tools.
Mine has not had a problem in 22K miles. And I don't see any future AT problems.
I do plan on swapping fluid every 20K. It is cheap enough to do for piece of mind.
BTW - Summit had the cheapest ATF price online with free shipping over 100.00. My dealership beat them and gave me a better price on the filter.
I love my local Jacky Jones Chevy dealership.
At 60K I replaced my fluid.
Fluid and filter is under 150.00.
You can do it yourself in about two hours. If you have tools.
Mine has not had a problem in 22K miles. And I don't see any future AT problems.
I do plan on swapping fluid every 20K. It is cheap enough to do for piece of mind.
BTW - Summit had the cheapest ATF price online with free shipping over 100.00. My dealership beat them and gave me a better price on the filter.
I love my local Jacky Jones Chevy dealership.
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 25,025
Likes: 2,716
From: Far NW 'burbs of Chicago
St. Jude Donor '13
From what I can tell, it looks like GM/Mobil came out with yet another "new and improved" ATF for the A8, this month (January 2019). So your car would not have that. My guess is that your factory fluid is not the oldest and not the newest. Only GM knows how significant that is, and they ain't tellin'.
There have been several versions of the A8 ATF since 2015, I don't have a list of them or dates available. If someone has that info, please post.
There have been several versions of the A8 ATF since 2015, I don't have a list of them or dates available. If someone has that info, please post.
Safety Car
Joined: Jun 2003
Posts: 4,250
Likes: 656
From: San Diego Ca
The TSB with multiple revisions with the last one being on Oct 11, 18 is 16-NA-175. The new bulletin came out Dec 13, 2018 and is a 18-NA-355.. Nobody has yet posted a copy of the new TSB here or on the Cadillac V fora. We have mulltiple links to the old TSB.
The above link references without identifying the new TSB by number. And I don't recall what else is going on besides simply the new "better" ATF but there has been talk of another wrinkle in the tune on the 8L90 referenced in the new TSB. But since no body has seen it, that is still simply speculation. Apparently high volume dealers are now receiving the new fluid.
The above link references without identifying the new TSB by number. And I don't recall what else is going on besides simply the new "better" ATF but there has been talk of another wrinkle in the tune on the 8L90 referenced in the new TSB. But since no body has seen it, that is still simply speculation. Apparently high volume dealers are now receiving the new fluid.
Last edited by pkincy; Jan 16, 2019 at 06:59 PM.
Safety Car
Joined: Jun 2003
Posts: 4,250
Likes: 656
From: San Diego Ca
Ok, here is some new info even if it is not the actual TSB.
Originally posted by GM Technical Assistance Center
8 Speed Torque Converter Shudder – New Service Procedure and New Mobil 1 Synthetic LV ATF HP Fluid Regional Rollout
GM CUSTOMER CARE & AFTERSALES
URGENT - DISTRIBUTE IMMEDIATELYDATE12/12/2018SUBJECT8 Speed Torque Converter Shudder – New Service Procedure and New Mobil 1 Synthetic LV ATF HP Fluid Regional RolloutMODELS8L45 and 8L90 ApplicationsTOAll Cadillac, Chevrolet and GMC DealersATTNService Manager, Service Director, Shop Foreman, Service Technician, Parts Manager, Parts Counter Personnel, Warranty Administrator, General Manager
A new transmission fluid exchange procedure and new formula of Mobil 1 Synthetic LV ATF HP transmission fluid is being released to address torque converter shudder on 8L45 and 8L90 applications. The procedure and new transmission fluid is being rolled out regionally due to the limited availability of both the new transmission fluid and tool kit availability. The dealer rollout was determined by paid warranty claims from TSB 16-NA-175. It is anticipated that the new transmission fluid and tool kit will be available nationwide by late January or early February 2019. Once the new transmission fluid and tool kit is available the detailed service procedure will be loaded into GM Service Information (SI) as a Technical Service Bulletin (TSB). TSB's 16-NA-175 and 18-NA-177 will be eliminated from SI. An additional Global Connect Message will be sent to announce these changes.
Selected dealers will receive a separate Global Connect Message this week advising how to obtain the new Mobil 1 Synthetic LV ATF HP transmission fluid, delivery of the no charge tool kit from Bosch and detailed service procedure.
The new fluid exchange procedure will require the use of the existing DT-45096 TransFlow machine and tool kit. The tool kit will ship from Bosch at no charge.
The December 2018 Emerging Issues Broadcast, course number 10218.12V will be available through the Center of Learning on Thursday, December 13. The broadcast contains a video demonstrating the procedure on a Chevrolet Colorado and details on the new Mobil 1 Synthetic LV ATF HP transmission fluid.
The detailed service procedure may seem complicated at first review. However, we are confident that once you've completed the procedure you will find it relatively easy.
Proper Diagnosis: Sometimes shudder is not caused by the torque converter clutch (TCC). In some instances, shudder is fish bite, chuggle, surge or vibration. Utilizing the GDS and or the PICO Scope will help confirm the issue is TCC shudder. We have seen cases of suspected TCC shudder turn out to be engine performance, tire/wheel vibration or a driveline vibration.
Please do not contact the Technical Assistance Center (TAC) seeking information on when the new Mobil 1 Synthetic LV ATF HP transmission fluid and tool kit will be available nationwide. TAC does not have any additional information.
For those dealers that are not among the initial selected group. Please continue to follow 16-NA-175 and 18-NA-177 until the new service procedure is available nationwide. We are working diligently to get the new service solution available to all dealers and will advise through an additional Global Connect message once available.
Thank you for your cooperation.
GM CUSTOMER CARE & AFTERSALES
Originally posted by GM Technical Assistance Center
8 Speed Torque Converter Shudder – New Service Procedure and New Mobil 1 Synthetic LV ATF HP Fluid Regional Rollout
GM CUSTOMER CARE & AFTERSALES
URGENT - DISTRIBUTE IMMEDIATELYDATE12/12/2018SUBJECT8 Speed Torque Converter Shudder – New Service Procedure and New Mobil 1 Synthetic LV ATF HP Fluid Regional RolloutMODELS8L45 and 8L90 ApplicationsTOAll Cadillac, Chevrolet and GMC DealersATTNService Manager, Service Director, Shop Foreman, Service Technician, Parts Manager, Parts Counter Personnel, Warranty Administrator, General Manager
A new transmission fluid exchange procedure and new formula of Mobil 1 Synthetic LV ATF HP transmission fluid is being released to address torque converter shudder on 8L45 and 8L90 applications. The procedure and new transmission fluid is being rolled out regionally due to the limited availability of both the new transmission fluid and tool kit availability. The dealer rollout was determined by paid warranty claims from TSB 16-NA-175. It is anticipated that the new transmission fluid and tool kit will be available nationwide by late January or early February 2019. Once the new transmission fluid and tool kit is available the detailed service procedure will be loaded into GM Service Information (SI) as a Technical Service Bulletin (TSB). TSB's 16-NA-175 and 18-NA-177 will be eliminated from SI. An additional Global Connect Message will be sent to announce these changes.
Selected dealers will receive a separate Global Connect Message this week advising how to obtain the new Mobil 1 Synthetic LV ATF HP transmission fluid, delivery of the no charge tool kit from Bosch and detailed service procedure.
The new fluid exchange procedure will require the use of the existing DT-45096 TransFlow machine and tool kit. The tool kit will ship from Bosch at no charge.
The December 2018 Emerging Issues Broadcast, course number 10218.12V will be available through the Center of Learning on Thursday, December 13. The broadcast contains a video demonstrating the procedure on a Chevrolet Colorado and details on the new Mobil 1 Synthetic LV ATF HP transmission fluid.
The detailed service procedure may seem complicated at first review. However, we are confident that once you've completed the procedure you will find it relatively easy.
Proper Diagnosis: Sometimes shudder is not caused by the torque converter clutch (TCC). In some instances, shudder is fish bite, chuggle, surge or vibration. Utilizing the GDS and or the PICO Scope will help confirm the issue is TCC shudder. We have seen cases of suspected TCC shudder turn out to be engine performance, tire/wheel vibration or a driveline vibration.
Please do not contact the Technical Assistance Center (TAC) seeking information on when the new Mobil 1 Synthetic LV ATF HP transmission fluid and tool kit will be available nationwide. TAC does not have any additional information.
For those dealers that are not among the initial selected group. Please continue to follow 16-NA-175 and 18-NA-177 until the new service procedure is available nationwide. We are working diligently to get the new service solution available to all dealers and will advise through an additional Global Connect message once available.
Thank you for your cooperation.
GM CUSTOMER CARE & AFTERSALES
Race Director
Joined: May 2001
Posts: 15,324
Likes: 2,080
From: Guelph, Ontario
From what I can tell, it looks like GM/Mobil came out with yet another "new and improved" ATF for the A8, this month (January 2019). So your car would not have that. My guess is that your factory fluid is not the oldest and not the newest. Only GM knows how significant that is, and they ain't tellin'.
There have been several versions of the A8 ATF since 2015, I don't have a list of them or dates available. If someone has that info, please post.
There have been several versions of the A8 ATF since 2015, I don't have a list of them or dates available. If someone has that info, please post.
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Thread Starter
Team Owner
Joined: Sep 2000
Posts: 25,025
Likes: 2,716
From: Far NW 'burbs of Chicago
St. Jude Donor '13
The one thing I do know is that whatever fluid they did use, it seems to be working well because at 9500 miles my A8 works perfectly in every respect, and I don't avoid using AFM at all either, I probably only use the paddles 5% of the time. The one thing I do worry about is when the time comes to get the transmission fluid changed (maybe when I hit the 50-60k mark?), how will I know for sure if that dealer will use the most up to date fluid or if they end up using the same fluid that originally went into the 2015s?
Our early MY 2017 had one of the earlier fluids and went 20k miles with lots of V4 time, and no problems. I changed to the newer-but-not-newest-now fluid in October and only put on a few miles before the salt closed in, but it's still fine.
By the time you want to do a fluid change, most every dealer should know about the new fluid and procedure. Unless it gets changed yet again...
Burning Brakes
Joined: Apr 2004
Posts: 1,022
Likes: 102
From: Sarasota FL
St. Jude Donor '13
I still think that some cars will need a new torque convertor if the flush doesn't fix it. Make you wonder what the REAL problem is and why GM is just putting a band aid on it with all these different fluids that they have used.
Race Director
Joined: May 2001
Posts: 15,324
Likes: 2,080
From: Guelph, Ontario
That's what worries me. Even though I'm a few years away from needing a transmission fluid change, the dealers up here probably don't do that many Corvette trans fluid changes so it could be quite a while before they figure out what's going on. Perhaps I should get my trans fluid changed at a large Corvette dealer in the US (since I'll be wintering in Florida starting in 4 years time, I could get it done down there)
Drifting
Joined: Jan 2018
Posts: 1,332
Likes: 630
Lubrication isn't the problem - AFM is the problem. Improving lubrication will only make the problem take longer to appear. Why would GM do this? Because the longer it takes for the problem to appear, the more likely the problem appears after the warranty has expired, and then they are no longer legally liable to fix it.
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 25,025
Likes: 2,716
From: Far NW 'burbs of Chicago
St. Jude Donor '13
That's what worries me. Even though I'm a few years away from needing a transmission fluid change, the dealers up here probably don't do that many Corvette trans fluid changes so it could be quite a while before they figure out what's going on. Perhaps I should get my trans fluid changed at a large Corvette dealer in the US (since I'll be wintering in Florida starting in 4 years time, I could get it done down there)
I've been known to stop by the parts department and ask to see what they have in stock, like for the ESP 0W-40 Dexos2. If it's the wrong stuff, I give them a gentle update and go somewhere else.
Le Mans Master
Joined: Feb 2005
Posts: 6,918
Likes: 1,441
From: Any City USA
That's what worries me. Even though I'm a few years away from needing a transmission fluid change, the dealers up here probably don't do that many Corvette trans fluid changes so it could be quite a while before they figure out what's going on. Perhaps I should get my trans fluid changed at a large Corvette dealer in the US (since I'll be wintering in Florida starting in 4 years time, I could get it done down there)
Race Director
Joined: May 2001
Posts: 15,324
Likes: 2,080
From: Guelph, Ontario
Not likely. I bought this C7 with the full intention of keeping it for a very long time, as I will be retiring early in just 3 years (at age 52) And if the C8 is a mid engine, it doesn't fit into our plans because my wife and I will be using our Corvette to travel from Ontario to Florida every winter, and a mid engine car won't have the same cargo space as the C7 does. I do love the look of the renderings I'm seeing on the C8 so far though.
Last edited by Patman; Jan 18, 2019 at 07:41 AM.
Le Mans Master
Joined: Feb 2005
Posts: 6,918
Likes: 1,441
From: Any City USA
Not likely. I bought this C7 with the full intention of keeping it for a very long time, as I will be retiring early in just 3 years (at age 52) And if the C8 is a mid engine, it doesn't fit into our plans because my wife and I will be using our Corvette to travel from Ontario to Florida every winter, and a mid engine car won't have the same cargo space as the C7 does. I do love the look of the renderings I'm seeing on the C8 so far though.
Race Director
Joined: May 2001
Posts: 15,324
Likes: 2,080
From: Guelph, Ontario
I'm not sure if you're joking or serious, but we already know we love Florida, my wife and I have travelled there at least 10 times in the past 8 years, and are going down there again in two weeks. We've been all over the state and plan on spending our winters in SW Florida, most likely Marco Island.
Thread Starter
Team Owner
Joined: Sep 2000
Posts: 25,025
Likes: 2,716
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Not likely. I bought this C7 with the full intention of keeping it for a very long time, as I will be retiring early in just 3 years (at age 52) And if the C8 is a mid engine, it doesn't fit into our plans because my wife and I will be using our Corvette to travel from Ontario to Florida every winter, and a mid engine car won't have the same cargo space as the C7 does. I do love the look of the renderings I'm seeing on the C8 so far though.
I agree about the likely luggage issue on the C8, and the GM trend toward smaller windows, smaller interiors, and garish styling; does not impress me.
But like everyone else, we'll just have to wait and see.
The nice thing about having a fairly low miles C7 is that we wouldn't have to jump on the C8 bandwagon in a hurry.
EDIT:
We drove our Corvette to Bonita Beach every winter for 7 years, finally grew bored and started going to Arizona which is a much longer drive but prettier out west. Decisions, decisions...
Last edited by Gearhead Jim; Jan 18, 2019 at 12:26 PM.