Triple flush
Racer
Joined: May 2000
Posts: 453
Likes: 51
From: Stuart Florida
Same with the dealer I use. They said it is a good preventative measure to change the fluid now. Going in next week for the service.
Pro
Joined: Nov 2010
Posts: 569
Likes: 63
From: Tulsa Oklahoma
My Dealer says they will do the flush under "power train warranty (5yr/50k mile)" . No cost to me, mines a 2016 (out of 3/36 warranty. South Pointe Chev. He says transmission must be "relearned" but they would do that also.
Melting Slicks
Joined: Jun 2017
Posts: 2,568
Likes: 1,183
From: Conyers Georgia
Well my service rep called me back today. According to GM, there is nothing wrong with my transmission and apparently copped an attitude with my service manager. I can't fault the service department. After all they did do two flushes under warranty and their hands are tied. They suggested maybe trying another dealer. The problem is GM. Not sure what my next step will be but dealer shopping is not on my list. GM is just stalling since I only have a little over a month on my warranty. The shudder isn't as bad as before the flushes so I may just bite the bullet and pay for a third myself and see.
Racer
Joined: Aug 2012
Posts: 465
Likes: 159
From: Minot ND
Called my dealer in Fargo, ND and asked for his policy on SB 18-NA-355 and 19-NA-121, updated effective July 9, 2019. He called back and said bring it in tomorrow and we'll take care of it. Dropped it off at 0830 the next day. No questions asked, no diagnostics, no arguments. It took 8 hours to complete, partly because it was the first one he had done, and partly because of the extensive warming up/cooling down process required by the SB. I had not had any shuddering problems so I have nothing to compare it to but everything is fine now. Dealer told me the new fluid did not accumulate/retain moisture like the old fluid so it really needs to be changed. Power train warranty covered all costs. Makes me feel better, if nothing else.
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Pro
Joined: Jul 2016
Posts: 698
Likes: 191
From: N. San Diego-Fallbrook California
Called my dealer in Fargo, ND and asked for his policy on SB 18-NA-355 and 19-NA-121, updated effective July 9, 2019. He called back and said bring it in tomorrow and we'll take care of it. Dropped it off at 0830 the next day. No questions asked, no diagnostics, no arguments. It took 8 hours to complete, partly because it was the first one he had done, and partly because of the extensive warming up/cooling down process required by the SB. I had not had any shuddering problems so I have nothing to compare it to but everything is fine now. Dealer told me the new fluid did not accumulate/retain moisture like the old fluid so it really needs to be changed. Power train warranty covered all costs. Makes me feel better, if nothing else.
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Last edited by SLEEKVET; Aug 23, 2019 at 10:31 AM.
Burning Brakes
Joined: Sep 2002
Posts: 767
Likes: 160
From: Central Florida
Had my 2018 GS (1/4/2018 build) flushed under warranty, no arguments, no BS.
Service advisor was aware of the issue; hell, even the cashier lady knew of the new fluid! Must have had a ton of vehicles with this issue!!
Anyway, main changes I feel is in the transition from V4 to V8, it is ABSOLUTELY seamless, you cannot feel it no matter how much attention you pay to it, also, car seems to go into V4 more often than prior to flush. This was immediately after flush.
Car shifts perfectly regardless of driving setting or speeds.
Service paperwork states a triple flush was performed, they kept the car two days and test drove approximately ten miles total.
Heading up to the NCM anniversary next week so will definitively put over 200 miles on it, fingers crossed.
Service advisor was aware of the issue; hell, even the cashier lady knew of the new fluid! Must have had a ton of vehicles with this issue!!
Anyway, main changes I feel is in the transition from V4 to V8, it is ABSOLUTELY seamless, you cannot feel it no matter how much attention you pay to it, also, car seems to go into V4 more often than prior to flush. This was immediately after flush.
Car shifts perfectly regardless of driving setting or speeds.
Service paperwork states a triple flush was performed, they kept the car two days and test drove approximately ten miles total.
Heading up to the NCM anniversary next week so will definitively put over 200 miles on it, fingers crossed.
Last edited by ZyberMunster; Aug 23, 2019 at 01:11 PM.
Burning Brakes
Joined: Aug 2004
Posts: 1,207
Likes: 147
From: St. Louis MO
I took my beautiful girl to the dealership today looking for the triple flush. Without the July 2019 revision of the 18-NA-355 TSB, all I could do was parrot the magic words and hope for the best.
That didn't work out for me.
They test drove the vehicle, claimed no shudder, and "programmed TCM with the latest calibrations, warranty claim code 18YN24490124."
I know I've been told to "find a dealer who knows how to do their job", but that's easier said then done. Now, I will have to schedule with a more distant dealer, and beg a ride from a fellow employee that will go out of their way to give me a ride back-n-forth. Without the TSB, you are at the whims of the dealer & his mechanic.
Please! Someone reading this, help us find the updated TSB!
That didn't work out for me.
They test drove the vehicle, claimed no shudder, and "programmed TCM with the latest calibrations, warranty claim code 18YN24490124." I know I've been told to "find a dealer who knows how to do their job", but that's easier said then done. Now, I will have to schedule with a more distant dealer, and beg a ride from a fellow employee that will go out of their way to give me a ride back-n-forth. Without the TSB, you are at the whims of the dealer & his mechanic.
Please! Someone reading this, help us find the updated TSB!
On Sept 6th they did the flush under "power train warranty (5yr/50k mile)" Invoice sez "TRANS FLUSH PERFORMED DOC 5181942."
In conclusion, having the GM doc to point to did help. I wish I could have said I got the doc from the Corvette Forum!
Safety Car
Joined: Mar 2018
Posts: 4,754
Likes: 1,650
PDF of TSB 18-NA-355 (dtd May 5,-2019) - last update
https://www.corvetteforum.com/forums...5-may-2019.pdf
https://www.corvetteforum.com/forums...5-may-2019.pdf
Last edited by MMD; Sep 8, 2019 at 10:29 AM.
Safety Car
Joined: Mar 2018
Posts: 4,754
Likes: 1,650
From what I have read the TSB 19-NA-121 (dtd July 9, 2019) you refer does 2 things. 1) Eliminates the Pico vibration test requirement, and 2) Adjusts dealer labor warranty charge-back billing because less time is required to perform the triple flush as the Pico test is no longer performed. The later TSB is more of an administrative change than a service/engineering change. The PDF link I cited earlier is still the most current in regards to the equipment necessary to perform the flush and other service requirements. Corvette is not the only GM model that incorporates the A8 transmission in their GM lineup. So the TSB also discusses all these other vehicles as well as any special considerations for each vehicle model.
Safety Car
Joined: Mar 2018
Posts: 4,754
Likes: 1,650
Why? It's not relevant. If anyone is considering this service all you have to refer do is your dealer to both of these TSBs. The older tells the dealer what the service issues are and how to perform the required service. The new TSB just tells the dealer what the dealer can charge back to GM. This is what I had done to my vehicle 2 days ago. Most, if not all, Chevy dealers are well aware of the issues associated with the A8. When I first called my dealer to get this service I had mentioned these TSBs and my service advisor indicated they were well aware of these TSBs and the service required. They had performed this service a few hundred times.