I may be in the wrong Forum with my question, but I did check on the C7 General Discussion Forum and really couldn't find an answer...so I have a 2018 Z06 with the A8 and hoped someone here might be able to answer. I guess there's been several Service Bulletins to the dealers outlining what to do and any inspections or charges to the owners with the "triple flush" solution, but it's been such a beat around topic, I simply wanted to know what the rule reads today (actually I'd be doing this in March 2021, when I get the car out of mothballs). Mine is a 2018 Z06 leftover that I bought in mid 2019, so the car is well within the 3 year/36,000 mile window (current mileage is 4500 miles). I've really never experienced any issues with the A8, but I'm nerdy enough to want the most up to dare, best transmission fluid in my car's trans-torque system and everything I've read says the Mobil One product is the real deal. My most recent info (about 1-2 years go) said that the dealer would perform the Triple Flush with no service department inspection if the customer complained of hesitation, sluggish performance (or whatever) in his C7 and if the car was still in basic warranty....no inspections by the dealer and if the dealer performed one, regardless if there was a problem or not, GM would not reimburse the dealer for any inspection on this well known issue. Does anyone know for sure that this is still the word of the law with the dealers, still the latest Service Bulletin and therefore if I get hassled it's because he dealer is a dick and not because of an update to "yesterday's" latest bulletin concerning no inspection is required. Thanks for any help!

 

I had my 2016 done in October, I showed them the service bulletin and indicated that I had the light throttle vibration.
They did the flush without any questions, my warranty was going to expire in March so I wanted to get it done while the weather was still nice in Wisconsin.

 

Very thoughtful question. You nailed it. Short answer, you really need to get this flush. Most dealers will perform the flush with little to no hesitation. However as you alluded to there are some real dicks out there in the manner how they handle this request. My suggestion would be if you are turned down then just try going to another Chevy dealer. Eventually you will find one who agrees to your request. Just bring a copy of the TSB with you. TSB 18- A-355 dated April 2020.

 

I had mine done in November. Like you, i just wanted the best upgraded fluid so I used the service bulletin as a reference and no questions asked by the dealer and they performed the triple flush for me under warranty (2017 ZO6, 6500 miles). I also had the rear diff, oil change and brake fluid flush done at the same time so they made a few bucks on me for routine service.

 

My dealer Bachman Chevrolet in Louisville did a triple flush under warranty on my 2016 Z07 A8 in Feb. without any problem although it is obvious that the car is heavily modified. Pays to have a good relationship with the service writer.

 

Everyone....your responses were perfect, for me. I really appreciate it...thanks!!

 

Haha I've experienced this surging before and thought I was crazy. Guess this will be added to the list of things the dealer needs to fix.

 

The most current version of 18-NA-355 is April 2020. The first couple of pages are a general description and tools required for this service. The triple flush procedure for Corvette begins on page 15. See attached PDF file for TSB. Most computers can read this PDF file. You may need the Adobe Acrobat App if your device cannot read it.

 

Thanks very much with your help on this one. I'll be taking my car into m local dealer (he does have a certified Corvette mechanic) this Spring to have the engine oil changed and have this Triple Flush done. I did mention it to him once early last year and he said that problem had to be confirmed with a PICO test (which I believe now is horse crap) and that this procedure would take about 3-4 hours and that the car had to be road tested after every oil change during the triple flush procedure. I now really believe he's the "expert who really knows nothing" that many of us have found in the various auto dealerships. Regardless, I'll start with the TSB you provided and if he jerks me around, I'll go to one of the several other Chevrolet dealers with Corvette knowledge in my area. Again, thanks very much for all your input and knowledge on this issue....this really is one of the main reason this forum is started!

 

Tzoid - Thank you. Be aware that sometime last year GM did away with the Pico Test requirement. What they did say was there is no longer a requirement for a Pico Test "unless" the vehicle owner had brought the car back for the shudder or notchy shift problem "after" the triple flush service had already been performed. GM was having so many people coming in to their dealer network with this problem that they found the reimbursement costs to the dealer for their labor charges was costing them a pretty penny to perform this testing as it takes a good deal of time to do. They felt it would save them money if they just did the triple flush without a Pico Test. They were confident that the triple flush with the new Mobil 1 synthetic oil would solve most problems associated with this transmission. Seems this may be the case. Many positives from folks here. What I did when I brought my vehicle in I just told the service advisor was that my 19 GS felt a little notchy whenever the car shifted between 1st and 2nd gear when the vehicle was cold. It seemed this was the magic words that my advisor bought and the service was done in a just a few hours. Read through the beginning block of the TBS and highlight where it tells the dealer the Pico Test is "only" required if owners bring it back the second time if the triple flush doesn't work. Just be firm but polite and you should have no problems. If they complain then go elsewhere. Good luck. This service is worth the effort.

 

I too am taking my newly purchased 2018 A8 in for service in the very near future. Car is still under warranty until Aug. of this year.
It sounds like it could be important to say the "right" words to the service dept.
What is the "shutter' like and when does it occur?
What is 'notchy" when shifting between 1st. and 2nd.?
Thank you all. I plan to get the mag.-ride update at the same time.
Tom

 

It's a C7 thing only Love. No need to worry about shutter or notchy gear shifting in your C8. A notchy gear shift, as I had, is when the transmission shift between 1st and 2nd gear was made (it could occur between other gears as well and it could be in the process of upshifting or downshifting) and there is a ever so slight momentary hesitation between the shift. You can almost feel like the shift wanted to shift earlier but it was delayed somehow. A shutter is a mild vibration that you may hear and certainly will feel through the steering wheel and/or seat. This will usually occur between a certain range of speeds and/or at certain range of engine engine RPMs. Many people have experienced shutter between 55-65 MPH. Shutter is mostly seen on an automatic transmissions as you have in your C8. Hope this helps.

 

Thank you MMD. My car is a C7 Z06 and your info will be helpful to me when I take her in for a flush.
Thanks again.
Tom

 

I would say this, the wording from the TSB posted earlier:

 

If you have been following this topic for 3 years you would know that the service bulletin history of TSB 16-NA-355 goes way back (numerous revisions) and they also discussed on numerous occasions that notchy shifting is another condition that would require a triple flush. This is what my 19 GS had and my local Chevy dealer took it in with no Pico testing being performed and flushed the oil. The old oil they used earlier in the transmission was identified as the problem for shudder and notchy (delayed) shifting. It cleared up my shifting in my transmission.

 

What does this have to do with my post? He asked for the right words to say to get the flush done and I answered to use the condition written in the TSB. That's it.

 

Your reply is incomplete. GM will also triple flush the fluid if the transmission shows signs of delayed shifting in lower gears. Numerous reports of owners indicating problems with shifts. I can pull up older copies of the TSBs if you want to see the big picture. The member that asked the question may not have a shudder condition.