yvic45

What is the latest bulletin to repair the 8 speed transmission?

Kevin A Jones

I believe it to be TSB# 18-NA-355 dated Jan 17, 2019

yvic45

Thanks Kevin

CP

Just had the whoopty doo fluid change and the RPMs still go up and down at speed in V4 mode. Grrrrr. Put the Range back in the ODBII socket.

RichieRichZ06

By "repair" what do you mean? Do you have an issue with the A8 or are you also "suffering" from "excessive shudder" or other "I read it on the internet" symptoms?

Mike Mercury

Since the beginning of the A8 reported problems... I have tried to circumvent the possibility of the "shudder" and premature failure of the TC by babying my 2015 (mainly via use of the Range device). Now that the "first quarter permanent fix" has been issued, I would like to have this procedure done by the dealer under warranty.

My local dealer says that although the powertrain is still under warranty, they would still have to go through the diagnosis procedure... and if there are no signs of the problems mentioned in the procedure... that warranty won't cover it.

If this is accurate, this sucks. Has anyone else ran into this? If the initial fluid used was later discovered to not hold up, shouldn't the warranty procedure be performed solely on the basis of when the car was mfgrd; regardless if the symptoms are showing or not?

RichieRichZ06

The shudder isn't causing premature failure of the TC unless of course you listen to the forums. We service drastically more Corvettes than any other dealer in CA and we've replaced one single TC since the C7 has been in production. One single unit out of literally thousands of C7 vehicles that we service. The TC replacements reported on here are mostly due to mis-diagnosis and not actual failures and most people reported there was little to no change in shudder for any length of time.

The new flush procedure is covered under power train warranty, assuming it's excessive enough to require being done. Dealers are required to measure the amount of shudder and take a snap shot of the data. If the shudder is above a required threshold, we can do the flush procedure without any issues. Due to the shudder mostly being a little bit annoying, GM isn't going to do a $500 fluid exchange just because. FWIW out of the 20 or so cars that we've had come in for the shudder, only a few of them were actually excessive enough to perform the flush.

Kevin A Jones

While I can certainly see your point as I also have an A8 that has not shown any symptoms, I can also see GM's in that they don't want absorb costs to change out fluid in all A8s (over 100,000) when only estimated 3%>5% have issues.

Cubby558

RRich,

I just recently returned from a trip to and from FL and noticed the shudder for the first time on my Z06 with roughly 6,800 miles. It’s due for an oil change and I have another small warranty issue, so I’m getting ready to take it in. My question is will they check this shudder to see if it qualifies for the flush and let me know without a charge for this, or is it hit or miss on it being covered.

hummiscorvettetaken

This forum has a way of turning us all in to automotive Hypochondriacs.

EcoBrick Bob

I have 2 C7's with the A8. My 15' Z-51 was purchased new. At around 7,500 mi I had noticeable shudder. My T/C was replaced (Hendrick Naples which fixed the issue for around 18 months and another 7,500 mi. The second fix was a single flush ( not triple ) in March 2018. Car has been in storage in Iowa since Oct and was OK to that point.

My 16' C7 A8 was purchased used with 34,000 mi. No work had been done on Tranny and had no shudder for first 2K. Shortly afterwards, I started noticing the shudder. When I called for an appointment in early Feb, Hendrick, (Naples) gave me a date, 7 weeks out, due to the excessive number of vehicles waiting for the triple flush with the new Mobil 1 super fluid. On the day mine was done, 5 other A8's were being flushed. The flush seems to be working, though I bought a Range, to eliminate the V-4 mode. With both Trannys, when I locked them into 8 Cyl. mode by going to "M" I did not have any shudder. Range will go with me to my 15' that's now permanently in Iowa. I just wish GM would let us flash the ECM to eliminate the V-4 mode, but ain't gonna happen due to Govt. Range it is!!!!

As for the tranny waiting to back up after putting into reverse, I have found that it only happens after they have been sitting for a week or so. Since it doesn't happen if I drive them daily, I just put up with it.

I'm surprised that there hasn't been any efforts to start a class action suit, considering all the A8 transmissions in multiple vehicles that have had these issues.

Diceman9

I may be one of those Hypochondriacs. I'm looking to buy a C7 but just about writing off any that have the A8. Probably stick with a M7. Am I over reacting? I wonder how many of you REALLY wished you didn't have the A8 now. Maybe its a low percentage that have the issue (I don't know) but if you have the issue, it seems to be a real PITA! Shelling out this kind of money for a car with the A8 issue is just wrong! (are you listening GM?) Your thoughts are appreciated.

orca1946

None in my G S.

Formula52

Got an appointment next Wednesday to get a tranny flush with the new and improved Mobil Tranny fluid. Not sure if they do a triple flush, but expect to get my butt rammed by the bill. I better bring vasolene with me lol....

Also getting my new Pilot Sport A/S 3 ZP tires installed (all 4) and a new battery for peace of mind (4 years old). It's a 2015 Z51 Coupe A8 of course.....

Let everyone know next week how it went....

Steve

KemahGT

The C7 section needs a specific “A8 automatic transmission shudder problems” sub forum.

Diceman9

https://www.corvetteforum.com/forums...-tracking.html

Diceman9

bump

BKorsaire

Hello,

I have no problem with my 2017 A8, bought new here in the USA but I'd like to know what this new transmission oil is that you guys are talking about! Thank you very much.

c5arlen

I really really hate shuttering... Is there a shutter-free year C7?... What year did shuttering
rear itself?... I don't spend much time over here.

iclick

I had a 2015 A8 Stringray and now have a 2017 M7 GS, and will affirm that I'm very happy that I no longer have an A8. Mine shuddered from day one driving back from the dealer with <50 miles on the clock, but early on it was sporadic and I couldn't make it shudder for dealer inspection for 18 months. What's more, my A8 had the delayed engagement syndrome, but it was even more sporadic and I never was able to demonstrate it to a dealer. When the shudder and tach oscillation issue was finally verified and a TC/3x-flush was done in early 2017 GM would not fix the delayed engagement issue even though the tranny was out of the car for the shudder problem. Why? It was never demonstrable to a dealer service tech and they wouldn't take my word for it. As the car was being repaired I began shopping for an M7 replacement and made the deal two weeks after the repair was completed. It ran fine for that short time, with one exception. To add insult to injury the delayed engagement occurred as I picked the car up at the dealer, of course with no service personnel around to witness it, but as had been the case in the past it would not repeat itself, so in total frustration I didn't even bother reporting it. After hassling with the A8 maladies for almost two years I had had enough.

Unless you simply must have a slushbox, or need the marginal performance improvement they afford and don't mind the risk of having major surgery conducted on your new car, I would advise future owners to stay away from the A8. When the work was done on my car two years ago there was no assurance it would last, and some owners were having the job done more than once. I didn't want to worry about it and currently don't see where GM has solved the problem entirely for all owners 3-4 years after it was first known. To be fair, 2015 cars were the most vulnerable with reports for subsequent years progressively decreasing, but you won't find me taking the risk again. YMMV.