b4i4getit

I can't understand why a problem they discovered a few years ago is still a problem. Where is the quality control on this transmission ?

Skippydoo

My 2014 is an M7 and sealed the deal on a new 2017 z51. Original order was an A8 but changed ny mind. 2017 Z51 M7 on the way.

Foosh

It doesn't sound like a quality control issue. It sounds more like a design issue. The A10 partnership w/ Ford is another clue that something perhaps isn't going well here.

Nobull

Don't be fooled that all the torque converter problems are limited to the A8. I have an early build A6 that also had the dreaded torque converter issue. To make things worse, the tc problem was discovered after replacing the flex plate (twice) and the torque tube. My car was in the shop for 5 weeks. If not for the warranty I guess I would have been out of pocket for somewhere around $8,000+ (with an emphasis on the the plus) for parts and labor. All in all it's a wonderful performance car for the money, but these driveline issues will not go away and seem to be multiplying! After the tc was replaced I asked the shop foreman (who serviced the car) if the torque converter that they installed had been upgraded or changed from the original design. The response was no--same design! They confirmed the tc problems but I was told that the GM rep said that a recall was too expensive for GM.

Crossed Flags Fan

Having the A6 myself (Feb 2014 build)I haven't had any problems and I'm currently at 30,000 miles. Sorry to hear you had or are still having issues.

KrikGS

UPDATE:

Spoke with service director today. Told him about my symptoms and my concern about the fact that a 2017 shouldn't be exhibiting them. He said it definitely sounds like TC failure but this is the first 2017 he's heard of that has that problem.

Bringing it in Thursday afternoon to drop off for diagnostics and TC replacement if necessary. They would have the car for 2-3 days not counting weekend. Said he was going to contact regional rep due to the fact that it is a 2017 exhibiting issues and that GM would more than likely want the TC to investigate.

Should know for sure by Friday I would think. Car exhibiting worse symptoms now. Currently at 3800 miles.

joemessman

Sorry to hear that. More than ever I think it is bad parts as opposed to design. If it was design all would eventually fail by 20,000 miles or so. Let us know how this goes. Thanks for informing us.

Foosh

"Bad parts" should be a much easier fix than overcoming a problem-prone design.

joemessman

Foosh I agree. I just hope that is what it is. Bad parts. If it was the design, and am by no means a total expert, then all of these A8 transmissions are due for failure at some point. When they replace the parts it doesn't even fix the problem for some folks! Maybe short term. A real puzzle, and I hope someone can figure this out eventually.

767guy

Sorry to hear about your problems with a new ' 17.

I have had two transmission tear outs , One for a TC replacement and the next for a complete transmission. I have driveline issues again and am holding off for a bit to see if there really is a fix.

I am very anxious to hear how you make out with Stingray Chevrolet and will follow your post.

Best of luck to you .

rw99

I have a brand new '16 Z06 A8, so please forgive me this basic question:

Does the A8 have issues if you drive it in manual mode all the time? It's my habit to use paddles for about 90% of my driving.

Thanks in advance for any learned summaries or thread references, I appreciate it.

Best,


Rich

KrikGS

No, as soon as I drop the lever to M, all the shuddering stops and the tach is steady as a rock. Also, it doesn't do it in V8 mode, only V4 mode.

iclick

I hate to be a beacon of negativity, but good luck with the 2-3 day prognosis. My 2015 has been in the shop for 23 days now and they claim they can't get TCs or the new fluid, which are presumably back ordered. I would recommend that you appeal to your dealer to order the parts, then let you know when they arrive. Otherwise it may languish at the dealer for weeks. Many report having waited 30 days or more for a TC swap.

Once this is done I'm out of the A8 club for good and into a new GS with M7. I don't blame the car, as it is a great creation, but rather a flawed tranny design that spans all brands it is linked to, like trucks, SUVs, Cadillacs, etc. Do a search on "8L90 torque converter shudder" (no quotes) for the evidence. Eliminate the "8L90" and you'll get hits across brand and model lines, as it is not limited to only GM vehicles and goes back 15 or more years. This leads me to believe the industry as a whole doesn't have a grip on this issue, so why would I think my A8 would be fixed by changing the TC now?

Yep, only V4 mode. I've never heard any reports of shuddering in V8 mode, and I've been searching for an explanation for 18 months. SMs from three local dealerships have no clue, but my guess is that the harmonics or vibrations created by deactivating four cylinders interferes with the operation of the TCC lockup mechanism. I can think of no other explanation.

djnice

If its a bad design and industry problem. Why doesn't it happen to everyone with an A8?

Foosh

Because even a 5% malfunction rate in let's say 36K miles is unacceptable in this day and age, and would be considered a problematic design.

berk4422

550 Miles on '17 GS, born on 11/18/2016 - I was in sport mode, going up a bridge, 1/8 throttle and applying a little more, about 35mph. Sort of felt like the transmission was going to downshift, acceleration was stuttering about 3 times over about 2 or 3 seconds. Does this sound like symptom of a bad TC as described in this thread?

If so, I don't think the TC is the problem. I think the TC has a higher than normal stall speed or the transmission is learning my driving behavior or a v4 to v8 electronics process.


Edit: I've experienced the same thing a couple of times in my A6 '15 Silverado.

djnice

Well, iclick says its not limited to GM and goes back 15 years. Man, that's a lot of automatic transmissions to include in the statics. What is the percentage of all automatic transmissions that have malfunctioned?

Are you sure its 5% of all A8's built, and how does that compare to malfunctions in all automatic transmissions built in the last 5 years?

I was reading another thread and one post said they had all the same problems with the A6. Also, if the issue is only exhibited in V4 mode then that sounds like a problem with the AFM design. Put the tranny in a car with no AFM and what % of malfunctions disappear?

Foosh

I never said it was 5%, and I don't know what it is. I don't think GM wants us to know either. However, if it were .01%, I suspect they'd be quick to tell us.

I was just illustrating the point that a small percentage of failures is considered unacceptable with today's technology.

djnice

From my experience that sounds like the transitions between V8 and V4. Does the car actually shake or is it just hesitation? The OP talks about shudder, which I assume is actual shaking of some sort. I have never observed so I don't know, will be interesting if someone explains it.

iclick

It may be that most (all?) A8s will have issues eventually, but I suspect most owners won't notice them at first. In fact, I'm the only one who's reported witnessing the shudder in the first 50 miles of ownership, while most seem to report it after 5-10k. Many owners don't put high mileage on their C7s, so it may be a matter of time before the problems show up in larger numbers. Just my 2¢,

Also, I think some owners feel the shudder and mistake it for road imperfections, as that's just what it feels like. In time I think more reports will surface as the shuddering gets worse and people start to tie it into something other than the road. Mine was sporadic and usually minor until the past two months when it got worse and began doing it during every ride. I also had very sporadic but rare bouts of delayed engagement when cold, another A8 malady that may or may not be TC related, but that seems to have improved over time.