Tnguy2

Guys,

I have an A8, my DD. When I start the car in the morning, I usually wait for a few minutes to warm the engine up, then put it gear (D), the whole car shakes hard, and sometimes there's a delay for a couple of seconds then it still shakes. The car operates normally after that hard shake and it's been going on for months now, and every morning it does the same thing.

Is this normal with your A8?

txapezl1

Not normal. I thought I blew my tranny up, but it was just a control module that needed reprogramming. Do you have a CEL on?

Tow

Needs service for sure. Depending on the year and production date you will most likely need the Stator support TSB and Toque converter replacement. They are all defective and will all fail sooner or later so make it sooner while the perpetrator is still on the hook for the repair.

atvBob

\Boost Monkey/

Very well known problem, about 3+ TSB's on this very issue. See below:

https://www.corvetteforum.com/forums...th-anyone.html

https://www.corvetteforum.com/forums...s-evening.html

https://www.corvetteforum.com/forums...ng-to-end.html

........And many more. Search "A8 transmission issue"...

Nice Ride

Obviously something is not right. I had the hard shift from 1st to 2nd on cold start with my 2015 Z51 A8 off and on for awhile. I found that when putting the car in D and starting off very slow and gently increasing RPM's the hard shift was more soft and over time it went away on its on. That said, as you describe I don't think I would wait for the trans to "learn" and adjust on it's on even if it might get better. Best to take it to the dealer sooner than later. You should eave it with them overnight with the clear understanding you will be back the next morning early so you can physically be in the car at first cold start up. A picture is worth a K words so if you can duplicate the event with the service tech present that is the first step toward resolution. Good luck.

Tnguy2

Thanks guys! Car is 2015
Bringing the car back for service is on my list.
I just went there for the Infotainment sceen and subwoofer replaced last month. Hopefully there's no more issue after this.

\Boost Monkey/

I had the same exact problem as OP...


The newest TCM reflash for this issue (Harsh shifts) worked for me thus far... But i suspect the fix is only temporary. MY ADVICE IS GET THE NEWEST REFLASH DONE FIRST... Then if reflashes don't work, the below TSB is your LAST RESORT:

obxchartercaptain

This is exactly the problem I have. I called a dealer and they told me it is a 16 hr job which means the whole tranny has to come apart.....this is something I don't want....given who works on these cars today...What happens if I choose not to get it fixed? What I do now is shift from Park to Drive then to Reverse then to Drive and back to Reverse and it moves without a problem....If I don't I have to wait about 30 seconds for it to build up pressure to move.

\Boost Monkey/

Who knows in the long term, but my bet is not good.

Yes, it's a big job which requires taking apart the rear end of the car, dropping the exhaust and rear suspension, rear bumper etc and then dropping the transmission. Then putting the trans on a special cradle device while they open up the TC.

Then reassemble everything.

Again, i stress to you to try the re-flash first for harsh shifts that GM released prior to the above stator TSB.

Also, there is one guy for sure on this forum that had the stator shaft support TSB done and it didnt fix the problem, and another guy that had the stator done first then a whole new TC... and then developed the harsh shift in the morning.

obxchartercaptain

I just called Stingray Chevy in Tampa, Fl...spoke to one of their "service advisers" He told me they are BACKED UP with tranny work and have only ONE tranny guy. They didn't know when they could get to it but to drop it off and they would "diagnosis" the problem....Not about to leave it there indefinitely....Really pisses me off to buy a $82,290.00 car and not be able to drive it when I want.....

Tow

Surprise Suprise!! NOT!! But But Mr. Tadge lier that he is said the A8 is very reliable. Im beginning to agree with that PeterMJ guy TJ is a POS.

\Boost Monkey/

They need to have the car overnight to simulate the problem, but after they simulate problem and approve the stator TSB work i posted above (assuming reflash doesnt work) they will need to order a few "special" tools (the cradle is one of them) that i can almost guarantee you they do not have yet, which can take weeks of your car sitting with them.

You need get them to look over the TSB, tell you they have all the specialty tools and are ready to work before you leave the car with them.

The re-flash only takes one overnight to simulate the problem, then one hour labor to reflash...then car is done.

kp

16-na-014 has been revised with more info in June.

http://www.corvetteactioncenter.com/...-off-1290.html

Under 3 seconds to engagement and they do not want the stator update done.

There is also a learn procedure for harsh engagement. I would make sure that was done before tearing the trans apart.

Len44

IIRC, Stingray Chevrolet has done a few of these operations with a pretty good success rate. If so, they would probably already have all the tools needed.

jagamajajaran

Putting yourself in league with PeterMJ tells us a lot about you. You remind me of a former forum member that made a big fuss about his C7 A8 problems, threatening lawsuits and a plan to make a scene at the NCM bash, but then got banned, came back with a new username, bashed Tadge and the C7 A8 even though he has now owned two, got banned again, came back, bashed, got banned...and on and on it goes.

It is seriously wrong for someone that had A8 problems to pose as so many different people on this forum.

Grand-C7

That is not normal for any car. You need to take it in and leave it over night so service can drive it cold in the morning.

Awwimer

Hey guys, just joined the forum to learn about my problems I am having with my A8. I had the same shift problems, then after they replicated it and had attempted a fix, it now slips between the 1/2 shift when cold. Was told it could not be replicated on my last visit, yet it does it every time. Dont know what to do next.

obxchartercaptain

I am really DISGUSTED.....I have absolutely no trust in the mechanics today....I can see them ripping the boot covering the shafts to the rear wheels when they take the tranny and rear end down....not to mention if they in fact do the repair correctly....Most people today have no pride in what they do....sorry for the rant but I am really upset about buying a $82,000.00 car and knowing they KNEW they had problems with their A8. The problems are showing up in GM's other vehicles as well with that tranny. I wanted to get a manual but thought of my wife and got the auto....she's never driven the damn thing and has no desire to.

Awwimer

I was told they basically added bearings in the valve body. (Shift kit?) Have another appointment for the radio screen and pdr that still doesnt work.