Vetteman Jack

I do not have the A8 in my car, but still interesting to read what the problems are and how GM is saying to solve the shudder.

Maxie2U

24 quart flush and drop the pan three time? If true I will just like the frig’n thing fail and have them replace it under the extended warranty.

RWCARR

I have a 2017 GS with A8. I had the shudder/washboard issue and during 2018 dealer performed the triple flush correction on two different occasions but neither corrected the issue. The dealer performed the latest flush with the new fluid last month, about 600 miles ago and so far, its been FANTASTIC! A completely different feel, smooth, no shudder or washboard feel. So far, this is the fix at least for my A8 issues

kitesurfer

I've taken 2 round trips to NC and back since my triple flush with the new stuff. it's running perfect!!!

Wesens

Had mine done today. Seems to have fixed the shudder and torque converter coming out of lock. They said on the invoice that the full problem resolution could take 200 miles of driving to complete. On my 20 mile trip home it never experienced the washboard effect or shudder. I'm hopeful as I've had this 2015 Z51 (15K miles) at the dealer more times than I want to think about! Shifts were smooth. Much different than before the flush and refill with the latest fluid.

Al Engel

To the C7, A8 owners who have replied after the completion of this latest "fix" with the revised Mobil trany fluid; 'thank you' for relaying your experience and result. From your replies, it sounds like "So far, so good" for this aproaching to fix the problem. Keep your replies coming to see if this "fix" holds up.

Al Engel 'Save the Wave'

Mgdr2525

5,400 miles on the C7 I purchased in September. Going in for oil change and, unfortunately, the transmission flush Tuesday.
The threads have scared me to death about the A8 fix. Has anyone had the shudder problem and the flush fix it? Looking at options.

dmaxx3500

I wonder if getting the tranny to 230+ degs, would burn off the moisture ?

Gearhead Jim

That's a good question. However, on the C6 it was recommended to keep the A6 below 230' (I think redline temp was 260) and so the cure might be worse than the disease. I'm not sure of the temp limits for the A8.

On our 2017 Z51 A8, I've never seen the tranny over 175' and even that took several consecutive autocross runs.
But your idea is still intriguing. Heating up the tranny every month or two could be a lot of fun.

RWCARR

So far, YES... I'm now at 700 miles after the new 2019 flush/fluid fix and its like driving a totally different car. No shudder, smooth shifts. Obviously time and more miles will tell but at this point..... all is well now.

jjwalkers

Yesterday I bought a 2016 Vette with 5,000 miles on it and all the way home I felt shutter. It felt like you were driving on a rough road which I wasn't or like driving over small bumps. When I got home I found a receipt for a Transmission flush done for the previous owner. I spoke to him and he said it was fine after the flush but traded it soon after. It is now my problem but at least it's under warranty.
As I have found out the flush is a bandaid and so is the torque converter replacement. As I understand it GM doesn't have a permanent fix at this time.

Al Engel

OK.... so from the replys to date, it appears the 'triple flushes' performed before the latest TSB, that did not include the new Moble 1 ATF, did not work. But those who got the new Moble 1 fluid appear to be having good experience. Interesting! Let's hear from folks who have had the latest Moble 1 fix and then had the shudder reoccur. If no problems are reported, sounds like GM and Moble finally got the problem nailed.


Al Engel, 'Save the Wave'

jjwalkers

I hope you are right Al. I go tomorrow to have the Transmission flushed for the second time.

Red C8 of Jax

I had the newest Mobil 1 fix last week and still have the shudder. What confuses me is that when I have the shudder, I can take the transmission out of gear (place it in N) and the shudder still continues. Thought I would give the so called fix about 200 miles and if the shudder continues, I will take it back to the dealer. I have a 2015 with 44K miles and the powertrain warranty is out in 7 months. Glad I purchased the GM Extended warranty. If you have an A8 and plan on keeping your car longer than 5 years, I would definitely get the GM extended warranty before the 3/36 runs out.

Johnfromflorida

I have 2016 Z51 and around 8500 miles at the end of 2018 it started to shutter. I got the triple flush at the beginning of 2019 and i was told by the service manager that the old fluid had moisture issues. It seemed like they did a quite a few and he knew what he was talking about. He said that they have not got any cars back with same isuue after the triple flush.

I am at 12000 + now and it is smooth. My shutter started and was most noticed at the buttom of the 7th gear around 37-40 mph. It would go to ATF V4 and start shaking. And it progressively got worst and noticeable on 8th gear and higher speeds. I have the range unit but i am not using it, I let it go to V4 ... Still no problems at all.

And it has the newest fluid. I accually asked for what type fluid they were gonna use to make sure.

jjwalkers

My 2016 Vette is at Chev as we speak. They first put a computer on it and it didn't react enough the get the fluid change, then I ask the mechanic to drive it on the highway and upon return, said ok that they would do a Fluid Flush. A little while later, the service tech said they are also changing the torque converter. He said and he may be wrong that the new torque converter is an upgraded one. That is good news if it's true. I also asked him to replace the filter while they have it opened up. It may not need it but let's start new. I will let you know if it helps the problem of the transmission shutter.

Update, the service tech didn't know what he was talking about. He said they were going to replace the TC and they did not but they did flush the Tranny. He said it will get better when you drive it about 200 miles but driving it home some 20 miles it felt pretty good. Time will tell.

rmorin1249

My TC was changed at about 12K miles. Slight shudder came back at about 18K miles. Dealer performed the triple flush and so far, so good. I'm at 20K miles now but also using a Range all the time.

CADbrian

When (approximate mileage count) did you begin using your Range device?

rmorin1249

Right after the new TC was installed, approximately 12.5k miles.

kemomill

Noticed the shudder at 8,000 miles. 2015 Z-51. Had the latest flush done and it's a different car. Shifts better than ever! Very smooth under normal driving but quick and firm under acceleration. Very pleased!!