[ANSWERED] 2016-2017 A8 TC Shudder
 

Al's Answer:

This round of “Ask Al” focuses on the Camaro 8-Speed Automatic Transmission. I want to be clear in that we will only be talking about the Camaro application, not any other GM products in this response. You asked for information on the complaint of Transmission Shudder. We define “shudder” as a shake or vibration during light throttle acceleration, and it usually occurs between 25 and 80 mph (40 and 128 kph) at a Steady State. I hope we have generally categorized the concern properly to what you are experiencing.

We regret that we did experience a number of customer warranty cases in the 2016 Model Year. While the 2016 Model Year was a fairly short one, we did our best to rapidly collect enough data about the fluid to determine a solution. The initial findings showed an issue with the quality of the friction modifier in the fluid collected from customer cars. This is an additive to the transmission fluid to prevent a ‘shudder’ feeling during a torque converter clutch operation. If a car that is experiencing shudder is not serviced early, the torque converter clutch material could become burnished and may require a torque converter replacement. The dealer has a specific service procedure that they will follow to determine the required service for your vehicle. So, if you believe you are experiencing shudder, see your Chevy dealer right away, because the earlier you get it serviced, the better. Please keep in mind, not all 8-Speed Automatic Transmissions exhibit this issue.

So, what is the service procedure? Once we determined the issue was due to the quality of the friction modifier in the fluid, we developed a service procedure to flush and fill the transmission fluid 3 times, which eliminates most of the shudder concerns. This service process may not work for a vehicle with shudder that goes too long without service, in which case it will most likely require a new torque converter. Since we started using Dexron HP transmission fluid in March of 2017 both in production and for service, we believe we have basically eliminated the shudder. When used for service, it only requires a single flush and fill.

To summarize, if you have not experienced the shudder, you probably won’t experience the issue. If you have a 2016 or 2017 (built before March 2017) that is experiencing transmission shudder, you should get it serviced as soon as possible. If you had the ‘triple flush’ and your problem is fixed, great. If not, you will likely need a new torque converter. As always, your first stop with questions is your qualified Chevrolet dealer service station.

Delayed....but delivered. :thumbsup:

:thumb:

X-Factor here in Houston just got round one of the flush and I'll be following that one for sure.

I'm satisfied that they identified the cause as the friction modifier and that it was solved on cars built after March 2017.

I had the triple flush and TC replaced in September 2017 and have put ~4,500 miles on it since. Still works great so I'm hopeful that it is a permanent fix.

Thanks Al. :respekt:

This particular problem doesn't apply to me, but this seems like a very reasonable response. People who have had the fluid flush, but are still having problems may have new hope with a replacement torque converter. :thumb:

The only part I wasn't sure about was the "qualified Chevrolet dealer". A trip to any of my local Chevrolet dealers would pretty much guarantee newly introduced problems. I really wish there were more that GM could do to ensure the service technicians were truly "qualified" as well as better incentivize technicians to take their time and perform quality work.

Since some of us have limited dealership resources, I hope questions about problems like this one are not excluded going forward. If a question is popular enough to gather the most votes, to me that makes it worthy of being passed along to Al's team. Issues that can easily be addressed by dealerships aren't likely to get enough votes anyway.

TY for unlocking the thread Mr. Wyndham sorry i jumped at you there. I'm not thrilled with the answer i think it was carefully thought out and designed for him not by him. I do get the need to not come out and admit the error made for obvious reasons still i like Al and was really hoping for something better. Like maybe saying they are doing the flush band-aid and TC replacement but working on a TCM re-map to solve the issue.

Why would they need to say something like that.:iono:

It's a simple answer but one that pretty much sums up the issue a lot better than folks are going to get at their local dealership. It's a fluid issue not a tune issue.

We all have our moments of "shoulda' thought before I typed"...these moments are fueled by passion for the car and the community. If you didn't care, you wouldn't be so enthusiastic about it.

So, no worries.

.......but I will say I had a real colorful response for you typed out....then held the delete key for a while. ;) :bellyroll:

So, what am I missing here?? If fluid "solved" the issue, why are we (dealers) still performing the flush procedure on 2018 vehicles? SI #16-NA-175 shows 2015-2018 , and a vin break of November 1, 2015 - EOP (end of production) 8L90 and 8L45 Automatic (RPOs M5U, M5T, M5N, M5X).

The item you listed doesn't mention 2018 once....?

It's not an actual fluid issue. The flush is to remove whatever may have been damaged metal shavings, debris, etc. From the fluid and housings. The issue is they put insanely high slip%'s into the A8 to make it feel more comfortable but that caused low fluid line pressure to happen in regular driving scenarios. I wish i could get someone from a speed shop who has seen the issue investigated it and fixed it to chime in because I'm not a mechanic just did a ton of research and asked around to our parts development community.

We live in the northeast we have thick skin. All them people from Massachusetts and Vermont driving around lol.

My thoughts exactly. I did hear 2018s supposedly aren't affected I'd like to see the TCM tunes side by side myself but you do work at a dealership so I'm deferring what's still being done to you.

?

Hmm.. When did they start building MY18 vehicles? Could have been a few in there before they fully implemented the fix? Although March 2017 sounds pretty early for MY18.

SOP for 2018 MY was June 2017.