MidLife+

Hoping for a real fix in 2019!!!

I have a 2016 Z06 A8. I have had the fluid flush, replaced the torque converter and a transmission valve body replaced. I bought a Range AFM disabler a couple months ago.

With all this I still have a very noticeable shudder. I have put on over 1000 miles after all the fixes giving it enough time to "self heal" and the shudder is as bad as it was to begin with.

If there isn't a real fix coming in 2019 as promised by GM I guess I am screwed. Anybody have a low mileage C6 GS A6 that wants to trade??

Have a great new year guys,

MA ZO6

I have done some searching on the internet about what the new procedure GM will come out with next year to resolve the shudder problem with the 8 speed transmission. I have found some information from people who claim they have inside information that GM will come with a new fluid and a new procedure to flush the fluid. The below information is from the GM techlink website and it seems to support that, I highlighted it in red at the end of the article.

My car already had the fluid flushed about a month ago and it did NOT solve the problem, hopefully the new procedure they come out with next year will fix it for good.

John

Changes in Transmission Oil Cooler Flush Requirements

Posted on November 20, 2018 by blogadmin

Recent GM studies have shown that automatic transmission oil cooler flush requirements have limited benefit on many current transmission repairs. Based on the studies, GM will no longer require a mandatory flush and flow test of the transmission oil cooler and the oil cooler pipes — including the auxiliary transmission oil cooler, if equipped — to be performed in every instance of transmission or torque convertor replacements or internal transmission repairs. (Fig. 1) As a result of this policy change, transmission repairs will be simpler, the environmental impact of waste oil will be reduced and Global Warranty Management transaction processing will be simplified.

Fig. 1



Transmission Repair Policy Changes

Effective December 1st, 2018:

• Job cards will no longer require a transmission flush code from the DT-45096 Transmission Oil Cooling System Flush and Flow Test Tool (DT-45096 TransFlow®machine). (Fig. 2)
• The Flush Code field in Global Warranty Management related to all applicable transmission labor operations should be left blank. The field will be eliminated mid-December.
• The Warranty Support Center will no longer require a flush code on warranty transactions.

Repair procedures in the Service Information will be updated to reflect the elimination of the transmission cooler flush requirement. In addition, related service bulletins, the labor time guide, and the GM Service Policies and Procedures Manual will be updated accordingly.

Fig. 2

The DT-45096 TransFlow machine continues to be a valuable GM Essential Tool that should be used when diagnosing transmission overheating conditions or a transmission failure due to a lack of lubrication. Technicians should continue to document the TransFlow code in the correction comments of the job card in instances when the DT-45096 flow test procedure is used to diagnose an overheating or lubrication concern.

TIP: Use only the appropriate GM automatic transmission fluid when performing a transmission repair. If the fluid in the DT-45096 TransFlow machine is different than what is used in the transmission, after performing the flush and flow test, use compressed air to blow the residual transmission fluid out of the transmission oil cooler and lines.

New Fluid Exchange Procedure

A new repair procedure for the DT-45096 TransFlow machine to exchange fluid also has been developed to address torque converter clutch shudder on 8L45 and 8L90 8-speed automatic transmissions (RPOs M5T, M5N, M5U, M5X). The new transmission fluid exchange procedure and new formula of Mobil 1 Synthetic LV ATF HP transmission fluid is being rolled out regionally due to the limited availability of both the new transmission fluid and tool kit. It is anticipated that the new transmission fluid and tool kit will be available nationwide by late January or early February 2019. Look for more information to be released soon in a service bulletin and the December 2018 Emerging Issues seminar (10218.12V).

– Thanks to Mark Gordon

Updated December 13, 2018

NSC5

Shudder with the Z06 model is very rare. I also have a 2016 but it has always either had a Range module or been driven in manual mode.

Your Z06 may well have another powertrain issue outside of the transmission given that you have had multiple transmission repair attempts including using the Range module but still have shudder. Although torque converter induced shudder is a VERY common problem with the 8L45/8L90 transmission family this isn't the only possible cause of shudder and because it is so common most techs are going to immediately blame just the transmission without checking for other causes. Part of the transmission shudder diagnosis for the 8L90 equipped Corvette is for the tech to drive it with the converter commanded both to lock and to unlock states and if shudder is present in either of these commanded modes then the torque converter is NOT the cause; torque converter induced shudder only occurs in normal mode (neither commanded locked nor unlocked) where the converter clutch is modulated to allow a small amount of slip under different operating conditions, primarily when the engine is running in V4 mode.

If you Z06 has another powertrain issue then all of the torque converter TSBs and magic fixes won't cure it.

FreeFlyFreak

Just read this on a Camaro forum relating to the new fluid solution and the root cause of the TCC shudder.

The original and first fix fluid was hygroscopic, it absorbed water. The fluid that absorbed water was "grabby" which caused the shudder because the tranny TCC is designed to slip some when the engine is in V4 to dampen the vibrations. The wet grabby fluid actually made that worse.
Which meant that people with vehicles in humid climates got the problem worse, quicker, and more often than people in dry climates. Hence the variability in different cars having different times yo shudder onset.

​​​​Sure seems like the best explanation so far, and the guy posting seems to know what he is talking about, and says he has "access"
The new TSB is 18-NA-355 which I haven't found online yet, but I'm sure will become public soon.

Helps explain why my 2016 Z51 with 8400 miles shows no sign of shudder (I am 3rd owner) because it was always in a dry climate.(SoCal high desert) until I bought it, now its in Norcal and it has been damp and humid this winter, so I will be getting this 3rd gen fluid ASAP before I get a problem In the meantime I'm avoiding V4 and have a Range module on the way.

You can read about it here:
https://www.camaro6.com/forums/showthread.php?p=10415776