xlr8rvette

The shutter started Friday. Went on Corvette club run Sunday. Shudder was worse. Spoke with two others who had the infamous A8 transmission problem. Both had this fixed by the transmission triple flush.. One encounterred this1500 mile from home. He said driving in Manual mode using paddles helped. I too used paddlke shifting which helped.

I've heard GM no longer does the triple flush and/or they charge. My extended warranty is good thru March of 2024, thus coverred. However, is there something other than the triple flush I should discuss?
Taking Vette to dealer Monday morning.. 2016 with 38, 500 miles.

Thank you,

Dcasole

Make sure you have the latest TCM update...... a change was made to modify the way the torque converter locks up

Dave

aklim

I don't think that is more than a Band Aid approach. The fluid has picked up enough moisture and now the problem is displayed. I would have changed it before it got to this point so hopefully, it isn't too late. Don't worry about the charge. Fix it before it fixes you.

Dreamer2

If I owned a C7 A8, I would pay for it regardless of any problems. $700 to get rid of the bad stuff in my car.

gsx1300r

I just purchased a 2017 GS with 11,700 miles. It has the problem as well - figured out after the purchase. Another way I see evidence is/ was during a 78 mph cruize to Funfest Friday - I could watch the tach at normal engage on smooth surface to running up a hundred or more RPM then clawing back down to the 1,800. A different type of observation - yet confirmation the problem is present. Flush Service is scheduled for next available later this month. Thanks for all the incredible wisdom that is shared about these cars on this site!

Curious, What is TCM update?

aklim

Wimp. Wait till the transmission dies and the new one comes with the correct fluid. No triple flush needed.

xlr8rvette

Took Vette to Dealer this morning. They will test and likely do the Triple Flush. GM now considers the flush to be a maintenance item, thus warranty does not cover. They haven't performed this on a Vette, however, stated the triple flush on a truck was $450.

I bought the Vette 4 1/2 years ago. It only had 2300 miles Around 2 years later the Vette did almost every bad thing imaginable when stopping for a signal...clunking noises and jumping around. I took it to dealer . At that time they said the computer showed that the dealer who I purcahsed it from had performed the triple flush.
They did a "tune up" on the transmission and all has been well until now (38.5 k miles).
I'm certainly not going to quibble over a few $100.. We will just call it a part of the "Corvette Tax".

aklim

$450 is a little light. I would make sure they know how much fluid it uses and exactly how to do it WITHOUT SKIPPING STEPS. I would probably want to watch him do it instead of the usual "leave keys, come back, pay money and whine if things don't work out."

Dreamer2

I wouldn’t trust the dealer that a triple flush was performed on a 2300 mile car before they sold it.

Dreamer2

seriously? Lol

aklim

Why would they?

aklim

People wait till it shudders to flush it.

Dreamer2

Why? The current fluid is wrong and could be causing damage prior to the shutter. Some have had to replace TC.
$50-60,000 car, I’d be paying the $700 upfront.

Tate75

I purchased a 2016 with 22k miles a few weeks ago and began experiencing the shudder. I took it to a nearby Chevrolet dealer with a Corvette mechanic and had it triple flushed for $425.00. I've only put about 1000 miles since, but so far so good. They wanted an extra $300 for the TCM update, I did not do this, as I will be making adjustments myself with EFILive.

gsx1300r

Thanks for the info! Best wishes with elimination of the shudder.

Still curios about the TCM Update and will dig deeper. Our local scientist tuner uses HP Tuners - and text me that I would have to send my TCM off to HP tuners for them to unlock (and they seemingly charge more now or since 2017). I went stupid deep changing my C6. I am hoping not to only make minor mod's on this C7 and accurate fuel air and shifting (plus elimination or the 4 cyl mode) may not be worth the $. If I want crazy this time am thinking the C7 Z06 should be my starting platform. Lot's to learn! Links to a solid or favorite thread on the TCM Update will be appreciated!

aklim

I'd be curious. In the Milwaukee area, it is about $900. You may be in a cheaper area but I would price it out. I usually avoid highest and lowest.

xlr8rvette

What is the TSM? Doubt I have any update.

Thanks

aklim

Transmission Control Module, maybe?

gsx1300r

Found and copied some content about it - most from Dave from a thread that may have been locked in 2020 - posts just stopped.

TCM update which modifies the way the TCM pulses the lock up converter and the new fluid which has a different friction modifier

3- TCM update to modify converter engagement was not done

latest TCM firmware update as this modifies how the converter locks up . The converter never really locks up 100 % , it actually pulses and this program changes the behavior of the lockup

Is there a way to check to see if the car has been updated for TCM??....... response

No not unless you have GDS2 software and a GM MDI device along with a subscription to the GM TIS web site , the Web site keeps track of all the firmware versions for every module in your car and any future updates that are available. I am not excatly surewhen the e TCM update came out as some cars might come already updated with the latest firmware . My 2015 did not so I updated it

I would ask the dealer to do a PICO test as this will tell them if its the trans or something else

Dave

Now also wondering what is the PICO...

aklim

Is there a way to tell what is available like Windows OS where it lists updates available.