[Inspector 17]

Just posting this for anyone who may experience the same situation I ran into. I experienced very rough shifting at several track day events. After the first time, I took it directly to the dealer and had them replace the transmission fluid. Took it back shortly after that when the overfill bulletin came out on the early 2017 cars. Next track day I had the same rough shifting but only when the transmission got warm. Last track day it got significantly worse to the point I had to stop running. Even when the transmission cooled it was shifting so hard it was jerking the car around. After several attempts to pull get some log data to GM, it's been determined that the clutch packs need replaced. I think it's just up to 5th gear but not entirely sure. Waiting on parts and then it will go in for surgery. We'll see how it does when I get it back.

[Stephen12ZL1]

Originally Posted by Inspector 17

Just posting this for anyone who may experience the same situation I ran into. I experienced very rough shifting at several track day events. After the first time, I took it directly to the dealer and had them replace the transmission fluid. Took it back shortly after that when the overfill bulletin came out on the early 2017 cars. Next track day I had the same rough shifting but only when the transmission got warm. Last track day it got significantly worse to the point I had to stop running. Even when the transmission cooled it was shifting so hard it was jerking the car around. After several attempts to pull get some log data to GM, it's been determined that the clutch packs need replaced. I think it's just up to 5th gear but not entirely sure. Waiting on parts and then it will go in for surgery. We'll see how it does when I get it back.

we are going to see more of this as you have stated. The A10 tranny is very very sensitive to over/underfilling. Most of them are slightly over-filled from the factory but from the dealer this is likely a cluster F$*@. I carefully drained the fluid from my car when it became time to change the fluid. Of course the only way to drain the fluid is to remove the entire pan. Swap the filter and pan gasket (this can be reused if you want). My car took exactly 7qts to make everything right. Be certain the correct ULV fluid was used and not another GM fluid variant (they easily could have used Dexron 6 or HP) which is INCORRECT and cannot be substituted. I am going to guess a tech saw a Camaro and used the wrong fluid and thought it would be "good enough". Check your service record and see what it state. Inquire with your service tech about the fluid used. Hope you resolve this quickly!

[Stephen12ZL1]

https://www.camaro6.com/forums/showthread.php?t=553829

[Snakebt6]

Originally Posted by Inspector 17

Just posting this for anyone who may experience the same situation I ran into. I experienced very rough shifting at several track day events. After the first time, I took it directly to the dealer and had them replace the transmission fluid. Took it back shortly after that when the overfill bulletin came out on the early 2017 cars. Next track day I had the same rough shifting but only when the transmission got warm. Last track day it got significantly worse to the point I had to stop running. Even when the transmission cooled it was shifting so hard it was jerking the car around. After several attempts to pull get some log data to GM, it's been determined that the clutch packs need replaced. I think it's just up to 5th gear but not entirely sure. Waiting on parts and then it will go in for surgery. We'll see how it does when I get it back.

I had a similar issue this weekend at a track event. First event with the car and its just passed the break in miles. I heard/felt a vibration while braking and the transmission started to behave erratically. I did a cool down lap and ended my day. The car drove, but the transmission jerks and bang shifts a bit and the check engine light is now on.

Taking it to the dealer in the am.

2020 ZL1 1LE

For the record I had an 18 ZL1 non 1LE and it was flawless and I had 10+ track days on it and changed the fluid twice as well during the period I owned it.

Ill keep you guys posted.

[Tank22]

Originally Posted by Snakebt6

I had a similar issue this weekend at a track event. First event with the car and its just passed the break in miles. I heard/felt a vibration while braking and the transmission started to behave erratically. I did a cool down lap and ended my day. The car drove, but the transmission jerks and bang shifts a bit and the check engine light is now on.

Taking it to the dealer in the am.

2020 ZL1 1LE

For the record I had an 18 ZL1 non 1LE and it was flawless and I had 10+ track days on it and changed the fluid twice as well during the period I owned it.

Ill keep you guys posted.

I have a 2020 1LE... experienced similar issues after some spirited back roads driving. The TCU failed and it took out the valve body. After replacement of both it wouldn't shift right. The upshifts were violent from 4-5 with a 2 second delay in shifting.

GM has replaced the transmission under warranty. The car has 1,500 miles on it total. I have a track day at the end of the month and we will see how it goes.

One thing to note: They found the battery had a bad cell which send weird voltage to the computer and may have been the cause of the original TCU failure.

[Snakebt6]

Wow..I had a bad battery at 1300 miles.

Changed it.. went to a track day at 1600 after the track alignment and 1500 mile service and here I am also.

Thanks for this and Ill pass it on to my dealer. Much appreciated.

[Tank22]

Originally Posted by Snakebt6

Wow..I had a bad battery at 1300 miles.

Changed it.. went to a track day at 1600 after the track alignment and 1500 mile service and here I am also.

Thanks for this and Ill pass it on to my dealer. Much appreciated.

I know of 3 more transmission failures where they all were found to have a bad battery.... You wouldn't think a battery could do that kind of damage. From what I understand there is a very specific procedure to charge the battery in this car once its gotten that low. Long story short... GM Accessories offers a battery tender for this car and the 6.2 corvette. I am going to ensure mine is plugged in anytime its going to be sitting. Its not my daily driver.

[Snakebt6]

No you wouldn't think so.

I actually passed this on to the mechanic and service writer for their info.

Thanks again for posting and ill post back what they come up with.

[ZX-10R]

Originally Posted by Tank22

I know of 3 more transmission failures where they all were found to have a bad battery.... You wouldn't think a battery could do that kind of damage. From what I understand there is a very specific procedure to charge the battery in this car once its gotten that low. Long story short... GM Accessories offers a battery tender for this car and the 6.2 corvette.

Slow, low amp charge is always better for battery life. These cars drain a battery very fast so need to be kept on a charger anytime they sit

This is the best automatic trickle charger on the market. Honestly that "GM" product looks like typical rebranded CTEK junk. I've pretty much tried them all over the last 25 years
https://www.amazon.com/gp/product/B0...rch_asin_title

[Tank22]

Originally Posted by ZX-10R

Slow, low amp charge is always better for battery life. These cars drain a battery very fast so need to be kept on a charger anytime they sit

This is the best automatic trickle charger on the market. Honestly that "GM" product looks like typical rebranded CTEK junk. I've pretty much tried them all over the last 25 years
https://www.amazon.com/gp/product/B0...rch_asin_title

Thanks,
The GM Chargers are made by NOCO and have performed really well... Same company makes the charger for the new Ford GT's lithium ion battery which has to be plugged in if the car sits for 24 hours or more.

[ZX-10R]

Saw a youtube review of the GM charger which said it gets "really hot" when charging - not a good sign. Optimate is the best, just not well known in U.S.

Nothing magic about these things, just the programming and durability

[Snakebt6]

So just and update on mine.

The mechanic let me know this weekend that the valve body in the transmission has a bad solenoid.

They are replacing the entire valve body with the transmission still in the car.

He said the TCM was good. It had no issues.

Ill keep you guys posted if this does the trick.

[Snakebt6]

Got the car back on Friday and put a few miles on it.

Seems "ok" but does hit really hard from 3rd to 4th under hard acceleration/deceleration as well. I hoped after a few miles if driving it that it would not be so aggressive but its still not quite right.

Part of me wants to take it to the track and let the cards fall where they may but im worried it may damage something else.

Under normal driving its just fine. Just when you get aggressive with it theirs an issue still.

Ill call the dealer in the morning and more then likely take it back.