[Tex2SS]

I have read a ton of threads on here about all the folks with the 2016-2018 8L90 transmissions with the torque convertor issues, but it seems like most of you were able to get these fixed under warranty.

I am curious to hear what direction folks have gone when they were not able to get this repaired under warranty. Stealership wants $9,000 to replace the tranny. F-that!

Did you have a mechanic take it apart and replace the TC, or did you just replace the entire transmission with something better? Cost? Downtime?

Thanks.

[Joshinator99]

Originally Posted by Tex2SS

I have read a ton of threads on here about all the folks with the 2016-2018 8L90 transmissions with the torque convertor issues, but it seems like most of you were able to get these fixed under warranty.

I am curious to hear what direction folks have gone when they were not able to get this repaired under warranty. Stealership wants $9,000 to replace the tranny. F-that!

Did you have a mechanic take it apart and replace the TC, or did you just replace the entire transmission with something better? Cost? Downtime?

Thanks.

Usually a triple flush and new torque converter fix that issue. One day job.

[arpad_m]

A good transmission tune doesn't hurt either.

When the current Mobil1 LV fluid was introduced in 2019, the triple flush was abandoned in favor of a single flush with the TransFlow machine. This is what my car got, along with a tune, and it's been perfect since then.

[Joshinator99]

Originally Posted by arpad_m

A good transmission tune doesn't hurt either.

When the current Mobil1 LV fluid was introduced in 2019, the triple flush was abandoned in favor of a single flush with the TransFlow machine. This is what my car got, along with a tune, and it's been perfect since then.

Agreed on the tune. I tuned mine immediately after buying my car new, never had any shudder.

Now 4+ years of 1000+ BHP, that was a different story…

[SomeGeoffGuy]

Find a trans shop and have them put in a convertor that you bring them (just go stock - ~$460). Make sure they put the new fluid in too - drop the pan, and give it a good flush. Don't let them re-use your old fluid - that is not a bad thing on a lot of jobs, but is on this one. Probably still cost you $1000 in labor or more depending on how many hours they charge you for dropping the trans - usually five or six hours.

My 2016 vert shuddered like crazy, and it was all in the fluid. The bulletin warns that the convertor has to be replaced if it goes too long, though. Nothing is probably wrong with your trans, but the convertor is probably shot. Is it just unbearable shuddering? That is the convertor.

-Geoff

[ctrlz]

Geoff covered it. I think you are going to need a new converter and full fluid change. Skip the new tranny. No need for the tune unless you want different shift parameters later on.

[SPLATT]

One thing I found out by accident on my son's 2017 was if you manually shifted it and kept it out of 8th it wouldn't shudder. This worked until I was able to get it flushed for him. It's been fine since the flush 1 1/2 years ago.

[Skyman2112]

Originally Posted by SPLATT

One thing I found out by accident on my son's 2017 was if you manually shifted it and kept it out of 8th it wouldn't shudder. This worked until I was able to get it flushed for him. It's been fine since the flush 1 1/2 years ago.

Thats a fact since the clutch doesnt lock up in 7th. If you catch it early enough a flush will work, as it did on mine.

[SSJ455]

I thought this was a recall with a TSB number. Wouldn't that mean it is covered regardless of a warranty?

[ctrlz]

Originally Posted by SSJ455

I thought this was a recall with a TSB number. Wouldn't that mean it is covered regardless of a warranty?

No. Like a lot of manufacturers Chevy was able to get around calling this a recall, probably because it is not a safety issue. Free service was only during the warranty period.

[Candie]

Originally Posted by Joshinator99

Usually a triple flush and new torque converter fix that issue. One day job.

I have had mine flushed twice and the torque convertor replaced. 4k mile later and the shudder is back. It is a 2017 with 30k miles. Am I out of options? Is there is solution to fix this permanently? I am at my wits end here.

[arpad_m]

Originally Posted by Candie

I have had mine flushed twice and the torque convertor replaced. 4k mile later and the shudder is back. It is a 2017 with 30k miles. Am I out of options? Is there is solution to fix this permanently? I am at my wits end here.

When was this work done? The correct fluid was introduced in Jan 2019 and became more widely available in late February, early March of that year.

Your last option is to get the transmission tuned, this will get rid of the preprogrammed TC clutch slip and keep the trans out of trouble if the shudder isn't super bad, ie the clutch has enough friction material left to properly lock up. It's not like you have any time left on the powertrain warranty anyway.

[Bumbleboy92]

Originally Posted by Candie

I have had mine flushed twice and the torque convertor replaced. 4k mile later and the shudder is back. It is a 2017 with 30k miles. Am I out of options? Is there is solution to fix this permanently? I am at my wits end here.

I had a similar experience with my 8L45. Had the dealership do the flush with the new fluid in November 2019. I double checked with the dealership it was the blue label correct PN. It fixed the shudder for a year (~20k miles) and it came back. Ended up getting the car tuned and turned off AFM, didn’t have any shudder for the rest of my ownership.

I still have a case of 6qt of the blue label ATF fluid back when I was gonna do the flush lol

[Candie]

Originally Posted by arpad_m

When was this work done? The correct fluid was introduced in Jan 2019 and became more widely available in late February, early March of that year.

Your last option is to get the transmission tuned, this will get rid of the preprogrammed TC clutch slip and keep the trans out of trouble if the shudder isn't super bad, ie the clutch has enough friction material left to properly lock up. It's not like you have any time left on the powertrain warranty anyway.

The TC was replaced in April of 2024. After taking to a mechanic friend I learned this morning that when they replaced the TC the dealership put in the old Dexron-VI fluid. How does that happened 4 years after the updated TSB. I have since called the service manager and raised holy hell. I am hoping that the correct fluid will fix my issue.