GM 8 Speed Transmission Problems Leads to Another Class Action Lawsuit

GM 8 Speed Transmission Problems Leads to Another Class Action Lawsuit

Have you had problems with your GM 8L45 or 8L90 transmission? If so, you’re not alone. In fact, so many people have had issues with this transmission that there is now another class action lawsuit against GM. If you’re a car owner with this transmission, read on to learn more about the lawsuit and what it could mean for you.

GM 8 Speed Transmission Problems and Complaints Explained

Owner complaints allege that vehicles equipped with GM’s 8L45E and 8L90 automatic transmissions are prone to a handful of problems. Problems such as: slipping gears, shifting into gears aggressively, shuddering or jerking, delayed acceleration, and having trouble slowing down. Additionally, the lawsuit claims dealerships began getting complaints from customers as early as September 2014, and GM should have known that these defects would adversely affect drivability.

The lawsuit also alleges these defects present a safety hazard as they severely affect the driver’s ability to control the vehicle speed, acceleration and deceleration.

GM’s 8L90 and 8L45 Transmissions Suffer from Similar Defects as the 6L50 Transmission

Vehicles with the 6L transmission lodged similar complaints with NHTSA as far as 2008. Owner complaints with the 6L transmission are very similar to those seen in the GM 8 speed transmission. Because the 8 speed transmission is based on the 6L, it’s no surprise that there are similar defects.

GM Vehicles Affected

The following vehicles are affected by the alleged GM 8 speed transmission defect:

Status of the GM Transmission Lawsuit

Class Action Currently Active

Won v. General Motors LLC (E.D. MI. Case No. 2:19-cv-11044-DML-DRG) is a class action lawsuit filed on April 10, 2019, which was consolidated with lawsuits filed by several other consumers on behalf of people who purchased or leased certain cars equipped with a 8L45 or 8L90 GM transmission.

Previously Filled GM 8 Speed Transmission Lawsuits:

  1. Shelton, et al. v. General Motors, Case No. 19-11802
  2. Ray v. General Motors, Case No. 19-11808
  3. Duffy, et al. v. General Motors, Case No. 19-11875
  4. Gutierrez, et al. v. General Motors, Case, No. 19-12371

What Some Owners are Saying About Their GM 8 Speed Transmission Problems

I just purchased a 2017 Denali with the 8 speed. The truck had 42K miles on it when I got it when I test drove it I felt the transmission act just a little bit different shifting but it was such a damn good looking truck I pulled the trigger. Now I’ve only put 500 miles on the truck and it is shifting hard clunk clunk going into second gear and third gear a little bit.

2019 Silverado – same thing. Did the tsb flush about 2k miles ago. Fixed for a while. Now I have a noticable kuh-thunk feeling if I hit the accelerator from a <10 mph roll. It’s going back in asap as I am nearing 36k/3-years.

I have a 2017 GMC Denali (52000 miles) with this exact problem. it will surge a bit when on cruise control

Questions About The GM 8 Speed Transmission Lawsuit? is not counsel or the settlement administrator in this class action investigation. Our goal is to inform owners of these vehicles of the current lawsuit.

This post will be updated as more information is officially announced. Please consider subscribing to this post for critical updates.

Last Updated on August 19, 2022

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18 thoughts on “GM 8 Speed Transmission Problems Leads to Another Class Action Lawsuit

  1. Christopher
    March 18, 2022 at 7:38 am

    Please share your experiences with the GM 8 speed transmission.

    1. Avatar
      Warren Anderson
      July 20, 2022 at 10:41 am

      I don’t know if the 2017 Buick lacrosse has that model of transmission but it is a 8 speed it definitely has shifting problems. I bought it and it is a certified Buick in 2019 the first problem happened while the car was on the 12 month bumper to bumper warranty car service light came on and when I was stop light the car slide to a stop car wouldn’t move at all rollback took it to Buick dealer picked car up almost made it home same thing happened service light came on and it slide to stop wrecker took it back to dealer in a month this happened to My wife but I drove it back to dealer and after a few weeks I got it back drove a while. All together this happened 6 times 5 wrecker trips . The last three times it been to a Buick dealer close to me on the fourth Trip I actually thought it was fixed when they found a ground loose in driver side door. Did not drive the car due to Covid and three surgeries on wife . Talking to dealer where I bought car they said they would be happy to trade. I believe I am stuck with a car that Will kill me the Way it stops by itself. It’s in shop right now I don’t know if there is any help for me . My wife and I are are in our seventies with only social security income . I told the dealer where it’s at that Buick needs to replace the car or buy back which I know they want to.

    2. Avatar
      August 27, 2022 at 2:08 am

      We bought our 2016 1500 LTZ with 50,000 km from the dealer. Beautiful truck! We started to notice some hard shifts from first to second. Told the dealer about it and they just said it’s normal with that 8 speed transmission.

      We now have 165,000km and it’s bad.. not it will have hard shifts it any hear now. Up shifting or down shifting. I can’t afford a new transmission.. it’s our only transportation. Not sure what to do now.

      1. Avatar
        Kenneth Stamey
        August 27, 2022 at 7:36 am

        Sounds like my 2016 Chevy Silverado ltz. Brought it with as is condition. 90000 miles. Started hard shifts and dealerships says it normal. Changed fluid and still hard shifts.. I would like to get on the lawsuit in North Carolina.

    3. Avatar
      Scott hayden
      October 12, 2022 at 6:56 pm

      I’ve got a 2019 GMC Sierra 1500 I bought truck with 18000 miles. When i hit it it had a slip or hesitation from 1st to 2nd. I took in to a dealer had them look at it and all they said was it needed to be reprogrammed. Well it still does it and I won’t something done about.

    4. Avatar
      Benjamin Nobiling
      December 19, 2022 at 7:17 am

      I bought my truck used unaware of it’s problems.I purchased an extended warranty when buying the truck and drove the truck for less than 2 months time and noticed the slip in the transmission took it to the shop, where they changed the transmission fluid and told me to come back if problems continued after 500-700 miles of driving which they did I put my truck back in the same shop where it sat from November 2 – December 15 the transmission had been approved to replaced by the extended warranty company but the dealerships shop technician told me he was unable to source a replacement for the vehicle or even the parts to rebuild the transmission. He asked the warranty company to help source a transmission they too, could not. So with no date to have my vehicle fixed and returned to me. I pulled my truck from the dealerships shop and put it in a transmission shop where it still is currently. I’ve owned this 2017 GMC Sierra for almost 4 months over half that time it has spent in the would be nice if GM would at the very least take care of my rental vehicle cost.

    5. Avatar
      Roberto Santiago
      February 6, 2023 at 6:20 pm

      I purchase a 2016 Camaro SS. The camaro has shudder issues. I have to pay around $600 for the tbs repair flush which I found absurd. I have extended warranty and apparently it does not cover fluids so I have to pay for thr fix. Wanting to know how can I be part of the class action suit.

    6. Avatar
      March 3, 2023 at 12:09 am

      My 2017 High Country shifts way too hard for a hoop-dee much less a 68k $ top of line Chevy…..thought I bought my dream truck…..I did ….but it’s a nightmare

    7. Avatar
      Alisa G
      March 28, 2023 at 3:38 pm

      I have a 2018 Chevy Tahoe. while driving on a hwy we lost acceleration while pushing on the gas peddle nothing was happening. We had to coast to side of road where my husband put the car in park then drive again and the car would not shift. We coasted again to side of road and on the third time of ths same thing happening (car wouldn’t shift to next gear) he turned off the car the put it back in drive and we were able to make it home. Since this happened on a Sunday we were not able to drop it off at the dealership until Monday. When we dropped it off at the dealership my husband also informed the dealership of a clunking sound when backing up thats been happen months prior to the acceleration issue. Dealership came back several days later and said the clunking sound is a broken motor mount. My car has never been off road and I drive like a grandma so Im not sure how a motormount broke. Couple days later We were told we needed a new transmission. My car has roughly 90,000 mile on it and I change the oil regualry with the required oil. I should not be having these problems.

  2. Avatar
    April 14, 2022 at 3:48 pm

    When accelerating the car shifts hard from 1-2, 2-3, and 3-4. At approx 55 mph the car shudders and feels like you are driving on the rumble strip and continues to do so up to 70 mph. After reaching highway speeds the transmission surges with engine speed fluctuating erratically. Upon deceleration from freeway speeds I have noted, more than once, a violent downshift that the first time it occurred it felt like the car was rear ended by another vehicle. The trans will slip infrequently after it has warmed up. This car is essentially undrivable if you have any concern about safety or reliability. I cannot and will not put my family at risk in this car. I have a 2017 Camaro that has 26xxx miles on it and its a yard ornament. Really hope this is resolved and the car fixed as it should have never left the assembly line with this type of known defect.

    1. Avatar
      June 19, 2022 at 5:54 pm

      This article resembles almost identically what I am experiencing with the 2018 Cadillac ATS that I unfortunately bought !!

      Dealership has been useless and is in denial of the symptoms I’m experiencing even though warranty still applies.


  3. Avatar
    A Ledoux
    June 20, 2022 at 8:21 pm

    Same issue in canada, approaching end of warrantee, and the dealership refuses to fix it citing normal operating parameters.

    Disgusted, the issue is infrequent, but sometimes in stop and go traffic the truck lurches forward when slowing to a crawl, its terrible.

    Because of the dealership refusing to fix the issue, nor document it on my file, this will be the last GMC product I buy ever.

    Overpriced piece of junk, and criminal actions from a company that new about the issue and did not disclose to me before purchase.

  4. Avatar
    Gail Downs
    July 31, 2022 at 9:20 pm

    I bought a 2016 Silverado brand new, that has the 8 speed transmission. I have experienced the hard downshift that feels like someone has rear ended you from the beginning and was told that it happens occasionally and there is no fix for it. Then at 35000 miles it started the terrible shuttering. I called the dealer and took it in under warranty, all they did was change the fluid and filter which seemed to fix it for the time being. The service manager told me that GM had problems with the pressure plate coming apart but that the filter and fluid change was what GM recommended for the fix. I asked how long that fix was supposed to work and got no answer. If the pressure plate is coming apart then why didn’t they replace it??? Still no answer. Now at 75000 miles it has started the shuttering again and is worse everyday that it is driven. I guess this time when I can get it back in the shop that it will have to come out of my pocket. Thinking very seriously about changing brands.

  5. Avatar
    August 19, 2022 at 8:47 pm

    I have a 2016 6.2 Sierra Denali and wow this is spot on what issues I’m having with this truck. I recently took to the dealership and the charge me $200 dollars to tell me that they needed to open the transmission and look at the internal parts for an additional $3K! I told them I could buy a refurb one just for the price of the diagnostics, and then I find this out, why would they not even bring this up to begin with I would have Never spent $200 on it.

  6. Avatar
    August 26, 2022 at 4:48 pm

    2018 Colorado with 28k miles. Just purchased it last year in 2021. I wasn’t driving it everyday but when I did I’ve noticed it shifts hard into second sometimes and I notice a delay once in a while in the other gears in stop and go traffic. Plus now that work is returning to in office and I’m driving it way more often, I’m starting to notice it more. Dealership said they didn’t notice it so they’ve been useless.

  7. Avatar
    Scott Blitz
    January 9, 2023 at 11:59 am

    Very same issue with my 2017 Cadillac CT6 3.0TT. Paid $75K for this car and GM will not correct the abrupt shifting from Park to 1 and 2 and again from 2 to 1 and Park. Same issue but worse when shifting into reverse.

  8. Avatar
    February 28, 2023 at 8:08 pm

    Bought my 2015 chevy high country with 42k miles started with the shuttering then taking off really quick at times. So I started using it in manual and as long as the RPMS are over 2000. It won’t shutter but once under 2000 RPM it will start again. I can’t believe GM has done nothing about it. Where is the customer loyalty at. Seems to be a pressure problem. Or something with that.

  9. Avatar
    May 25, 2023 at 10:04 am

    Got my 2017 Chevy silverado brand new from a dealership and couple Weeks after I call to complain about harsh shifting and torque noise in the transmission and every time was bringing it in for service I was complaining about driving on a highway and felt like I got hit from behind by another vehicle and they just ignored. My transmission stop working twice in a period of 1 year, I called GM to complain and all they gave was a free oil change. 😞

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