We’ve been watching the General Motors 8-speed transmission in the GMC Sierra 1500 and Chevy Silverado 1500, and in addition to several complaints about sudden shifts and hard jerks, there is a lawsuit pending. Now we hear for 2021 models, at least, GM has announced a Customer Satisfaction Program for some vehicles that involves replacing the transmission.
Ostensibly, these two issues don’t look related. According to GM Authority, the problem here is that the 8-speed automatic transmission may have broken a carrier ring. As that publication states, a broken carrier ring could prevent the transmission from operating as intended.
So, GM is going to replace those transmissions with a new one at no cost to the owner.
We’ve reached out to GM to see if we can get our hands on the original communication regarding this Customer Satisfaction Program, but at the time of writing this story, our contact hadn’t been able to source it for us yet. In fact, the only reference we’ve found anywhere on the web to the Customer Satisfaction Program number N21232809, is in the GM Authority story.
We do, however, know that this program only covers 90 (yes, ninety!) trucks. We also know this transmission issue is not listed on the NHTSA website as a recall or a tech service bulletin.
The bottom line on the GM 8-speed transmission
There’s seems to be lot going on with this transmission, and while the GM 8-speed transmission isn’t in every Sierra and Silverado, it’s going to be in a lot of them – especially the less expensive models since this transmission is most frequently paired with the 2.7-liter turbocharged engine.
Right now this is only applying a minuscule number of trucks, but we’ll be curious to see if it widens out eventually — or if there’s something else altogether that will pop up. So, we’ll continue to keep an eye out for more developments on the GM 8-speed transmission drama.
My 2021Silverado 8 speed is having intermittent clunks into low gear at stop lights. I have not received the recall notice, I was told that the newest 8 speed s were good, BS!
I have a 2019 8 speed and it had the same annoying thud into gear at low speeds. Stop and go style driving would often cause the thud to happen. It seems to have softened up by itself a little bit over time.
Like you said GM made several improvements to the 8 speed for the new generation 2019+ Silverado meant to improve shift quality including a modified torque converter, but it seems it didn’t get the job done.
My 2021 brand new Chevy Silverado RST Z71 1500 with 6,680 miles on it just blew the transmission!!! Seriously 8 speed isn’t fixed I’m stuck in a loaner car they are currently tearing down my transmission! Never even went on a gravel road and just made my 2nd payment the day before it went down ! NO WARNING NOTHING , parked at Sams club ran in came out started my truck and put it in drive and nothing ! RPMs went up and I went NO WHERE! Put it in reverse NO WHERE! Had to call a tow truck ! I’m not happy at all for what was paid for this truck !!!
it just happened to my 2021 Silverado trail boss at 650 miles. I was a couple hours from home and had to have it towed.
What about thr Colorado 8L45 clunking an shaking . Gm just going to through us truck owners to the wind . Nice job GM .
I own a 2016 GMC Sierra 1500 and have experienced many of the same problems listed previously. In addition my transmission would “shudder” at speed similar to driving over a rough dirt road. Truck is now at dealer’s and I was told the transmission will either be repaired or replaced altogether. Awaiting decision from GM.
Having problems on my Serena 8 speed had transmission flushed and new filter fluid was dirty but still having the shifting problem at low speed. Disappointed gm won’t address the problem especially being a diehard gm person
I have a 16′ Sierra that was Ok (more or less) until i hit around 70K miles and then it started getting worse..I had the trans service done in the mid-80K range and after 4-500 miles it really smoothed out..Now at 117K it’s starting all over again. It’s due for an oil change so i’ll talk with the dealer to see if another flush might help..
Good Luck to all
I just bought a new 2022 chevy silverado z71 and having shifting problems between 1 and 2nd gear it does it every morning and gm said its normal to do that thats bs i had 3 chevys before this one and never did this and they said there is no fix which i think is hard to believe i hope something is done about this!!!!!!
Same here Gary on my 2022 Z71. Dealer said they could not replicate the issue when I left it. I guess I will go back again and drive them around myself. It vibrates and shifts funny at 1200 RPM
I have a 2021 Lt Silverado 5.3 with an 8 speed. I have 14K and it currently flairs 1-2 shift, every morning, I contacted the dealer where I purchased the truck! Explained what was going on and was told he hadn’t heard of it. He’s said drop it off and they would look at it! Said I needed alternate transportation and was told GM didn’t offer this service anymore!!!!
i have a 2019 silverado rst with 8 speed auto trans bucks when cold from 1st to second dealer replaced trans oil with full synthetic oil still does it i have a round knob on the top left of my dash one side is for trailering the other side has a checkered flag if i turn the knob to the checkered flag the problem goes away worth a try
I have a 2017 LT with the 8 speed trans. I never had a problem until last week; catastrophic transmission failure
my name is Robert, i have a 2018 GMC i’v had inthe shop for 70 days total, still having trouble, truck will only get 15 miles oer gallon, until the tranmission temp. gets up to 150 or higher. frist off ruff shifting, then torque converter kicking in and out, talked to GMC coustmer about replacing the tranmission, she said no, still having problems with it, so they double the warranty, this not helping my gas mileage, only getting 15 mpg and not getting 20 mpg it takes over one hour before gpm will change, and still has ruff shifting, also will take off on its own from time to time. would like to trade it off but they’er asking too much fro them now