There are 8 owner-reported powertrain & transmission complaints for the 2020 Chevrolet Suburbanin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
Transmission is not functioning properly at 74,300 miles. Engine kept slipping while driving uphill and the RPMs were not matching vehicle speed. Could not go above 50mph while merging onto freeway which was very dangerous. Whirring noise occurred every time I accelerated which was also noted By dealer and transmission shop. No check engine lights on. Took to dealer, but the misdiagnosed it since no lights were on. Took to Transmission shop, and they found that the transmission had several issues that were not displayed. Besides the shop running specific tests, there are still no warning lamps or messages displayed on the vehicle dashboard or using an OBD2 sensor.
Driving through residential area and noticed loud noise from under hood. Went to pull out onto state highway and wasn’t able to get up to speed almost causing an accident because I could not accelerate. Had to maintain speed at or below 40mph. Brought vehicle to dealership and they confirmed that the transmission was shot. Also went to a local transmission repair shop and he stated that he sees 1-2 of this same transmission weekly. That 2016-2020 Chevrolet transmissions are no good and that Chevrolet knows this. This is a $7000 repair on a vehicle that just hit 100,000 miles. Vehicle has always been well maintained. Just wondering how GM doesn’t have a recall on this particular transmission if there are so many reported problems with it. I was fortunate to be able to pull off of the highway and take back roads to get to the dealership. There was no slipping, no warning signs whatsoever. It just made the loud noise and then boom. Done.
SEVERE TRANSMISSION SHUDDER. LAST MONTH HAD TAKEN MY 2020 CHEVROLET SUBURBAN TO THE WEST CHEVROLET DEALER LOCATED IN ALCOA, TENNESSEE. I WAS ADVISED BY A TECH THAT THE VEHICLE NEEDED A NEW TORQUE CONVERTER. I PAID 2,200.00 FOR THIS REPAIR. THIS REPAIRS DID NOT FIX THE ISSUE. AFTER PAYING MY BILL AND DRIVING THROUGH THE PARKING LOT, IT STARTED BACK IMMEDIATELY. THE TECHNICIAN ADVISED THEIR WAS NOTHING ELSE THEY COULD DO AFTER EXPRESSING HOW BIG OF A SAFETY CONCERN IT. SO I ATTEMPTED TO DRIVE IT HOME. AS I ENTEREDED INTO A BUSY 4 LANE HIGHWAY (ALCOA HIGHWAY) THE VEHICLE WOULD MOVE AND BEGAN SHUDDER VERY BAD, ALMOST CAUSING A CRASH. AFTER DOING LOTS OF RESEARCH, IT APPEARS I AM NOT THE ONLY ONE HAVING THIS ISSUE. I HAVE ALSO REACHED OUT TO SEVERAL NEWS MEADIA OUTLETS TO ASSURE THIS IS ADDRESSED TO PREVENT BY FAMILY GETTING HURT AND/OR KILLED DUE TO THE FAILURE OF THE 6L80 TRANSMISSION PROBLEMS. PLEASE TAKE INTO CONSIDERATIONS OF THE SERIOUNESS OF THIS ISSUE. THE VEHICLE NEEDS A NEW TRANSMISSION THAT I CAN NOT AFFORD. THE VEHICLE HAS NO CODES/WARNING DISPLAYED ON THE DASH WHICH PUTS MY FAMNILT AND I AT RISK WHEN DRIVING.
Driving on the highway and I started to slow down even while pressing the accelerator. Pulled over and turned the car off and then back on. I was able to almost get to an exit but then it completely stopped moving. Turned it off and on again but car would not move. Not a single light turned on until the last time I attempted to move the car. Had it towed to Chevy dealer and transmission was completely out. Had 2 different mechanic places (dealer and private) tell me that it is extremely common once a 2020 suburban hits around 100k miles. That is completely irresponsible of GM to not put something out so that owners can at least have knowledge that there could be a potential problem. No warning signs, no lights on that is an accident waiting to happen and a potential wrongful death lawsuit coming your way if something isn’t put out.
The contact owns a 2020 Chevrolet Suburban. The contact stated while driving 10 MPH and depressing the accelerator pedal, the vehicle failed to respond as needed. No warning lights were illuminated. The contact pulled over and turned off and restarted the vehicle however, the failure persisted. The contact stated that the dealer was contacted. The vehicle was towed to a dealer and was diagnosed with transmission failure. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The VIN was not included in NHTSA Campaign Number: 24V797000 (POWER TRAIN). The manufacturer was notified of the failure but offered no assistance. The failure mileage was 93,000.
On October 27, coming back from a family trip at 10 PM at night on a major highway, the suburban all of a sudden quit. Traveling at 70 miles per hour, all of a sudden, when pressing the gas pedal, the car would not accelerate and the RPM gauge was erratically moving. The car started to slow down till it eventually just quit and it would not go anymore. We were stranded in the middle of the highway with cars coming and going both ways. It was scary, it was dark, and dangerous. A tow truck was called and they told the suburban to a Chevrolet dealership 60 miles away. The following day, the dealership informed us that the transmission was not repairable and that they had found metal pieces in the transmission. They informed us that the only way to repair was to replace with a new transmission. They informed us that these transmissions are faulty and that it’s common for them to replace transmissions in suburbans about twice a month. We were not happy to find this out because this is the second transmission in a second Suburban that we have owned that we have had to spend $12,000 on between both vehicles. The car was out of warranty, Therefore, the expense was totally on us. I need help trying to see if I can get reimbursed for these expensive faulty transmissions that are not our fault! We have serviced car when due. There were 4 small children in the car and we could’ve had a tragic accident because car quit suddenly! Please help!
Engine making ticking on passenger side when first started in the morning. Service bulletin is out but dealers are not doing a recall. Engine can fail while driving from this if it gets worse. GM admitted problem in Service Bulletin No 19-na-218 lifter and push rod failure is the problem.
I had to replace my rear differential due to grinding and metal shavings in the rear end. Recently had to take my truck in for repairs due to the motor mounts breaking. Discovered the front differential is also damaged with metal shavings due to grinding. The auto shop reached out to the local Chevy dealership to order the part to place. Was told the front diff is on back order due to this being a common problem.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on May 4, 2026