2020 Chevrolet Colorado power train problems

“My 2020 Colorado at 14k miles, the dealer did the transmission oil flush and it helped till the warranty ran out. Now I have the same problem again at 32k miles. I bought the truck because GM said the problem with 8L/45 trans was fixed in 2019. To my knowledge there has been no update to the slipping clutch in GM's torque convertor. If I were to replace the convertor with another one just like it I could have the same problem. My Dealer ([XXX])says my lifetime warranty (that I got with my new Colorado) doesn't cover the transmission? And that if they do another $600 oil flush they don't guarantee it will fix anything. I think when the flush is done, they don't change the trans filter. I'm sure the clutch particles that are left behind after the flush are probably stopping up the filter. I just replaced the DOD/AFM cam and lifters in my GM car's 6.2 liter. It's a shame that manufacture's can get away with these kind of problems. Thanks, [XXX]”

“My truck has been shuddering and when put into gear it sounds like the bottom is falling out of it. Now when I am driving my truck is shuddering very hard and skipping gears. I have been having this issue since I bought the truck with only 47k miles and I have only put 40k miles on this truck in the past 3 years that I have owned it. I keep the maintenance up on my truck and have since I’ve owned it and I have already put a complaint into GM, when I bought the truck it has had electrical issues and the dealership is not helping. My warranty is out on this truck and GM said there is nothing they can do to help with my transmission or electrical problems. This truck has not even hit 100k and I’m so upset that I am having these many problems and no one is wanting to help, they just want my money. I can’t afford an attorney or I would sue this dealership for selling me a Lemon and for GM knowing about there faulty transmission in my year truck and not standing behind it!”

“Vehicle has 54,250 miles. Vehicle has a rear differential bearing going out by hearing and feeling the grinding at all speeds and the transmission jerks shafting gears. Both could cause an accident if totally fail. Chevrolet has a service bulletin out from what my local garage says. Mechanic also says Chevrolet will not warranty the product. Vehicle is now being looked at by a Chevrolet dealer. The vehicle is OUT OF WARRANTY. My son, who is [XXX] and not familiar with vehicles thought it was the tires causing the whining and vibration. Took the vehicle in several times to Chevy and they ignored the issue.”

“The vehicle experienced a sudden and progressive transmission failure during normal driving conditions. Symptoms included harsh shifting, delayed engagement, loss of power transfer, and eventual inability to reliably propel the vehicle. The failure created a safety risk due to unexpected loss of acceleration and unpredictable drivetrain behavior while in traffic. The transmission issue was not the result of improper maintenance. The vehicle was maintained according to manufacturer recommendations. The condition worsened over time and ultimately required dealer inspection. A dealership inspected the vehicle and attributed the failure to a transmission defect, characterizing it as a maintenance issue despite no evidence of neglect. The transmission and related components remain available for inspection upon request. No warning lights provided adequate advance notice prior to the functional failure. The issue occurred without driver misuse and under ordinary driving conditions.”

“The contact owns a 2020 Chevrolet Colorado. The contact stated that while accelerating, the vehicle vibrated and shook abnormally, as if driven over ripples on the roadway. No warning lights were illuminated. The vehicle was taken to the dealer, and the tires were balanced. The contact picked up the vehicle and stated that the failure persisted. The vehicle was taken back to the dealer, where it was diagnosed that the transmission oil failed to heat up as intended, and condensation had built up in the transmission. The dealer added Mobil 1 transmission oil to heat up the oil and remove the condensation. The contact was informed by the dealer that the vehicle needed to be driven between 200 and 400 miles to remove the condensation. The manufacturer was made aware of the failure and filed a claim and referred the contact to the NHSTA Hotline for assistance. The failure mileage was approximately 80,000.”

“Transmission shuttering mostly at interstate speeds but as slow as 35 mph. Under light to medium light pedal acceleration. Truck feels as if it's going over Road ripples. I'm disappointed to find out this is a common problem with Chevy 8-speed Transmissions. It happens every time I drive it. From time to time it'll shake the truck a little violently”