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GM faces possible class action lawsuit over 8-speed transmission

General Motors has been hit with a class-action lawsuit from owners who allege the eight-speed automatic transmission found in several rear-wheel-drive Chevrolet, Cadillac and GMC models between the 2015 and 2019 model years has a defect that causes the vehicles to hesitate and jerk when accelerating or slowing down. The lawsuit was posted to ClassAction.org and spotted by GM Authority. Problems with GM's Hydra-Matic 8L90 and 8L45 transmissions have been well-documented on Internet forums and via complaints filed with the National Highway Traffic Safety Administration, with many reporting damage to their vehicles. The lawsuit was first filed in December in U.S. District Court for the Southern District of Florida but appears to have been transferred recently to New York. Autoblog sought comment from Theodore Leopold, the lead attorney for the plaintiffs. "These transmissions have a common defect," the complaint reads. "Drivers attempting to accelerate or decelerate their cars feel a hesitation, followed by a significant shake, shudder, jerk, clunk, or 'hard shift' when the vehicle's automatic transmission changes gears." The problem also occurs when the vehicles accelerate in a single gear, without shifting, the plaintiffs allege. "Drivers have reported that the shift is sometimes so violent, they feel as though they have been hit by another vehicle." The problem is believed to center on the transmission, torque converter or both. The complaint says it causes undue friction, causing hydraulic systems and gears to function improperly and sometimes leaves metal shavings throughout the transmission, leading to costly repairs and replacement of parts or the entire transmission. It says GM has known about the problems since shortly after it introduced the transmissions, and has issued 13 technical service bulletins, none of which have resolved the problem. GM declined to comment on the lawsuit. The plaintiffs say GM should have warned consumers about the issues and covered repairs under each vehicle's three-year/36,000-mile bumper-to-bumper warranty. They're seeking statewide classes in at least six states: California, Florida, Illinois, New York, Oklahoma and Texas.

How GM engineers are using diaper 'snow' to keep you warm

Testing how snow affects General Motors' vehicles isn't really a problem right now for the company's engineers, but in the dog days of summer the process isn't exactly easy. The only real option is for them to book time at the automaker's climatic wind tunnel. However, a flash of brilliance from an engineer allows snow to be simulated regardless of the temperature outside, and the discovery is all because of his daughter's wet diaper. The realization came to GM Thermal Systems engineer Nicholas Jahn while he was swimming with his daughter and noticed how her diaper ballooned in size in the water. He found out the substance that makes this possible is called sodium polyacrylate. When the material gets wet it grows and forms fluffy flakes that are a close imitation of snow. Best of all, the stuff can be prepared easily any time of the year, and it's reusable. The engineering team uses the material to test the effectiveness of the heating systems of GM's vehicles. They spread the sodium polyacrylate over the inlets at the base of the windshield to obstruct the airflow and then crank the heater. After some time, they can see how much is being sucked into the system and design more efficient systems in the future. See how the process works in the video above and read about the diaper discovery in GM's press release below. Diapers Change Chevy Cruze Winter Warm-up Time GM validation engineer uses diaper material "snow" to reduce frigid drives 2015-01-06 DETROIT – An item commonly found on an infant's changing table is helping General Motors' engineers simulate snow year round, ensuring heating systems in cars like the 2015 Chevrolet Cruze can quickly and efficiently warm its interior. Packed snow can prevent air from entering the inlet panel at the bottom of the windshield, obstructing the flow of air into the heating system and reducing the amount of air it can push out. This can lead to less efficient warming of the car's interior and windshield defrosting. "The last thing anyone wants to do when it's freezing cold out is scrape their windshield," said Nicholas Jahn, GM Vehicle Thermal Systems engineer. "The testing we perform on the Chevrolet Cruze with the diaper material allows us to maximize the car's heating capabilities." Ironically, Jahn stumbled upon his diaper-based testing method in the middle of summer. During a swim with his daughter, he noticed her diaper multiplied in size when it came into contact with water.

Submit your questions for Autoblog Podcast #321 LIVE!

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