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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.

Is the skill of rev matching being lost to computers?

If the ability to drive a vehicle equipped with a manual gearbox is becoming a lost art, then the skill of being able to match revs on downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. The usefulness of rev matching in street driving is limited most of the time – aside from sounding cool and impressing your friends. But out on a race track or the occasional fast, windy road, its benefits are abundantly clear. While in motion, the engine speed and wheel speed of a vehicle with a manual transmission are kept in sync when the clutch is engaged (i.e. when the clutch pedal is not being pressed down). However, when changing gear, that mechanical link is severed briefly, and the synchronization between the motor and wheels is broken. When upshifting during acceleration, this isn't much of an issue, as there's typically not a huge disparity between engine speed and wheel speed as a car accelerates. Rev-matching downshifts is the stuff they would teach at the automotive equivalent of the Shaolin Temple. But when slowing down and downshifting – as you might do when approaching a corner at a high rate of speed – that gap of time caused by the disengagement of the clutch from the engine causes the revs to drop. Without bringing up the revs somehow to help the engine speed match the wheel speed in the gear you're about to use, you'll typically get a sudden jolt when re-engaging the clutch as physics brings everything back into sync. That jolt can be a big problem when you're moving along swiftly, causing instability or even a loss of traction, particularly in rear-wheel-drive cars. So the point of rev matching is to blip the throttle simultaneously as you downshift gears in order to bring the engine speed to a closer match with the wheel speed before you re-engage the clutch in that lower gear, in turn providing a much smoother downshift. When braking is thrown in, you get heel-toe downshifting, which involves some dexterity to use all three pedals at the same time with just two feet – clutch in, slow the car while revving, clutch out. However, even if you're aware of heel-toe technique and the basic elements of how to perform a rev match, perfecting it to the point of making it useful can be difficult.

2015 Chevy Spark will have lighter, smaller battery

As General Motors gets ready to release the 2015 Chevy Spark EV, it is retooling the Brownstown Battery Assembly to build a new battery system for the chirpy little electric car. The new Spark will lose a few pounds and kWh from its lithium-ion pack, but it will keep all of it's performance specs. The current Spark EV uses a 21-kWh lithium-ion battery pack with bits made by A123 Systems (known as B456 Systems during bankruptcy). For the 2015 model, GM is going to build a 19-kWh battery system in-house that will use 192 LG Chem cells. Losing a bit of energy capacity means that the battery system for the 2015 Spark EV will be 86 pounds lighter but it will keep the EPA-rated 82-mile range and 119 MPGe. The 2015 Spark EV also keeps its $26,685 (plus destination) starting price from the 2014 model. The car will once again qualify for a federal tax credit of up to $7,500. LG Chem also supplies the cells for GM's other plug-in vehicles from its facility in Western Michigan. The Brownstown production line currently builds the battery packs for the Chevy Volt, the Opel Ampera and the Cadillac ELR. You can read our first drive of the 2014 Chevy Spark here. Brownstown Battery Assembly Expands Capabilities Will build battery system for 2015 Chevrolet Spark EV 2014-05-14 DETROIT – General Motors will bring all its electric vehicle battery building capabilities in-house with production of battery systems for the 2015 Chevrolet Spark EV at its battery assembly plant in Brownstown, Mich. "Using our in-house engineering and manufacturing expertise enabled us to deliver a battery system that is more efficient and lighter than the 2014 Spark EV without sacrificing range," said Larry Nitz, executive director of GM global transmission and electrification engineering. "Our successful working relationship with LG Chem has allowed us to deliver a new battery system for the Spark EV that helps us to better leverage our economies of scale." A newly designed battery system features an overall storage capacity of 19 kWh and uses 192 lithium ion cells. The cells are produced at LG Chem's plant in Holland, Mich. The battery system weight of 474 lbs. is 86 pounds lighter than the system in the 2014 Spark EV. The Spark EV battery is built on a dedicated production line at Brownstown, which also manufactures complete battery packs for the Chevrolet Volt, Opel Ampera and Cadillac ELR.