2004 Gmc Sierra 2500hd Sle 4x4 Extended Cab Short Bed 6.6l Lly Dmax No Reserve on 2040-cars

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GM 8-speed transmission lawsuit granted class action certification

A story on Autoblog about potentially faulty 8-speed automatic transmissions from General Motors in 2019 has, as of the day this was published, 166 comments, mostly from owners of cars and trucks who say they are experiencing "a hesitation, followed by a significant shake, shudder, jerk, clunk, or 'hard shift' when the vehicle's automatic transmission changes gears." At the time, lawyers were seeking statewide classes in at least six states. As of today, the Detroit Free Press reports that a judge has granted class action status to a lawsuit brought by 39 plaintiffs across 26 states covering the transmission issue. The lawsuit specifically applies to vehicles that are equipped with GM's 8L90 or 8L45 8-speed automatic transmissions made between 2015 and March 1, 2019. Both of these transmissions are similar units, the 8L45 being slightly lighter version used in fewer vehicles than the beefier 8L90, and are designed for front-engine, rear- or all-wheel drive applications. The lawsuit alleges that the erratic transmission behavior makes some vehicles unsafe to drive. Ted Leopold, partner at Cohen Milstein and the court-appointed lead counsel for the case, said in a statement, "General Motors knowingly sold over 800,000 eight-speed transmission vehicles, which they knew to be defective for years, and yet made the business decision not to tell its customers before purchase." He added, "Dealers were directed to tell the customers that harsh shifts were ‘normal' or ‘characteristic.Â’ Such decision making is both highly irresponsible and emblematic of what GM believes it can get away with." The vehicles included in the court order with potentially faulty transmissions includes: 2015-2019 Chevrolet Silverado 2017-2019 Chevrolet Colorado 2015-2019 Chevrolet Corvette 2016-2019 Chevrolet Camaro 2015-2019 Cadillac Escalade and Escalade ESV 2016-2019 Cadillac ATS, ATS-V, CTS, CT6, and CTS-V 2015-2019 GMC Sierra, Yukon, Yukon XL, and Yukon Denali XL 2017-2019 GMC Canyon Some additional details of the lawsuit can be found at the Cohen Milstein site, including claims that "since 2015, GM has issued thirteen versions of a “technical service bulletin,” or “TSB,” related to this shifting issue alone." The statement from Cohen Milstein says that a "second action regarding GM vehicles with 8L transmissions is also underway in Battle v. General Motors, LLC, 2:22-cv-108783.

2024 Chevrolet Silverado EV output jumps to 754 hp and 785 lb-ft

A couple of days ago, GMC unleashed its 2024 Sierra EV Denali Edition 1 pickup, the luxury truck division's version of the 2024 Chevrolet Silverado EV. As has been the case between Chevy and GMC for decades, GMC designers worked to put ample visual difference between the two pickups that share the similar underpinnings. Unlike what's been the historical case, GMC announced output figures for the Sierra EV well above those for the Silverado. Preliminary estimates for the battery-electric Sierra with the dual-motor powertrain are 754 horsepower and 785 pound-feet of torque. Chevy revealed the 2024 Silverado EV in January with 664 hp and 785 lb-ft in RST trim. We're not sure what happened after the GMC debut, but the Bowtie has updated the Silverado's output to match the GMC with 754 hp and 785 lb-ft. Chevy truck communications spokesperson Sean Szymkowski submitted a statement to various outlets explaining, "As we prepare for production of the Silverado EV, our engineering team has further refined the estimated performance specs for the 2024 Chevrolet Silverado EV RST First Edition. GM now estimates horsepower to be up to 754 and torque up to an estimated 785 lb-ft when Wide Open Watts mode is engaged." It's possible Chevrolet did so in order to forestall backlash about the disparity, or it's possible the automaker already planned to do so after the GMC dropped. On the ICE side, buyers have got used to powertrain parity, the Silverado and Sierra offering the same engines with the same outputs even with pricing about $3,600 apart on the respective top trims. No matter how the decision was made, the benefits redound to Silverado EV buyers. By the way, the "Wide Open Watts" reference refers to the driving mode required to extract these peak power figures. In the GMC Sierra EV, this is called Max Power Mode. We're still looking for clarity on the output figures in everyday driving modes, we believe those will be the same 510 hp and 615 lb-ft that's the maximum in the lower trim Silverado EV Work Truck.    With a year to wait before the Silverado RST EV reaches reservation holders, and with the Chevrolet Work Truck providing real-world feedback before the RST arrives, don't be surprised at more tweaks made to both the Silverado and Sierra EVs before they hit the market. Related video: GMC reveals the all-electric 2024 Sierra EV

'Killing a Duramax' Gale Banks YouTube series methodically tunes a diesel to death

Learning or perfecting a skill by watching YouTube videos is known as attending YouTube University. GM Authority picked up on one of the video site's more fascinating courses, hosted by Gale Banks; in a fair world, he should be referred to as Professor Banks when it comes to diesel engines and truck tuning. A few months after GM introduced the updated L5P 6.6-liter Duramax diesel V8 in the 2020 Chevrolet Silverado HD and GMC Sierra HD that ships with 454 horsepower and 910 pound-feet of torque, Banks decided he wanted to methodically tune the engine to death. The purpose of the resulting series, called "Killing a Duramax," is to push more power out of the engine in order to discover which parts break and when — or, as Banks puts it, force-feed the Duramax "until the crank hits the street and the heads hit the hood." With that knowledge, Banks can figure out all the weak points on his way to building what he calls a "Superturbo," that being a supercharged, twin-turbo race engine with more than 1,000 hp. What makes the series fascinating is Banks' knowledge, paired with the company's comprehensive iDash engine monitoring system that keeps tabs on a glut of parameters every step of the way. So for instance, you get Banks explaining the differences between inches of mercury and barometric pressure, how those are different from the water content of the air measured in grains, then showing those readouts on the iDash, then explaining in detail how they affect the air density in the Duramax system. The stock Borg-Warner variable turbo gets a lot of airtime — Banks accuses it of being "out to lunch" because he feels it's the weakest link on the engine. That turns into a turbo teardown and a deep explanation of performance pitfalls, such as when air pressure on the turbine begins to diverge from the boost pressure coming from the compressor. Banks says he can keep close tabs on where power's coming from, because the iDash monitors the horsepower contribution provided by the ambient air, the turbo, and the intercooler separately. The major changes so far are a stouter Precision 7675 turbo and TurboSmart wastegate (episode 5), a twin intake (episode 6), a custom liquid-cooled intercooler from a marine engine, a new GM oil cooler and synthetic oil (episode 10), and new injectors (episode 11).