2008 Gmc Yukon Xl 1500 Denali Sport Utility 4-door 6.2l on 2040-cars

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GM opens official investigation into C8 Corvette transmission leaks

In March 2020, a month after Chevrolet began customer deliveries of the 2020 C8 Corvette, a GM dealer technician created a Reddit thread about a leaking gearbox in a Corvette with 32 miles. That car hadn't even been sold yet. Since then, as a search of "C8 Corvette transmission leak" shows, it's been tales of woe for some owners. Something in the Tremec TR-9080 transaxle in the back of the mid-engined Corvette doesn't work as it should, the fault able to cause codes that the transmission needs service, or that the driver needs to shift to park. In some cases, the battery would die because of follow-on issues after the initial transmission code, that code preventing the car from powering down. As Autoevolution reports, GM filed paperwork with the National Highway Traffic Safety Administration in August to look into what's going on. Between forum threads and GM's investigation document, there are several issues mentioned. The most common appears to be the dual-clutch transmission leaking fluid due to gasket failures like the one suffered by one owner at 858 miles, and another for an owner currently enduring a second leaking transmission. The Midengined Corvette Forum reported that Chevy engineers redesigned the TR-9080 pan, fitting Corvettes with the new unit at some point in the 2021 model year. The original pan was stamped steel unit affixed to the engine with two studs and 13 bolts, plus "reinforcement plates." The updated pan is said to be a cast aluminum unit affixed with two studs and 17 bolts, omits the reinforcement plates, and gets a new machined new groove around its edge to seat the gasket seal. The GM paperwork now at the NHTSA mentions a P1789 code, and says one reason for it could be "debris on the park position sensor magnet causing an incorrect position reading to the TCM." This might be caused by another issue mentioned in forums, which is clogged transmission filters. GM gives instructions for returning transmission filters to the company, and a poster on one forum said the Corvette tech at the dealer where he bought his Corvette told him the automaker "requires every used transmission filter to be returned to GM."  Whatever's going on, the problems haven't stopped, and they go beyond the P1789 code. Over the weekend, a 2022 Corvette owner posted on Corvette Forums that he got a check engine light on his car after just 850 miles.

GM extends vehicle production cuts into mid-March due to global chip shortage

DETROIT — General Motors said on Tuesday it was extending production cuts at three North American plants until at least mid-March due to the global semiconductor chip shortage, while vehicles at two other factories would only be partially built. GM, whose shares dipped 1% after the announcement, did not disclose the impact volumes or say which supplier and vehicle parts were affected by the chip shortage. But it said it would focus on keeping production running at plants building its highest-profit vehicles, full-size pickup trucks and SUVs. GM said it intended to make up as much lost production as possible once the shortage chip eased. "Semiconductor supply remains an issue that is facing the entire industry. GM's plan is to leverage every available semiconductor to build and ship our most popular and in-demand products," GM spokesman David Barnas said. GM said it was extending downtime at its U.S. plant in Fairfax, Kansas, its Canadian factory in Ingersoll, Ontario, and its Mexican facility in San Luis Petosi until mid-March when it would reassess the situation, he said. In addition, GM would build but leave incomplete for final assembly vehicles at Wentzville, Missouri, and its Mexican plant at Ramos Arizpe. GM vehicles affected by the idled plants include the Chevrolet Malibu sedan, Cadillac XT4 SUV, Chevy Equinox, and GMC Terrain SUVs. Vehicles to be left incomplete for now included the Chevy Colorado, GMC Canyon pickups and Chevy Blazer SUV. This week, GM had said it was idling the three factories where it has now extended downtime and said it would halve production at a plant in South Korea. The chip shortage has affected many automakers, including Toyota, Volkswagen, Stellantis, Ford, Renault, Subaru, Nissan, Honda and Mazda. Asian chipmakers are rushing to boost production but say the supply gap will take many months to plug. German chipmaker Infineon said the shortage would get worse in the near term. The chip shortage is expected to cut global output in the first quarter by more than 670,000 vehicles and last into the third quarter, IHS Markit said. AutoForecast Solutions estimated total lost production this year could reach 1 million vehicles. Honda and Nissan said on Tuesday they would sell 250,000 fewer cars in total this financial year due.

Diesel Power finds the ultimate modified oil-burner

For nine years, Diesel Power magazine has run the Diesel Power Challenge, this year's grindfest being "a week-long torture test that features seven events, nine trucks, 8,000 horsepower, and nearly 15,000 pound-feet of torque." The road to being crowned "the most powerful truck" starts with a dyno run, and then continues through the completion of a CDL-style obstacle course, an eighth-of-a-mile drag race while towing a 10,000-pound trailer, a quarter-mile drag race without a trailer, a fuel economy test in the mountains and finally a sled-pulling test through a 300-foot-long packed-mud pit.
What kind of trucks get into such a fight? Last year's winner, for instance - who upgraded his truck this year to prove he didn't "luck into the win" - drives a 2008 Ford F-250 Super Duty with a 6.4-liter Power Stroke V8 upgraded with a custom intake, Elite Diesel triple turbos and a two-stage nitrous system. Another competitor has a 2005 Dodge Ram 2500 powered by a 5.9-liter Cummins inline-six, upgraded with Garrett turbos, dual-stage nitrous, a seven-inch exhaust stack and twin fans built into the bed to cool the Sun Coast Omega transmission. The numbers on that truck: 1,255 horsepower, and 2,063 pound-feet of torque at the wheels. Naturally, as the image above might suggest, things don't always end well.
You'll find all five videos covering this years challenge below. A scene in the dyno video sums it all up perfectly: a competitor leaves his nitrous on too long and the crew is treated to some ominous poppings, he leans out the window, throws both hands up and shouts, "Amer'ca!"