1999 Gmc Truck Yukon Denali 4wd Good Shape 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 natural gas-powered vans recalled due to possible leak

General Motors is recalling almost 3,200 of its compressed-natural-gas powered utility vans because of possible leaks. GM and the National Highway Traffic Safety Administration (NHTSA) released a notice last week saying that 3,196 Chevrolet Express and GMC Savana CNG vans are on recall, though no accidents have been reported due to the possible issue. The recall is specifically for vans for model years ranging from 2011 to 2014. The recall stems from a potential leak from the compressed natural gas high-pressure regulator, and such a leak could cause a fire or explosion. GM will replace the vehicles' high-pressure regulator in order to fix the problem, will do it free of charge and is instructing owners to contact Chevrolet or GMC customer service to arrange for the parts replacement. Utility vehicle makers like General Motors have pushed for fleet sales of CNG-powered vans and trucks for the past few years and have touted them for their cheaper refueling costs relative to standard gasoline, not to mention the fact that natural gas can be readily sourced from throughout North America (thanks, fracking). According to CNGPrices.com, compressed natural gas sells for about $2.22 a gallon, on average, while the AAA is pegging the average price of gas at $3.34 a gallon. NHTSA has posted information on the recall here. Featured Gallery News Source: NHTSA via Reuters Green Chevrolet GM GMC Natural Gas Vehicles CNG gmc savana

Redesigned 2021 GMC Yukon gets a diesel, AT4 model, Denali-exclusive interior

GMC's most robust family hauler is getting a complete redesign for the 2021 model year, including a new, off-road centric AT4 model, an upscale interior exclusive to its luxurious Denali model, an available air suspension, and, last but not least, a diesel engine.  With Americans obsessing over trucks, it's no surprise that GMC is going hard with its AT4s-for-everybody strategy; the Yukon is no exception. This will be the first model year for the new trim on GMC's largest SUV. This off-road model gets all the goodies you'll need to veer off the beaten path with confidence, including an extra 2.0 inches of ground clearance with the adaptive suspension option (more below), a two-speed transfer case, standard Goodyear all-terrain tires, an off-road mode for GMC's "Traction Select" drive mode system, hill descent control, and some extra underbody skid plates. Since GMC is a premium brand, even the AT4 gets some luxury appointments, such as a heated steering wheel, heated and ventilated front seats, and heated outboard second-row seats. The interior is also adorned in black leather with tan accents and "AT4" embroidery in the seat backs.  Speaking of premium, GMC will introduce an air-ride adaptive suspension with an off-road ground clearance mode as a late-availability option for several Yukon models, and this feature will be included on the Denali trim.  The Yukon and Yukon XL are GMC's variants of Chevrolet's full-sized SUVs, the Tahoe and Suburban. Their fundamental body-on-frame architecture is also shared with GM's half-ton pickup trucks, and thanks to that common engineering, they can also share powertrains. That's normally just a trivial side note when it comes to a new GM SUV announcement, but this time around, it's a bit more meaningful thanks to the introduction of a new light-duty, inline-six diesel in GM's truck lineup last year.  Yep, that means that for 2021, like the Tahoe and Suburban, the Yukon is getting a diesel option. The 3.0-liter Duramax makes the same 277 horsepower and 460 pound-feet of torque as it does in GM's trucks.  GMC's standard engine is still the 5.3-liter V8 that makes 355 hp and 383 lb-ft of torque. The 6.2-liter V8 is also an option like before, producing 420 hp and 460 lb-ft of torque. All engines come with a 10-speed automatic and a choice of rear- and four-wheel drive.