1963 Gmc 1500 Cab Wide-side Pickup, Rare 305 Ci V6, on 2040-cars

Auto blog

GM recalls select Tahoes, Yukons, Escalades for rear driveshaft issue

GM is recalling a number of its full-size SUVs due to an issue with the rear driveshaft assembly that could ultimately result in driveshaft failure. The actual number of total vehicles involved in the recall is small at just 1,789, but it’s spread out across the entire 2021 model year full-size GM vehicle lineup. That means a small number of every model is being recalled, including the Chevrolet Tahoe, Suburban, GMC Yukon, Yukon XL and the Cadillac Escalade and Escalade ESV. GM traced the issue back to certain driveshaft assemblies with ball bearings that were not properly heat treated. If theyÂ’re not properly heat treated, GM says that the balls may deform over time, causing noise and vibration. Continue to drive in this condition, and GM says the affected joint in the driveshaft assembly could seize, causing loss of drive power. However, the problem wonÂ’t present itself all at once, as GM says there will be a gradual increase of noises and vibrations before total failure. For those few owners with affected vehicles, GM says that it will replace the left and right rear driveshaft assemblies with properly-built units. Per usual with recalls, this will be done at your local dealership at no cost to the owner. If you have one of the recalled SUVs, expect to be notified mid-March. Related video:

GMC explains why the Hummer EV SUV has only 830 horsepower

GMC's 2022 Hummer EV pickup made its debut in late 2020 with a headline-grabbing 1,000-horsepower rating. Its SUV sibling broke cover yesterday with 170 fewer horses, so GMC executives had some explaining to do. Al Oppenheiser, the EV's chief engineer, pointed out that the SUV's wheelbase is about nine inches shorter than the truck's, which is called an "SUT" in GMC-speak. It's also about 20 inches shorter overall. Size matters in the electric car world; GMC can't stuff the SUT's big battery pack in the more compact SUV, and this directly influences power. He added that it would have been possible to build a 1,000-horsepower SUV by making changes to the battery pack's layout. His team would have needed to reduce cargo capacity and get rid of the flat loading floor, which were compromises that engineers were not prepared to make. Ultimately, 830 horses should be plenty for most drivers. "Frankly, we are not sorry that it's only 830 horsepower. There aren't many internal combustion engines that can say that. Will we be able to grow horsepower in the future? We are going to push that capability, and as the technology gets to the point where our batteries are smaller and more efficient, we will improve performance with any chance we get," Oppenheiser said. It helps that the Ultium battery technology GMC uses is extremely modular. Less powerful versions of the Hummer SUV are in the cards, too. At launch in early 2023, the model will exclusively be offered with the aforementioned 830-horsepower drivetrain, which offers around 300 miles of driving range. Pricing will start at $105,595 before options are factored in. Several months later, GMC will release an EV2X variant with up to 625 horsepower, about the same amount of driving range, and an $89,995 price tag before incentives. Related video: This content is hosted by a third party. To view it, please update your privacy preferences. Manage Settings. GMC Hummer EV reveal

'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).