2004.5 Gmc Sierra 2500hd 4x4 Duramax. Mechanic Special on 2040-cars

Auto blog

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.

Leaked GM document shows GMC Sierra I6 diesel is more powerful than F-150's

GM told us earlier this year that the 2019 GMC Sierra would be getting a 3.0-liter I6 diesel option, but it never mentioned power or fuel economy figures. Hold the phone though, because a leaked GM Canada document just showed up online that lists out the details we've been waiting for. Originally published by TFL Truck, the 3.0-liter oil-burner supposedly makes 282 horsepower and 450 pound-feet of torque. For those who are counting, that's more than the Ford F-150's 250 horsepower and 440 pound-feet from its 3.0-liter diesel. It soundly bests the 240 horsepower and 420 pound-feet of torque from Ram's 3.0-liter diesel as well. Fuel economy is another story, though. The promotional material states that it will get 28 mpg on the highway, which is 2 mpg short of the F-150's 30 mpg — mind you, it's only capable of that magical 30 mpg figure in rear-wheel drive form. There's another caveat here, too; these are numbers for Canada, so they're not exactly finalized EPA figures. However, we wouldn't expect drastic differences between the two when the American numbers come out. The leaked documents also state the diesel Sierra will be capable of towing 7,800 pounds. That number seems remarkably low when compared to the F-150, which can tow up to 11,400 pounds with its diesel. Extra power and torque would have us assume that GM could get even better numbers than Ford, so we're going to hold our final judgment for official word. A 10-speed automatic will do the shifting on the diesel, just like on the 6.2-liter V8. Since the Chevy Silverado is also expected to get this engine, we can assume the figures would be almost, if not identical, to those we see here. We recently drove the 2019 Sierra and Silverado without the diesel engines, so go check those reviews out if you'd like to know more of our thoughts on the redesigned GM trucks. Related video:

GMC's Denali offerings are going great guns

The Denali trim that GMC uses to denote its top-of-the-line vehicles was introduced back in 1999, partly as a way to challenge the recently introduced Lincoln Navigator. Fifteen years later, and with GMC the tenth-largest US automotive brand by itself Denali has become a sub-brand that keeps the cash registers ringing at the Renaissance Center HQ. While GMC increased sales by 9 percent in 2013, TheDetroitBureau.com reports that that Denali sales rose by 20 percent.
There are currently five Denali models in the GMC line, with the Denali trim available on all but its commercial vans. In 2010, when the now-discontinued Yukon XL Hybrid was also on sale, GMC sold 32,886 units of its top trim. Last year, that number had increased to 75,558, with almost no help from traditional marketing spends. Go to YouTube and search for "GMC Denali commercials" - the few actual commercial results are from years ago. GMC marketing director Roger McCormack tells TheDetroitBureau.com, "It's largely all been organic."
As sales have grown, so has the tide of money GMC rakes in from the additional luxury features on Denali models. The 2015 Chevrolet Tahoe starts at $44,600, yet its 2014 Yukon Denali doppelganger starts at $58,320, pricing that includes additional features like the larger 6.2-liter V8, nicer interior, head-up display and magnetic ride control suspension. The Yukon XL Denali starts at $60,965, but the article says the "average customer" likely to spend "up and above $70,000" to take one home. How does that happen? On a top-trim Tahoe LTZ, the top-tier wheel option is a set of 20-inch chrome wheels for $400; on the 'base' Yukon Denali you can swap for a set of 22-inch chrome alloys for $2,995. Add it up, and an analyst at AutoTrends Consulting said that kind of margin "epitomizes the concept of obscene profitability." We say when it comes to Denali, GMC appears to stand for "Grabbing More Cash."