GM 8 speed transmission. My next question to Crazy was going to be I'm not up on the new GM transmissions. I know the ZF is supposed to be able to shift straight between gears, like if I'm in 8th gear and the computer calls for 4th gear because I floored it, it shifts straight from 8th to 4th without having to hit 7 then 6 then 5 before getting to 4.
Does the new GM transmission do this? Also, what power levels are they rated for? The ZF is supposed to be good for something like ft lbs, for the version used in the Hellcat. GM 8-Speed 8L90 M5U Hydra-Matic Automatic Transmission The Hydra-Matic 8L90 production code M5U is a fuel-saving and electronically controlled eight-speed automatic transmission developed and produced by General Motors for use in rear- and rear-biased all-wheel-drive vehicles with a longitudinal powertrain orientation.
Designed and built by GM, the 8L90 transmission speed is expected to contribute up to 5-percent greater efficiency, when compared to the previous 6L90 six-speed automatic. Smaller steps between gears, compared to the Hydra-Matic 6L90 six-speed automatic, keep the engine within the sweet spot of the rpm band, making the most of its horsepower and torque to optimize performance and efficiency.
The 8L90 has a torque capacity of pound-feet Nm. Extensive use of aluminum and even magnesium also make it more than eight pounds 4 kg lighter than the six-speed in Corvette applications. Along with design features that reduce friction, the 8L90 is expected to contribute up to 5-percent greater efficiency, when compared with a six-speed automatic.
TSB Seems To Fix 8-Speed Automatic GM Transmission Problems
Five clutches are used, three at a time, leaving only two open clutches in each gear state. Optimized clutch sizing and off axis binary pump contribute to outstanding spinloss attributes. All applications feature adaptive shift controls. Several features such as grade braking, Performance Algorithm Shifting, and Driver Shift Control are available on some of the applications.
Performance Algorithm Shifting PAS monitors how assertively the driver is using engine output and other vehicle sensors to determine at what engine speed to upshift of downshift. Driver Shift Control allows the driver to shift the transmission like a clutchless manual gearbox.
Electronic safeguards prevent over-revving if the wrong gear position is selected. The 8L90 uses VFS control components to monitor clutch pressures with optimum accuracy. The result are faster and more precise shifts. The torque converter is mm in diameter and features a lock-up clutch, although clutch and converter specifications vary depending on the application. The 8L90 uses electronic controlled capacity clutch ECCC technology, which employs a small, regulated amount of slip to dampen out engine pulses for a smoother running drivetrain, especially during shifting.
Low Maintenance The 8L90 uses Dex 6 HP Transmission fluid, which was developed to have a more consistent viscosity profile as well as improved lubrication characteristics. Clutch-to-clutch architecture, with external transmission control module Maximum engine power: hp kW Maximum engine torque: lb-ft Nm Maximum gearbox torque: lb-ft Nm Gear Ratios First: 4. Joined: 27 Oct Posts: Location: Waikikamukau.Owners of the Chevrolet Colorado and other models are complaining about hesitation and shifting issues.
Owners of the affected vehicles may be entitled to compensation. The proposed class-action lawsuit includes all consumers who purchased or leased the following vehicles in California, Florida, Illinois, New York, Oklahoma and Texas:. Car Complaint Article. The GM vehicles are equipped with GM 8L45 or 8L90 automatic transmissions that allegedly hesitate when drivers accelerate or decelerate. Drivers claim the transmissions can shift so hard it feels like being hit by another vehicle.
GMC transmission review. Chevrolet Colorado Service Bulletin. Claims handled on contingency with no payment required from consumer. Site Terms, gm 8 speed transmission problems, recall, class action, gmc 8 speed transmission problems.
Powered by WordPress. Site Terms, gm 8 speed transmission problems, recall, class action, gmc 8 speed transmission problems Share this: Twitter Facebook. Like this: Like Loading Leave a Reply Cancel reply.A group of plaintiffs claim that General Motors GM manufactured vehicles between and that were equipped with defective transmissions. According to the GM transmission class action lawsuit, the shift from the transmission is so violent that it feels as if the vehicle has been hit by another car.
11 Things You Need to Know about Ford & GM’s 10-Speed Transmission
One purchaser even reported almost driving through his garage door when the transmission shifted from reverse to drive. Plaintiffs in the GM class action claim that the defect is related to internal issues with the transmission and torque converter.
As a result, metal shavings are generated in the transmission and circulate throughout the component, the GM class action states. The GM class action lawsuit claims that the only repair for the defect is a complete replacement of transmission components.
This includes the torque converter, valve body, or, in serious cases, the entire transmission. The plaintiffs claim that GM is aware of the transmission issue and has even released 13 technical service bulletins TSBs related to it. Despite this internal acknowledgement of the problem, GM has allegedly failed to warn consumers about the defective nature of their transmissions.
Plaintiffs in the GM class action seek to represent several state-based Classes of consumers who purchased or leased a passenger vehicle equipped with a GM 8L45 or 8L90 transmission on or after April 10, Plaintiffs are represented by Michael L. Pitt and Beth M. Leopold, Andrew N. Friedman, Douglas J. McNamara, and Julie A. District Court for the Eastern District of Michigan. Top Class Actions Legal Statement. Please note: Top Class Actions is not a settlement administrator or law firm.
Top Class Actions is a legal news source that reports on class action lawsuits, class action settlements, drug injury lawsuits and product liability lawsuits. Top Class Actions does not process claims and we cannot advise you on the status of any class action settlement claim. You must contact the settlement administrator or your attorney for any updates regarding your claim status, claim form or questions about when payments are expected to be mailed out.2019 Chevy Silverado issues
I am concerned also about my older GM Grand Prix.June 20, — GM 8-speed transmission problems have caused a proposed class action lawsuit that alleges GM's 8L90 and 8L45 transmissions shake, shudder, kick, jerk, buck and experience problems during acceleration and deceleration. According to the lawsuit, the following vehicles are equipped with the allegedly defective 8-speed transmissions. The 8-speed model 8L90 and 8L45 transmissions allegedly malfunction whether a vehicle is decelerating or accelerating, causing drivers to pay expensive repairs for problems General Motors allegedly knows about.
But even with alleged knowledge of transmission problems and the cost to customers, the automaker continues to market and sell the vehicles. GM owners complain about transmissions that shift and engage harshly and can leave them stranded on the roads at any time. The proposed class action includes all consumers in the U. The GM 8-speed transmission lawsuit was filed in the U. General Motors, LLC. Proposed class action alleges 8-speed transmissions buck, shudder, shake, jerk and shift harshly.A group of consumers alleges in a recently filed class action lawsuit that a defect in the GM 8L90 and the 8L45 transmissions included in vehicles made between and causes problems when drivers try to shift the vehicles.
Ultimately, GM owners and lessees face mounting repair costs because of the alleged defect, the complaint says. According to the GM class action lawsuit, the alleged transmission defect presents a safety risk to drivers and passengers in through GM vehicles equipped with GM 8L90 or GM 8L45 transmissions.
The defect can, according to the plaintiffs, cause the vehicle to shudder and jerk so violently that owners have complained that it feels as if they have been hit by another car.
The plaintiffs say that one GM owner reported that he almost drove through his garage door because the gear shifted so violently due to the alleged defect. The plaintiffs are represented by Theodore J. Leopold, Andrew N. Friedman, Douglas J. McNamara, and Julia A. General Motors, Inc. District Court Southern District of Florida.
Top Class Actions Legal Statement. Please note: Top Class Actions is not a settlement administrator or law firm. Top Class Actions is a legal news source that reports on class action lawsuits, class action settlements, drug injury lawsuits and product liability lawsuits. Top Class Actions does not process claims and we cannot advise you on the status of any class action settlement claim. You must contact the settlement administrator or your attorney for any updates regarding your claim status, claim form or questions about when payments are expected to be mailed out.
Same thing. What a piece of junk. About ten miles from home my truck started jerking and rumbling like it was loosing power. I pulled over in the middle of the night to Pop hood and check for issues.
Put my GMC in neutral to check transmission fluid and was ok, right color, no paces of metals, no bad smell and level of oil was ok. Got back in the truck and it was the same thing, jerking, rumbling and vibrating noises. It suddenly killed when I put it in park. Like everyone one else on these complaints. I have even changed to batteries within the last five years on this truck. I bought a high countrynothing but problemsmultiple recallsac condenser went out which there is a class action lawsuit for going onfuel injectors need replacingnow the transmission is shifting and down shifting hardI feel your pain Chevrolet has gone down hill big time.
I purchased a Yukon Denali with 6. Thankfully I purchased the offered extended warranty which has paid for itself more than 3 times over. I started to have the shutter with the transmission and took it to the dealership I purchased from in which they swapped out the transmission fluid and explained the newly updated thicker fluid would not cause this to happen again. I am still having problems with it to this day and the dealership now cannot figure out what is causing the hard shift.
I too would like information on the class action lawsuit. I would also like any information on individuals who were able to have their transmission replaced under warranty if anyone has had any luck. I too am having all these same issues in my Yukon Denali. I also had an injector go out. I would like to know if anyone has been able to get their transmission fixed and what is causing this.
Dealer cannot fix and tells me all is fine. I cannot deal with the dangerous lurching and neck breaking shifting from and then from gears. If you travel at speeds over 50, you cannot focus on anything in the rear view mirror or side mirrors.Remember Me? What's New? Results 1 to 19 of Thread: 8 speed torque convertor parameters. Thread Tools Show Printable Version. I have a terrible shutter in the convertor and if the dealer doesn't get it fixed this time I wanted to try to fix if myself.
I looked and all there is currently is lockup speed settings for the convertor. Nothing to do with pressure or desired slip. Getting a new torque convertor next week under warranty. Darn thing shutters so bad you think your driving on rumble strips. Does it worse on the highway below 70 mph. I have to take it out of 8th gear if I'm not running on the interstate.
If it makes you feel any better, my mi 6. Didn't the Escalade's have the same issue?
Or maybe I made that up. Originally Posted by schpenxel. New Escalades have the 8 speed also. I still would like to set the desired slip to 0 in high gear if the pids ever become available.
Maybe after the warranty runs out. They design it to slip some when it's in V4 mode to reduce normal engine vibrations felt. When in V8 mode the desired slip speed will be 0.
My truck is in for converter replacement right now. Sucks to be on the bleeding edge sometimes. Dealer service adviser tried to blame my "big wheels and tires" and I said "Hey, talk to your sales manager.
He's the one putting these aftermarket parts on several trucks in your lot! Problem isn't so much the desired slip as it is the engagement in lower gears Kill the engagement up through 5th so it only engages in 6th, 7th and 8th and you shouldn't have many more problems The only reason the OE does this is for fuel economy and to be honest - you won't notice much of a loss if any In fact a good tune on the engine side will usually offset any loss and then some The converters in these things are super thin and super small - just a design flaw That's exactly what I do, unlock the converter until overdrive and relatively light pedal.We know, advertisements are annoying and slow down the internet.
Unfortunately, this is how we pay the bills and our authors. We would love for you to enjoy our content, we've worked hard on providing it. Please whitelist our site in your adblocker, refresh the page, and enjoy!
For its part, GM has filed 13 technical service bulletins concerning the unit, none of which remedied the issue. So yes, it would have cost GM money.
Jonathan is an automotive journalist based out of Southern California. He loves anything and everything on four wheels. I rented a C7 with miles on it a few weeks ago in Fla. It had this trans and was showing some of these symptoms described.
What an mess. The 8-speed is terrible. Luckily, my GS has the 7-speed manual, as I would never buy a sports car with an auto. Sure, a DCT is better than a standard auto, but I want to feel the vehicle. I want to call the shots. Throwing levers is what makes driving a sports car fun. Wanting to shift you own gears is nothing out of the ordinary.
Most owners are not having issues. The owners with the new fluids are reporting good results. The long and short of this was GM has spent the last couple years trying a number of fixes and finally just has found the issue. Also the shudder issue us not just a GM issue as other brands and transmission have suffered the same fate. To this point mine shifts great and has been a good transmission, The majority of owners are also like my experience.
There has been a lot of miss information on this topic and the fact GM had no real answer till last winter has been difficult. But the reality is GM never abandoned the customers and they continued to look for a fix and it finally appears to be here.
Even the BCM voltage to the shifter has to be adjusted or it will not go into park these days.