— GM 8L90 and 8L45 transmission problems have caused a proposed class action lawsuit that alleges the 8-speed transmissions are defective in the following vehicles in California, Illinois, Michigan, New Jersey, New York and Texas.
ALTO 8L90 Performance Transmission Rebuild Kit & Billet Input Shaft - Level 2 (Added Clutch Capacity) Instructions are included for C3, C4 & C5 Clutch Packs. However, if you're inexperienced with the 8L90 we recommend that you purchase a Service Manual. We also sell the manual.
- 2015-2017 Cadillac Escalade
- 2015-2017 Cadillac Escalade ESV
- 2016-2019 Cadillac ATS
- 2016-2019 Cadillac ATS-V
- 2016-2019 Cadillac CTS
- 2016-2019 Cadillac CT6
- 2016-2019 Cadillac CTS-V
- 2015-2019 Chevrolet Silverado
- 2017-2019 Chevrolet Colorado
- 2015-2019 Chevrolet Corvette
- 2016-2019 Chevrolet Camaro
- 2015-2019 GMC Sierra
- 2015-2019 GMC Yukon
- 2015-2019 GMC Yukon XL
- 2015-2017 GMC Yukon Denali
- 2015-2017 GMC Yukon Denali XL
- 2017-2019 GMC Canyon
According to the plaintiffs, GM 8L90 and 8L45 transmission problems have plagued their vehicles because dealerships have been unable to remedy. The automatic transmissions allegedly act up when drivers attempt to accelerate or decelerate.
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- 8L90 Transmission. The 8L90 transmission is an 8-speed longitudinal automatic transmission that was designed to shorten the steps between gears and improve fuel economy beyond the 6L80 and 6L90 transmissions. The 8L90 is found in GM high-horsepower vehicles highlighted by the Corvette and common daily driven vehicles like the Yukon and Silverado.
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'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. Said shudder, shake and hesitation also occurs while the subject vehicles are accelerating in a single gear, and not actively shifting gears.'
The plaintiffs say 8L90 and 8L45 transmissions can violently shift to the point drivers believe they were hit by other vehicles. The transmission problems allegedly occur within the transmissions or torque converters that cause friction on the surfaces and failures of the gears and hydraulic systems.
This allegedly causes metal shavings to circulate through the 8L90 and 8L45 transmissions, damaging the torque converters and transmissions.
According to the lawsuit, owners and lessees are stuck with repeated repairs that include flushing the transmissions of metal shavings, but in the end the vehicles still suffer multiple problems. The plaintiffs say they can't depend on their vehicles, something that if they would have known likely would have caused them to purchase different vehicles.
General Motors has allegedly known about the 8L90 and 8L45 transmission problems since 2015 when the automaker started issuing technical service bulletins (TSBs) and other bulletins to dealerships. The bulletins are meant to assist dealers if customers complain about issues with the transmissions by making repairs such as these:
- Complete the “clutch drive learn procedure”
- Replace the valve body
- Flush the cooler lines and cooler
- Flush the transmission
- Remove debris from and clean the transmission pan
- Replace the transmission filter
- Replace the transmission fluid
- Replace the entire transmission
According to the plaintiffs, none of the repairs have truly fixed the transmission problems and the automaker continues to conceal the alleged defects from customers.
Documents from the lawsuit reference numerous preliminary information (PI) and technical service bulletins sent to dealers beginning in October 2015 up to October 2018. The bulletins were sent because of problems with the 8-speed transmissions that shudder, jerk, lurch and have delayed responses, specifically GM 8L45 and 8L90 transmissions.
Starting in October 2015, GM issued PI bulletin PIP5337 entitled, “Shake or Shudder on Acceleration Excessive Engine RPM Fluctuation,” for vehicles equipped with 8L90 transmissions.
According to the PI, customers were complaining about:
“A shudder feeling that may be described as driving over rumble strips or rough pavement. These conditions may be caused by an internal torque converter issue. A revised torque converter that addresses these conditions will be available soon.”
8l90 Transmission Mount
The plaintiffs claim bulletin PIP5337 has been updated at least 10 times since it was issued.
In September 2014, GM issued TSB 14-07-30-001 entitled, “Information on Transmission Adaptive Functions,” this one concerning problems with 8L90 transmissions.
“Some customers may comment on low mileage vehicles with automatic transmission that shift feel to be too firm (harsh) or may slip or flare. Customers should be advised that the transmission makes use of an adaptive function that will help to refine the shift feel while driving and improve shift quality.”
Then came TSB 16-NA-175 entitled “Shake and/or Shudder During Light Throttle Acceleration, Between 48 and 104 KM/H (30 and 65 MPH) at a Steady State,” which applied to vehicles equipped with 8L90 transmissions.
8l90 Transmission Flush
In June 2016, GM issued PI bulletin PIP5405 with the subject line, “Surge Misfire Feeling Sensation During Highway Steady State Driving,” which was followed by TSB 16-NA-014 entitled, “Delayed Engagement After Sitting With Engine Off.”
In April 2017, GM issued PIE0405 entitled, “Engineering Information—Torque Converter Shudder,” a bulletin that was updated in September 2017.
In January 2019, GM issued TSB 18-NA-355 entitled, “Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH (40 and 128 KM/H) at Steady Speed.”
According to the lawsuit, General Motors issued more than 12 additional bulletins related to 8-speed transmission problems. In addition, instead of sending dealers multiple bulletins, the plaintiffs say the automaker should have warned consumers about vehicles equipped with faulty transmissions.
The GM 8L90 and 8L45 transmission lawsuit was filed in the U.S. District Court for the Eastern District of Michigan, Southern Division - Francis, et al., v. General Motors, LLC.
The plaintiffs are represented by Pitt McGehee Palmer & Rivers, Cohen Milstein Sellers & Toll, and Gordon & Partners.
CarComplaints.com has owner-reported complaints about vehicles named in the GM lawsuit.
| 8L90 | |
|---|---|
| Overview | |
| Manufacturer | General Motors |
| Production | 2014–present |
| Body and chassis | |
| Class | 8-speed longitudinalautomatic transmission |
| Chronology | |
| Predecessor | 6L80 |
| Successor | GM 10L90 |
The 8L90 is an eight-speed automatic transmission built by General Motors Company. It is designed for use in longitudinal engine applications either attached to the front-located engine[1] with a standard bell housing or in the rear of the car adjacent to the differential (as in the Corvette). It is a hydraulic (hydramatic) design. GM also produces a similar design with the smaller 8L45.
The 8L90 is the subject of a class-action lawsuit filed in December 2018 that alleges the transmission suffers from persistent 'shudder' issues and that GM has known about the problems since its introduction and has failed to provide a solution, instead choosing to wait until the unit is out of warranty.[2]
Specifications[edit]
| Gear Teeth and Ratios[3] | Planetary Gearset: Teeth | Count | Total | Avg. | |||||
|---|---|---|---|---|---|---|---|---|---|
| Model Type | Version First Delivery | Sun 1 Ring 1 | Sun 2 Ring 2 | Sun 3 Ring 3 | Sun 4 Ring 4 | Brakes Clutches | Ratio Span | Gear Step | |
| Gear | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | R |
| 8L90 M5U | 860 Nm · 635 lb·ft[4] 2014 | 41[5] 79 | 46 86 | 37 73 | 25 89 | 2 3 | 6.9991 | 1.3204 | |
| Ratio | 4.5600 | 2.9709 | 2.0751 | 1.6876 | 1.2700 | 1.0000 | 0.8455 | 0.6515 | - 3.8176 |
| 8L45 M5T | 2015 | 41 79 | 41 79 | 41 79 | 26 94 | 2 3 | 7.0107 | 1.3208 | |
| Ratio | 4.6154 | 3.0385 | 2.0648 | 1.6583 | 1.2587 | 1.0000 | 0.8494 | 0.6583 | - 3.9278 |
Applications[edit]
| Model years | Make and model | Final drive ratio |
|---|---|---|
| 2015–2017 | Cadillac Escalade[6] | 3.23 |
| 2015–2019 | Chevrolet Corvette (C7) Stingray [7] | 2.41 (std) |
| 2.73 (Z51) | ||
| 2015–2019 | Chevrolet Corvette (C7) Z06 [8] | 2.41 |
| 2015–present | Chevrolet Silverado/GMC Sierra[9] | 3.23 (std.) |
| 3.42 (Max Trailering Package) | ||
| 2015–2017 | GMC Yukon Denali/Denali XL | 3.23 |
| 2016–present | Cadillac ATS-V | 2.85 |
| 2016–present | Cadillac CTS-V | 2.85 |
| 2016–present | Cadillac CT6 | 3.27 |
| 2016–present | Chevrolet Camaro | 2.77 |
| 2017-present | Chevrolet Express/GMC Savana (2.8L diesel engine only) | |
| 2015-present | Chevrolet Colorado/GMC Canyon | 3.42 |
References[edit]
- ^'USA Information Guide Model Year 2018'(PDF). Retrieved 15 July 2019.CS1 maint: discouraged parameter (link)
- ^'Class Action Lawsuit Filed Over Alleged Shifting Defect in Certain General Motors Transmissions'. Retrieved 2 February 2019.CS1 maint: discouraged parameter (link)
- ^'New 8-Speed Enables Quicker, More Efficient Corvette'. www.gm.com. General Motors. 20 August 2014. Archived from the original on 22 December 2014. Retrieved 21 August 2014.CS1 maint: discouraged parameter (link)
- ^'Transmission Repair Cost Guide'. Retrieved 15 July 2019.CS1 maint: discouraged parameter (link)
- ^'WIT · Whatever It Takes · Automatic Transmission Parts Catalog 2018+2019 Page 268'. Retrieved 15 July 2019.CS1 maint: discouraged parameter (link)
- ^'2015 Cadillac Escalade Updated with 8L90 8-Speed Automatic and More Tech [Photo Gallery]'. Retrieved 12 August 2014.CS1 maint: discouraged parameter (link)
- ^'Chevrolet Confirms 2015 Corvette Stingray To Utilize 8L90 Eight-Speed Gearbox'. Retrieved 9 April 2014.CS1 maint: discouraged parameter (link)
- ^'Supercharged 2015 Chevy Corvette Z06 takes the C7 beyond the ZR1 [w/video]'. Retrieved 25 January 2014.CS1 maint: discouraged parameter (link)
- ^'GM confirms 2015 Silverado, Sierra to get 8-speed automatic'. Retrieved 18 June 2014.CS1 maint: discouraged parameter (link)
External links[edit]
8l90 Transmission Issues
8l90 Transmissions