GM 8L90 transmission
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.
8L90 | |
---|---|
Overview | |
Manufacturer | General Motors |
Production | 2014–present |
Body and chassis | |
Class | 8-speed longitudinal automatic transmission |
Chronology | |
Predecessor | 6L80 |
Successor | GM 10L90 |
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
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
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
- "USA Information Guide Model Year 2018" (PDF). Retrieved 15 July 2019.
- "Class Action Lawsuit Filed Over Alleged Shifting Defect in Certain General Motors Transmissions". Retrieved 2 February 2019.
- "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.
- "Transmission Repair Cost Guide". Retrieved 15 July 2019.
- "WIT · Whatever It Takes · Automatic Transmission Parts Catalog 2018+2019 Page 268". Retrieved 15 July 2019.
- "2015 Cadillac Escalade Updated with 8L90 8-Speed Automatic and More Tech [Photo Gallery]". Retrieved 12 August 2014.
- "Chevrolet Confirms 2015 Corvette Stingray To Utilize 8L90 Eight-Speed Gearbox". Retrieved 9 April 2014.
- "Supercharged 2015 Chevy Corvette Z06 takes the C7 beyond the ZR1 [w/video]". Retrieved 25 January 2014.
- "GM confirms 2015 Silverado, Sierra to get 8-speed automatic". Retrieved 18 June 2014.