GM 8L transmission
| 8L45 · 8L90 · 8L80 | |
|---|---|
| Overview | |
| Manufacturer | General Motors |
| Production | 2014– |
| Body and chassis | |
| Class | 8-speed longitudinal automatic transmission |
| Related | ZF 8HP · Aisin-Toyota 8-speed · MB 9G-Tronic |
| Chronology | |
| Predecessor | 6L 45 · 6L 50 · 6L 80 · 6L 90 |
| Successor | 10L 80 · 10L 90 · 10L 1000 |
All 8L transmissions are based on the same globally patented gearset concept as the ZF 8HP from 2008. While fully retaining the same gearset logic, they differ only in the patented arrangement of the components, with gearsets 1 and 3 swapped.
The 8L90 is the first 8-speed automatic transmission built by General Motors. It debut in 2014 and is designed for use in longitudinal engine applications, either attached to the front-located engine with a standard bell housing or mounted in the rear of the car adjacent to the differential (as in the Corvette). It features a hydraulic (Hydramatic) design.
The 8L45 is the smaller variant and debuted in 2015 in the 2016 Cadillac CT6. It is designed for use in longitudinal engine applications attached to the front-located engine with a standard bell housing. It is a hydraulic (Hydramatic) design sharing much with the 8L90 transmission. Estimated weight savings over the heavier-duty 8L90 is 33 lb (15 kg). A second generation of the 8L45 was introduced in 2023 model years and has a new RPO code of "N8R"
The 8L80 is an update to the previous 8L90 version and has a new RPO code of "MFC". Debuted in the 2023 model years of the Chevy Colorado and GMC Canyon.
Gear Model |
R | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Total Span |
Span Center |
Avg. Step |
Compo- nents |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 8L90 · M5U · 2014 | −3.818 | 4.560 | 2.971 | 2.075 | 1.688 | 1.270 | 1.000 | 0.845 | 0.652 | 6.999 | 1.724 | 1.320 | 4 Gearsets 2 Brakes 3 Clutches |
| 8L45 · M5N · 2015 | −3.928 | 4.615 | 3.038 | 2.065 | 1.658 | 1.259 | 1.000 | 0.849 | 0.658 | 7.011 | 1.743 | 1.321 | |
| 8L80 · MFC · 2023 | |||||||||||||
| ZF 8HP 70 · 2008 | −3.297 | 4.696 | 3.130 | 2.104 | 1.667 | 1.285 | 1.000 | 0.839 | 0.667 | 7.043 | 1.769 | 1.322 | |