GM 9T50 transmission
Transversely-mounted automatic transmission
From Wikipedia, the free encyclopedia
The General Motors Hydra-Matic 9T50 and similar 9T45, 9T60, and 9T65 are part of the 9TXX family of electronic automatic transmissions with nine forward speeds for light-duty transversely-mounted applications. It was designed and manufactured by General Motors, equipped on automobiles starting with the 2017 model year; the 9TXX family was developed from an earlier joint GM–Ford 6-speed automatic transmission. Ford sells derivatives of the 9TXX with one forward speed removed as the 8F family.
| 9TXX (9T45, 9T50, 9T60, 9T65) | |
|---|---|
| Overview | |
| Manufacturer | General Motors |
| Production | 2019–present |
| Body and chassis | |
| Class | 9-speed transverse automatic transmission |
| Related | Ford 8F |
| Chronology | |
| Predecessor | 6F35/6F50/6F55 |
Design / history
Ford and GM announced a joint venture to share automatic transmission designs in April 2013: GM would adopt a 10-speed longitudinal transmission primarily designed by Ford, and in exchange, Ford would adopt the GM 9TXX 9-speed transverse transmission.[1] Ford declined to use the GM 9TXX, however, as the promised improvement in fuel consumption was less than expected, and removed one gear, resulting in the Ford 8F family.[2][3]
During the development of the 9TXX, GM received 60 new patents while building 800 prototypes.[4] It was developed from the 6T41 (Gen 3)[5] and designed to occupy approximately the same volume as that prior six-speed automatic and retain that transmission's on-axis design, which aligns all the planetary gears with the crankshaft. The addition of three gears was facilitated by adding a "selectable one-way clutch" which can act either as a sprag clutch, freewheeling in one direction and locking up in the other, or freewheeling in both directions. In addition, the transmission supports start-stop systems by including a spring-loaded hydraulic accumulator to engage the first-gear clutches upon restarting the engine.[6] The 8th gear ratio of the 9TXX corresponds to the 6th gear ratio of the 6T40, allowing lower engine speeds in 9th gear.[5] Two of the three planetary gear sets have similar designs between the 9TXX and 6T40; for the third, the 9TXX switches to a compound set.[7]
Models
Applications
9T45
- 2018– GMC Terrain (1.5 L LYX & LSD)[10]
9T50
- 2019– Cadillac XT4 (2.0 T LSY)* 2020– Cadillac XT6 (2.0 T LSY, 3.6 L LGX)
- 2019– Chevrolet Blazer (2.5 L LCV)[11]
- 2017– Chevrolet Malibu (2.0 T LTG)
- 2020– GMC Acadia (2.5 L LCV)[10]
The 9T50 and similar Ford 8F35 both share components with the GM 6T40 and Ford 6F35.[9]
9T60
- 2020– GMC Acadia (2.0 T LSY)[10]
9T65
- 2018– Buick Enclave (3.6 L LFY)
- 2017– Buick LaCrosse (3.6 L LGX)
- 2019– Chevrolet Blazer (3.6 L LGX)[11]
- 2018– Chevrolet Traverse (3.6 L LFY)
- 2018– GMC Acadia (3.6 L LGX)[10]
In December 2020, GM initiated a program to repair or replace 9T65 transmissions which were causing issues. Repairs were limited to external components only.[12] The program applied to vehicles that had less than 18,000 mi (29,000 km) and had been delivered within the past 18 months.[13] A recall was issued in March 2023 for certain crossover vehicles which may have a transmission that was assembled using an incorrectly sized sun gear.[14]