GM 9T50 transmission

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.

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. 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.
During the development of the 9TXX, GM received 60 new patents while building 800 prototypes. It was developed from the 6T41 (Gen 3) 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. The 8th gear ratio of the 9TXX corresponds to the 6th gear ratio of the 6T40, allowing lower engine speeds in 9th gear. 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.

Models

1	2	3	4	5	6	7	8	9	R	Final drive
4.689	3.306	3.012	2.446	1.923	1.446	1.000	0.747	0.617	2.960	2.89, 3.17, 3.32, 3.47, 3.63, 3.80

The last two digits of the model number indicate maximum GVWR and towing capacity, with higher numbers having a larger capacity.

Model	Max. trailer weight	Max. GVWR
9T45
9T50
9T60
9T65

Applications

9T45

2018– GMC Terrain

9T50

2019– Cadillac XT4 * 2020– Cadillac XT6
2019– Chevrolet Blazer
2017– Chevrolet Malibu
2020– GMC Acadia

The 9T50 and similar Ford 8F35 both share components with the GM 6T40 and Ford 6F35.

9T60

2020– GMC Acadia

9T65

2018– Buick Enclave
2017– Buick LaCrosse
2019– Chevrolet Blazer
2018– Chevrolet Traverse
2018– GMC Acadia

In December 2020, GM initiated a program to repair or replace 9T65 transmissions which were causing issues. Repairs were limited to external components only. The program applied to vehicles that had less than and had been delivered within the past 18 months. 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.