9TXX (9T45, 9T50, 9T60, 9T65)
Overview
ManufacturerGeneral Motors
Production2019–present
Body and chassis
Class9-speed transverse automatic transmission
RelatedFord 8F
Chronology
Predecessor6F35/6F50/6F55

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.[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

9TXX gear ratios[8][9]
123 456 789 R Final drive
4.693.313.01 2.451.921.45 1.000.750.62 2.96 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.[9]

Model differences[9]
Model Max. trailer weight Max. GVWR
9T45 1,743 kg (3,843 lb)2,700 kg (6,000 lb)
9T50 2,598 kg (5,728 lb)2,730 kg (6,020 lb)
9T60 3,080 kg (6,790 lb)
9T65 2,473 kg (5,452 lb)2,930 kg (6,460 lb)

9T45

Applications

9T50

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

Applications

9T60

Applications

9T65

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]

Applications

See also

References

  1. ↑ Brooke, Lindsay (April 15, 2013). "Ford and GM finally consummate 9- and 10-speed joint development". Automotive Engineering. Archived from the original on March 25, 2018. Retrieved 12 December 2023.
  2. ↑ Martinez, Michael (April 23, 2018). "No thanks, Ford says to 9-speed offered by GM". Automotive News. Retrieved 12 December 2023.
  3. ↑ Tracy, David (April 23, 2018). "Why Ford Isn't Using GM's Nine-Speed Automatic Transmission". Jalopnik. Retrieved 12 December 2023.
  4. ↑ Amend, James M. (December 7, 2016). "New 9-Speed Pushes Tech Limit, GM Says". Wards Auto. Retrieved 12 December 2023.
  5. 1 2 Riley, Mike (August 1, 2019). "General Motors 9T50 Nine Speed FWD: Part One". Transmission Digest. Retrieved 18 December 2023.
  6. ↑ Markus, Frank (October 7, 2016). "Peeking Inside the GM/Ford Transverse Nine-Speed Automatic". Motor Trend. Retrieved 18 December 2023.
  7. ↑ Riley, Mike (September 1, 2019). "General Motors 9T50 Nine Speed FWD: Part Two". Transmission Digest. Retrieved 18 December 2023.
  8. ↑ "General Motors 9T50 Nove Velocidades Treinamento Técnico" [General Motors 9T50 nine-speed technical training] (PDF) (in Portuguese). Cambio Automatico do Brasil. Retrieved 12 December 2023.
  9. 1 2 3 4 Brayton, Bill (June 28, 2019). "Fun with transmissions: There's a New 9 Speed On The Block". Gears. Retrieved 12 December 2023.
  10. 1 2 3 4 "2021 GMC Trailering Guide" (PDF). General Motors. Retrieved 12 December 2023.
  11. 1 2 "All-New 2019 Blazer Arrives with Attitude" (PDF). TechLink. Vol. 21, no. 2. General Motors. January 2019. Retrieved 12 December 2023.
  12. ↑ McEachern, Sam (December 3, 2020). "GM Initiates Pilot Program To Replace 9T65 9-Speed Transmission". GM Authority. Retrieved 12 December 2023.
  13. ↑ "New 9T65 Transmission Replacement Pilot Program Bulletin Information" (PDF). TechLink. Vol. 23, no. 11. General Motors. June 2021. Retrieved 12 December 2023.
  14. ↑ Panait, Mircea (24 March 2023). "GM Built Certain 9-Speed Transmissions Incorrectly, Recalls 7,840 SUVs". Auto Evolution. Retrieved 12 December 2023.
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