Ward's article on the 9T50.
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“We don’t see the benefit of going higher than 10 forward speeds,” Meagher tells WardsAuto following a presentation on the technologies here.
But never say never, he adds, noting that when GM deployed its revolutionary lineup of 6-speed automatic transmissions a decade ago no one imagined hardware and software technology would advance so dramatically to permit 9- and 10-speed executions.
“So you never really know for sure,” he admits.
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The new 9-speed yielded GM 60 new patents and required 800 prototypes. It is the same size as the old 6-speed and weighs about 22 lbs. (10 kg) more. The most unique element of the unit is an industry-first deployment of a selectable 1-way clutch, which can hold torque or operate freely depending on the situation.
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The unit is filled with Castrol-brand DEXRON-VI fluid to eliminate service changes under normal driving conditions. GM says the fluid features consistent viscosity, consistent shift performance and reduced degradation.
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In-house logics software inside a 32-bit transmission control module handles all shift events for smooth, precise ratio changes, GM says. It also monitors transmission performance and compensates for wear in parts such as the clutch plate to maintain consistent performance over time.
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The controller is mounted outside the gearbox to reduce packaging and manufacturing complexity, and it pulls vehicle-specific calibration from the cloud to be added to the core program as the car or truck exits the assembly line. It also enables manual shift control and grade logic, GM says.
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The 9T50 features a wider 7.6:1 overall ratio, compared with 6.0:1 in its 6-speed predecessor, a deep 4.69 first gear for off-the-line performance and a tall 0.62 top gear for fuel-efficient, low-rpm highway cruising and optimal NVH.
Sixth gear is equivalent to eighth gear on the new transmission, too, so compared with the 6-speed the 9-speed offers two fuel-saving overdrive gears. Seventh gear is the direct-drive gear, while ninth gear is in use up to 52% of the time.
Quote:
“We don’t see the benefit of going higher than 10 forward speeds,” Meagher tells WardsAuto following a presentation on the technologies here.
But never say never, he adds, noting that when GM deployed its revolutionary lineup of 6-speed automatic transmissions a decade ago no one imagined hardware and software technology would advance so dramatically to permit 9- and 10-speed executions.
“So you never really know for sure,” he admits.
Quote:
The new 9-speed yielded GM 60 new patents and required 800 prototypes. It is the same size as the old 6-speed and weighs about 22 lbs. (10 kg) more. The most unique element of the unit is an industry-first deployment of a selectable 1-way clutch, which can hold torque or operate freely depending on the situation.
Quote:
The unit is filled with Castrol-brand DEXRON-VI fluid to eliminate service changes under normal driving conditions. GM says the fluid features consistent viscosity, consistent shift performance and reduced degradation.
Quote:
In-house logics software inside a 32-bit transmission control module handles all shift events for smooth, precise ratio changes, GM says. It also monitors transmission performance and compensates for wear in parts such as the clutch plate to maintain consistent performance over time.
Quote:
The controller is mounted outside the gearbox to reduce packaging and manufacturing complexity, and it pulls vehicle-specific calibration from the cloud to be added to the core program as the car or truck exits the assembly line. It also enables manual shift control and grade logic, GM says.
Quote:
The 9T50 features a wider 7.6:1 overall ratio, compared with 6.0:1 in its 6-speed predecessor, a deep 4.69 first gear for off-the-line performance and a tall 0.62 top gear for fuel-efficient, low-rpm highway cruising and optimal NVH.
Sixth gear is equivalent to eighth gear on the new transmission, too, so compared with the 6-speed the 9-speed offers two fuel-saving overdrive gears. Seventh gear is the direct-drive gear, while ninth gear is in use up to 52% of the time.