Dissecting The New GM Nine-Speed Automatic Transmission
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Nine is quickly becoming the new six. After years of rule by the six-speed automatic transmission, nine-speed autos are beginning to gain footing, slowly replacing the six-speed as standard.
For General Motors, it tapped rival Ford to co-develop a new, in-house nine-speed automatic. It was engineered alongside the ten-speed automatic gearbox for rear-wheel drive vehicles, which Ford took the lead on, while GM focused on the nine-speed for front-wheel drive applications.
Motor Trend took a look into what’s actually inside GM’s latest transverse 9T50 transmission, and not surprisingly, it’s full of modern engineering.
According to GM transmission expert Scott Kline, the nine-speed gearbox’s goal was to use the same six-speed design, but add three additional cogs. Thus, it keeps its on-axis design, keeping the planetary gears aligned with the crankshaft.
To keep width and length down, GM and Ford completely redesigned the system responsible for shifting the reverse and first gears. Instead of the six speed’s old two-clutch system, a “selectable one-way clutch” was developed and stacked together.
This allows for the clutch to lock like a multiplate clutch resisting motion in both directions, ditching a conventional multiplate design.
To keep engine vibrations speeds at a minimum, a new torque converter is present, which allows for small bursts of 10-60 RPM speed differentials. It allows for smoother operation regarding the lock converter and greater efficiency altogether.
The nine-speed automatic also has been engineered for start-stop functions with transverse engines, meaning there’s a large oil-pressure accumulator to help the clutches in first gear while the engine restarts. As for maintenance, a second filter has been fitted to ensure debris do not enter the gearbox. The filters are reportedly sized to never need replacing.
While the 2018 Chevrolet Equinox ushers in the era of the nine-speed automatic for GM, expect the 2017 Chevrolet Malibu to come soon after, likely on the sedan’s Premier trim.
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The other nine speed transmission (M3E) is already at dealerships in the Premier (2LZ) Malibu. It’s paired with the 2.0L (LTG) which recommends using premium gas, but doesn’t require it…
What is the difference between the ZF version and the GM version?
Wonder why they didn’t use a 10 speed for FWD too?
Most front wheel driven cars don’t probably don’t have have torque spread to pull through gear spreads of 7-8:1. The 4-cyl Jeep Cherokee won’t hit 9th until you’re going 75mph or more, and then you have to be going downhill.
Sean,
My 2017 Malibu Premier already has the 9 Speed. All the magazine articles and websites I’ve seen published fail to mention this. Please mention this. 2018 is two years down the road!
The 2018 model year is less than a year away.
A 2018 vehicle can be sold on January 2 2017.
October 1st of 2017 is the start of the 2018 model year.
The point is… The Malibu is out now and it has the transmission in it now and there is no mention of it!