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Transmission Spotlight: 6L80E/6L90E


Here is a six-speed automatic transmission that has been developed by General Motors. Both the 6L80E and 6L90E models are designed for all-wheel-drive vehicles that are rear biased and have a longitudinal powertrain orientation. Both transmissions are meant to conserve fuel, and each is controlled via a six-speed automatic transmission that is a quality successor to the SL family of transmissions.


6L80E/6L90E Transmission Overview

The Hydra-Matic transmission has a modular design, and it shares some components that allow it to accommodate varying torque levels, engines, and applications. Each of the versions that have been developed has a unique gear set that is configured to allow for a wide range of ratios when compared to a more conventional type of gear set inherent with many automatic transmissions today. This enables the transmission itself to allow for great fuel savings, while at the same time permitting the vehicle to accelerate nicely.

General Motors decided on a modular concept for these transmissions in order to allow for common components to be able to be used interchangeably, thereby allowing for tools to be used during the manufacturing stage that allows for four variants within the six-speed family of transmissions. All of the versions on the market today use three gear sets. This includes one gear set that is a simple input planetary design, while two are output gear sets.

Some of the applications do allow for Performance Algorithm Shifting. This type of shifting can sense how assertively a driver is using the output of the engine in order to make a determination as to whether or not an upshift or downshift is necessary based on the engine speed. There is also a Driver Shift Control that will permit the driver to actually shift the transmission, similar to that of a gearbox that is clutches and manual. There are electronic safeguards built into to keep the driver from over-revving the engine in the event that the incorrect gear is selected by accident.

One other interesting component with these transmissions is the Advanced Control System. This is what allows the temperature to stay constant in comparison to a module that is mounted on the body. Since the transmission and the module are actually assembled at the same time and together, there are not any additional steps required during the assembly process for the vehicle.


6L80E vs. 6L90E

When comparing the two transmissions, it is important to keep in mind that the 6L90 is more heavy duty than the 6L80, even though both are six-speed automatic versions. The former also comes with a stronger input gear set. This has two more pinion gears, which gives it six in total. The output gear set on the 6L90 is also wider than the 6L80, giving it more flexibility. The 6L90 also has one more clutch plate that can match up with the requirements of certain applications when necessary.

It is interesting to note that the 6L90E transmission does share roughly 75 percent of the same parts as that of the 6L80E transmission. The case on the 6L90 is a bit longer, and it can make use of more fasteners for the transmission and the corresponding transfer case. This tends to lead to better drive performance and less noise and vibration.

Which transmission you end up choosing depends on your vehicle and your unique needs. If you need a bit more power, you might look at going with the 6L90E transmission. If that is not something you are after, the 6L80E transmission will likely suit you just fine. Both are built for performance, and they will each give the driver the power they need to excel on both long and short journeys.