koshervorti.blogg.se - Automatic transmission

#Automatic transmission drivers#
#Automatic transmission manual#
#Automatic transmission full#
#Automatic transmission series#

Other cars use a vacuum modulator to apply pressure to the throttle valve. The further the gas pedal is pressed, the more pressure is put on the throttle valve. Some cars have a simple cable linkage connected to a throttle valve in the transmission. There are two different ways that this is done. To shift properly, the automatic transmission has to know how hard the engine is working. First, we'll discuss the key components of the hydraulic system then we'll see how they work together. Passageways molded into the metal are an efficient way to route fluid without them, many hoses would be needed to connect the various parts of the transmission. The passageways you can see route fluid to all the different components in the transmission. It is really the brain of the automatic transmission, managing all of these functions and more. You've probably seen something that looks like this before.

If you put the transmission in second gear, it will never downshift or upshift out of second, even from a complete stop, unless you move the shift lever.

If the car is going too fast, it will wait until the car slows down and then downshift.

If you move the shift selector to a lower gear, the transmission will downshift unless the car is going too fast for that gear.

If you floor the gas pedal, the transmission will downshift to the next lower gear.

#Automatic transmission full#

If you accelerate gently, shifts will occur at lower speeds than if you accelerate at full throttle.

If the car is in overdrive (on a four-speed transmission), the transmission will automatically select the gear based on vehicle speed and throttle pedal position.

They are actuated by hydraulic cylinders inside the case of the transmission. The bands in a transmission are, literally, steel bands that wrap around sections of the gear train and connect to the housing. In this transmission there are two bands.

#Automatic transmission series#

Each gear shift triggers a series of events like these, with different clutches and bands engaging and disengaging. The big sun gear is held to the housing by a band so that it could not rotate. The small sun gets disconnected from the turbine by a clutch so that it can freewheel. The planet carrier gets connected to the torque converter housing by a clutch. To get the transmission into overdrive, lots of things have to be connected and disconnected by clutches and bands. Nothing is connected to the turbine the only input comes from the converter housing. The small sun gear freewheels, and the larger sun gear is held by the overdrive band. In this transmission, when overdrive is engaged, a shaft that is attached to the housing of the torque converter (which is bolted to the flywheel of the engine) is connected by clutch to the planet carrier. For instance, when we discussed overdrive, we said: In the last section, we discussed how each of the gear ratios is created by the transmission. Let's take a look at how the planetary gearset works.

The planetary gearset is the device that makes this possible in an automatic transmission.

#Automatic transmission manual#

The key difference between a manual and an automatic transmission is that the manual transmission locks and unlocks different sets of gears to the output shaft to achieve the various gear ratios, while in an automatic transmission, the same set of gears produces all of the different gear ratios.

#Automatic transmission drivers#

In order to protect the transmission from serious damage, drivers who tow should buy vehicles equipped with transmission coolers. When towing or hauling heavy objects, your vehicle's transmission can get hot enough to burn up the transmission fluid. So the transmission uses gears to make more effective use of the engine's torque, and to keep the engine operating at an appropriate speed. A car like this would wear out very quickly and would be nearly undriveable. If you did, you'd quickly find out that you had almost no acceleration when starting out, and at high speeds, the engine would be screaming along near the red-line. You've probably never tried driving a manual transmission car using only third gear.