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vs. Automatic Transmission: Which is Better
he name says it all. Manual transmissions are
the ones that you shift from one gear to the next. Automatics shift
themselves, based on a series of engine load and vehicle speed
signals. All you do is
put them in drive.
The transmission is a
series of gears, meshed to provide a patch for the power to travel.
By moving the shifter, the slider locks one of the gear sets to the
output shaft, providing a specific path for power flow.
Each gear set provides a different gear ratio, so by shifting
through the gears, you can choose which gear range suits the driving
transmissions also provide different gearing, but they use oil
pressure to apply individual clutch packs or bands inside the
transmission to create the various gear ranges.
By applying a clutch pack or bans, the clutches grab onto one
of the gear train components, which either holds or turns that
combination of holding and turning enables the gear set to create
different gear ratios within the transmission.
really makes the automatic transmission different is that it shifts
measuring engine load and road speed electronically, a computer
system controls transmission operation.
The computer decides when the transmission should shift and
then delivers an electrical signal to create the shift.
The transmission still uses oil pressure to control the
clutches, but now the computer regulates which clutches apply and
difference between automatic and manual transmission is how they
transfer power from the engine.
Manual transmissions use a clutch; automatics use a fluid
coupling called a torque converter.
torque converter is an oil-filled device that uses oil flow to
transfer power. An
impeller mounted to the crankshaft sling the oil into a turbine,
which connected to the transmission input shaft.
This oil movement transfers the motion from the crankshaft to
the input shaft without the two being connected mechanically.
That’s why you can come to a complete stop in a car with an
automatic transmission, without having to press a clutch pedal. There’s no mechanical connection that has to separate.
the oil gets through the turbine, it’s redirected through another
set of fins called a stator. The
stator prevents the “used” oil from dragging against the torque
converter, so it increases the torque converters’ efficiency.
very efficient, there is some power loss through the torque converter.
What's more, during normal operation, torque converters create a lot
of heat. To eliminate that heat and pick up a little extra
efficiency, most manufacturers now add a torque converter clutch to
the converter. This clutch applies once the car is cruising down the
road to create a direct mechanical connection between the engine and
transmission, eliminating the slip and reducing operating
most cars use one of these types of transmissions, there are a few
less-common types. Some early vehicles used semi-automatic transmissions,
which still required manual shifting but didn't have a clutch pedal.
Some of these transmissions were based on a manual transmission,
using vacuum and electric controls to operate the clutch. Others
were closer to automatics, but without the governor to force the
CVT, or continuously variable transmission, uses a special belt that
runs between two pulleys to transmit power between the engine and
the wheels. As the power and speed requirements change, the pulleys
change in width, which alters how deeply the belt rides in them.
This changes the effective radius of the pulley, which varies the
whether you buy a car with a manual or automatic transmission is
really a matter of preference – there’s no good choice or bad
choice. It won’t be
long before we won’t have to worry about transmissions at all.
Some of the new electric or hybrid gas/electric cars don't use any
transmission at all. The primary motor on these cars is electric,
and it operates under a much wider range of speeds, so a
transmission isn't necessary!
Car's Mechanical Condition
Easy Steps to Make Your Clutch Last Longer -some of these
may surprise you.
is a Differential? -During a turn, the outer wheels drive
farther than the inner wheels, and this is an important function of
with Transmission Problems -learn about some common
transmission problems for manual and automatic transmissions.
the Suspension and Steering -relatively dependable and
trouble-free; however, there are a few things you should do to keep
both in good working order.
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