A car's transmission
is a complex and important part of the drivetrain that controls the transfer of power from the
internal combustion engine to the car's wheels. Essentially, it allows your car
to physically move. If you're an experienced driver, you may already know that
car transmissions come as manual or automatic transmissions - but what does a
car transmission do? Let's get into gear and learn the basics.
The Basics of Car
Transmissions
Simply put, your car's
transmission works with the engine to regulate the amount of torque (rotating force) that is transferred from the car's internal
combustion engine and
converted into physical movement through the car's wheels. The transmission is
perhaps one of the most critical components of your car. Without it, your
engine would not be able to utilize its power.
While the makeup of a
car's transmission system may differ slightly between automatic and manual
variants, both transmissions have gears, output shafts, and input shafts. Most
transmissions have five or six sets of gears and a reverse gear, connected by a
series of gear sets (which you could call a connecting belt).
Each gear has a
different gear ratio, which is best described as a girth. These ratios make one
gear spin faster than another, since smaller gears have to spin more to cover
the same distance as larger ones. When you accelerate, your transmission (or
you, manually) switches between these different gear ratios to change the
amount of power it has to transfer to your car.
What is the
function of the car transmission?
A car's transmission
maximizes the efficiency of an engine to reduce its fuel consumption while
ensuring that power is generated and transferred effectively.
When you first step on
the accelerator, such as after waiting at a stop sign, your car's transmission
uses a lower gear ratio, which transfers enough torque at a lower speed (RPM)
to accelerate efficiently. When you need to reach a higher top speed, such as
on a highway, your transmission uses a gear with a higher gear ratio to propel
your car at a higher speed while keeping the engine speed as low as possible.
Manual transmission
vs. automatic transmission
As we have learned,
car transmissions come in either manual or automatic . Automatic transmissions tend to be more
efficient because they use sensors that allow the transmission system to change
gears more efficiently. Automatic transmissions are common in modern cars in
the US and their main difference is that manual transmissions require you to
use a clutch, whereas an automatic transmission only requires you to use the
accelerator pedal while driving. With an automatic transmission, your car's
transmission automatically changes gears mechanically as your driving conditions
change.
Where is the
transmission in a car?
Your car's
transmission is almost always mounted directly to your car's engine, allowing
the connected belt and gear system to convert combustion power directly from
the source.
In a manual
transmission car, the gear lever you use to change gears is probably located
between the driver and passenger seats (or sometimes on the steering wheel).
The clutch pedal, which you also use, is most likely located to the left of
your brake pedal.
How does a car
transmission work?
Your car's
transmission is a manual transmission and essentially works the same whether
your car has a manual or automatic transmission. However, there is one small
difference that you may want to be aware of, especially if you ever have to
drive a car with an unfamiliar transmission.
manual transmission
When using a manual
transmission, you as the driver must use a gear lever and a clutch pedal.
Operating a manual transmission car is different and may take some practice to
get the hang of. Here's what that process looks like:
- While driving, you use a gearshift lever
(the physical “stick” usually located between the driver and passenger
seats or behind the steering wheel) and a clutch pedal to change between
gears.
- To change gear, you press the clutch pedal
firmly, which disconnects the engine from the input shaft. Then you
physically operate the gear lever to disengage the gear your car is
currently in. This moves the gears on the input shaft, disconnecting the
transmission of power between the transmission and the engine.
- While still depressing the clutch pedal,
move the gear lever, select the new gear, and then release the clutch.
This restores the transmission of power between the input shaft and the
engine, sending the power back to your wheels.
automatic
transmission
With an automatic
transmission, you don't have to physically shift your car between gears like
you would with a manual transmission. Typically, this type of transmission
system also doesn't have a clutch pedal - instead, onboard sensors and
processors can be used to change gears as you change speed.
Maintenance of your
car transmission
Because of the
critical role a car's transmission plays in your car's performance, it can be a
particularly important component to maintain. Without a healthy transmission,
your engine can be put under excessive strain, which can lead to wear and tear
and eventual failure. Following a regular maintenance schedule is probably the best way to extend the life of
a car transmission.
In summary
Your car's
transmission can be simply understood as the mechanical system that controls
how much power from the torque is transferred from your car's engine to the
wheels. It can be a particularly important component to maintain, as its job is
to maximize your engine's fuel efficiency and prevent it from overloading
itself. And while manual and automatic transmissions perform the same function,
manual transmissions require you to manually shift gears while driving, which
can come with a learning curve.