A car transmission is one of the most important components of a vehicle. It’s what moves the power from the engine to the wheels.
There are a variety of car transmissions. Some are automatic, while manual transmissions in stick-shift cars require the driver to complete extra steps for the vehicle to operate effectively. Where is a transmission in a car located? Typically, a transmission is mounted onto the chassis of a vehicle in the front.
If you’ve wondered about how a transmission works, the process varies depending on the type of transmission. Whatever type of transmission it is, the answer to what does a transmission do is to enable the gear ratio between the drive wheels and engine to adjust as the car slows down and speeds up.
When a vehicle is stopped, the transmission disconnects the engine from the drive wheels so that the engine can keep idling when the wheels aren’t in motion. Transmissions also enable quick acceleration from a stop and enable the engine to run more slowly to cut down on wear while the vehicle is driving at consistent speeds.
What is Transmission in a Car?
A car transmission is the gearbox of a vehicle. It’s roughly analogous to the gear shifter and chain system that bicycles use.
These components are always mounted directly on the engine to allow the attached belt and gear system to effectively convert the combustion power generated by the engine into physical momentum.
Remember how a car engine works:
- Fuel (gasoline) is ignited in the combustion chamber of your vehicle’s engine.
- When the fuel ignites, the expanding gas and heat from the miniature explosion pushes a series of pistons into your engine’s cylinders.
- When the pistons are pushed, they move up and down, turning your engine’s crankshaft.
- The crankshaft then turns the drive wheels of your car. This mechanism converts explosive energy into mechanical energy.
So, where does transmission come into play? Without a transmission, the explosive power of a typical car’s internal combustion engine would simply be too high for starting or stopping your car or when you need to drive relatively slowly.
A typical car transmission consists of five to six sets of gears and a series of gear trains (essentially belts or chains running around the outside of two or more gears) — which allow a driver to control how much power is delivered to the car without changing how fast the engine is running.
Put another way, a car transmission helps ensure your engine is turning at the correct speed without overspeeding or under speeding for your needs. It also ensures your wheels are getting the right amount of power. Without a transmission, any car would be difficult to start and stop and totally unreliable.
A transmission changes gears depending on car speed and how far down you push the pedal of your car so that the engine’s RPM or “revolutions per minute” are kept appropriately low.
Transmission Diagram
What does a transmission do?
A car transmission is one of the most important components of a vehicle. It’s what moves the power from the engine to the wheels.
There are a variety of car transmissions. Some are automatic, while manual transmissions in stick-shift cars require the driver to complete extra steps for the vehicle to operate effectively. Where is a transmission in a car located? Typically, a transmission is mounted onto the chassis of a vehicle in the front.
If you’ve wondered about how a transmission works, the process varies depending on the type of transmission. Whatever type of transmission it is, the answer to what does a transmission does is to enable the gear ratio between the drive wheels and engine to adjust as the car slows down and speeds up.
When a vehicle is stopped, the transmission disconnects the engine from the drive wheels so that the engine can keep idling when the wheels aren’t in motion. Transmissions also enable quick acceleration from a stop and enable the engine to run more slowly to cut down on wear while the vehicle is driving at consistent speeds.
How does a transmission work?
The transmission works by transmitting the power that comes from the engine to the wheels along the driveshaft and axle allowing you to drive the car. It does all of this by using gears and gear ratios that are selected either automatically or manually by the driver.
Regardless of the type of transmission, the basic principles are the same. The engine produces power, which is then transmitted to the transmission. Inside the transmission, there are a series of gears that control the speed and torque of the wheels.
The gears in a transmission are arranged in a series of concentric shafts. Each shaft has several gears that are mounted on it, and these gears can be engaged or disengaged by the driver or the car’s computer. The gears on one shaft can mesh with the gears on another shaft, which allows the transmission to change the speed and torque of the wheels.
Automatic transmissions are by far the most common transmissions in cars today. They use a fluid coupling called a torque converter instead of a clutch to transfer power from the engine to the transmission. The torque converter allows the engine to continue running while the car is stopped, and it also provides a smoother ride by allowing the engine to operate at lower RPMs.
In an automatic transmission, the car’s computer uses a series of sensors to determine the optimal gear ratio for the current driving conditions. The computer can shift gears automatically, which allows the driver to focus on steering and braking.
How Does a Manual Transmission Work?
Manual transmissions have a clutch pedal and a shifter the driver uses to manually change gears. These types of transmissions consist of a set of gears along a pair of shafts, called the input and output shafts.
How does a manual transmission work? With a manual transmission, the driver has to select the proper gear and engage or disengage the clutch. The transmission uses a flywheel, pressure plate and clutch to engage and disengage the engine from the transmission.
The flywheel and pressure plate are connected to the engine. The clutch is sandwiched between them and is splined to the transmission input shaft. The term “push in the clutch” means to release the pressure plate, which disengages the clutch from the engine. Every time you make a shift, you have to push in the clutch first.
How Does An Automatic Transmission Work?
The main automatic vs. manual transmission difference is that with an automatic transmission, the process that powers a manual transmission happens within the transmission itself. Automatic transmissions typically don’t use clutches. Instead, the automatic transmission relies on a torque converter to change gears.
The first automatic transmission, which was more like a semi-automatic transmission because it still had a clutch, has been around in some form since the early 1900s. The first true automatic transmission used in a production car was the Hydro-Matic, in a 1939 Oldsmobile for the 1940 model year. The inventor was Earl Avery Thompson.
Most large SUVs and trucks have traditional automatic transmissions.
Types of car Transmissions
Cars are continuously evolving, improving, and becoming more efficient. That goes for the transmission as well.
There are four Types of Transmissions:
- Manual transmission.
- Automatic transmission.
- Continuously variable transmission (CVT)
- Semi-automatic and dual-clutch transmissions.
#1. Manual Transmission.
If you want to be more connected to your car then manual transmission is the way to go. In a manual transmission car, the driver uses a clutch pedal and a gear stick situated on the floor between the front seats or on the centre console, to put the vehicle in the right gear.
Driving a manual transmission is a skill that needs to be learnt and practiced to understand how to get the most efficiency, power and acceleration from the car. Among transmission types, manual transmissions are the most fuel-efficient. This, however, depends on the driving style as aggressive gear usage will give you the lowest mileage.
MORE: What is Manual Transmission?
#2. Automatic Transmission.
This transmission uses a torque converter, planetary gearset, and clutches to automatically shift through the vehicle’s gears. Though some allow the driver expanded control over the process, you are mostly stuck with neutral, drive, and reverse modes.
To operate an automatic transmission, all you have to do is choose from the familiar P-R-N-D-L choices on the shift knob. Automatic transmissions simplify the process and allow inexperienced drivers to get the hang of the basics quickly.
However, the mechanical complexity plays a significant disadvantage. Whenever your auto stick breaks, the repairs can be very costly. Plus, you have less control over speed and RPMs, potentially impacting your fuel economy.
MORE: What is Automatic Transmission?
#3. Continuously Variable Transmission (CVT).
Continuously variable transmissions, or CVTs, function the same as an automatic transmission with one significant difference – there are no gears, instead operating through the use of belts and pulleys. Sensors are equipped with the transmission that feeds information to an onboard computer, adjusting the ratio for the belts and pulleys.
Because this transmission heavily relies on the computer, your engine will always function optimally, providing significant fuel economy. You could even say that no other transmission type will beat it in terms of MPG.
You will experience no delays in shifting gears with CVTs, and whenever they break, they often require significantly less money and labor to repair than an automatic. The only drawback is subjective and brings us back to the driving authenticity argument.
MORE: What is CVT Transmission?
#4. Semi-automatic transmission.
Like the old trusty manual, semi-automatic employs a mechanical clutch to shift gears. The driver does not control the action of the clutch, and there’s no clutch pedal. Instead, the process is automated through electronic, pneumatic, and hydraulic controls. This allows you to automatically shift gears through buttons or paddles on the steering wheel.
Semi-automatic transmissions are typically installed in racing vehicles or high-end sports cars. While it is suitable for professionals, everyday drivers may not appreciate the high cost, maintenance, and frequent repairs.
Which Transmission is best?
The best transmission option comes down to a personal preference and what’s available.
- Manual transmissions are popular for driving enthusiasts and sports car owners.
- Automatic transmissions are a common choice for uncomplicated driving.
- CVT transmissions are excellent for fuel efficiency and smooth acceleration.
- DCT transmissions are popular for high-performance models and those who drive them.
Shop for the car you want, then get to know the transmission it has. And it’s a great idea to learn how to drive the different types, especially manual transmissions, as a life skill.
Is Driving Automatic or Manual Better?
There are perks to both! Let’s explore the benefits of both transmissions below:
| Automatic Transmission | Manual Transmission |
| 1. Good for beginners 2. Great in stop-and-go traffic 3. Allows less driver input 4. Widely available | 1. Feels like you’re in control while driving 2. Superior acceleration 3. Fuel efficient 4. Lower purchase price |
Most Common Car Transmission Problems
As one of the most expensive repairs to any vehicle, it’s pretty important to catch any issues early on. It’s natural for a transmission to experience wear and tear over time and proper maintenance can help with extending the life of a car transmission.
Here are some common signs there may be a problem with your car’s transmission:
- Transmission won’t engage or stay in gear.
- Shifts are delayed or missing gears.
- Transmission slipping or engine is revving high.
- Transmission fluid is leaking.
- If there’s a burning smell.
- If there is buzzing, clunking, humming noise.
- Car has no power.
- Check Engine Light or Over Drive Light is on.
- Gears are grinding when shifting.
- The clutch pedal grabs very low or very high.
Related Post: 7 Warning Signs Of A Bad Transmission
Is it OK to drive with a bad transmission?
Short answer: no! The only thing you should do if you think you have a faulty transmission is go for a quick jaunt to your local mechanic. If you have a bad transmission it’s only a matter of time before your vehicle literally won’t be able to drive anywhere.
Even if it is something as easy as running out of transmission fluid your car can be irreparably damaged. If you actually do run out of transmission fluid it’s like running out of your engine oil. You’ll damage your vehicle and have a very expensive bill when you get it replaced.