“The basic concept of the transmission is to take the power generated from the engine and convert it into kinetic energy to move your vehicle forward. To do so, the automatic transmission needs a torque converter and planetary gearset.”
To understand the basic workings of the transmission, you need to know what torque is. Torque is a twisting force or a rotational force. Imagine you are using a wrench to tighten a bolt. The rotational force you are giving to the wrench is torque, making the wrench to move in a circle. When we are operating a vehicle, we will need torque as our engine has a very narrow range of RPM(Revolutions Per Minute). With that limited range, we would have had only one or two speeds, which would make our driving very dangerous and messy. So, to have a wider range of speeds, the transmission shifts it to a different torque or speed depending on your driving condition. For instance, if you depress a pedal to stop, you are trying to counteract the rotational force of the engine to hold the wheels still, and that's when torque is required. By shifting gears on the transmission that are connected to a selector mechanism, you can adjust torque and speed, and continue moving at the proper speed.
Torque converter and planetary gear sets are the two main components of the transmission system. A torque converter is a fluid coupling, sandwiched between the engine and the transmission. To convert torque, a special component called stator is used. The stator's almost 90 degrees curved blades allow the torque multiplication to happen as the transmission fluid flows through it. The planetary gearset is made up of the sun gear, the planet gear, and the ring gear which rotates together. By changing the input speed and holding and freeing the carrier, the planetary gearset provides low speed, high speed, and reverse.
By creating varied gear ratios, the transmission increases or reduces the power that it gets from the engine and transmits the energy through the output shaft and then the differential, which leads to the wheels. Once the output shaft gets the rotary motion, the power gets transferred to the differential. The differential will turn that rotary motion which is at 90° to the parallel motion to the wheels. In short, the automatic transmission converts the torque produced by the engine into the power that turns the wheels and controls RPM to create more torque through various gear combinations.
The transmission does not require as much maintenance as the engine but having it checked regularly will make your transmission sustain a little bit longer. Here are some tips for keeping your transmission in good condition.
1. Check your transmission fluid during engine oil check
Transmission fluid provides lubrication to the components of your transmission. If its level is low, it can cause overheat and wear out the parts. So, make sure you have sufficient transmission fluid during your engine oil check.
2. Avoid Extreme Conditions
If you tend to drive your car in extreme conditions, such as extreme heat, you need to check your automatic transmission fluid about every 30,000km(20,000 miles) or 24 months.
3. Maintain your Engine’s Cooling System
Your cooling system protects your transmission as well as your engine from overheat. So keeping your cooling system in good shape also helps mitigate the risks of the transmission become damaged by excessive heat.
4. Look for Leaks
Transmission fluid is usually pink or red-colored, and if you notice a similar liquid spilled on your driveway, have your car inspected by a mechanic and solve the leakage.
5. Make a complete stop before shifting gears
Whenever you shift your gears, make sure that your vehicle came to a stop first. If you suddenly change your gear without making a stop, the gearbox can be damaged.