So that a car can move quickly from the stand still, it uses a transmission system. Its job is to provide high tractive force to the wheels in lower gears. The same transmission system has higher gears that move the car at high speeds at relatively low engine RPMs. The article answers most commonly asked questions related to manual transmission.
1. What is the function of a transmission?
The basic function of the transmission system is to control the torque and speed that’s sent forward to the wheels from the engine. So in effect, its purpose is to provide a level of flexibility to you and make engine’s power & torque more useable.
2. What are the different components of a Manual Transmission and what do they do?
The most common type of manual transmission consists of a gear stick, shift rods (also known as 'shift rail') & shift fork, input shaft (coming from the engine), output shaft, lay shaft (counter shaft), synchroniser mechanism with dog clutch, and a clutch assembly that links the engine to the transmission. The engine is connected to the transmission system using a clutch plate. To be exact, it’s the gear on the input shaft from the engine that is actually in mesh with a lay shaft gear of the transmission system, and the flywheel bolted to the crank of the engine connects to the clutch on the other side of the input shaft. The lay shaft carries different gears which are in constant mesh with the gears of the output shaft, the input gear is in constant mesh with the gear of the lay shaft. The shift forks on the shift rods are used to engage different gears using the gear stick, the engagement happens with the use of synchronisers and dog clutch. So, in simpler terms, the power from the engine is transmitted via layshaft and output shaft to the differential. And the clutch is used to engage or disengage the engine when needed.
3. What happens in the background when a gear lever is used to engage different gears through the H Gate?
The different gears present on the output shaft are actually mounted on bearings and engaged with the output shaft via synchroniser cones and dog clutch. So, when you move the gear lever to engage different gears, a synchroniser cone first comes in contact with the gear and matches the speed using friction, subsequently the dog teeths are engaged to gear for the drive. After the clutch is released, the engine is connected to the transmission and it starts driving the car.
4. What happens when a Clutch pedal is pressed?
When the clutch pedal is pressed, the engine is disconnected from the transmission system. It is done so that the engagement between gears is smooth. When the engine is disconnected from the transmission, the synchronisers can connect the hub and gear smoothly.
5. What can I do to avoid clutch wear?
Partially engaging the clutch is biggest cause for clutch wear. Ideally, the clutch should either be fully engaged or disengaged. To avoid clutch wear do not hold it close to the bite point. Rather than making a gear change every time you see an obstacle on the road, it’s better to drive with a moderate speed if you are on a rather busy road, making more gear changes directly increases clutch wear.
Not using the gearbox for slowing will also prevent clutch wear, therefore, you should avoid dropping a gear until the car’s speed is reduced and you should do that with brakes instead.
6. How is a reverse gear achieved?
The reverse gear is achieved by using an idle gear. The idle gear between the two other gears reverses the direction of motion and that’s how reverse is achieved. You must know that there’s no synchroniser mechanism in case of reverse gear and therefore you would hear a gear grinding noise if you try and engage it without stopping the car and while it’s moving in the forward direction.