Inside your Manual Transmission

Are you someone who proudly claims to be a manual transmission driver? In a time where more automatic cars are being produced and electric cars seem to be the future, knowing how to drive stick is slowly becoming a rare skill among today’s Aussies. That said, manual vehicles have been part of the auto world since the beginning, but do you really know how it all works? We’re here to break it down as we deep dive inside the workings of a manual transmission - you know, for old time’s sake.

What is a manual transmission?

The most important thing to know about manual transmission is that it enables the driver to choose between up to six different gears (depending on the car). Using a gear box, the driver can switch between lower gear ratios - which offer more torque, less speed, or higher gear ratios - which offer less torque, higher speed. Essentially this puts the driver in complete control over how much power and speed the car uses and when.

Now that seems pretty straight forward, but how do these gears actually change beyond shifting a gear stick in various formations? What we can’t see sitting below the gearbox is an intricate mechanism involving a clutch and various interconnected shafts:

Mounted on the output shaft and constantly interconnected to the countershaft are the “gears”. The amount of torque (or power) that is produced depends on which gears are engaged.

How does a clutch work?

The clutch is positioned between the engine and the gearbox. It’s purpose is to dissociate the engine from the transmission to allow the gears to change more smoothly. When you step on the clutch pedal, it disconnects the power flow between the engine and gearbox. This then allows the engine to continue running, even while the rest of the car isn’t getting any power. Once the engine is disconnected from the transmission, you can easily change gears. When you then let go of the clutch, power is restored to the engine, only now in a different gear.

Putting it all together

1. To begin, you must disengage the clutch to disconnect the power between the engine’s input shaft and transmission. This enables the engine to continue running without providing power to the rest of the car.

2. Now with the clutch disengaged, you can use the gear stick to move the car into first gear, causing the shifting fork to move towards the first gear that is mounted to the output shaft.

3. This first gear on the output shaft is connected to another gear that is mounted on the countershaft; which connects to the engine’s input shaft via a gear, spinning at the same speed as the input shaft.

4. Attached to the shifting fork is what we call a synchroniser collar. This does two things at the same time: 1) firmly mounting the driving gear to the output shaft so that the gear can provide power to the output shaft; 2) enables the gears to match the speed of the output shaft.

5. With the synchroniser collar interconnected with the first gear, the gear is firmly attached to the engine's output shaft. You can then re-engage the clutch enabling the vehicle to be in gear, re-connecting this power to the engine.

To then move to the next gear, you disengage the clutch again, moving the gear stick into second, causing the same chain reaction of moving parts to the next gears; so on and so forth.

What is riding the clutch?

Riding the clutch is when the driver keeps their foot on the clutch pedal while driving. This means the clutch remains partially disengaged. It can happen to anyone and is quite a common occurrence for learner drivers. However, riding the clutch too often will cause premature wear and tear on the clutch system, so it is recommended to avoid as much as possible to prevent the component from failing.

The importance of clutch fluid

Clutch fluid is an important part in the clutch mechanism. Clutch fluid is found in what is called the ‘clutch master cylinder’ and when you disengage the clutch, this fluid moves to an area called the ‘slave cylinder’ which is located within the clutch.

This transfer of fluid creates pressure that helps to engage and disengage the clutch. This is because it is too heavy to move on its own. Once you release the clutch pedal, the clutch fluid moves back to the clutch master cylinder until it is needed again.

If the master cylinder has a leak or not enough clutch fluid, there won’t be enough pressure to disengage and engage the clutch, meaning you won’t be able to change gears. It’s therefore important to keep an eye on your clutch fluid levels. Please also note that clutch fluid is different to manual transmission fluid, which is used to keep the gearbox lubricated for smoother transitions.

What it means to have dual clutch

Dual clutch transmission cars are best described as a combination of manual transmission and automatic transmission. They use two clutches, however there is no clutch pedal to disengage the clutch manually. Instead, hydraulics are used to control the clutches (as so with a standard automatic transmission).

Both clutches operate interdependently: one clutch operating the even gears (2, 4 and 6); the other operating the odd gears (1, 3, 5 and reverse). Using this dual mechanism, gears can manually be changed without interrupting the power flow from the engine to the transmission.

Is your manual transmission humming on the right gears? Perhaps you need some more clutch fluid, or you've been riding the clutch a bit too often? No matter the issue mycar is here to help with any clutch and transmission repairs. Contact us on 13 13 28 or find us at your nearest mycar location today.