What is a Sequential Gearbox, & How Does It Work?

High-performance race cars have unique gearboxes that enable them to pick up quickly and is called sequential gearbox. This kind of gearbox is similar to the manual gearbox with some slightly different features and functionality. This guide will teach you what a sequential gearbox is and how it works.

What is a Sequential Gearbox?

Have you ever ridden a motorcycle? In a motorcycle, you shift gears by slightly pressing the gear lever, either up or down, depending on the type of motorcycle. Slightly pressing up and down or clicking the gear lever is the fastest way of shifting gears. A sequential gearbox will let you change gears by clicking the gear level up or down. 

In a sequential gearbox, you will shift gears manually. Though there is an order you must follow, it does not allow you to skip gears like the manual gearbox. The gear selection is unique to the transmission type. You can either up or downshift.

How a Sequential Transmission Works

You understand how sequential transmission works better if you have a basic understanding of how manual transmission works. The five-speed manual transmission gearbox is popular in the automotive industry. 

You will realize that the manual transmission has three forks controlled by three rods. On the outer part, you will see a gear shifter lever connected to the three rods. It is the gear lever that engages the three rods whenever you shift. 

When you look at the shift rod from the top, you will tell what the gears look like in neutral, reverse, first, and second gear. From this is an ‘H’ pattern that enables you to shift smoothly between the control rods of the three forks. You can thus move the rod freely back and forth.

The sequential gearbox works similarly. It has gear selector forks moving the collars to engage and disengage the gears. The difference comes in the manipulation of the control rods. Instead of the ‘H’ pattern, it has a different motion.

In race cars, you can shift the lever by pushing it forward or pulling it backwards and Up or down. Pushing the shifter forward lets you move to a higher gear, for example, from 2 to 3. If you want to drop the gears from 3 to 2, you only need to pull the gear lever backwards.

The formula One car has two paddles on both sides of the steering wheel. The left paddle shifts up while the right pedal shifts downwards. A motorcycle has only a single shifter that you can pull or push to change gears. The difference is that you will do everything with your foot. 

The up and down or pull and push motion aims to rotate the ratcheting drum. Moving the lever increases the rate at which the drum rotates. The rotation initiates the rods to move as per the grooves in the drum as you change the gears.

Conclusion

The working principle of a sequential gearbox is almost similar to the manual gearbox. In both, you will shift the gears by touching the shifter. The difference is that you can skip the gears in the manual gearbox, but this is impossible in a sequential gearbox. You have to move from one gear to another. Such a sequence is the origin of the name sequential.