The Gearbox – every car has one, every driver knows how to use one but not all car owners know how they work. We don’t need to know the intricate details of how our cars work, but basic knowledge is invaluable, especially if things start to go wrong.
Here is a quick guide to the inner workings of the gearbox.
What is it?
In short, the gearbox is part of the transmission system, which ensures the vehicle doesn’t exceed the maximum revs per minute (RPM) and explode.
Like most drivers, we’re sure there has been a time when you are driving along and you forget to shift, or you miss the gear and the car makes a horrendous sound like its struggling – that indicates you’re close to the “red line”.
Alongside this, the gears also help to ensure the car is driving at optimum performance. Imagine riding a bike – you shift gears to make the ride easier going from smaller gears to larger and therefore managing how hard and fast you’re peddling, this is exactly what happens in a car, you’re shifting to larger gears as you speed up to decrease the pressure on the engine and optimise the performance of the engine.
How does it work?
Let’s start with the part you actually see – the gear stick.
The purpose of the gear stick is for the driver to select the correct gear. The standard manual engine in the UK comes with 6 gears – neutral, first, second, third, fourth, fifth and reverse. You always start in first gear, and work your way up, just like the bike.
Inside the gearbox there are three shafts, these are all connected to the gear stick through what is known as “selector rods”, the selector rods lie parallel to the shafts carrying the gears and connect the gear stick to the main shaft.
The main shaft is where all the gears are located and is connected to the selector rods – the selector rods have a forked end when you select the gear on the gear to stick the selector rods will engage with the main shaft by using that fork.
The main shaft is powered by the layshaft, the purpose of the layshaft is to allow the gears to move freely until the main shaft engages.
The input shaft is powered by the engine and gives the layshaft the power to rotate the gears.
When you use the reverse gear, the selector rods engage what is known as an “idler gear” which causes the main shaft to reverse direction.