How does a truck transmission work?

Have you ever wondered what’s going on beneath the floor of a truck when the accelerator is pushed down?

Most people think of the engine as being at the heart of any vehicle. And while engines are useful for turning fuel into mechanical energy, it would be useless without the transmission. A truck transmission takes the engine’s rotating force, navigates through a complex gear mechanism and turns the drive wheels to get tonnes of cargo moving.

First, it’s important we lay out exactly what we are talking about.

Our friends in the United States talk about the transmission meaning the gearbox alone. But in the UK, the term tends to refer to the whole drivetrain – including the clutch, gearbox and driveshafts.

Ecodrive Transmissions work across the whole drivetrain, offering a range of services including on-site support, transmission and axle removal and refit and gearbox repairs and overhauls.

How does the transmission work?

The transmission may be the least understood part of any vehicle.

The most important part of the transmission is the clutch and gearbox. These components act as the gateway and interlocutor between the engine and the rest of the vehicle.

The gearbox adapts the output of the internal combustion engine by changing the gear ratio. Switching between smaller and larger gears stops the engine from overworking itself and helps keep the vehicle running and at optimum efficiency.

The clutch, meanwhile, engages and disengages the gearbox, meaning that the gears can change without being damaged.

On a classic ‘classic’ rear-wheel-drive transmission, the power is then transported down a rotating drive shaft before it meets differential, which redirects the power to turn the axles that the wheels are mounted on.

Every vehicle from an economy hatchback to four-wheel-drive SUVs and heavy goods vehicles all have a drive train, but all are slightly different.

Since the 1959 Mini pioneered the front-wheel-drive transaxle, mounting the small engine transversely – sideways – in line with the front wheels, most cars have adopted similar front-wheel drive configurations.

Most trucks and tractors, however, are still rear-wheel drive.

Most rigid trucks have either a 4×2 or 6×2 axle configuration, where the first number refers to the number of wheels and the second refers to the number that receive power.

Many larger tractor units have a 6×4 axle configuration, meaning that both rear axles are driven by the drive train.

To maintain the roadworthiness of these commercial vehicles, guidelines indicate that the transmission should be inspected every six weeks. But it may need inspecting more or less frequently depending on the condition of the vehicle. A full service is usually only necessary once each year.

For more information about Ecodrive’s transmission services, speak to a member of the team today. Call: 01204 701 812.