DAS Demo
You may have heard other drivers or your mechanic refer to your car's transmission, but how much do you know about this crucial system fitted to your car? It may only be something you've had to discuss because something has gone wrong, in which case you're all too aware of the cost of having one repaired or replaced.
The transmission is the entire assembly that sits behind the flywheel and the clutch. Europeans call it a gearbox, but technically that's just one part of the system. In short, your car's transmission is what enables the engine to output at varying speeds, and is therefore intrinsically linked to your performance driving experience.
The main crank in your car's engine is driven by a series of pistons, which turn it at a certain number of revolutions per minute (rpm). According to the car and your speed, the engine can turn at anything below its redline, usually between 5500 and 7000 rpm in typical engines. Connecting the wheels to the end of the crank simply wouldn't work, as the speed of the crank is too variable and can go too high. As such, you need a system that manages the revolutions of the crank so they're maintained at a usable level for driving. This is what the transmission does.
In your car's transmission, gears are used to manage this process. The gears are just simple toothed wheels or cogs which turn together to reduce or increase the number of revolutions that the crank makes. This process is generally known as gearing up or down. If the input gear has to spin half a revolution to drive the output gear once, then the car is gearing up. If the reverse is the case, the car is gearing down. Meshing many of these gears together in different sizes creates a mechanical system that can gear up and down very quickly.
The layshaft in your transmission is connected to the clutch. This is the input shaft, and when the clutch is engaged, this is always turning. The gears on the layshaft will spin around the output shaft without turning it until the gear stick is moved. When the gear stick moves, selector forks and gears on the output shaft are engaged, changing the way in which the two shafts interact with one another. As different gears are engaged, different gears on the layshaft are engaged with others on the output shaft, effectively controlling the rpm of the crank.
If the clutch is let out too soon, the gearbox attempts to engage the gears at the same time as trying to drive the car. This causes a “grinding” noise, which is the sound of the gears on the layshaft skipping across those on the output shaft and failing to engage properly.
On modern cars, it's very common to have an automatic transmission, which manages this process without having to manually engage the car. A manual transmission is generally regarded as more responsive and is therefore favored by many drivers of performance cars.
The transmission plays an intrinsic part in the process of driving your car. It ensures you can reach a desired speed quickly and safely, protecting the car's engine throughout the process, but it remains a relatively sensitive system and is prone to damage. As such, a regular maintenance schedule is highly recommended. This can only be undertaken by a fully trained mechanic, so if you have any questions about your transmission and any maintenance that's required, consult our service department for advice.
