What is double clutching and how does it work?

Double clutching is a term that you may have heard of. Also known as double declutching, it’s a driving technique that’s involves the clutch being depressed twice while upshifting or downshifting.

You can only use this technique in cars that have a manual gearbox. Learn more about what you need to know about double clutching in our guide.

How does double clutching work?

Double clutching allows you to carry out smooth gear changes at any engine speed.

Before synchromesh gearboxes were first used in the late 1920’s by General Motors, double clutching was the only way you could change gears. Today, modern manual cars have synchromesh gears, consisting of a set of small gears inside the transmission which match the speed of the gearbox’s output shaft to the engine speed.

With double clutching, you disengage the engine from the gearbox twice, allowing the engine speed to match the speed of the next gear before engaging it. It reduces the speed difference between gears, thus allowing the synchronisers to match the gear and engine speeds, creating a smooth gear shift.

When would I need to double clutch?

While it’s not necessary to double clutch with a car that has a modern manual gearbox, you can use this driving technique in both older and newer cars.

When you are changing gears with a synchromesh manual gearbox, you are locking the gears to the input or output shaft. Therefore, allowing you to increase your car’s speed or to slow it down. However, the gears inside the gearbox can wear out over time, due to a combination of high mileage and age.

Double clutching can help reduce the amount of wear and tear on your gearbox as you’re not relying on the synchronisers to do all the gear shifts for you. It means that you can shift from one gear to another smoothly. If you start to hear a crunching or grinding noise when shifting between gears, then there are signs that the gearbox may need to be fixed or be booked in for a service.

How to double clutch

When it comes to how to double clutch, let’s assume that you are in fifth gear, driving at 50mph on a dual carriageway and want to change down a gear.

1. Depress the clutch.
2. Move the gear shift from fifth into neutral.
3. Let the clutch out.
4. Blip the throttle, increasing the revs slightly (also known as rev matching).
5. Depress the clutch again, go into fourth gear, then release the clutch.

It’s a similar process with double declutching, which involves shifting up the gears. Instead of blipping the throttle, you lower the engine revs slightly, in line with the rotation speed of the gearbox.

Double clutching is a driving technique that requires some practice but can increase the lifespan of your car.

Is double clutching useful?

Yes, double clutching can be a useful driving technique to use. Not only will it prevent transmission damage, but also extend the life of your gearbox.

When you are driving at high speed, matching the gearbox and engine speeds when downshifting can prevent the wheels from locking up. This is useful if you must come to an emergency stop or you’re navigating a slippery part of a motorway. Double clutching can also be used on track days too.

If your car has an old clutch and needs to be replaced, our car clutch repair and replacement service can ensure that your vehicle continues to run smoothly. To find out more about our clutch service, contact your nearest branch or get in touch with us today.