If you own a car, there's a good chance that you've ever seen or used a drive belt tensioner. This little device is used to keep the drive belt from becoming too loose, and can sometimes be a required component of your car's engine system. Fortunately, many vehicles don't even require a tensioner! In fact, most models equipped with serpentine belts are able to use the belt without one. However, there are a few cases where a tensioner is a necessity.

In this guide, we'll examine the ins and outs of drive belt tensioners so that you'll know exactly what they're for and how to choose one that works best for your vehicle. We'll also take a look at the most common types of tensioners and explain what they do, how to choose the right one for you, and how to replace an old or broken one when the time comes.

So, let’s get started

What is drive belt tensioners

The simplest explanation is that a drive belt and tensioner keep the drive belt from slipping on the pulleys that it connects to. This slippage can cause damage to the belts themselves or the other components attached to them. Since keeping the drive belt properly tightened is important in order to keep other components working properly, a drive belt tensioner replacement is often used to help achieve that goal.

Let's take a look at a typical example of how it works. If you'd prefer not to do that, you can skip ahead to the next section, where we'll cover different types of tensioners and their uses in greater detail.

Let's say that the drive belt that drives your alternator has become worn or damaged in some way and is sagging slightly as a result. An improper tension would cause the belt to slip over the pulley like this...

but a proper tension would prevent it from doing so and allow the pulleys to spin freely instead. Here's how it would look after it's been properly tensioned...

As you can see, the tensioner helps keep the alternator running smoothly by maintaining the proper tension on the drive belt that connects to it. Without the added pressure of the tensioner, the drive belt would slip more easily and become damaged over time.

In some cases, however, a tensioner is not only optional but can actually be dangerous to your safety. Read on to learn more!

Do I need a drive belt tensioner?

Not all vehicles are equipped with Car belt tensioners; in fact, many cars and trucks on the road today are designed to function perfectly well without them. If you're not sure whether or not your vehicle has one installed, the easiest way to find out is to simply check the owner's manual that came with the car when you first bought it.

If the manual doesn't include any information about tensioners at all, it may be safe to assume that they're not necessary in your particular vehicle. Of course, that doesn't necessarily mean that you don't have to worry about them.