In today’s article, we will learn how it works, the different types that we find on the market and the importance of this key element for the accessory drive system.

How does a belt tensioner work?

As we have seen in previous articles, the auxiliary drive belt transmits rotational energy from the engine crankshaft to all engine accessories.

What happens is that, during the operation of the auxiliary drive system and as our vehicle’s engine speeds up and slows down, the belt can stretch or even lose some tension, hence the importance of the tensioner pulley within this system.

The aux drive tensioner or serpentine belt tensioner is, therefore, an element responsible for exerting a regulated amount of pressure/tension on the belt and thanks to this the belt can rotate all those pulleys as needed.

Potentially, its main function is to guarantee that the auxiliary belt has the optimum tension, although among its basic functions we also find:

• Maintain the correct and tight tension on the pulley by compensating for any possible loss of tension in the auxiliary belt.
• Maintain correct alignment with the rest of the accessory belt drive system.
• Avoid slipping and vibrations that cause premature wear of the elements and that avoid fatigue in the auxiliary belt.
  

Keep learning: Understanding the Drive Belt Tensioner

Main types of drive belt tensioners

As auxiliary drive belts with poly-V belts, tensioners have also been upgraded in recent years. The two most common types of tensioners in the auxiliary drive system are hydraulic tensioners and mechanical tensioners, the last one being able to be manual or automatic. Let’s see its characteristics below:

Mechanical Tensioner

This type of tensioner can be subdivided into manual tensioners, where the mechanic will be in charge of providing the correct prescribed tension manually, and automatic tensioners.

Automatic tensioner is the most common tensioner on the market. This tensioner is characterized by the fact that it adjusts itself according to the need of the moment and its working conditions.

It has a spring located inside with an oscillating arm that maintains pressure on the belt and moves always keeping the strap in place.

Hydraulic Tensioner (with hydraulic shock absorber)

In this case, the hydraulic tensioner is based on a hydraulic shock absorber that stands out for its high performance, exerting precise tension and dynamic behavior. It can operate with a larger range of dynamic belt lengths than mechanical tensioners. 

These tensioners have an arm and a roller at the ends, and it is through the hydraulic element with an integrated pressure spring that they achieve the necessary belt tension.

Belt tensioner failure signs

A damaged or faulty tensioner will directly affect the performance and functionality of the auxiliary drive belt and will cause the entire system early failure. In general, a tensioner that does not work as it should show some warning signs. Among the most common signs and causes are:

1. Squeaking noise or unusual noise when starting the engine or during operation when the steering is turned all the way to one side. If the tensioner is loose and not exerting pressure, aux belt can squeak.
2. Accessories failure. If any of the engine accessories such as the alternator, air conditioner compressor or power steering are disengaging, this may be caused by a bad or faulty tensioner.
3. Premature aux belt failure. If you notice unusual wear on the serpentine belt, such as frayed edges or cracks in the belt itself, this is due to a malfunction of the drive belt tensioner.

Keep learning: Top 5 causes of serpentine belt failure

Too often, when the auxiliary belt shows signs of aging and needs to be replaced, it is overlooked to inspect the well condition and function of the other elements, including the drive belt tensioner. This error can cause premature wear of the serpentine belt and a new replacement operation.

All components are subject to stresses and wear, so during the auxiliary belt replacement process, it is highly recommended replace all components at the same time. This ensures optimal operation and longer lasting performance.

Dolz Kits, the most competitive kits on the market

Industrias Dolz has a complete range of Auxiliary Drive Belt Kits, designed following the experience of original manufacturers such as Audi, Volkswagen, or Renault to guarantee the best engine performance and the greatest comfort.

These kits include all the necessary components for a professional repair, that is, all in one package: poly-V belt, tensioning rollers, inversion and all the necessary accessories depending on the vehicle application.

For further information on any of our product lines, commercial information, or technical product specifications (including replacement guidelines) you can contact us here.

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As this component of the vehicle works continuously when the engine is running, it is important to have access to a guaranteed auxiliary drive kit that offers optimal performance.

However, high temperatures, vibrations and the general wear and flexing over time all have an impact on the auxiliary drive belt, which translates into the need of a replacement and an aux belt installation.

In today’s article, learn how to perform an auxiliary belt installation and how to choose the right drive kit to ensure a longer lifespan.

Auxiliary drives: differences and types

The aux drive belt (as part of the whole auxiliary drive kit) is in charge of powering several key components in its periphery thanks to a pulley system, and that some are of vital importance such as the alternator.

There are two types of aux drive belt:

• Serpentine belt: shaped like an isosceles trapezoid in cross section, is characterized by being thinner and smaller and generally only drive one peripheral at a time.
• V-belt: also known as poly v, poly belt or poly vee belt, it represents the most efficient and long-lasting option today, as it solves slippage and alignments issues and presents less maintenance needs.

Related content: What does a car’s auxiliary drive belt do and why should you care?

Auxiliary drive kit replacement: step by step

The only way to know when it’s time to replace the auxiliary drive belt is to visually check its state of wear, not only of the drive belt but also of the other peripheral components. If the strap is worn, it will have cracks, fraying or irregularities of all kinds. Therefore, the periodic inspections of the auxiliary transmission belt represent a more than reliable method to make this decision, since its wear will depend, among other factors, on the use that is given to the vehicle and the temperatures that it works.

The auxiliary drive belt installation should then include the following steps:

1. 1. Disconnect the car battery to ensure safety during all operations. It’s also advisable to perform the aux belt installation when the engine is cold.
   2. While observing the current auxiliary drive belt kit, create a faithful representation of its routing and its configuration. Draw a sketch or take a picture of the routing. Also, look under the hood and around the engine compartment for the belt path and make sure you are familiar with the setup.
   3. In order to remove the auxiliary drive belt, you’ll first need to release the tension so that it can later slide off easily. Modern cars may use automatic tensioners that have a spring located inside with an oscillating arm that maintains pressure on the belt and moves always keeping the strap in place. If this is the case, use a crescent wrench or socket wrench to lock the tensioner into a retracted position. Other vehicles use tensioners or accessories that must be manually locked to provide the correct tension.
   4. Observe tensioners and pulleys to ensure they’re in good condition. Pulleys must be aligned, in order to avoid belt damage or noises, and automatic tools can be used for this.
   5. Jam nuts must be tight to the back of the bracket, ensuring a minimal torque.
   6. The new auxiliary drive kit must be installed following the configuration observed during step two. The accessories drive belt must be aligned with pulley grooves, in order to avoid belt damage.
   7. The correct tension must then be applied, which again can be done manually or automatically. 
   8. Check the correct installation of the aux drive kit, then start the engine and let the transmission run for a few minutes. Check its operation through a drive test run.

Recommended: Dolz announces the addition of its new Auxiliary Drive Kits product line

Dolz, your trusted dealer for auxiliary drive kits

At Dolz we work to provide our customers with this competitive advantage by accessing our high-quality Auxiliary Drive Kits. 

Designed to ensure great engine performance, they follow premium standards from original manufacturers such as Audi, Volkswagen, or Renault and include all the necessary components for a professional repair, that is all components are delivered in one package: V-ribbed belt or auxiliary belt, pulleys and idlers, drive tensioners all the necessary accessories depending on the vehicle application.

Get in touch with us to learn more about our quality standards and proven benefits of our auxiliary drive belt kits.

La entrada Auxiliary drive kit installation: a step-by-step guide se publicó primero en Industrias Dolz.

Accessory belts or auxiliary drive belts have become increasingly relevant with the evolution of vehicles and their current possibilities. In fact, as FEAD (Front End Auxiliary Drive) systems have become less spacious in physical terms, their importance in terms of propulsion has also increased significantly, requiring more power capacity with fewer cylinders and space.

In such a context, the role of auxiliary belts has come to the fore, evolving considerably over the years in both design and materials. Some changes that were reflected in increasingly longer accessory belts and more durable materials.

In today’s article, we learn about the main types of transmission belts that are housed in the vehicle, and we talk about the particularities of each of them.

What is the main difference between an auxiliary drive belt and a timing belt?

Driving belts are power transmission devices that are able to transfer power between elements such as shafts, pulleys or sheaves. Although they may have a similar appearance, both play two completely different roles.

The timing belt is used to synchronize the rotation of the crankshaft and camshaft so that the engine valves open and close at the precise time for the intake and exhaust of each cylinder.

On the other hand, the accessory belt or aux drive belt is the one that transmits the movement of the crankshaft pulley to different components of the vehicle, such as the alternator to charge the battery and to power the electrical system when its engine is running or the power steering. It’s attached to the crankshaft and camshaft via several pulley, while the tensioner pulleys rest on the outside.

While the timing belt almost always has one side full of notches or teeth (they are called toothed or synchronized for that reason), the auxiliary drive belt usually does not have notches but parallel longitudinal grooves and is usually somewhat narrower and thinner than the first one.

Types of transmission belts and their application

Transmission belts are generally made of rubber and can be classified into different types depending on their application.

The auxiliary drive system transmits power from a drive pulley to accessories. There is the classic design with multiple belts that drive different accessories like the alternator and power steering pump. Although it is also common to find systems with a serpentine belt capable of driving all the accessories by itself. It is true that in some engines you can find toothed or synchronized belts such as timing belts driving an accessory, generally the two most common types of auxiliary drive belts are the following: 

V-belt

The V-belt, shaped like an isosceles trapezoid in cross section, is responsible for driving so-called secondary or auxiliary accessories. Years ago, this system activated elements such as the electric generator and the water pump, but now others have been added, such as the power steering pump or the Air Conditioning compressor.

These types of belts solved alignment and twisting problems by focusing on the pulley groove. And more importantly, they had a much stronger grip than the auxiliary belts of yesteryear because their shape is basically a wedge.

These belts are characterized by being thinner and smaller and generally only drive one peripheral at a time. So, it’s quite common to find multiple V-belts on an engine, but only one serpentine belt.

Currently, most of the modern applications of this type of auxiliary belt have been replaced by the ribbed or poly-V belt that we will see below.

Poly V-belt

The poly-V belt (also known as auxiliary ribbed belt, poly belt and poly vee belt) is a type of belt that has played a crucial role in the capabilities of vehicles to transfer greater power and overcome the challenges presented by today’s increasingly complex systems.

This type of belt is a further development of the V-belt and has several longitudinal grooves in its design.

As tension increases, this type of belt fits hard into the grooves, increasing friction and thus transmitting torques with minimal power loss.

Due to its flexibility and high efficiency, the Poly V belt has become one of the most popular choices among vehicle manufacturers.

For this reason, its multiple advantages take on more prominence than ever:

• Support higher loads.
• It’s more flexible.
• Allows enveloping angles in small spaces.
• Increased system performance.
• Support higher speeds.

Unlike other drive belts, it has its teeth or grooves parallel to the direction of the belt.

Choosing the right auxiliary drive kit will ensure the vehicle runs smoothly and efficiently over a longer life cycle.

When should an auxiliary drive belt be replaced?

An auxiliary drive belt has a very variable useful life depending on the use of the vehicle.

Made of highly durable synthetic rubber (Ethylene Propylene Diene type M or EPDM), it is a component that must be inspected visually to detect the need for its replacement.

If the belt is worn, it will have cracks, fraying or irregularities of all kinds.

Although among the most obvious symptoms of failure of the auxiliary belt system are:

• Steering hardening.
• Vehicle battery failure.
• Failure in the air conditioning.
• Humming in the engine.

Related content: Understanding the Drive Belt Tensioner (Friction Wheel)

Dolz Kits, knowledge and experience at your service.

The Dolz Kits Range includes:

• Timing Belt Kits with water pump.
• Timing Belt Kits without water pump.
• Auxiliary Drive Kits.
• Timing Chain Kits.

All of them are manufactured according to original equipment (OE) specifications and are guaranteed for 2 years from the date of purchase or 50,000 km.

La entrada Types of transmission belts and main differences se publicó primero en Industrias Dolz.

As we have pointed out on previous occasions, internal combustion engines are sensitive to outside temperature, their performance varying according to the degree of temperature. For this reason, it is important that engine in the most suitable temperature range.

In today’s article we talk about the drive belt tensioner (also known as friction wheel), designed to ensure accurate the engine’s condition and performance.

Drive belt tensioner, main features

This complex component has a torsion bar tensioner as an elastic element, replacing the classic spiral spring. It is an adjustable tensioner, and its main function is to optimize the thermal management of the engine.

As it does? Once the engine has reached a certain temperature and its thermal state needs to be checked, this tensioner activates and drives the water pump.

The drive belt tensioner powers the crankshaft pulley to the water pump pulley, which is engaged and disengaged by an electric actuator.

All this innovative system results in less mechanical loss during the disconnection phase of the water pump.

Dolz continues expanding its line of products for vehicle transmissions with SKD173T and SKD174T for PSA Peugeot, Citroën and BMW Mini (Prince Engine), available for dealers and workshops.

Prince Engine

Awarded as the best engine in its category in the “International Engine of the Year” since 2007.

Prince engine is a compact engine family of 1.4 to 1.6 L in displacement that includes the most modern features, such as direct fuel injection, turbocharging or variable valve shock.

Advantages of drive belt tensioner

Among the main benefits of this unique system, we find:

• Reach engine temperature faster and more efficiently.
• At start-up, the water pump is switched off, for a better engine performance.
• Reduce fuel consumption.
• Reduce CO2 emissions.

Maintenance recommendations

In short, cars are intricate machines that need regular care to function properly. The transmission of the vehicle is of paramount importance for the correct performance of any engine. For this reason, it is advisable to carry out an effective maintenance that helps the proper performance of its elements and extends its useful life.

Common causes of driveline problems include improper installation of belts and pulleys, environmental factors, or faulty transmission components, but by far the biggest cause is improper maintenance. 

To do this, Dolz recommends:

• Follow a preventive maintenance program.
• Ensure the correct installation of the components.
• Before placing the tensioner, clean the mounting surface.
• Perform in the same operation the replacement of all the elements related to the transmission, including the water pump.

Related content:  3 reasons to replace both the timing belt and the water pump at the same time 

Why choose Dolz?

About us

Dolz offers a wide range of cooling and power transmission products for passenger cars and heavy-duty vehicles.

With innovative technologies, Industry 4.0, and in-house production, Dolz is a reliable supplier and manufacturer that has locations in more than 70 countries around the world and three factories in Spain (Castellón), Argentina (Buenos Aires) and China (Shouzou). 

Product Range

Water pumps – Timing Belt Kits – Timing Chain Kits – Thermostats

Selecting the best supplier is a must. Do not hesitate to contact us if you have any questions or require more information about our products.

Since 1934 …yes we have!

La entrada Understanding the Drive Belt Tensioner (Friction Wheel) se publicó primero en Industrias Dolz.