Engine belts are crucial to the performance of the engines and hydraulic systems of heavy equipment machines like excavators, tractors and skid steers.

Belts have a variety of uses, but they generally serve to transfer power between various parts of the engine and help coordinate between systems.

The quantity and types of belts used in your machine depend on your machine’s make and model, as well as its age. Some engine belts are generic, while others are specific to particular models.

Here’s what you need to know about heavy equipment engine belts. And, how to maintain them to keep your machine running smoothly.

Types of Belts in Heavy Equipment

Belts are used in heavy equipment to transfer power between parts of the engine and to allow various systems to coordinate with each other.

While the types of belts used vary by machine, most engine belts fall into one of several categories:

V-belts

These are the most common type of engine belt used in heavy equipment engines. They are named V-belts because they have a V-shaped cross section. V-belts are used to transfer power from the engine to various components such as the alternator, water pump and air compressor. V-belts have a flat back and angled sides that grip the pulley, providing high friction and a secure grip. They are typically made of rubber.

Serpentine Belts

Serpentine belts are flat and ribbed. They’re used to drive several components including the alternator, power steering pump and air conditioning compressor. Serpentine belts are named for their “serpentine” path around the various pulleys. They are similar to V-belts in that they are made of rubber, but they are wider and have a different shape.

Air Conditioning Belts

These belts are used to drive the air conditioning compressor, which is responsible for cooling the air inside the machine’s operator cab.

Fan Belts

Also called alternator belts, these belts are used to drive the engine’s cooling fan and alternator. They are similar to V-belts in that they have a V-shaped cross section, but they are narrower.

What Types of Machines Need Belts to Operate?

Most heavy equipment that features an internal combustion engine will require belts in order to operate. Here are some common machines that need belts:

1. Tractors
2. Excavators
3. Skid steers
4. Backhoes
5. Loaders
6. Dozers
7. Forklifts

What Determines the Number of Belts in a Machine?

The number of belts required by a particular machine is dependent upon its size, complexity and number of internal systems.

For example, a small skid steer may only require a single belt to drive the engine and a few accessories such as the alternator and hydraulic pump, whereas a large excavator may require several belts.

Another factor that determines how many belts a machine requires is the type of engine it uses. Machines with a diesel engine, for example, may require more belts than those with a gasoline engine due to design differences between the two engines.

Machines with complex hydraulic systems may require more belts to drive the additional pumps, while machines with fewer accessories or simpler hydraulic systems may require fewer belts.

Where Each Belt is Located

Belts in heavy equipment machines are located in various parts of the machine depending on the type and model of the machine. Here are common locations for each type of belt:

V-belts

These belts can be found in various locations including the engine, alternator, water pump and air compressor. They are typically wrapped around pulleys which mount to the engine or other components.

Serpentine Belts

These belts are typically wrapped around a series of pulleys, with one pulley driving the engine and the others driving accessories like the alternator, power steering pump and air conditioning compressor.

Air conditioning Belts

AC belts can be either on its own or within a serpentine system around the engine. Several models usually have it located on the passenger side of the machine.

Fan Belts

Fan belts are located on the front of the engine.

How Often Does a Belt Need to Be Replaced?

The frequency with which a heavy equipment belt needs to be replaced can vary depending on several factors, including the type of belt, the type of machine and the operating environment. You should inspect your machine’s belts frequently and replace any belts that show signs of wear or damage.

Here are some symptoms of a heavy equipment belt that needs replacing:

1. Visible signs of wear or damage, such as cracking, fraying or stretching.
2. Squealing or squeaking noises when the equipment is running.
3. The belt slips on the pulleys during operation.
4. Reduced power output or struggling performance.

The cost to replace each belt can vary depending on the type of equipment and the specific belt needed. The cost can range from $25 for a small V-belt to several hundred dollars for a large serpentine belt.

What Happens if You Don’t Replace a Broken Belt?

If you don’t replace a belt on time, it can lead to several issues depending on the type of belt. Here are some potential consequences of not replacing a belt on time:

1. Reduced Performance: A worn or damaged belt can cause reduced power or performance.
2. Equipment Downtime: If a belt breaks while the machine is in use, it can cause the machine to shut down – leading to costly downtime.
3. Damage to Other Components: A broken or damaged belt can also cause damage to other components in the equipment, such as pulleys, bearings or the engine.

Safety Hazards: In some cases, a broken or damaged belt can create safety hazards such as flying debris or loss of control of the machine.

Get Help from the MechLink Shop

If you’re in need of a replacement heavy equipment belt, make sure you’re purchasing one from a reputable seller. MechLink’s online parts catalog features a selection of belts, including V-belts, fan belts and alternator belts. Still can’t find the part you need? Get in touch with one of our parts experts for personalized assistance.