Engine Belts

Does your belt squeal on a cold start, or are the ribs showing cracks? This category contains V-belts and serpentine belts, which typically drive the engine's accessories such as the alternator and water pump. For you who need to replace a worn belt or need the right length for a modified belt drive.

V-belt or serpentine belt?

A V-belt has a V-shaped cross-section and is typically found on older engines, often with one belt per accessory. A serpentine belt – also called a multi-rib or poly-V belt – has several longitudinal ribs and can be routed around several pulleys in one drive. The belts here drive accessories. If you need the belt that drives the camshaft, you will find it under timing belts, and the full range is gathered under belts and pulleys.

How to choose the right belt

The belt must match the profile, number of ribs and length. In designations such as HKS FINE TUNE V-BELT/4PK875, the numbers typically indicate the number of ribs and the length in millimetres, and with Gates, for example, the dimensions often appear in the product name. Also check:

• whether the belt routing is original, or whether you have changed pulleys or accessories
• whether the belt needs flanges or another design that suits your pulleys
• what tension the belt requires, and whether the tensioner should be replaced at the same time

Fitting and maintenance

A belt can squeal if it is worn, incorrectly tensioned or contaminated with oil or coolant. Cracks in the ribs, frayed edges and glazed surfaces indicate that it should be replaced. A worn tensioner can cause the same symptoms, so check it together with the belt – you will find new parts under belt tensioners. Brands in the category include Gates, HKS, OMIX and Peterson Fluid Systems.

Frequently asked questions

How can I tell if the drive belt needs replacing?

Look for cracks across the ribs, frayed edges, glazed wear surfaces and missing pieces. Squealing on start-up or at full steering lock can also indicate wear or incorrect tension. The interval depends on the car and the belt.

What is the difference between a drive belt and a timing belt?

A drive belt drives accessories such as the alternator and water pump via friction. A timing belt has teeth and keeps the camshaft and crankshaft synchronised, so it must be fitted according to the engine's specific procedure.

Do I need a different belt length if I change the pulleys?

It depends on the change. Smaller or larger pulleys, a removed accessory or a new belt routing change the required length, so it must be measured or calculated for your specific setup before you choose a part number.