Drive Belt / Serpentine Belt / Timing Belt / V-Belt

Vehicle manufacturers employ various designs for their automotive engines. Older vehicles may have a number of v-belts that drive accessory components where newer vehicles will use one or two serpentine belts.

In general, all drive belts, serpentine belts, timing belts and v-belts function in a similar manner. The belts take power from one part of the engine and apply it to another area, either in the engine or an engine accessory which may include the alternator, power steering pump, water pump, A/C compressor and possibly engine timing or valve timing.

Typical Drive Belt / Serpentine Belt System

The diagram depicts a simplified version of a typical drive or serpentine belt system. Consult your owners manual for specific information about your vehicle.

When your vehicle is running, the Crankshaft Pulley is the power source for the drive belt system. The Serpentine Belt or Drive Belt wraps around several pulley wheels attached to devices that will be powered by the drive belt. These devices include: Power Steering Pump that pumps power steering fluid to the power assisted steering system to make turning the vehicle relatively effortless. This system is always engaged. Air Conditioning Compressor that compresses refrigerant gas to allow for interior passenger compartment cooling. On the front of the A/C Compressor pulley is a clutch plate that is activated by controls on your dashboard and by electronic regulators. So even though the pulley wheel on the A/C compressor is always spinning, the compressor is not always engaged and working.

Alternator that creates electricity to recharge the battery and provide electrical current to fire the spark plugs in the ignition system. The Alternator is always on when the engine is running, but at lower RPMs the alternator may only create enough energy to fire the spark plugs. Higher RPMs may be required to recharge the battery.

Water Pump that moves engine coolant through the engine. When the thermostat is in the open position, the waterpump will pump water back from the radiator and into the engine. The interior heater's fluid return line may also connect to the water pump. The water pump is always spinning when the engine is on.

Idler Pulley that maintains proper belt tension.

Some manufacturer's use a drive belt to maintain engine timing. In this case, the belt path will include one or two timing pulleys that drive the overhead camshaft to open and close the combustion valves at precisley the right time. This may be a seperate belt from the auxiliary system belts.

Belt Wear and Incorrect Belt Tension
It’s important to keep these belts in good working order to prevent a serpentine or drive belt failure that could result in being stranded or possible engine damage. The drive belts should be checked at standard oil change intervals for signs of wear including belt tension, excessive cracked surface, glazing or frayed edges. Any drive belt that displays damage should be replaced and your vehicle manufacturer’s recommendations should be followed for drive belt interval replacement.

EZ Lube Serpentine Belt Inspection and Replacement

EZ Lube will inspect your drive belts as part of our Full Service Oil Change. Should your serpentine or drive belt shows signs of damage or possible failure, replacement belt service is available.

Serpentine Belt / Drive Belt / V-Belt Inspection and Service Info >>