Belts at 1A Auto
What are the belts and where are they located?
In fashion, belts are an important accessory. In your car, belts are important for running your engine accessories. As the engine’s pistons go up and down, the crankshaft rotates. The crankshaft is connected to a pulley at the front of the engine that spins along with the crankshaft. The belt or belts connect this pulley to other pulleys, turning them. These pulleys run accessories like the water pump, A/C pump, power steering pump, and the alternator.
Older cars used a series of belts called V-belts. Each belt ran one or two of these accessories in a V-shaped, triangular path—hence the name. Each belt had to be placed in front of the other on the crankshaft pulley in the correct order. That made things complicated and took up a lot of space. To reduce the hassle, more cars today use one serpentine belt that snakes around all the pulleys. Some cars may use a serpentine belt to run most of the pulleys and a V-belt for some outlier. Serpentine belts are longer than V-belts. The belt itself is made of strong but flexible rubber grooved on one side.
What can happen if engine belts fail?
- loss of charging to the electrical system by the alternator
- loss of engine cooling from the water pump
- stiffer steering from the power steering pump
Since most modern vehicles only use one main serpentine belt to drive all of the accessories, it is very important that the belt is in good working order.
How do I know if my belts need to be replaced?
Often times, your belts will tell you if they need to be replaced. A worn belt can make a number of different noises, including chirping, squealing, or rumbling. If you hear strange noises—especially rhythmic noises—coming from under the hood, the belt should be the first part you check. Look for cracks on the belt, visible fraying, or a shiny, glazed appearance. Fraying may indicate that the belt is misaligned on the pulleys and may require you to check that your pulleys are installed correctly. A glazed appearance may mean that the belt has been subject to high heat or an oil leak. Oil can make rubber wear more quickly.
Although belts have a long lifespan, it’s fairly normal for them to wear over time. Serpentine belts can last from 60,000 to 100,000 miles. V-belts usually last about half that. As the belt begins to wear, it loosens. This can make it slip and skip across the pulleys, leading to the noises discussed above. It also makes the belts less efficient at running the accessories. If the water pump isn’t working correctly, you may experience engine overheating. If the power steering pump isn’t working right, it might become difficult to steer at low speeds. If the alternator isn’t working right, your battery might recharge more slowly. If a worn belt is left unattended for too long, it can wear through and come apart. In that case, the crankshaft won’t be able to run the related accessory, and in some cases, you might not be able to start the car at all.
Can I replace the belts myself?
Replacing a belt is relatively straightforward. Before you begin, you’ll want to make sure you know how your belt is routed. Your car should have a belt-routing diagram under the hood. If it does not, there may be one in your owner’s manual. Otherwise, you should take photos or make sketches of the belt routing before you take it off. If you have to replace a V-belt, you will have to remove any other belts that are in front of it. Since the belts all see the same amount of work, you might want to replace them as a set.
Belts are held taut by belt tensioners. A tensioner will have a slot in it or a bolt that will usually accept a 3/8 inch drive ratchet or a 15mm socket and ratchet. With the ratchet, turn the tensioner to loosen the belt. Then you can pull the belt off.
While the bolt is off, you can inspect the pulleys. If any of these appear worn or loose, now would be a good time to replace them. As the belt loosens, the tensioner will push harder to keep it taut. A worn belt can also result in wear on the tensioner, so you should check the tensioner any time you replace the belt.
Pull the tensioner again to put the new belt on. Then slowly release the tensioner to tighten the belt. Check against your diagram that you have the belt routed correctly. Then start the engine to check that the belt is running all the accessories. If it is, then you’ve successfully replaced the belt.