We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is a Crankshaft Pulley?

By Lori Kilchermann
Updated Jan 27, 2024
Our promise to you
WikiMotors is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WikiMotors, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The crankshaft pulley is attached to the engine's harmonic balancer and drives the engine's accessories through the use of a rubber belt or system of belts, depending on the year and type of vehicle in question. Prior to the mid-1980s, most vehicles manufactured worldwide used a system of V-belts to drive an engine's component accessories. Since then, a single belt known as a serpentine belt has been driven by the crankshaft pulley and directed power to all systems in the engine compartment. While a serpentine-type crankshaft pulley is manufactured with a surface capable of driving the single belt, a V-belt system uses a crank pulley capable of driving from one to four V-belts.

The standard automotive engine is equipped with belt-driven features to provide charging for the electrical system, coolant circulation for the engine and heating system and hydraulic pressure for the power steering system. Optional belt-driven components are the air conditioning compressor and heavy hydraulic pumps for pickup trucks and tow vehicles as well as supercharger units for high-performance vehicles. All of these components are driven off of the crankshaft pulley. Some vehicles also use the crankshaft pulley to trigger the ignition system with flying magnets mounted on or in the pulley.

The engine's crankshaft is made of very heavy cast iron in most cases and solid steel in very high-performance engines. The crankshaft's snout must be made very strong to withstand the stress of placing the crankshaft pulley and the stress created from driving all of the components off of that single pulley. If the crankshaft pulley were allowed to wobble, the belts or belts would be easily thrown off of the pulley and the components depending on the drive power of the pulley would fail. Fortunately, the factory-stock fasteners and thread-locking liquids are commonly fail-proof and the crankshaft pulley typically remains tightened and in place for the entire life of the vehicle.

While the crankshaft pulley spins at revolutions equal to that of the operating engine, the various belt-driven components are turning at speeds much faster in most cases than the engine speed. This is accomplished by alternating the various pulley sizes with different-sized pulleys to change the final drive ratio to a more productive component drive speed. By placing a variety of different-sized pulleys on the engine components, each component can turn at a different speed all while being turned by the same drive pulley on the crankshaft.

WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.