Pulleys - Crank, Underdrive

Pulleys – Crank, Underdrive are critical components in engine accessory drive systems, designed to transfer rotational force from the crankshaft to auxiliary systems like the alternator, power steering, and air conditioning. A crank pulley, also known as a crankshaft pulley, is mounted directly to the engine’s crankshaft and plays a key role in maintaining proper belt tension and alignment.

Underdrive pulleys are engineered to reduce the rotational speed of accessory components, decreasing parasitic drag on the engine and improving performance at higher RPMs. These pulleys and cranks are often used in performance tuning to enhance throttle response and increase horsepower output. Proper installation may require a specialized crank pulley tool to ensure precise alignment and torque, reducing wear on belts and bearings.