The Whirlpool WP6-3700340 idler pulley assembly helps maintain proper tension on the dryer drum belt for smooth and consistent drum rotation. Installed within the dryer’s drive system, the pulley applies tension to the belt while allowing it to move as the motor turns the drum. Proper belt tension helps support steady drum movement and reduces unnecessary slipping or vibration during operation. Replacing a worn, noisy, damaged, or seized pulley can help restore normal dryer performance and reduce belt-related operating issues.