3937555 - Genuine Cummins Belt Tensioner

Cummins 3937555 Belt Tensioner - Genuine Cummins Automatic Drive Belt Tensioner for B/C Series and ISB/ISC Engines The Cummins 3937555 is the spring-loaded automatic tensioner on the accessory/serpentine drive. Its spring keeps constant load on the belt through a pulley on a swinging arm, taking up slack as the belt stretches and wears so it doesn't slip, squeal, or throw. Set it and the spring does the rest - no manual adjustment. Fitment & Specifications: - Application: Cummins B Series, C Series, ISB, QSB, ISC (5.9L / 6.7L / 8.3L) - Type: Automatic spring-loaded accessory drive belt tensioner Verify fitment with us before ordering to ensure the correct part for your application.