Belt Tensioner 3976832 3937556 for Cummins 4BT 3.9 6BT 5.9 6CT C8.3L 6C 6CT 6CTA

Belt Tensioner 3976832 3937556 for Cummins

This belt tensioner carries OEM cross-reference numbers 3976832 and 3937556 and is designed for Cummins 4BT, 6BT, 6CT, and 6CTA diesel engines.

Overview

This belt tensioner is a direct replacement for Cummins engine applications, maintaining proper tension on the serpentine or accessory drive belt. It fits 4BT 3.9, 6BT 5.9, 6CT C8.3L, 6C, 6CT, and 6CTA models, ensuring reliable operation of the alternator, water pump, and other belt-driven components.

Built For Performance

• Heavy-duty construction with a sealed bearing for long life
• Spring-loaded tension arm provides consistent belt force
• Corrosion-resistant coating on pulley and bracket
• Precision-machined pulley for smooth rotation
• Tested to meet OEM performance standards

Fits These Machines

• for Cummins 4BT 3.9
• for Cummins 6BT 5.9
• for Cummins 6CT C8.3L
• for Cummins 6C
• for Cummins 6CT
• for Cummins 6CTA

On-The-Job Use

• Commonly used in industrial generators, agricultural equipment, and construction machinery
• Required for engine rebuilds and belt system overhauls
• Applies to both on-highway and off-highway Cummins applications
• Replaces worn tensioners to prevent belt slip and noise

Specs At A Glance

Good To Know

Q: Is this tensioner the same as the original Cummins part? A: This tensioner is an aftermarket replacement built to OEM specifications, not a genuine Cummins part, but it is designed to match fit and function.

Q: Can I install this tensioner without special tools? A: Installation typically requires basic hand tools, but always refer to the engine service manual for proper tensioning procedures.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.