Gates 38783 Accessory Drive Belt Tensioner Assembly - Alternator

OE Automatic Belt Tensioner for GM HD Trucks

The Gates DriveAlign Premium OE Automatic Belt Tensioner, part number 38783, is built for accessory drive systems that need consistent belt control and OE-style fit. It is a direct replacement for select Chevrolet Silverado 2500 HD and 3500 HD, plus GMC Sierra 2500 HD and 3500 HD applications.

Gates applies OE system design experience to this DriveAlign Premium OE Automatic Belt Tensioner line, focusing on rigid manufacturing tolerances, correct fit, and dependable belt tracking for the accessory drive belt system.

Key Features

• OE Performance grade automatic belt tensioner assembly
• Thermoplastic construction
• V-ribbed belt application
• Single flanged pulley design
• 6-groove pulley for accessory drive belt routing
• 1 mounting hole for direct-fit installation
• 71 mm outside diameter pulley with 25 mm width
• 17 mm bearing bore inside diameter
• Contents: tensioner assembly

Detailed Description

Gates 38783 is an accessory drive belt tensioner assembly engineered for OE-style replacement on GM heavy-duty trucks. It is listed for the alternator position on 2020-2025 Chevrolet Silverado 2500 HD and Silverado 3500 HD, as well as 2020-2025 GMC Sierra 2500 HD and Sierra 3500 HD. Earlier 2017-2019 Silverado HD and Sierra HD applications are also covered in the fitment data. This part cross-references GM 12673657 for the same application.

For buyers searching for a 2020-2025 Chevrolet Silverado 2500 HD alternator belt tensioner, a 2020-2025 GMC Sierra 3500 HD accessory drive belt tensioner, or a Gates 38783 OE replacement tensioner for GM HD trucks, this assembly matches the listed vehicle applications and belt system requirements.

What It Helps Address

• Belt squeal caused by weak or inconsistent tension
• Accessory drive belt tracking issues
• Premature belt wear from poor pulley control
• Loss of proper alternator belt tension
• Noise from a worn tensioner pulley or spring mechanism

Installation Notes and Tips

Verify the vehicle year, make, model, and alternator position against the fitment list before installation. Inspect the V-ribbed belt, pulley alignment, and surrounding accessory drive components at the same time so the new tensioner can operate within the correct belt path. Confirm the pulley groove count and mounting style match the original configuration on the truck.

Quality Assurance

Gates manufactures DriveAlign Premium OE Automatic Belt Tensioners to rigid tolerances and specifications so the part delivers OE fit, form, and function for the listed Chevrolet Silverado HD and GMC Sierra HD applications. Part number 38783 is built as an OE-performance replacement for the accessory drive belt system.