Dayco 89572 Accessory Drive Belt Idler Pulley - Upper

Accessory Drive Belt Idler Pulley for GM Applications

Dayco 89572 is an accessory drive belt idler pulley built with a steel body and a single bearing for serpentine belt systems. It is a direct-fit service part for a wide range of Chevrolet and GMC trucks and vans, including Silverado 2500 HD, Silverado 3500 HD, Sierra 2500 HD, Sierra 3500 HD, Express, and Savana applications.

Key Features

• Steel construction for durable accessory drive belt support
• Serpentine belt design for modern accessory drive systems
• Single bearing design with 17 mm inner diameter and 12 mm bearing width
• Flat pulley profile
• Maximum belt width: 6-rib
• Fits upper and N/A positions depending on application
• Dayco part number 89572 for catalog and service reference

Detailed Description

This Dayco accessory drive belt idler pulley is engineered for vehicles that use a serpentine belt routing with a flat pulley surface. The steel pulley body and single-bearing design help maintain belt tracking in accessory drive systems found on Chevrolet Silverado 2500 HD and Silverado 3500 HD, GMC Sierra 2500 HD and Sierra 3500 HD, as well as Chevrolet Express 2500, Express 3500, GMC Savana 2500, and Savana 3500 models. Part number 89572 also applies to select Chevrolet Captiva Sport, Buick Regal, Buick LaCrosse, and Saab 9-5 fitments.

For fitment-based searches, this part is commonly referenced as a Dayco 89572 idler pulley for Chevrolet Silverado 2500 HD upper applications with dual alternators, GMC Sierra 3500 HD upper applications with dual alternators, and single alternator configurations on select 2020-2021 heavy-duty trucks. It is also listed for 2025-2026 Chevrolet Silverado 2500 HD and Silverado 3500 HD, plus 2025-2026 GMC Sierra 2500 HD and Sierra 3500 HD.

What It Helps Address

• Accessory belt noise caused by a worn idler pulley bearing
• Belt tracking issues in serpentine drive systems
• Visible pulley wear or surface damage
• Accessory drive vibration from a deteriorated pulley assembly
• Service replacement needs on GM trucks, vans, and select passenger vehicles

Installation Notes and Tips

Verify the pulley position and belt routing before installation, especially on applications listed as upper or N/A. Confirm the belt width is 6-rib and match the bearing dimensions to the original component before service. On 2020-2021 Silverado 2500 HD, Silverado 3500 HD, Sierra 2500 HD, and Sierra 3500 HD models, check whether the vehicle uses a single alternator or dual alternators so the correct Dayco 89572 application is selected.

Quality Assurance

Dayco is a recognized name in accessory drive belt system components, and this pulley is built to meet the dimensional and material requirements listed for the application. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.