Dayco 89566 Accessory Drive Belt Idler Pulley - Left Upper, Smooth Pulley or Supercharger

Dayco 89566 Accessory Drive Belt Idler Pulley

The Dayco 89566 accessory drive belt idler pulley is built for serpentine belt systems that require a smooth, steel pulley with stable belt tracking. It is a direct-fit service part for select Ford Mustang and Ford GT applications, including supercharger and left upper positions.

Key Features

• Steel pulley construction for durable belt-system service
• Serpentine belt application
• Smooth, flat pulley design
• One bearing design for consistent rotation
• Max belt width: 10 rib
• Bearing inner diameters: 30 mm and 11.2 mm
• Dayco part number 89566

Detailed Description

Dayco 89566 is an accessory drive belt idler pulley designed for serpentine belt routing in select Ford performance and truck-based applications. The steel construction and smooth, flat face support proper belt contact where a non-grooved pulley is required. This part number 89566 is listed for 2007-2012 Ford Mustang supercharger left applications, 2013-2014 Ford Mustang left upper applications, and 2005-2006 Ford GT smooth pulley applications. It also references the 2012-2016 Ford F-150 3.5L V6 Turbo note tied to the Mustang left upper listing.

For buyers searching for a Ford Mustang idler pulley, Ford GT smooth pulley, or Dayco 89566 accessory drive belt idler pulley, this component is specified for serpentine belt systems with up to a 10-rib belt width. The single-bearing design and steel body make it a straightforward replacement when the original pulley surface or bearing condition no longer supports smooth belt operation.

What It Is Used For

• Replacing a worn or noisy serpentine belt idler pulley
• Restoring proper belt routing on supercharger drive systems
• Addressing belt squeal caused by pulley surface wear
• Correcting belt tracking issues on smooth pulley applications
• Servicing select Ford Mustang and Ford GT accessory drive systems

Installation Notes and Tips

Verify pulley position, belt type, and rib count before installation. This part is listed for Left Upper, Supercharger, and Smooth Pulley positions, so match the vehicle application exactly to the existing pulley location. Confirm bearing dimensions and belt routing during service, and inspect the serpentine belt for wear before returning the vehicle to operation.

Quality Assurance

Dayco is a recognized name in belt drive components, and this pulley is built with steel construction and application-specific fitment details for select Ford platforms. Part number 89566 is cataloged for direct replacement use in the listed applications.