Dayco 89840 Accessory Drive Belt Idler Pulley - Grooved Pulley

Dayco 89840 Accessory Drive Belt Idler Pulley

Dayco 89840 is an accessory drive belt idler pulley for serpentine belt systems. Built with a polymer pulley body and a single bearing, it is specified for grooved pulley applications on select Toyota and Scion performance coupes.

Key Features

• Accessory drive belt idler pulley for serpentine belt routing
• Polymer pulley construction
• 6-groove pulley profile
• Single bearing design
• Bearing inner diameter: 17 mm
• Bearing width: 12 mm
• Maximum belt width: 6 rib
• Direct fitment for select Toyota GR86, Toyota 86, and Scion FR-S applications

Fitment Details

• Fits 2022-2026 Toyota GR86, Grooved Pulley
• Fits 2017-2020 Toyota 86, Grooved Pulley
• Fits 2013-2016 Scion FR-S, Grooved Pulley

This Dayco 89840 idler pulley is used in the accessory drive system to guide the serpentine belt across the correct path and maintain proper belt tracking at the grooved pulley location. It is a fitment-based replacement for Toyota GR86, Toyota 86, and Scion FR-S models that use a 6-rib serpentine belt interface.

Common Problems It Can Address

• Noise from a worn idler pulley bearing
• Belt misalignment at the grooved pulley position
• Serpentine belt routing issues caused by pulley wear
• Visible pulley surface wear or damage
• Accessory drive vibration related to pulley bearing condition

Installation Notes and Tips

Verify pulley style, groove count, and belt width before installation. Confirm the grooved pulley position matches the vehicle application and inspect the serpentine belt, tensioner, and adjacent pulleys for wear at the same time. Proper alignment is important for quiet operation and consistent belt tracking.

Quality Assurance

Dayco manufactures accessory drive components for OE-style service replacement applications. Part number 89840 is built to match the listed pulley dimensions and fitment requirements for the specified Toyota and Scion vehicles.