Dayco 89086 Accessory Drive Belt Idler Pulley

Accessory Drive Belt Idler Pulley for Mercedes-Benz

Dayco 89086 is an accessory drive belt idler pulley built for serpentine belt systems. It uses a polymer pulley body with a single bearing and a 6-groove profile to match the belt routing used on select Mercedes-Benz applications.

Key Features

• Accessory drive belt idler pulley for serpentine belt systems
• Polymer pulley construction
• 6-groove design for 6-rib serpentine belts
• Single-bearing design
• Bearing inner diameters: 14.6 mm and 8.3 mm
• Bearing width: 31.5 mm
• Max belt width: 06 rib
• Dayco part number 89086

Detailed Description

This Dayco idler pulley is specified for Mercedes-Benz models including the 1990-1993 300E, 300SE, 300TE, 300CE, and 300SEL, plus later applications such as the 1994-1997 E320, S320, C280, and 1996-1999 S420 and S500. It also covers the 2000-2002 SL600 and 1996-1998 SL500, making Dayco 89086 a direct-fit service part for a wide range of serpentine accessory drive systems.

As an accessory drive belt idler pulley, this component helps maintain belt routing and smooth belt travel across the front-end drive system. The polymer pulley material and 6-groove profile are matched to the belt type and width requirements listed for this application. This part cross-references Gates 38090 for the same application.

Common Issues This Part May Address

• Noise from a worn or rough idler pulley bearing
• Belt tracking problems caused by pulley wear
• Serpentine belt vibration from an out-of-round pulley
• Accessory drive belt routing issues on Mercedes-Benz engines
• Visible pulley damage, cracking, or surface wear

Installation Notes and Tips

• Verify belt routing and pulley alignment before installation.
• Inspect the serpentine belt, tensioner, and adjacent pulleys at the same time.
• Confirm the 6-rib belt width and bearing dimensions match the original part.
• Check the mounting surface for wear or contamination before final assembly.

Quality Assurance

Dayco manufactures accessory drive components for service replacement use, and this pulley is built to match the listed Mercedes-Benz fitments and dimensional requirements. Confirm application by year, model, and belt configuration before ordering.