Hayden 5989 Accessory Drive Belt Idler Pulley

Hayden 5989 Accessory Drive Belt Idler Pulley

The Hayden 5989 accessory drive belt idler pulley is a direct-fit replacement for serpentine belt systems that need stable belt routing and consistent tension control. Built with a black plastic pulley body and smooth groove design, it matches OE-style service requirements for select Mercedes-Benz applications.

Use this Hayden pulley when servicing the accessory drive belt system on Mercedes-Benz E300, SL500, and 190E models, as well as select 300D, 350SD, 350SDL, 300SDL, and 300TD applications. Hayden 5989 is an OE-style pulley replacement that meets or exceeds OEM requirements.

Key Features

• Accessory drive belt idler pulley for serpentine belt systems
• Black plastic construction with smooth pulley surface
• 1.000 in. belt width / 25.4 mm pulley width
• 3.1875 in. outside diameter / 80.963 mm outside diameter
• 0.375 in. bore diameter / 9.525 mm inside diameter
• Single mounting hole design
• Back idler pulley style
• Meets or exceeds OEM specifications
• Mounting hardware not included

Product Details

Hayden Pulley 5989 is an idler / tensioner pulley designed for accessory drive belt routing in serpentine belt systems. The smooth groove quantity and back idler style support proper belt tracking where a non-grooved pulley is required. This part cross-references Gates 38048 and Dayco 89044 for the same application. It is a practical replacement choice for Mercedes-Benz E300, SL500, and 190E service work where pulley wear, noise, or belt alignment concerns are present.

Common Issues This Part Can Address

• Squealing or chirping from a worn idler pulley
• Belt tracking problems caused by pulley surface wear
• Accessory drive belt noise during engine operation
• Visible cracking, roughness, or play in the pulley assembly
• Service replacement for aging serpentine belt system components

Installation Notes and Tips

Verify pulley diameter, bore size, and belt width before installation. Inspect the serpentine belt, tensioner, and adjacent accessory pulleys at the same time to confirm the full belt path is in serviceable condition. Because mounting hardware is not included, reuse or source the correct hardware separately as needed. Confirm fitment against the vehicle’s existing pulley configuration before final assembly.

Quality Assurance

Hayden 5989 is listed as meeting or exceeding OEM requirements for the specified application. The Hayden Pulley line focuses on OE-style replacement components for accessory drive belt service, with dimensions and construction intended to match the original pulley setup on covered Mercedes-Benz models.