807757T 18-6457 Serpentine Belt Idler Pulley for MerCruiser

Product Overview

This serpentine belt idler pulley provides smooth, reliable tension for the drive belt system on MerCruiser marine engines. Designed to reduce vibration and extend belt life, it is a direct replacement for worn or failing pulleys. Marine mechanics and boat owners use this idler pulley to restore proper belt operation in stern drive and inboard applications.

Key Features & Performance

• Precision-engineered to match OEM specifications for MerCruiser serpentine belt systems
• Durable sealed bearing reduces friction and resists moisture contamination
• Corrosion-resistant coating protects against marine environment exposure
• Direct bolt-on installation with no modifications required
• Replaces OEM part numbers 807757T and 18-6457 for exact fitment

Common Uses

• Replace worn or noisy idler pulleys on MerCruiser 4.3L, 5.0L, and 5.7L engines
• Used in marine stern drive and inboard belt drive systems
• Suitable for both saltwater and freshwater boat applications
• Maintenance replacement during water pump or alternator service

Technical Specifications

• Part Number(s): 807757T, 18-6457
• Type: Serpentine belt idler pulley
• Bearing Type: Sealed ball bearing
• Material: Steel with corrosion-resistant coating

Frequently Asked Questions

Q: Will this pulley fit my MerCruiser 4.3L engine? A: This idler pulley is compatible with many MerCruiser V6 and V8 engines that use OEM part 807757T, but verify your engine’s part number before ordering.

Q: Is the pulley pre-lubricated and ready to install? A: Yes, the sealed bearing comes fully lubricated and requires no additional grease for installation.

Product appearance and specifications may vary slightly by batch. Compatibility may vary by serial number. Verify fitment before purchase.