Dayco 89747 Automatic Belt Tensioner

The Dayco 89747 is an automatic serpentine belt tensioner engineered to maintain consistent tension on serpentine belt drive systems. Dayco's No Slack tensioner line features the brand's original, patented flat spring design, which provides less operating range variation compared to conventional coil spring tensioners.

This tensioner reduces the risk of premature accessory bearing failure caused by excessive tension during new belt installation, and helps prevent belt noise, slippage, and poor accessory performance that can result from low tension as the belt ages and stretches.

Key Features:

• Original, patented flat spring design for consistent tension with minimal operating range variation
• Heavy-duty cast aluminum spring case and arm to resist cracking and fatigue
• Steel pivot tube (on applicable designs) for enhanced stability and critical torque requirements
• Thermoplastic rubber spring slot plugs and rubber O-ring seals to keep out contaminants
• PTFE strip wound within the spring for abrasion resistance and smooth operation
• Coated flat wire spring resists rust
• Lubricated nylon pivot tube bushing promotes quieter performance and longer service life
• Zinc-coated mounting bolts for corrosion resistance

The Dayco 89747 is built to OE specifications and designed to outperform and outlast competitive replacement parts, delivering quieter operation and extended service life in demanding conditions.