Dayco 89430 Heavy Duty Automatic Belt Tensioner Assembly

The Dayco 89430 is a heavy-duty automatic belt tensioner assembly engineered for demanding serpentine belt drive applications. This professional-grade tensioner maintains constant tension on serpentine belts, eliminating belt noise, reducing slippage, and ensuring reliable performance in high-torque environments.

Key Features:

• Heavy-duty cast aluminum arm and spring case for exceptional durability and resistance to cracking and fatigue
• Patented flat spring design engineered to handle higher torque and power pulses from diesel engines
• 90mm diameter flat pulley with 27mm width, rotating counter-clockwise
• Double lifetime lubricated pulley bearings for long-lasting, dependable service
• Highly damped mechanism utilizing wave spring and bonded rubber ring to absorb radial shocks during operation
• Lubricated nylon pivot tube bushing and spring bushing for quieter performance
• PTFE strip wound within spring for superior abrasion resistance
• Coated flat spring with high resistance to rust
• Zinc-coated mounting bolt that resists corrosion
• Made in the USA

This automatic tensioner prevents premature accessory bearing failure caused by excessive belt tension when new belts are installed, while maintaining proper tension as belts stretch over time. The robust construction and advanced damping technology make it ideal for heavy-duty trucks and commercial vehicles. Cross references include Gates 38256, General Motors 15021742, and CARQUEST 38256.