Dayco 89258 Accessory Drive Belt Tensioner Assembly - Air Conditioning or Smooth Pulley

Accessory Drive Belt Tensioner for GM A/C Systems

Dayco 89258 is an automatic serpentine accessory drive belt tensioner assembly for air conditioning compressor belt applications. It is built for vehicles that need consistent belt tension on the A/C drive system, including Chevrolet Silverado, GMC Sierra, Cadillac Escalade, and related GM platforms.

• Automatic accessory drive belt tensioner assembly
• Serpentine belt type
• Clockwise rotation
• Single pulley design
• 60 mm pulley diameter with 20 mm width
• Flat pulley surface

Fitment and Application Details

Compatible with a wide range of GM trucks, SUVs, and vans in the air conditioning position. Fits 1999-2008 Chevrolet Silverado 1500, Air Conditioning; Fits 2001-2008 Chevrolet Silverado 2500 HD, Air Conditioning; Fits 2007-2008 Chevrolet Silverado 3500 HD, Air Conditioning; Fits 2000-2008 Chevrolet Tahoe, Air Conditioning; Fits 2000-2008 GMC Yukon, Air Conditioning; Fits 2003-2008 Chevrolet Express 2500, Air Conditioning; Fits 2003-2008 GMC Savana 3500, Air Conditioning; Fits 2002-2008 Cadillac Escalade, Air Conditioning. This part cross-references Gates 38159 and Dorman 419-109 for the same application. Dayco 89258 also covers additional Chevrolet, GMC, Buick, Hummer, Saab, and Isuzu models listed in the fitment data.

What This Tensioner Helps Address

• Belt slack in the serpentine accessory drive system
• Noise from a worn or weak A/C belt tensioner
• Uneven belt tracking on the compressor drive circuit
• Loss of proper belt tension during accessory operation
• Service replacement for worn tensioner assemblies on GM A/C applications

Installation Notes and Tips

Verify pulley direction, diameter, and width before installation. Confirm the vehicle uses the air conditioning belt application listed for Dayco 89258, and review the referenced technical bulletin for compressor belt warning notes on affected GM platforms. Match the existing serpentine routing and inspect the belt, pulley surfaces, and adjacent accessories before replacing the tensioner.

Quality Assurance

Dayco manufactures accessory drive components for OE-style service replacement applications. Part number 89258 is specified as an automatic tensioner assembly with the listed pulley dimensions and rotation direction for the covered vehicles.