Gates 38178 Accessory Drive Belt Tensioner Assembly

OE Belt Tensioner for GM Truck and SUV Applications

The Gates DriveAlign Premium OE Automatic Belt Tensioner, part number 38178, is built for accessory drive systems that rely on consistent belt tension and smooth pulley tracking. It is a direct-fit style replacement for a wide range of Chevrolet, GMC, Hummer, Buick, Saab, Isuzu, and Oldsmobile applications, including Chevrolet Colorado, GMC Canyon, and Chevrolet Trailblazer models.

Key Features

• Gates DriveAlign Premium OE Automatic Belt Tensioner for accessory drive belt systems
• Steel construction for strength and durability in engine-bay service
• V-ribbed belt design with smooth/backside contact surface
• Single-pulley tensioner assembly with one mounting hole
• OE Performance comparison rating for factory-style fit, form, and function
• Dimensions: 70 mm outside diameter, 30 mm width, 17 mm bearing bore inside diameter

DriveAlign Premium OE Design

Gates DriveAlign Premium OE Automatic Belt Tensioners are engineered from Gates’ original equipment system design experience and manufactured to rigid tolerances. That focus on OE fit and function helps the tensioner maintain proper belt load across the accessory drive system, which is important on vehicles such as the Chevrolet Colorado, GMC Canyon, and Hummer H3. Part number 38178 is built for applications that require a smooth-running automatic tensioner assembly with OE-style dimensions and mounting geometry.

This part cross-references Continental 49280 and Dayco 89269 for the same application.

What This Tensioner Helps Address

• Belt squeal caused by weak or inconsistent belt tension
• Accessory drive belt flutter or vibration
• Uneven pulley tracking on V-ribbed belt systems
• Noise from a worn automatic belt tensioner assembly
• Loss of proper belt tension on GM truck and SUV accessory drives

Installation Notes and Fitment

Compatible with 2004-2012 Chevrolet Colorado, 2004-2012 GMC Canyon, 2006-2010 Hummer H3, 2009-2010 Hummer H3T, 2002-2009 Chevrolet Trailblazer, 2002-2009 GMC Envoy, 2005-2009 Saab 9-7x, 2003-2008 Isuzu Ascender, 2007-2008 Isuzu i-290, 2007-2008 Isuzu i-370, 2004-2007 Buick Rainier, 2002-2006 Chevrolet Trailblazer EXT, 2002-2006 GMC Envoy XL, 2006 Isuzu i-280, 2006 Isuzu i-350, 2004-2005 GMC Envoy XUV, and 2002-2004 Oldsmobile Bravada.

Before installation, verify belt routing, pulley alignment, and mounting-hole location against the original tensioner. Confirm the belt type is V-ribbed and compare the OE-style dimensions to the removed component to ensure proper fit on the accessory drive belt system.

Quality Assurance

Gates manufactures this DriveAlign tensioner to OE-quality standards with controlled tolerances for fit, form, and function. The part number 38178 is designed as an OE-performance replacement for vehicles that depend on stable accessory drive operation.