Gates VCP858 Engine Variable Valve Timing (VVT) Sprocket

Gates VVT Sprocket for OE-Style Timing Control

Gates VCP858 is an engine variable valve timing sprocket built to OE specifications for fit, form, and performance. Also referred to as a cam phaser or cam actuator, this steel timing chain-driven component is designed to restore proper valve timing response in supported applications.

Compatible With 2002-2004 Chevrolet Trailblazer, 2002-2004 GMC Envoy, and related VVT-equipped platforms, Gates VCP858 is engineered for direct replacement service on the engine valve train. It is a practical choice when diagnosing timing-related drivability concerns on vehicles such as the Chevrolet Trailblazer and GMC Envoy.

Key Features

• OE Exact grade type for factory-style fit and function
• Steel construction for durability and service life
• Timing chain drive type
• 58-tooth design with .16 tooth thickness
• Single-row chain configuration
• Outside diameter: 5.88 in.; height: 2.59 in.
• Mounting hole quantity: 1

Product Details

The Gates Engine Variable Valve Timing Sprocket line is designed for OE performance replacement in applications that rely on precise cam timing control. Gates VCP858 is manufactured to match original specifications in fit, form, and performance, helping maintain the timing response needed for smooth engine operation. This part cross-references Dorman - OE Solutions 917-255 for the same application.

Use Gates VCP858 when servicing the variable valve timing system on supported Buick, Chevrolet, GMC, Isuzu, and Oldsmobile models. It is listed for 2004 Buick Rainier, 2002-2004 Chevrolet Trailblazer, 2002-2004 Chevrolet Trailblazer EXT, 2002-2004 GMC Envoy, 2002-2004 GMC Envoy XL, 2004 GMC Envoy XUV, 2003-2004 Isuzu Ascender, and 2002-2004 Oldsmobile Bravada.

Common Issues This Part May Address

• Incorrect cam timing response from a worn VVT sprocket
• Engine performance loss related to valve timing control
• Reduced fuel economy caused by timing system wear
• Increased emissions from inconsistent cam phasing
• Power delivery concerns tied to a failing cam actuator or cam phaser

Installation Notes and Tips

Verify engine code, timing chain condition, and OE part number before installation. Because this component works within the valve train, timing marks and cam/crank synchronization should be checked carefully during service. Replace related worn timing components as needed to maintain proper system operation.

Quality Assurance

Gates designs this VVT sprocket to OE specifications and tests it to help restore engine performance, fuel economy, power delivery, and emissions control in the listed applications. Part number VCP858 is built from high-quality steel for durability and maximum service life.