Dayco 85018 Engine Timing Belt Tensioner Hydraulic Assembly

Hydraulic Timing Belt Actuator for Audi and Volkswagen

The Dayco Hydraulic Timing Belt Actuator, part number 85018, is an engine timing belt tensioner hydraulic assembly for select Audi and Volkswagen applications. It helps maintain proper timing belt tension in vehicles such as the Audi A4, A4 Quattro, A6, A6 Quattro, S4, Allroad Quattro, and Volkswagen Passat.

Key Features

• Dayco Hydraulic Timing Belt Actuator for engine timing belt tension control
• Direct-fit application coverage for select Audi and Volkswagen models
• Supports consistent belt tension in timing belt service applications
• Cross-references Dorman 420-171 and Gates T43026 for the same application
• Part number 85018 for catalog and service identification

Product Details

Dayco 85018 is a hydraulic timing belt actuator used in the valve train system to help maintain correct timing belt tension as engine conditions change. This product line focuses on timing system service for European vehicles, including Audi A4 and A6 family models, Audi S4, Audi Allroad Quattro, and Volkswagen Passat applications. It is listed for multiple model years from 1998 through 2005, with fitment notes that include specific chassis coverage for 1998 Audi A4 and A4 Quattro and GLX coverage for the 1998 Volkswagen Passat.

What It Helps Address

• Timing belt slack or inconsistent belt tension
• Noise from a worn hydraulic timing belt actuator
• Timing system service on Audi A4, A6, and S4 engines
• Replacement needs during timing belt maintenance on Volkswagen Passat models
• Restoration of proper belt tension control after actuator wear

Installation Notes and Tips

Install this hydraulic timing belt actuator during timing belt service and verify all timing marks before engine start-up. Follow the vehicle service procedure for the specific Audi or Volkswagen engine code, and confirm the chassis note for 1998 Audi A4, A4 Quattro, and 1998 Volkswagen Passat GLX applications. Replace related timing components as required by the service manual.

Quality Assurance

Dayco is a recognized name in engine drive and timing components, and this hydraulic timing belt actuator is cataloged for direct application matching across the listed Audi and Volkswagen vehicles.