Gates 39400 Accessory Drive Belt Tensioner Assembly

Overview of Gates DriveAlign Premium OE Automatic Belt Tensioner

The Gates DriveAlign Premium OE Automatic Belt Tensioner 39400 is engineered to maintain optimal tension on the accessory drive belt system. Designed specifically for BMW and Mini models including Cooper, Cooper Clubman, Cooper Countryman, Cooper Paceman, X1, and X2, this tensioner assembly ensures reliable belt performance and longevity.

• Thermoplastic construction for durability and resistance to wear
• Single pulley design with a smooth backside contact surface
• Compatible with V-ribbed belt types
• Two mounting holes for secure installation
• Precise dimensions: 2.56 inch (65 mm) outside diameter, 1.02 inch (26 mm) width, and 0.67 inch (17 mm) bearing bore inside diameter
• OE exact comparison rating for direct replacement

About the DriveAlign Premium OE Automatic Belt Tensioner Line

The DriveAlign Premium OE Automatic Belt Tensioner product line by Gates focuses on delivering original equipment quality and fitment. This line is designed to meet or exceed factory specifications, providing consistent belt tension to prevent slippage and premature wear. The 39400 tensioner assembly is part of this line, offering precise engineering and materials that align with the demands of BMW and Mini accessory drive systems.

Detailed Product Description

This accessory drive belt tensioner assembly features a thermoplastic body that balances strength and lightweight properties. The single pulley included has a smooth backside contact surface, optimized for V-ribbed belts commonly used in BMW and Mini vehicles. With two mounting holes, the tensioner ensures a secure fit and stable operation. The bearing bore inside diameter measures 0.67 inches (17 mm), supporting smooth rotation and reducing friction. The outside diameter of 2.56 inches (65 mm) and width of 1.02 inches (26 mm) are designed to match OEM specifications, making the Gates 39400 a reliable replacement part for maintaining proper belt tension and alignment.

Common Applications and Issues Addressed

• Restores proper tension to V-ribbed accessory drive belts
• Eliminates belt slippage and associated noise
• Prevents premature belt wear and damage
• Corrects misalignment issues in the belt drive system
• Supports smooth operation of engine accessories such as alternator and power steering pump

Installation Notes and Tips

When installing the Gates DriveAlign Premium OE Automatic Belt Tensioner 39400, ensure the mounting surface is clean and free of debris. Verify the tensioner aligns correctly with the V-ribbed belt path on BMW Cooper, Cooper Clubman, Cooper Countryman, Cooper Paceman, X1, and X2 models. Use appropriate tools to secure the two mounting bolts firmly without over-tightening. After installation, inspect belt tension and pulley alignment to confirm proper operation.

Quality Assurance and Warranty

The Gates DriveAlign Premium OE Automatic Belt Tensioner 39400 is manufactured to meet original equipment standards, providing consistent performance and durability. This part carries an OE exact comparison rating, ensuring it matches factory specifications for fit and function. While specific warranty details are not provided here, Gates products typically come with manufacturer-backed quality assurance to support reliability in automotive applications.