Description
Product Overview
Part Name: Engine Belt Tensioner
Part Numbers: 3979979 / 20935521 / 3979579 / 20739751 / 21422765 / 21819687 / 7403979979
Vehicle Compatibility: Suitable for Volvo FH and Volvo FM trucks equipped with Euro 4, Euro 5 and Euro 6 engines between 2010–2024. Ensures correct auxiliary-belt tension for alternator, water pump and compressor systems.
Configuration: Constructed with a hardened steel pulley, sealed high-load bearing and precision spring arm. Designed to deliver stable belt alignment, reduced vibration and long-term tension reliability in heavy-duty applications.
Function: Maintains proper belt tension, prevents slippage, minimizes noise and supports reliable rotation of engine accessories essential for cooling, charging and air-management systems.
Technical Specifications
Type: Heavy-duty belt tensioner assembly
Material: Reinforced steel pulley with sealed bearing and corrosion-resistant tensioner housing
Application: Fits Volvo FH and FM engines requiring the listed tensioner part numbers
Cross-Reference: Matches OEM tensioners with identical pulley diameter, mounting footprint and spring load characteristics
Installation: Replace when belt wear, vibration, bearing noise or tension irregularities occur
Service Interval: Typically renewed every 150,000–250,000 km depending on usage and service conditions
Delivery & Availability
Stock Options: Engine belt tensioners available in ready stock
Delivery Time: 3–7 days internationally
Payment & Security
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.