Gates K040311SF Serpentine Belt - Air Brake Compressor or Air Pump

OE Stretch Fit Belt for Accessory Drive Systems

The Gates K040311SF Premium OE Stretch Fit Micro-V Belt is built for vehicles that use a stretch-fit accessory drive system instead of a conventional tensioner setup. Its self-tensioning design helps the belt seat correctly on the pulley path for steady accessory drive performance.

For drivers searching for a stretch fit serpentine belt for Ford and Lincoln applications, the K040311SF offers OE exact comparison rating and Gates Micro-V construction in a 4-rib, 14 mm profile.

Key Features

• Gates Premium OE Stretch Fit Micro-V Belt
• Part number K040311SF for direct identification
• Stretch-fit automotive V-ribbed belt design
• 4-rib construction with 14 mm top width
• Effective length: 31.1 in. / 790 mm
• Outside circumference: 31.820 in. / 808 mm
• Nylon cord material for belt stability
• OE Exact comparison rating

Product Details

Gates Micro-V Stretch Fit Belts use self-tensioning technology to match unique stretch-fit drive systems, helping the belt install and operate at the intended tension without a separate adjustment procedure. This makes the K040311SF a practical choice for accessory drive belt replacement where OE-style fit and belt geometry matter. The Gates Premium OE Stretch Fit Micro-V Belt line is focused on coverage for modern stretch-fit applications, including Ford and Lincoln vehicles that specify this belt format.

This part cross-references Ford OE numbers (e.g., FC4Z 8620 H, 25-040311SF) for the same application.

What This Belt Helps Address

• Squealing or chirping from a worn accessory drive belt
• Cracking, glazing, or fraying on the existing serpentine belt
• Incorrect belt fit on stretch-fit pulley systems
• Loss of accessory drive consistency from belt wear
• Replacement needs on Ford and Lincoln stretch-fit belt applications

Installation Notes and Tips

Verify the belt length, rib count, and cross-section before installation. Stretch-fit belts are installed on systems built for that design, so follow the vehicle service procedure and use the correct routing path for the specific Ford or Lincoln application. Inspect pulleys and accessory drive components for wear before installing the new belt.

Quality Assurance

Gates is a long-standing supplier in the accessory drive belt market, and the K040311SF is built to OE Exact comparison standards for stretch-fit applications. Use the part number K040311SF to confirm the correct belt specification before ordering.