Sierra Serpentine Belt 18-15100, Replaces 57-8638763, MerCruiser

The Sierra 18-15100 is a premium aftermarket serpentine belt engineered for MerCruiser applications, built to OEM specifications for correct fit, form, and function. Measuring 106.25 inches in length and 0.69 inches in width, this belt is constructed from high-quality polychloroprene rubber reinforced with polyester fiber tensile members, giving it strong resistance to marine engine oil exposure and stable performance across a wide temperature range. The adjustable serpentine design allows it to drive multiple engine accessories from a single belt path, making it a straightforward replacement for boat owners performing routine maintenance or addressing a worn, cracked, or glazed belt. Each Sierra belt is manufactured to consistent quality standards and is backed by Sierra's industry-leading customer satisfaction warranty, giving buyers confidence that the replacement part will perform as reliably as the original equipment it replaces. This belt is cataloged under Mercury Marine / MerCruiser serpentine belt applications and directly interchanges with OEM part number 57-8638763, so it can be ordered with confidence when that number is found stamped on the original belt or listed in engine documentation.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-15100
• Length: 106.25 inches
• Width: 0.69 inches
• Material: Polyester, Rubber
• Belt Style: Serpentine, Adjustable
• Color: White
• Weight: 0.6 pounds
• UPC: 808282145347
• Category: Mercruiser Serpentine Belts

Fitment

• Mercury Marine / MerCruiser

Replaces (OEM)

• 57-8638763

Frequently Asked Questions

What does the Sierra 18-15100 serpentine belt fit? The Sierra 18-15100 is cataloged for Mercury Marine / MerCruiser engine applications and is designed as a direct-fit replacement serpentine belt for those engines.

What is the OEM equivalent to Sierra 18-15100? Sierra 18-15100 directly interchanges with OEM number 57-8638763, so either number can be used to identify the correct replacement belt.

How long and wide is this belt? The Sierra 18-15100 serpentine belt measures 106.25 inches in length and 0.69 inches in width.

What material is the Sierra 18-15100 belt made from? It is constructed from polychloroprene rubber reinforced with polyester fiber tensile members, giving it oil resistance and temperature stability for marine engine use.

Is the Sierra 18-15100 a genuine Mercury part or aftermarket? The 18-15100 is a Sierra-brand aftermarket belt manufactured to OEM quality standards, not a Mercury-branded original part, but it is built to match the fit, form, and function of the original equipment belt it replaces.

How much does the Sierra 18-15100 belt weigh? The belt weighs 0.6 pounds.

What color is the Sierra 18-15100 serpentine belt? This belt is white in color.

Is this belt adjustable? Yes, the 18-15100 is an adjustable serpentine-style belt.

What is included when ordering the 18-15100? Each order includes one Sierra 18-15100 serpentine belt.

Does Sierra offer a warranty on the 18-15100 belt? Yes, the Sierra 18-15100 is covered under Sierra's industry-leading customer satisfaction warranty.

What UPC is associated with part 18-15100? The Sierra 18-15100 serpentine belt carries UPC 808282145347.