Sierra Drive Bellows 18-2747, Medium Size, Replaces Mercury Marine 816431A1

The Sierra 18-2747 Drive Bellows is a medium-sized replacement bellows designed for stern drive applications, serving as a direct equivalent to Mercury Marine OEM part 816431A1. This bellows forms part of the sealing system between the transom and the outdrive, protecting the U-joint, driveshaft, and gimbal bearing assembly from water intrusion while allowing the drive unit to pivot and tilt during steering and trim operation. Over time, drive bellows are subject to constant flexing, exposure to fuel, oil, and saltwater or freshwater, which causes the rubber to deteriorate, crack, or lose its watertight seal -- a failed drive bellows is a common cause of water entering the boat's bilge through the drive unit. Replacing a worn or cracked bellows with the Sierra 18-2747 restores a proper watertight seal at this critical point in the drive train.

Sold as a single unit (package quantity of 1), the Sierra 18-2747 is manufactured to match the fit and function of the original Mercury Marine 816431A1 bellows, making it a straightforward drop-in replacement for boat owners and marine technicians servicing the drive shaft area of applicable stern drive units.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2747
• Product Type: Drive Bellows
• Size: Medium
• Package Quantity: 1
• Weight: 1.14 pounds
• Package Dimensions: 13.97 cm (L) x 13.97 cm (W) x 13.208 cm (H)
• Country of Origin: Taiwan
• UPC: 030999752956
• GTIN: 00030999752956

Replaces (OEM)

• Mercury Marine 816431A1

Frequently Asked Questions

What is the Sierra 18-2747 drive bellows used for? It seals the connection between the transom and the outdrive on a stern drive unit, protecting the U-joint, driveshaft, and gimbal bearing area from water intrusion while allowing the drive to pivot and tilt.

What size is the 18-2747 drive bellows? The 18-2747 is a medium-sized drive bellows, as designated in its listing title.

What OEM part number does the 18-2747 replace? It replaces Mercury Marine part number 816431A1.

How much does the Sierra 18-2747 drive bellows weigh? The Sierra 18-2747 drive bellows weighs 1.14 pounds.

What are the package dimensions of the 18-2747 bellows? The package measures 13.97 cm long by 13.97 cm wide by 13.208 cm high.

How many bellows come in the package? One drive bellows (18-2747) is included per package, matching the package quantity of 1.

Where is the Sierra 18-2747 manufactured? The 18-2747 drive bellows has a country of origin of Taiwan.

Is the Sierra 18-2747 a genuine OEM part or a replacement equivalent? The 18-2747 is a Sierra-branded replacement bellows manufactured to match the fit and function of OEM Mercury Marine part 816431A1, rather than a Mercury-branded original part.

What UPC is associated with the 18-2747 drive bellows? The UPC for the Sierra 18-2747 drive bellows is 030999752956.

Why would a drive bellows need to be replaced? Drive bellows like the 18-2747 flex constantly and are exposed to water and fuel, which over time causes the rubber to crack or lose its seal, allowing water to enter through the drive unit -- replacing it with the correct size, such as this medium 18-2747, restores the watertight seal.