Sierra 18-2751 U-Joint Bellows, Medium, Replaces Mercury Marine 60932A4, Fits Mercruiser TR/TRS Drives

The Sierra 18-2751 is a medium-size U-joint bellows built to seal the connection between the transom assembly and the drive unit on Mercruiser TR/TRS stern drives, S/N 3377316 and up. This bellows keeps water out of the u-joint and gimbal area while allowing the drive to pivot and steer, protecting the u-joint, gimbal bearing, and driveshaft from water intrusion and corrosion. It is a direct equivalent for the Mercury Marine OEM part 60932A4, so it installs using the same mounting points and hardware as the original bellows it replaces. The product ships as a single U-joint bellows and includes a clamp for installation. Sierra manufactures this part (produced by Teleflex Marine) to a round profile matching the original equipment shape, and it is sized specifically for the medium application used on TR/TRS drives rather than the larger or smaller bellows used on other Mercruiser drive generations. Because stern drive bellows are wear items exposed to constant flexing, heat, and saltwater or freshwater immersion, replacing a cracked, torn, or hardened bellows before it fails is the standard way to prevent water from reaching the gimbal bearing, u-joints, and ultimately the engine. This bellows is sold under part number 18-2751 and should be matched to your drive's serial number range before ordering.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2751
• Item Type: U-Joint Bellows
• Size: Medium
• Shape: Round
• Included Components: U-Joint Bellows, Clamp
• Weight: 1.37 pounds
• UPC: 030999312921
• GTIN: 00030999312921
• Category: Mercruiser Bellows
• Manufacturer: Teleflex Marine

Fitment

• Mercruiser TR/TRS drives, S/N 3377316 and up

Replaces (OEM)

• Mercury Marine 60932A4

Frequently Asked Questions

What does the Sierra 18-2751 U-joint bellows fit? The 18-2751 is sized for Mercruiser TR/TRS drives, serial number 3377316 and up, sealing the u-joint and gimbal area between the transom assembly and the drive unit.

Is the 18-2751 a direct replacement for Mercury Marine 60932A4? Yes, Sierra part 18-2751 replaces Mercury Marine OEM part 60932A4 and uses the same mounting configuration.

How much does the U-joint bellows weigh? The Sierra 18-2751 U-joint bellows weighs 1.37 pounds.

What size bellows is this? This is the medium-size U-joint bellows in Sierra's 18-2751 lineup, matched specifically to TR/TRS drive applications.

What is included with part number 18-2751? The package includes one U-joint bellows and a clamp for installation.

What shape is the 18-2751 bellows? It has a round shape, matching the profile of the original equipment bellows on TR/TRS drives.

Who manufactures the 18-2751 bellows? It is a Sierra-branded part, manufactured by Teleflex Marine.

Why does a stern drive u-joint bellows need to be replaced? The bellows on a TR/TRS drive flexes constantly and is exposed to water, so it cracks or hardens over time; a failed bellows lets water reach the u-joints and gimbal bearing, which is why Sierra offers 18-2751 as a preventive replacement part.

Does the 18-2751 fit all Mercruiser drives? No, this specific part number is matched to Mercruiser TR/TRS drives with serial number 3377316 and up; other Mercruiser drive generations use different Sierra bellows part numbers.

What is the UPC for the Sierra 18-2751? The UPC for the Sierra 18-2751 U-joint bellows is 030999312921.

Is this a genuine Sierra part or an aftermarket copy? The 18-2751 is a genuine Sierra-branded U-joint bellows, manufactured by Teleflex Marine, not a generic aftermarket substitute.