Propeller shaft seal, water-lubricated, 50mm (70mm tube) with water inlet - 3819723

This water-lubricated propeller shaft seal is a proven, low-maintenance solution for boats with a 50mm propeller shaft and a 70mm stern tube . The seal replaces the Volvo Penta 3819723, among others, and is widely used in both maintenance and repowering of propeller shaft systems.

The rubber stuffy box uses water lubrication combined with a grease reservoir , minimizing friction, wear, and leakage. Annual lubrication with propeller shaft grease is sufficient for reliable operation.

Technical operation

This propeller shaft seal combines a flexible rubber housing with internal sealing lips. During operation, outside water reaches the seal through the stern tube, ensuring continuous cooling and lubrication of the sealing lips. This creates a durable water barrier without excessive wear on the propeller shaft.

The seal is mounted below the waterline and is suitable for mounting on almost any conventional propeller shaft installation.

Dimensions

• Axle diameter (A): 50.00 mm
• Propeller shaft tube (B): 70.00 mm
• Length (L): 120,00 mm

Key Benefits

• Suitable as a replacement for Volvo Penta 3819723
• Quick and easy installation
• Water lubricated for low friction and long life
• Very low maintenance (lubrication once a year)
• Compact construction
• Ideal for repowering or overhaul

Installation & maintenance

The propeller shaft and stern tube should be clean, smooth, and free of burrs. After installation, the supplied propeller shaft grease is applied to the seal. After launching, the seal should be pressed against the propeller shaft several times to activate the water lubrication and bleed the Volvo Seal.

Under normal conditions , lubrication once a year or every 200 operating hours is sufficient. Replacement is recommended after approximately 4 years or 500 operating hours .

📄 Installation Guide: View the official instructions (PDF)

Application

Suitable for motorboats and sailboats with a conventional propeller shaft installation. Widely used as an alternative to traditional grease gaskets and older rubber seals.