PSS Shaft Seal, 2.5-Inch Shaft, 4-Inch Tube

For larger boats with a 2.5 in propeller shaft and a 4 in stern tube, this PSS shaft seal replaces the packing gland with a dripless mechanical seal. A stainless rotor spins with the shaft against a fixed carbon sealing face. The result is a dry stern tube with no packing to tighten or replace.

The bellows keeps steady pressure between the sealing faces as the shaft turns. Sizing has to match exactly, since shaft diameter, tube diameter, and compressed length all affect how well it seals. Larger shafts also need correct venting or water injection to keep the faces cool.

Verify the shaft and stern tube measurements before installation and follow every PSS installation step. After launch, inspect for leaks and proper cooling, and stick to the bellows replacement schedule. Browse more Engine Parts & Maintenance for other drivetrain parts.

Key Features

• Fits 2.5 in shaft, 4 in stern tube
• Dripless mechanical seal
• Stainless rotor and carbon face
• Requires correct venting or water injection