PSS Shaft Seal 1-½" Shaft 2-¾" Tube

The PSS Shaft Seal 1-½" Shaft 2-¾" Tube is a marine mechanical seal engineered to prevent water intrusion where your propeller shaft passes through the hull. This component sits at the critical interface between your stern tube and shaft, creating a watertight barrier that keeps bilge water out and protects your engine compartment. PSS shaft seals have become the global standard for this application, installed as OEM equipment on countless production vessels and favored by serious cruising sailors and commercial operators who cannot afford failure.

This model accommodates a 1-½" shaft diameter fitted into a stern tube measuring 2-¾" to 2-⅞". The seal features a 3.75" rotor diameter and 3.25" carbon cuff diameter, with an installed length of approximately 9.175" that compresses to 8.175" under load. The 2" stern cuff length provides sufficient engagement for reliable sealing. The design uses dual-stage compression and a self-adjusting packing system that compensates for normal shaft wear over time, eliminating the need for periodic manual adjustment—a significant maintenance advantage on vessels operating offshore or in remote anchorages where service access is limited.

This shaft seal is specified for sailboats, trawlers, and auxiliary-powered cruising vessels with shafts in this diameter range. Whether you're dealing with a replacement during a haul-out, upgrading from an older stuffing box, or installing equipment on new construction, the PSS system eliminates the corrosion and maintenance headaches of traditional rope packing. Salt water exposure, thermal cycling, and shaft deflection all demand a seal that adapts rather than hardens—precisely what this design delivers across thousands of vessels worldwide.