PSS PRO Shaft Seal 1-3/4" Shaft & 3-1/2" Tube

The PSS PRO Shaft Seal 1-3/4" Shaft & 3-1/2" Tube (MPN 03-134-312) is a mechanical face seal engineered for marine propulsion systems requiring superior corrosion resistance and extended service life. Built on a proven foundation of stainless steel and carbon sealing components, this professional-grade shaft seal adds reinforced silicone bellows and a secondary shaft retention collar to handle the demanding conditions of saltwater and freshwater boating environments.

Construction features 316 stainless steel hose clamps with rolled edges and non-perforated design, eliminating pinch points that trap water and accelerate corrosion. The PSS PRO Shaft Seal accommodates a 1-3/4" shaft diameter with a 3-1/2" tube fitment, making it compatible with mid-range inboard and inboard/outboard marine powerplants. An optional Nitronic 50 rotor upgrade is available for operators running highly corrosive environments—areas where standard stainless faces rapid pitting or crevice corrosion from mineral-laden or polluted water sources.

This seal is specified for serious cruising vessels, commercial fishing boats, and offshore tenders where downtime equals revenue loss. Weekend fishermen benefit from reduced maintenance intervals and longer intervals between seal replacements. The secondary shaft retention collar prevents catastrophic seal failure by capturing the rotor assembly in the event primary seal degradation occurs, providing a safety margin that budget marine seals lack.

PSS Shaft Seal is the market standard for high-performance marine mechanical seals, recognized across the recreational and commercial boating sectors for consistent leak-free operation and extended component life in salt spray and immersion environments. This PRO specification represents the upper tier of PSS's product line, justifying the investment for boats that demand reliability.