PSS Shaft Seal 2-¼" Shaft 3-½" Tube

The PSS Shaft Seal 2-¼" Shaft 3-½" Tube is the marine industry's leading mechanical shaft seal, engineered to prevent saltwater and freshwater ingress at the propeller shaft where it exits the stern tube. This seal system protects the bearing surface and stuffing box from corrosion and leakage—critical in both freshwater and saltwater environments where even minor seepage can lead to catastrophic bearing failure and costly engine damage.

Built for 2-¼" shaft diameters with a stern tube bore of 3-½" to 3-⅝", this seal assembly delivers a total length of 9.625" (8.375" when compressed), making it compatible with standard production and retrofit installations on vessels ranging from 30 to 60 feet. The carbon cuff design and rotor diameter of 4.2" work together to create a reliable dynamic seal that handles both forward and reverse shaft rotation without degradation. Installation as OEM equipment on countless production vessels worldwide confirms its proven performance and marine engineering acceptance.

This PSS shaft seal serves both weekend anglers maintaining single-engine fishing boats and serious offshore operators running multi-day blue-water expeditions. Whether protecting a 35-foot center console, a sportfishing yacht, or a commercial workboat, the seal prevents the slow seep that turns into bilge problems and the catastrophic failures that strand you at sea. Replacement intervals depend on hours and operating conditions, but the PSS design's compatibility with existing installation hardware means straightforward maintenance without major system redesign.