PSS Shaft Seal 1-¾" Shaft 3-½" Tube

The PSS Shaft Seal 1-¾" Shaft 3-½" Tube is a critical marine engine component designed to prevent water intrusion and oil leakage where your drive shaft passes through the hull. After years on the water, every serious boater knows that a failing shaft seal means a flooded bilge, rust, and expensive engine damage—sometimes in the middle of your best fishing trip. This PSS seal is purpose-built to maintain a watertight barrier while allowing smooth shaft rotation, making it an essential maintenance item for inboard and I/O vessels with 1-¾" diameter shafts.

This shaft seal operates using a dual-action design: a rotor that spins with the shaft and a stationary carbon cuff that creates a precision seal against saltwater and freshwater environments. The 3-½" stern tube diameter accommodates a wide range of modern hull configurations, while the total length of 9.175" (compressing to 8.175" when fully installed) ensures proper engagement in standard shaft logs. The robust construction handles the constant rotation, vibration, and pressure cycling that marine propulsion systems demand, resisting corrosion and wear far longer than emergency patch-ups or inferior aftermarket alternatives.

Whether you're cruising coastal inlets or anchoring in freshwater lakes for days at a time, this PSS Shaft Seal replacement prevents the slow seep that turns a weekend into a salvage operation. Installation requires draining the shaft log and removing the old seal—a job most experienced boat owners can handle with basic marine tools in an afternoon. Verify your shaft diameter and stern tube size before ordering; this model fits 1-¾" shafts in 3-½" to 3-⅝" diameter tubes, making it compatible with most recreational and light-commercial inboard installations built over the past two decades.