COLLARIN EJE 2-1/2`` (AL)

Function and technical context

The 2-1/2" aluminum shaft collar is the component responsible for fixing and centering the transmission shaft as it passes through the hull of the boat, guaranteeing correct alignment between the engine and propeller. It is part of the power transmission system, working in close relationship with the bollard, the stuffing box and the shaft bearings. Its function is to axially retain the shaft and prevent unwanted longitudinal displacements that could compromise the transmission of engine torque. The aluminum manufacture makes it especially suitable for marine environments where corrosion resistance combined with reduced mass is required. A poor collar can cause abnormal vibrations, accelerated stern tube wear, and even water entry into the hull if the sealing assembly is compromised.

When to replace this part?

The most common symptoms of a deteriorated shaft collar are noticeable vibrations in the engine room or on the floor of the boat, clunking or scraping noise from the running shaft, and visible play when manually moving the shaft longitudinally. It is recommended to inspect the collar at each annual beaching or each time the transmission system is intervened; Since it works in an environment of continuous exposure to salt water, galvanic corrosion can compromise its integrity even if it does not externally present obvious damage. Replacing it preventively during seasonal maintenance prevents serious navigation breakdowns and prolongs the useful life of the shaft and tube assembly.

Compatibility table