COLLARIN EJE ALTA RESISTENCIA Ø 28 mm (Z

Function and technical context

The high-strength shaft collar with a diameter of 28 mm is a component of the underwater transmission that works directly on the tail shaft, acting as a retaining element and axial positioning of the same within the horn or shaft support. Its main function is to maintain the shaft in its correct longitudinal position, avoiding axial displacements that could compromise the alignment between the motor, coupling and propeller. When working in an environment of continuous immersion and subject to the vibrations typical of marine propulsion, the quality of the material and the dimensional fit are decisive: a worn or broken collar can cause axial play in the shaft, generating excessive vibration in the hull, accelerated wear of the stuffing box or the horn, and even the entry of water into the interior of the boat if the sealing system is compromised.

When to replace this part?

The most common symptoms of a deteriorated shaft collar are the appearance of unusual vibration or noticeable knocking in the tail shaft, detectable axial play when manually moving the shaft with the engine stopped, and premature or asymmetrical wear of the stuffing box or stern tube bearing. It is recommended that the collar be inspected at each seasonal maintenance or each time the shaft is disassembled for alignment work or propeller replacement. Replacing it preventively in the event of any sign of visible wear, corrosion or loss of adjustment avoids serious navigation breakdowns and the high cost of an emergency grounding.