SHORT COLLAR 28mm SHAFT.

Function and technical context

The 28 mm short shaft collar is an axial positioning and fastening element that works directly on the boat's drive or tail shaft, ensuring that the shaft maintains its correct longitudinal position within the propulsion assembly. Its main function is to prevent unwanted axial displacement of the shaft, which is essential to preserve the alignment between the propeller, stern tube bearing and stuffing box. When this component shows excessive wear, corrosion or cracks, the shaft can experience axial play, generating abnormal vibrations in the propulsion line, premature wear of the horn and possible damage to the hull seal. Its correct installation is, therefore, critical for the integrity of the transmission system and for the operational safety of the vessel.

When to replace this part?

The most common symptoms of a deteriorated shaft collar include noticeable vibrations in the hull at certain revolutions, clunking or knocking noises coming from the shaft line, and visible or measurable axial play in the drive shaft. It is recommended to inspect the collar at each docking or seasonal maintenance, paying special attention to the condition of the fixing screws, possible fretting marks on the shaft and signs of galvanic corrosion. Replacing this component preventively in the event of any sign of looseness or wear prevents major breakdowns in the horn and stuffing box that could compromise navigation on the high seas.

Compatibility table