COLLARIN EJE 1 1/4" STD (AL)

Function and technical context

The 1 1/4" aluminum shaft collar is a retention and positioning element that works directly on the boat's transmission shaft, ensuring that it does not move axially during navigation. Its function within the transmission system is critical: it maintains the correct alignment between the shaft and the bearings, preventing the axial loads generated by the propeller from moving uncontrollably into the interior of the hull. If this component fails or becomes loose, the shaft can shift longitudinally, causing severe damage to the stuffing box, stern tube bearings and, in extreme cases, water entering the interior of the hull. Its aluminum construction makes it especially suitable for marine environments where weight reduction and corrosion resistance are determining factors.

When to replace this part?

The most common symptoms of a worn or damaged shaft collar are: noticeable axial play in the drive shaft when manually pushed or pulled, abnormal noises or vibrations while driving, and premature or irregular wear of the stuffing box or horn. It is recommended to visually inspect the collar during each seasonal maintenance, checking that the fixing screws are correctly tightened and that there are no signs of galvanic corrosion, cracks or deformation of the housing. Replacing the collar preventively if there is any sign of looseness is a low-cost measure that can avoid serious breakdowns in the propulsion system, especially in offshore navigation where a repair in the water is not feasible.