COLLARIN EJE 1 3/4'' STD (ZN)

Function and technical context

The axle collar is the axial retaining element that maintains the drive shaft in its correct longitudinal position within the propulsion assembly, preventing unwanted displacements that would compromise the alignment of the drive train. It works in the propeller transmission and drive system, acting as a precision stop between the shaft and the pillow block or support bearing. Made of zinc (ZN), it also fulfills a passive cathodic protection function, sacrificing itself against galvanic corrosion that affects submerged metal components. Its correct operation is essential to maintain the design axial clearances: if it wears out or gives way, the shaft can move longitudinally, generating vibrations, accelerated wear of seals and bearings, and even loss of tightness in the horn. The nominal diameter of 1 3/4'' (inches) determines its fit on the shaft, so exact dimensional correspondence is imperative for safe installation.

When to replace this part?

The most common symptoms of a damaged shaft collar are: unusual vibration in the shaft line at certain revolutions, noticeable axial play when manually moving the shaft, premature wear of the horn seal or presence of water in the bilge associated with the stuffing box area. As it is a zinc component, visual inspection is simple: when the part has lost more than 50% of its mass or presents cracks, it must be replaced immediately. It is recommended to check the collar during each seasonal maintenance and replace it preventively every 1-2 seasons depending on the navigation conditions and the aggressiveness of the marine environment. Replacing the collar preventively is significantly more economical than repairing damage resulting from a failure in the shaft line while underway.

Compatibility