BEARING 30-18859M REC93306-204U0

Function and technical context

The 30-18859M REC93306-204U0 bearing is a precision bearing component that is part of the marine transmission system, responsible for providing axial and radial support to the propulsion shaft. This bearing ensures correct shaft alignment within the gearbox, allowing rotational forces to be efficiently transmitted from the motor to the propeller. It works in demanding operating conditions, supporting combined loads in a saline environment where corrosion and fatigue are critical factors. If this bearing wears or fails, the shaft loses alignment, causing excessive friction, abnormal drive vibration, and in extreme cases, can cause irreversible damage to the entire drive system.

When to replace this part?

Symptoms of transmission bearing wear include unusual vibration while cruising, grinding or grinding noise from the gearbox, and progressive loss of precision in shaft engagement. It is recommended to inspect this component during each seasonal maintenance and, especially, if changes are detected in the dynamic behavior of the propulsion. Preventatively replacing the bearing before wear worsens prevents offshore repairs and prolongs the life of the entire marine drive chain.

Engine Compatibility Table

Mercury/MerCruiser

Equivalent manufacturer part numbers