LOWER CASING 6F5-45312-01-4D

Function and technical context

The lower casing integrates the base structure of the powertrain, housing critical components of the water cooling system and the engine lubrication circuit. This piece works submerged in the marine environment, where it supports variable hydrostatic pressures and is exposed to corrosion due to salt contact. Its structural integrity is essential to avoid water infiltration into the internal passages, which would cause accelerated corrosion of cylinders, damage to bearings and progressive loss of engine power. Any crack, deformation or weakening of the seal puts the tightness of the closed refrigeration circuit at risk.

When to replace this part?

The lower casing should be inspected each boating season, especially after operations in silty waters or on rocky bottoms where contact or impact is likely. Symptoms indicating the need for replacement include water in the engine crankcase, visible corrosion with deep pits, cracks in the reinforcing ribs, or deterioration of the coupling flanges that compromises the tight seal with the top cover. Preventive replacement of this component during major overhauls prevents emergency repairs at sea and significantly extends the life of the propeller.

Equivalent manufacturer part numbers