FLAT COLLAR 120mm.

Function and technical context

The 120 mm flat collar is a fastening and sealing component that acts as a coupling or retaining element in transmission systems, tail shafts or pipelines of outboard and stationary marine engines. Its main function is to keep the mechanical assemblies where it is installed aligned and watertight, avoiding unwanted axial displacements and guaranteeing the integrity of the assembly. A flat collar in poor condition can cause looseness in the shaft, abnormal vibrations, loss of tightness or even damage to higher-cost adjacent components, such as seals, bearings or the drive shaft itself. Its correct installation and periodic replacement is key to the reliability and safety of the boat.

When to replace this part?

The most common symptoms of a damaged flat collar include unusual vibrations in the drive line, metallic noises when the shaft rotates, or noticeable play in the assembly where it is housed. It is recommended to visually inspect this component during each seasonal maintenance, paying special attention to galvanic corrosion marks, deformations or loss of roundness. Replacing the flat collar preventively when detecting the first signs of wear prevents more serious navigation breakdowns and considerably reduces the total repair cost.