YAMAHA 93101-22M15 VERTICAL SHAFT UPPER SEAL

Function and technical context

The vertical shaft upper seal is a critical component on Yamaha outboard motors that seals the area where the drive shaft passes through the motor housing. This element works in the transmission system, preventing the entry of salt water and contaminants into the engine while allowing the constant rotation of the shaft. Its function is essential to maintain the tightness of the area most exposed to the marine environment, avoiding leaks that would compromise internal lubrication and cause accelerated corrosion in the precision components of the propulsion group.

When to replace this part?

Upper seal wear is typically manifested by loss of lubricant in the vertical shaft area, rust formation around the connection, or water ingress into the lower casing. This type of seal should be inspected at each seasonal inspection and replaced preventively every 5-7 years of continued use or when visible signs of elastomer degradation appear. The preventive change of this seal avoids costly repairs derived from internal corrosion and guarantees the tightness of the engine in high-altitude navigation.

Equivalent manufacturer part numbers