Importance of seals in the transmission and shaft area
Gearbox and shaft seals are critical components in the drivetrain. They prevent lubricating oil from escaping and water or dirt from entering the gearbox and shaft guides. Functioning sealing systems ensure lasting performance, prevent consequential damage to bearings and gears and reduce maintenance costs.
What are transmission seal kits?
Transmission seal kits are complete sealing kits that contain all relevant sealing rings, O-rings, housing seals and shaft seals for a specific Yanmar transmission or shaft area. Thanks to the package concept, all the necessary seals for a complete overhaul or repair are available, which reduces service times and incorrect orders.
Shaft seals - function & use
Shaft seals are elastic seals that seal rotating shafts and:
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Prevent oil loss from the gearbox housing
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Prevent the ingress of water and dirt
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Ensure low-friction guidance of the shaft
They are indispensable in areas with lubrication systems and water contact, e.g. for saildrives, Z-drives or shaft guides.
Gearbox seal kits - structure & components
A gearbox seal set typically comprises
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Housing and flange seals
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O-rings for axial/radial sealing connections
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Shaft seals and bearing seals
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Special seals for covers/service openings
These sets are matched to the correct material and shape and ensure tight transitions between assemblies.
Selection criteria: Engine & gearbox type
For the right choice of seal kits/seals, you should note the following:
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Yanmar engine and transmission model
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Transmission or Saildrive type (e.g. mechanical/electrical)
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Year of manufacture & serial number
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OEM reference number of the original part
Only an exact assignment ensures a precise fit, tightness and long service life.
Assembly and installation instructions
The following applies when installing the seals:
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Remove old seals completely, clean surfaces
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Createclean, grease-free sealing surfaces
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Align new gaskets precisely, do not damage them
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Observe the tightening torques according to the manufacturer's specifications
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Replace gear oil/lubricant and check system
Careful assembly prevents leaks and increases the service life of the system.
Maintenance, inspection & typical fault patterns
Regular inspection and maintenance includes
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Visual inspection for residual oil traces on housing/flanges
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Checking shaft seals for ageing/brittleness
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Function test after service and seal replacement
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Replacement in the event of recognizable leaks or pressure loss
Typical signs of a sealing problem are oil film, leaking lubricant, increased consumption or noise in the gearbox area.
