TAIL GASKETS AND SEALS KIT 5031456

Function and Technical Context

This outboard motor stern seal and gasket kit ensures a watertight seal for the internal components of the transmission and stern shaft, preventing saltwater or freshwater from entering the motor-stern assembly. It operates within the transmission and propulsion system, acting as a protective barrier at the joints between the lower section (gearbox) and the upper section of the propulsion unit. A failure in any of these gaskets or seals can lead to water contamination of the gearcase oil, accelerated corrosion of gears and bearings, and in severe cases, total loss of propulsion. The kit combines all the necessary sealing elements for a complete overhaul or replacement of the stern drive into a single package, making the task easier for the mechanic and ensuring a comprehensive renewal of the sealing system. It is compatible with Johnson, Evinrude (OMC), and Suzuki engines in the 40 and 50 hp ranges, with direct equivalence to Sierra part number 18-8337 and OMC part numbers 0769586 and 5031456.

When should this gasket and seal kit be replaced?

The most common symptoms indicating deterioration of the stern seals and gaskets are the presence of emulsified water in the gearbox oil (whitish or milky-colored oil when a sample is extracted), visible oil stains in the joint area between the stern and the transom, or abnormal vibration during navigation associated with play in the shaft. It is recommended to inspect and replace the stern sealing kit every season or whenever the gearbox is opened for an oil check, as this replacement is low-cost compared to repairing gears damaged by water contamination. Performing this replacement as a preventive measure every time the stern drive is disassembled is the practice most recommended by marine repair shops to avoid costly breakdowns while underway.

Compatible Johnson/Evinrude Engines

Equivalent Manufacturer Part Numbers