OIL BOTTLE GUN

Function and technical context

The 55005 Tail Oil Metering Gun is a precision tool designed specifically for the controlled introduction of lubricant into marine propulsion tail drive systems, including MerCruiser Alpha and Bravo units and OMC systems. It acts directly on the transmission lubrication circuit, where the tail oil protects helical gears, thrust bearings and O-rings subjected to high torsional loads and the permanent aggressiveness of the marine environment. Its calibrated dosing system ensures that the volume of lubricant introduced is exactly what the manufacturer specifies for each tail model, eliminating both underfilling and overdosing, both of which are detrimental to the integrity of the seals and the internal pressure of the system. In salt water environments, where galvanic corrosion acts rapidly on the metal components of the transmission, correct lubrication is the first line of defense against gear seizure and premature deterioration of propeller bearings.

When to use or replace this tool?

This dosing gun must be used for each tail oil change, an operation that the manufacturers MerCruiser and OMC recommend carrying out at least at the beginning and end of each nautical season, or every 100 hours of navigation on intensive use vessels. Indicators that indicate the urgent need to change the tail oil include the milky or grayish color of the lubricant when the check rod is removed—a direct indication of water contamination due to seals in poor condition—as well as a level below the minimum or the presence of metal particles in the extracted oil. Having a suitable filling tool such as this gun allows the procedure to be carried out without spills, without the risk of introducing air into the circuit and with the security of correct filling from the bottom point of the tail, which prevents serious transmission breakdowns during the navigation season.

Equivalent manufacturer part numbers