The Warner hydraulic marine gear assembly consists of a hydraulically operated multiple disc clutch in combination with
a hydraulically actuated reversing gear train, an oil pressure regulator, an oil sump independent of the engine oil system
and an oil cooler mounted on the engine.
Oil pressure for the operation of the marine gear is provided by an oil pump incorporated within the gear housing and
driven continuously while the engine is running. The oil is delivered under pressure from the pump to a combination
marine gear control valve and pressure regulator valve.
The pressure regulator valve maintains constant pressure over a wide speed range and the control valve directs the oil
under pressure to either the forward or reverse piston cylinder. The operating oil pressure range for the marine gear at
operating speed is 120 to 140 psi (827 to 965 kPa) and the maximum oil temperature is 225°F (107°C). Minimum oil
pressure is 100 psi (689 kPa) at idle speed (600 rpm).
Shifting from forward to reverse drive through neutral may be made at any speed; however, it is advisable to shift at low
speeds, below 1000 engine rpm, to avoid damage to the engine, reverse gear or shaft. The marine reverse and reduction
gear is lubricated by pressure and splash. The quantity of oil in the marine gear will vary with the inclination of the
engine and must be properly maintained to the full mark on the dipstick to ensure satisfactory operation.
It is recommended that vessels utilizing a marine gear have-a suitable locking device or brake to prevent rotation of the
propeller shaft when the vessel is not under direct propulsion. If the marine gear is not in operation and the forward
motion of the vessel causes the propeller shaft to rotate, lubricating oil will not be circulated through the gear because the
oil pump is not in operation. Overheating and damage to the marine gear may result unless rotation of the propeller
shaft is prevented.
Consult an authorized Detroit Diesel Allison Service Outlet for major repairs or reconditioning of the marine gear.