Twin Disc Marine Transmission MG-5050SC

Warning: This procedure requires trained personnel with PPE!

Check for lint or other material from rags or towels used in the parts cleaning process

Check for chips or shavings in the transmission system

For units with spin-on filters, this will require cutting the filter element apart to access the element core

If the filter is clean, install a new filter element and then change the oil and filter element after 1000 hours of service. If the filter is dirty, change the element and operate for another eight hours. Check the filter again.

Situations involving debris in the hydraulic system will require that heat exchangers and all connecting lines and hoses be thoroughly cleaned. If the heat exchanger cannot be disassembled, or if it cannot be assured that all debris is removed, the heat exchanger should be replaced.

Remove and clean the suction strainer at every oil change or sooner if necessary

Drain the transmission by removing the oil drain plug from the rear/bottom of the transmission

Change oil and filter element after each 1000 hours of operation, or six months, whichever comes first. Change the oil more frequently if conditions warrant.

Remove and clean the suction strainer at every oil change or sooner if necessary. See illustrations in Section 6.2 for the location of the suction strainer for your transmission.

Drain the transmission by removing the oil drain plug from the rear/bottom of the transmission. See the illustrations in Section 6.2 or service literature for your transmission for location of transmission and filter drain plugs.

NOTE: Dispose of used oil and oil filters in accordance with federal, state or local laws. Exercise precautions to prevent environmental contamination during any transmission servicing procedure.

1. Remove the breather or the oil fill closure from the top of transmission case.

2. Pour new oil through breather or closure opening. Fill with recommended clean oil, taking necessary precautions to prevent entry of dirt or debris. (See lubrication plate on transmission and information transcribed to the front of this manual for additional oil information.);

See the transmission lubrication plate. Capacity given will be the internal quantity required to fill the transmission to its proper level, but may not include the quantity to fill the external hoses and heat exchanger. Check oil level per Section 3.3, Start-Up.

1. Place the transmission control in NEUTRAL.

2. As soon as engine starts, check the transmission oil pressure (oil pressure gauges are required for all installations). Pressure should register within 15 seconds. If no pressure is indicated, stop the engine and determine the cause.

3. Check the oil level as follows.

a. Fill the transmission to LOW mark on the dipstick.

Run the engine at idle until oil temperature reaches operating range.

b. Continue running at idle and check the oil level with the oil level gauge (dipstick). The level should be at the FULL mark on the gauge. Add or remove oil as necessary to bring the level to the FULL mark on the gauge.

Engine running at low idle and marine transmission in neutral

Transmission control in NEUTRAL

Pressure registered within 15 seconds

Transmission filled to LOW mark on the dipstick

Warning: Do not obstruct the flywheel housing vents

Free flow of air for cooling the coupling

Operating air temperatures above -6°C (22°F) and below 82°C (180°F) must be maintained

Visual inspection of the coupling after the first 100 hours of operation

Visual inspection of the coupling every 2000 hours thereafter, or every six months, whichever comes first

Check for torsional vibration, misalignment, degradation by contaminants (oil), heat, ultraviolet radiation, and excessive system torque

Check for cracks or other signs of distress on the surface of the rubber

Check the flywheel housing vents frequently