Twin Disc Marine Transmissions

Twin Disc was founded in 1918 and produced the first "dual disc" clutch available for tractors. This new clutch was designed to work under high horsepower and torque conditions which would normally burn out a single disc clutch. Twin Disc quickly began to also produce transmissions for construction equipment, industrial torque converters, and marine transmissions.

Today, Twin Disc manufactures more than 100 different marine transmissions in two basic categories: standard shift and QuickShift. These transmissions can be used for applications requiring 35 horsepower to over 4,000 horsepower. Twin Disc's industrial-grade transmissions utilize helical gearing, oil-cooled clutches, and minimal external plumbing.

QuickShift Transmissions

Twin Disc's QuickShift transmissions employ a proprietary clutch actuating system to shift quickly and smoothly. This also allows maximum control at near-zero propeller speeds of less than 50 rpms. At the same time, shifting from neutral to either full reverse or full ahead is achieved with cushioned torque delivered instantly.

QuickShift transmissions provide excellent maneuvering control, instant propeller power, and a smooth power curve at full-throttle operation or slower speeds. Driveshaft power optimization also prevents any driveline shock. From pleasure craft to ocean-going vessels, there is a QuickShift transmission option for your needs.

Twin Disc Marine Transmission Duty Categories

Twin Disc marine transmissions are categorized by service definitions which include hours of usage, percentage of full-throttle operation, and applications. There are standard and QuickShift transmission options available for each of the duty categories below.

Light Duty

• Usage: Less than 1,500 hours per year.
• Full-throttle operation: No more than 2 hours out of 12.
• Applications: Planing-hull vessels (customs/patrol boats, fire boats, and sportfishing charter boats) as well as some stern and bow thruster boats.

Intermediate Duty

• Usage: Up to 2,000 hours per year for the MG(X)-5114 model and smaller ones. Up to 3,000 hours a year for models larger than the MG-5114.
• Full-throttle operation: 50% of operating time.
• Applications: Planing-hull vessels (crew boats, ferries, fishing boats), some stern and bow thruster boats, as well as some displacement hull yachts.

Medium Duty

• Usage: Up to 4,000 hours per year.
• Full-throttle operation: 80% of operating time.
• Applications: ferries, inland water tow boats, midwater trawlers, supply/crew boats.

Continuous Duty

• Usage: Continuous 24-hour operation
• Full-throttle operation: Little to no variation in power settings or engine speed
• Applications: displacement hull boats over 60 feet long, fish and shrimp trawlers, tug/tow boats

As a leader in marine transmission systems, Twin Disc's transmissions are well-known for being durable, quiet, and smooth shifting.