D-I INDUSTRIAL Co. Ltd is one of the world’s leading manufacturers of marine transmission, marine steering system and power take offs with a reputation as the most reliable company in the market.
D-I is chosen to supply marine transmission systems to major engine manufacturers including Doosan, Hyundai, Mitsubishi and Boudouin. D-I also supplies to distributors for Caterpillar, Cummins, John Deere, Scania and Volvo Penta among others for their marine engines and now supplies products to more than 50 countries.

Please click on one of the links below for more information on the vast range of Gearboxes, PTO’s & Steering systems available


Reverse reduction type with hydraulically actuated multi disc clutches. Suitable for high performance applications in workboats, fishing boats, commercial, tugboat, inland workboats etc. A robust design also withstands continuous duty in workboat applications. Fully works tested, reliable and simple to install. Design, manufacture and quality control standards comply with ISO 9001. Compatible with all types of engines and propulsion systems, including waterjets and surface piercing propellers, as applicable.

  • Cast-iron case, vertical off set and direct mounting.
  • Same torque capacity & ratio in both ahead and astern.
  • Easy maintenance & robust design.
  • Precisely ground gear teeth for long life and smooth operating.
  • “Go home” function in emergency.
  • Various applications : for pleasure, light, medium and contiuous duty.
  • Strictly quality controled by complying with ISO 9001.

Manual Steering Systems

  • Suitable for the smaller boats.
  • Easy installation due to the simple structure.
  • Adopting a superior quality seal for the piston of the cylinder to
    ensure the safe power transfer without internal leakage.
  • Chromium plated stainless steel bar to prevent the
    piston of the cylinder from corrosion.
  • Chromium plated connecting rod for anti-corrision.

Power Steering Systems

  • Convenient and easy maneuverability due to the small size of wheel.
  • Rudder will not move when hands are taken off of the wheel.
  • Manual maneuverability is possible due to the built-in auxiliary pump (orbitrol) in the steering wheel.
  • Chromium plated stainless steel bar to prevent corrosion of the piston and cylinder.
  • Regulated oil supply by the pump due to vane pump controlling the constant flow.

Power Take Off

A power take off is a device suitable for transferring power to multiple applications simultaneously. The main utility is to drive generators, hydraulic pumps, rollers or winches etc.

  • Independently driving two output shafts and a continuous rotating pulley on the input shaft.
  • Minimal engine power loss while the P.T.O is not in use by adopting a no-load circuit.
  • Brake system to prevent from dragging.
  • Zinc anode installed to help protect the oil cooler from corrosion.
  • Easy and direct installation of a hydraulic pump to the P.T.O . It is possible to install high-volume pump ( 200 ℓ / min, 175 kgf/cm2 ).