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R & D Flexible Shaft Coupling f/5" B/W, Hurth - 20HP/100RPM Capacity

SKU 910-029
Sold out
Original Price $855.00
Current Price $704.00

Experience a smoother, quieter, and more durable boat drivetrain with the R&D Flexible Shaft Coupling. Engineered to protect your investment, this coupling absorbs vibrations, misalignment, and shock loads, ensuring the long-term reliability of your boat's transmission.

  • Vibration and Noise Reduction: The polyurethane flange creates a flexible barrier that minimizes drivetrain noise and vibration, providing a quieter and more comfortable boating experience.
  • Shock Load Protection: The coupling absorbs transmission shock loads caused by the propeller and high-speed gear changes, helping to prevent costly transmission damage.
  • Fail-Safe Design: The steel compression straps ensure the coupling remains functional in both forward and reverse, even in the event of a polyurethane disc failure, for uncompromised performance.

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  • Description
  • Shipping & Returns
  • Flexible Shaft Coupling for 5" B/W, Hurth - 20HP/100RPM Capacity

    The R&D Flexible Couplings are fabricated from a contoured flexible disc molded in tough yet resilient new type polyurethane. The contoured disc gives clearance for the bolt heads, and is able to flex freely to take up any temporary misalignment of the engine and shaft, due to flexing of the boat structure or the engine moving on its rubber vibration isolation mountings. Forward thrust is taken in compression on the disc between the two half couplings and reverse thrust is taken again in compression on the disc between the two fail straps. In the unlikely event of a disc failure the steel straps make the coupling fail safe and ensure drive is maintained in both forward and reverse.

    To calculate power of coupling required:
    Horse Power of Engine x Reduction Ratio x 100 = HP/100RPM
    Engine Speed

    Example:
    Ford 150 HP at 2500 RPM with Borg Warner Velvet Drive 72C 2:1 Reduction Ratio
    Engine Horse Power is 150 HP, Max Rated RPM is 2500, Reduction Ratio is 2:1
    150/2500 X 2 x 100 = 12hp per 100RPM
    Coupling required is 910-009

    The R & D Marine Flexible Coupling fits between the transmission output flange and shaft coupling. It is designed to protect a boat's drivetrain. The unit will reduce vibration, compensate for some misalignment, isolate the shaft and absorb shock loads.

    The flexible disc is machined from a resilient and durable polyurethane. It allows the unit to flex, absorbing vibrations and temporary misalignment of the shaft and engine due to movement of the engine or flexing in the vessel's structure.

    The polyurethane disc is backed up by two metal compression straps, one on either side of the flexible coupling. These metal straps hold the system in constant compression whether the drivetrain is in forward or reverse. This feature extends the life of the system dramatically.

    The R & D Marine Flexible Coupling will also absorb shockloads resulting from gear changes, or the propeller striking a submerged object. The polyurethane disk will distort with light shock loads and is designed to be sacrificial in the event of severe shock load, saving on expensive drivetrain repairs. If the disc is destroyed from massive shockload the metal compression straps keep the coupling intact ensuring that the drive system is functional in both forward and reverse.

    Why R&D Marine Flexible Shaft Couplings?
    • Polyurethane flange creates a flexible barrier to reduce drivetrain noise and vibration to quiet your drivetrain
    • Absorbs transmission shock load caused by the propeller and high speed gear changes. This helps to reduce and avoid costly transmission damage
    • Fail safe design, both forward and reverse thrust is taken in compression from the steel straps, giving a durable design even in extreme conditions
  • Shipping

    Most orders ship on the same business day or the next business day. Some orders ship directly from the manufacturer, and these may take an additional 1-2 days to process, depending on the manufacturer. Contact us to confirm ship times.

    We currently offer FREE 2-day shipping on all orders over $50 to the contiguous 48 states in the USA.

    Flat rate shipping of $7.95 USD for orders under $50 within the contiguous 48 states.

    Overnight shipping rates available at checkout. 

    Shipping for orders to states or US territories outside of the contiguous 48 states will be calculated at checkout.

    30-Day, No-Hassle Returns

    To return an item, send an email to info@secondreef.co. Please include your full name and order number in your email.

    Returns must be requested within 30 days of the receipt of your order. The product must be returned unopened in the original packaging. We do not accept returns of used products.

    Refunds are subject to a 5% restocking fee to cover the non-refundable credit card processing fees we incur and the administration required.

    View our full shipping and returns policies here.