R & D Flexible Shaft Coupling f/5" B/W, Hurth, & Volvo - 25HP/100RPM Capacity

The R & D Flexible Shaft Coupling for 5" B/W, Hurth, & Volvo engines is engineered to solve one of the most common reliability problems in marine propulsion: misalignment between engine and gearbox. After decades on the water, any experienced boater knows that shaft coupling failure leads to expensive downtime and potential engine damage. This flexible coupling absorbs vibration and compensates for minor angular and axial misalignment, protecting your drivetrain and extending component life. Whether you're running a 25HP fishing rig or relying on consistent power for commercial operations, this coupling delivers the durability marine applications demand.

Built by R & D Marine with a 25HP/100RPM capacity rating, this coupling features a flexible design that reduces shock loads transmitted through the drivetrain during acceleration and rough water operation. The 5-inch bore width accommodates B/W, Hurth, and Volvo gearbox configurations—the workhorses of recreational and commercial marine engines. The flexible element isolates torsional vibration while maintaining precise shaft alignment, which is critical for fuel efficiency and smooth operation. At just 5 pounds and compact dimensions of 6 x 4 x 6 inches, installation is straightforward, and the unit requires minimal maintenance once properly seated on the shaft.

Boaters and marine technicians standardly specify R & D flexible couplings as preventive upgrades during routine engine service or when replacing transmissions. The coupling is compatible with inboard installations featuring B/W, Hurth, and Volvo gearboxes in the mid-range horsepower category. Proper installation—ensuring the coupling is centered and securely fastened—guarantees years of vibration-free operation. For anyone operating an older or moderately-powered inboard vessel, this component is insurance against unexpected shaft failure and the consequent repair costs that catch most boaters off-guard.