Cushion Hub Bushings 

To protect propeller, engine and lower gear unit gears, most manufacturers of outboard and sterndrive engines provide their propellers with built-in rubber shock absorbing cushion hubs. The reason for this required protection is that most modern gearshift motors transmit shock when shifting gears and also to absorb shock if the propeller hits an object. In other words, the cushion hub reduces the inertia effect on the propeller. Remember, a cushion hub is a safety device designed to break down and slip under excessive torque loading. The cost of the cushion hub replacement is relatively inexpensive when compared with expensive engine damage, which could result if the device did not slip or if the propeller is converted to a solid drive.

Many Mercury Marine Propeller Co. propellers now utilise the new corrosion resistant Flo-Torq II Hub assembly which allows cross compatibility between most brands of recreational outboard and sterndrive engines. The "slide-in" nature of the Flo-Torq II Hub assembly allows customers to easily and quickly replace damaged hubs themselves.