to fig3 and 4 a flexible coupling 45 has a driven half 46 and a driver half 47 the driven half 46 is securely connected to a winch drum drive shaft 33 by a key 48 positioned in a key way 49 formed between the shaft 33 and the face of a coaxial bore 50 the key 48 is secured in the key way 49 as by two radially counter sunk externally threaded set screws 51 the driven half 46 is further secured to the shaft 33 as by one or more radially counter sunk externally threaded set screws 52 the outer face of a driven half 46 carries a series of six as shown axially projecting stud couplers 53 each stud 53 has a large diameter head and a threaded shank 54 rotatably inserted into a mating axial bore 55 a stud 53 is further secured to the driven half 46 as by a radially counter sunk externally threaded screw 56 the driver half 47 is securely connected to a hydraulic motor drive shaft 40 by a key 58 positioned in a key way 59 formed between the shaft 40 and the face of a coaxial bore 60 the key 58 is secured in the key way 59 as by one or more radially counter sunk externally threaded set screws 61 the driver half 47 is further secured to the shaft.