Free - Twin Disc MG-506 Troubleshooting Guide Twin Disc MG 506 Marine Transmission Parts - Coupling Section Loading... 1 Twin Disc MG506 Coupling for Output Shaft For gears with the following ratios: 1.50 to 1, 1.97 to 1, 2.50 to 1 Price: $ 2,733.43 Qty: ^ Pictures In Stock Add to Cart Go Back Free - Twin Disc MG-506 Troubleshooting Guide