Free - Twin Disc MG-509 Troubleshooting Guide Twin Disc MG 509 Marine Transmission Parts - Rubber Block Section Loading... 1 Rubber block for Twin Disc marine gears . Price: $ 7.26 Qty: ^ Pictures In Stock Add to Cart 2 Allison and Twin Disc Coupling for marine gear . Price: $ 900.00 Qty: ^ Pictures Availability Out of stock 3 Mechanical & Electric Gauges See Our Gauges Page 4 Controls Cables & More... See All Control, Cables & More 5 Marine Water Pumps See All Marine Water Pumps 6 Fresh Water Pumps See All Fresh Water Pumps Free - Twin Disc MG-509 Troubleshooting Guide