Automatic Transmission Oil Cooler Line Connector (800-759) by Dorman®. Location: to Rear Of Transmission. Quantity: 1 Piece. Thread: 1/4″ x 18 x 1.85″. Dorman’s Auto Trans Oil Cooler Line Connectors are constructed from high-quality materials to provide a leak-free connection between transmission lines or between the radiator and the transmission. Replacement restores the radiator to proper operation.