T-H Marine CMC High Speed Hydraulic Power-Lift Transom Jack - 5-12 Set Back CMC High Speed Hydraulic Transom Jack is ideal for fresh or salt water use. Made of 6061 T6 alloy aluminum extrusions and fastened with stainless steel fasteners. This transom jack has no welds or castings to break. The CMC Hydraulic Transom Jack has a dependable, self-contained and waterproof hydraulic actuator that has a maximum lifting capacity of 7853 pounds of thrust. You will have no problem lifting even a V-6 300