TM 9-2320-209-20-3-3 18-89. A-FRAME SHEAVE DISASSEMBLY AND ASSEMBLY (TRUCK M756A2) . NOTE This task is the same for the upper and lower sheave assemblies. This task is shown for the lower sheave assembly. TOOLS : 1 7/8-inch wrench (2) 7/16-inch wrench Pliers SUPPLIES : None PERSONNEL: One EQUIPMENT CONDITION: Truck parked, engine off, handbrake set. a. Preliminary Procedure. Remove sheave assembly from truck. Refer to TM 9-2320-209-10. 18-482