TM10-3930-660-20 18-23. BOOM CHAIN PULLEYS - REPLACE This task covers: a. Removal b. Installation Initial  Setup Tools Tool Kit, Automotive Mechanics Materials/Parts Lockwashers (6, 8, 21, 26) Loctite 242 (App. C, Item 39) Shop Equipment, Automotive Maintenance, Common #2 Less Reference Power TM10-3930-660-10 Equipment  Condition Vehicle parked on level ground. Boom lowered/retracted. REMOVAL   -   RETRACT   CHAIN   PULLEY 1. FULLY RETRACT BOOM, TM10-3930-660-10. 2. REMOVE CHAIN CLEVIS (3). a. Remove nut (1) and washer (2). b. Remove retract chain clevis (3).  DO not change the position of locknut (4). 18-90