TM10-3930-660-20 18-23. BOOM CHAIN PULLEYS - REPLACE  (Cent’d) 5. 6. 7. SECURE RETRACT CHAIN CLEVIS (3). Secure retract chain clevis (3) with washer (2) and nut (1). Tighten nut (1) until locknut (4) is tight against boom. CHECK/ADJUST  CHAIN  ADJUSTMENT  ,  PARA. 18-24. CHECK/ADJUST HYDRAULIC HOSES AND ELECTRICAL CABLE , PARA. 18-25. REMOVAL -  EXTEND CHAIN PULLEY 1. FULLY RETRACT, THEN EXTEND BOOM SEVERAL INCHES . Loosen locknut (14) as needed to reduce chain tension during clevis pin removal. 2. 3. 4. 5. REMOVE RETAINER RINGS (15) AND CLEVIS PIN (16);   SEPARATE CHAIN FROM CLEVIS  (17). a. Remove retainer rings (15) and clevis pin (16) from extend chain clevis  (17). b. Separate chain (18) from clevis (17). LOOSEN HOSE TENSION. Loosen jamnuts (19). REMOVE TWO CAPSCREWS (20), TWO LOCKWASHERS (21), TWO FLATWASHERS (22), PULLEY SUPPORT (23), AND PULLEY  (24). a. Remove two Capscrews (20) , two lockwashers (21), and two flatwashers (22). Discard lockwashers  (21). b. Remove pulley support (23), and pulley (24) to provide workroom. REMOVE CAPSCREW (25) AND LOCKWASHER (26).  DISCARD  LOCKWASHER  (26). 18-92