12-85. TM 9-2320-361-20 This task covers: a. Removal b. Installation INITIAL SETUP: APPLICABLE MODELS M764 REFERENCES (TM) TM 9-2320-361-10 TM 9-2320-361-20P EQUIPMENT CONDITION • Parking brake set (TM 9-2320-361-10). • Horizontal drivechain cover removed (para. 12-87). NOTE • The replacement procedure for first and second reduction leveling worm drivechains are the same. This procedure covers the second reduction drivechain. • Horizontal leveling worm drivechain may have cotter pins or a spring clip fastener for a retainer. This procedure covers a spring clip. 1. Loosen nut (3) and screw (2). 2. Hold shaft (4), and turn eccentric bushing (5) until first and second reduction drivechains (6) and (1) are loose. 3. Remove spring clip (11) and link plate (10) from connecting link (9). 4. Remove connecting link (9) from second reduction drivechain (1) and remove second reduction drivechain (1) from sprockets (7) and (8). 1. Install second reduction drivechain (1) on sprockets (7) and (8) and install connecting link (9) on second reduction drivechain (1). 2. Install link plate (10) and spring clip (11) on connecting link (9). 3. Hold shaft (4) and turn eccentric bushing (5) until first and second reduction drive chains (6) and (1) are tight. 4. Tighten nut (3) and screw (2). 12-136