12-87. TM 9-2320-361-20 This task covers: a. Horizontal Drivechain Cover Removal d. Vertical Drivechain Cover Removal b. Horizontal Drivechain Adjustment e. Vertical Drivechain Adjustment c. Horizontal Drivechain Cover Installation f. Vertical Drivechain Cover Installation INITIAL SETUP: APPLICABLE MODELS M764 MATERIALS/PARTS Four lockwashers Safety wire (Appendix C, Item 22) REFERENCES (TM) TM 9-2320-361-10 TM 9-2320-361-20P EQUIPMENT CONDITION Parking brake set (TM 9-2320-361-10). a. Horizontal Drivechain Cover Removal 1. Remove safety wire (11) from retaining collar (10), loosen setscrew (9), and remove retaining collar (10) from shaft (14). Discard safety wire (11). 2. Remove nut (3), lockwasher (2), and screw (13) from cover (12) and shifting handle bracket (1). Discard lockwasher (2). 3. Remove screw (8), lockwasher (7), washer (6), bushing (5), and cover (12) from gear (4). Discard lockwasher (7). 1. Check freeplay by pushing up at midpoint of drivechain. Acceptable freeplay is 0.5 in. (1.27 cm). NOTE If freeplay is acceptable, proceed to subtask c. If freeplay is unacceptable, perform steps 2 through 4. 2. To adjust freeplay, loosen nut (16) and screw (15). 3. Hold shaft (17) and turn eccentric bushing (18) until freeplay is 0.5 in. (1.27 cm). 4. Tighten nut (16) and screw (15). 1. Install cover (12) on gear (4) with bushing (5), washer (6), new lockwasher (7), and screw (8). 2. Install screw (13) through cover (12) and shifting handle bracket (1) with new lockwasher (2) and nut (3). 3. Install retaining collar (10) on shaft (14) alined with slot and tighten setscrew (9). 4. Wrap new safety wire (11) around retaining collar (10) and setscrew (9). 12-140