TM-9-1240-400-34&P Technical Manual for M109 Telescopes and Mounts Download
Page 218 of 344
TM 9-1240-400-34&P 5-19. FINAL INSPECTION INSTRUCTIONS (CONT). CHECKING AND ADJUSTING ELEVATION KNOB TORQUE AND BACKLASH (CONT) 6 Remove three capscrews (9) and three lockwashers (10) that secure telescope mount subassembly (11) to housing (8). Remove telescope mount subassembly (11). Do not remove two pins (12) unless damaged. 7 Place gunner’s quadrant (1) on level bar (2) and rotate bevel gear (13) until minimum travel (elevation 1333 mils and depression 89 mils (9911)), as read on elevation counter (4), can be met. Ensure that slight overtravel (one or two gear teeth) is obtained. 8 With telescope mount subassembly rotated clockwise to a stop, install telescope mount subassembly (11) and secure with three lock- washers (10) and three capscrews (9). 9 Check that elevation counter (4) readings at elevation of 1333 mils and depression of minus 89 mils are within 1.0 mils of the angle indicated by gunner’s quadrant (1). 10 Level M137 telescope mount using elevation and cross-level vials (14). Check that elevation counter (4) indicates "0000". 11 If required, loosen four screws (15), pull elevation counter (4) back and rotate gear (16) to set elevation counter to "0000". Tighten four screws (15). 12 Recheck elevation knob (3) travel. Adjust travel as required by repeating steps 5 thru 9. 5-64