TM-9-1240-401-34-P
TELESCOPE MOUNT M146: M118A2 AND M118A3; TELESCOPE MOUNT M145: M145A1; PANORAMIC TELESCOPE: M117 AND M117A2; FIRE CONTROL QUADRANT: M15; PERISCOPE: M42
TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL
JULY 1993
TM-9-1240-401-34-P - Page 122 of 590
TM9-1240-401-34&P
4-10. GENERAL SUPPORT SYMPTOM INDEX
Troubleshooting
Procedure
(Page)
COUNTER BOX ASSEMBLY
Elevation handwheel is erratic and rough during movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.4-8
Elevation handwheel exceeds 0.5 mil backlash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
..4-8
Elevation handwheel requires torque in excess of 11 pound-inches (1.24 N-m) to rotate . . . . . .
..4-9
CROSS-LEVEL MECHANISM
Cross-level mechanism knob requires torque in
LEVEL ASSEMBLY
excess of
11
pound-inches (1.24N-m) to rotate .
. 4-9
Cross-level bubble or pitch level bubble do not center within one graduation . . . . . . . . . . . . . . . .
..4-9
4-11. GENERAL SUPPORT TROUBLESHOOTING
MALFUNCTION
TEST OR INSPECTION
LOCATION
CORRECTIVE ACTION
COUNTER BOX ASSEMBLY
1. ELEVATION HANDWHEEL (1) IS ERRATIC AND
ROUGH DURING MOVEMENT.
step 1.
step 2.
step 1.
Step 2.
Check for worn wormshaft assembly.
Notify depot maintenance.
Check for worn gears.
Notify depot maintenance.
2. ELEVATION HANDWHEEL (1) EXCEEDS 0.5 MIL
BACKLASH.
Check for loose or worn bearings.
Notify depot maintenance.
Check for worn wormshaft
Notify depot maintenance.
assembly.
4- 8
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