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
LEVEL ASSEMBLY
Cross-level bubble or pitch level bubble do not center within one graduation . . . . . . . . . . . . . . . ...4-9
4-11. GENERAL SUPPORT TROUBLESHOOTING
MALFUNCTION
LOCATION
TEST OR INSPECTION
CORRECTIVE ACTION
COUNTER BOX ASSEMBLY
1. ELEVATION HANDWHEEL (1) IS ERRATIC AND
ROUGH DURING MOVEMENT.
step 1. Check for worn wormshaft assembly.
Notify depot maintenance.
step 2. Check for worn gears.
Notify depot maintenance.
2. ELEVATION HANDWHEEL (1) EXCEEDS 0.5 MIL
BACKLASH.
step 1. Check for loose or worn bearings.
Notify depot maintenance.
Step 2. Check for worn wormshaft assembly.
Notify depot maintenance.
4-8
