TM 5-6675-250-20
2 - 1 0 . T R O U B L E S H O O T I N G - ( C o n t i n u e d)
T a b l e 2 - 3 . T r o u b l e s h o o t i n g ( C o n t i n u e d)
M A L F U N C T I O N
TEST OR INSPECTION
CORRECTIVE ACTION
GYROSCOPIC REFERENCE UNIT (GRU) (Continued)
3 . G R U I N S E C U R E I N T R I P O D A S S E M B L Y.
Step 1.
Check to see if hold-down clamp(s) are loose.
T i g h t e n.
Step 2. Check for defective hold-down clamp(s).
a. Visually inspect hold-down clamp(s) (1, 2, and 3) for wear or other
d e f e c t s.
b. Remove screw (4) attaching GRU (5) to lower clamps (6).
Place suitable material under base of GRU to support weight of the GRU
unit. Damage can result to GRU if dropped.
c. Rotate locking arm (7) counterclockwise and slide clamp outward
from GRU (5).
d. Remove GRU (5) from tripod (8).
e. Rotate locking arm (7) counterclockwise and disengage from rec-
tangular nut (9).
f. Raise locking arm (7) with bolt (10) attached from the base (11).
g. Remove washer (12), upper clamp (13), lower clamp (6), and rec-
tangular nut (9) from the base (11).
h. Remove screw (14) and separate bolt (10) from locking arm (7).
i. Apply MIL-G-21164 molydisulfide lubricant, item 4, Appendix C, to
threads of bolt (10).
j. Engage tang on upper clamp (13) in slot in lower clamp (6).
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