REPAIR OF GYROSCOPIC REFERENCE UNIT
removing theodolite. Retain the GRU
housing in the tripod assembly or a holding
Repair and adjustment of the gyroscopic reference
fixture when removing the theodolite.
unit (GRU) consists of; replacing the theodolite,
(1) Remove three socket-head screws securing
t r i p o d assembly, gearbox assembly, tilt switch, cag-
t h e theodolite.
i n g link, time totalizing meter, uncage
light, upper housing cover seals, and adjustment of
disconnect the electrical connector from 1A1J3
t h e caging mechanism and the upper band clamp
b e t w e e n the theodolite and GRU housing.
(3) Complete removal of the theodolite by
r a i s i n g clear of the GRU housing.
Ensure that the GRU is securely held when
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