Chapter 4 REPAIR OF GYROSCOPIC REFERENCE UNIT

TM 5-6675-250-24

REPAIR OF GYROSCOPIC REFERENCE UNIT

4-1. General

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

indicator

(2)

Raise

the

theodolite

sufficiently

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.

assembly.

(3) Complete removal of the theodolite by

4-2. Theodolite (fig. 4-1)

r a i s i n g clear of the GRU housing.

a. Removal.

CAUTION

Ensure that the GRU is securely held when

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