C1, TM 9-2320-211-20
Section XLIII. MAINTENANCE OF NONELECTRICAL
GAGES AND MEASURING DEVICES
2-332. General
proper opening of the instrument cluster from the
front.
a. Speedometer
Tachometer. T h e
and
(2) Install the speedometer mounting bracket
speedometer and tachometer are mechanically
on the studs at the back of the instrument cluster.
operated units which are connected by flexible shaft
(3) Install the lockwasher and nut on the
assemblies to their respective sending units.
upper stud, and tighten the nut.
b. Tachograph. Late production 5-ton, M52A1
(4) Assemble the lockwasher and wiring
and M52A2 tractors may have a tachograph
harness stud on the lower mounting stud, and
assembly installed in the instrument panel of the
tighten the stud.
vehicle cab which replaces the tachometer and
(5) Position the wiring harness on the stud
speedometer. The face of the tachograph indicates
and secure the harness to the stud with a washer
vehicle speed, engine rpm and time. The time is
and nut. Tighten the nut.
recorded by a 24-hour clock in the unit which
(6) Insert the end of the flexible shaft in the
requires winding before each trip. The tachograph
speedometer, and tighten the connector nut.
contains a paper chart which records vehicle speed,
(7) Secure the instrument cluster to the panel
engine rpm, and stop-and-go periods on a 24-hour
basis. The tachograph face is equipped with a red
warning light which indicates overspeeding of the
engine, and is set to flash at 3,000 engine rpm on
a. Removal.
the M52A2 and at 2,300 engine rpm on the
(1) Unscrew the nut securing the flexible shaft
M52A1. The two drive cables which operate the
to the speedometer (fig. 2-33), and pull the shaft
speedometer and engine rpm tachograph are the
end from the speedometer.
same as those used on the original speedometer and
(2) Unscrew the nut securing the flexible shaft
tachometer.
to the speedometer sending unit on front of the
2-333. Speedometer
transfer case. Pull the shaft end from the sending
unit.
(3) Disconnect the four clips securing the
a. Removal.
shaft to the vehicle. Remove the shaft and clips,
(1) Remove the instrument cluster [para 2-
and remove the clips from the flexible shaft.
143)
b. Installation.
2) Unscrew the nut securing the flexible shaft
(1) Place the four clips on the flexible shaft
to the speedometer. Pull the shaft away from the
and secure the flexible shaft to the vehicle with the
wpeedometer.
clips.
(3) Remove the nut and washer securing the
NOTE
instrument cluster wiring harness to the stud on the
When positioning the flexible shaft in the
speedometer. Pull the harness off of the stud.
vehicle, be sure that the end with the
(4) Remove the wiring harness stud and the
driving key is at the sending unit on the
lockwasher from the lower mounting stud.
transfer case.
(5) Remove the nut and lockwasher from the
(2) Insert the end of the flexible shaft in the
upper mounting stud.
sending unit on the front of the transfer case, and
(6) Remove the mounting bracket from the
tighten the connector nut.
studs, and pull the speedometer unit out of the front
(3) Insert the square end of the flexible shaft
of the instrument cluster.
in the speedometer, and tighten the connector nut.
b. Installation.
(1) Insert the speedometer unit into the
