TM 9-2320-211-20
(3) Unscrew the nut securing the air line from
Tachometer Sending Unit (Drive
the air manifold to the right side of the sending
Adapter)--Multifuel
Models
unit, and remove the line from the unit. Unscrew
NOTE
the nut securing the air line from the air manifold to
The tachometer, which is mounted on the
the rear of the sending unit, and remove the line
instrument panel, is driven by an adapter.
from the unit.
The drive adapter, which is mounted on the
(4) Remove the two screws and washers
timing cover, is driven by the camshaft.
securing the sending unit to the back side of the cab
a. Removal (fig. 2-163)
cowl, and remove the sending unit from the vehicle.
(1) Remove the tachometer drive adapter and
b. Installation.
drive shaft from the tachometer takeoff adapter.
(1) Position the low air pressure sending unit
(2) Remove the t a c h o m e t e r t a k e o f f a d a p t e r
on the back side of the cab cowl behind the in-
and the adapter gasket.
strument panel, and secure it with the two screws
and lockwashers.
(2) Position the line from the air manifold at
the threaded opening in the right side of the sending
unit, and tighten the connector nut. Position the
line from the air manifold at the threaded opening
in the rear of the sending unit, and tighten the
connector nut.
(3) Connect the bayonet type connector on the
ignition switch-to-low air pressure sending unit
cable to the terminal connector on the bottom of the
sending unit.
(4) Connect the bayonet type connector on
t h e low air press sending unit-to-air pressure
warning buzzer cable, to the terminal connector on
the top of the sending unit.
2-169. Horn Assembly
NOTE
Multifuel models have the horn and
solenoid assembly mounted on the right
b. Installation (fig. 2-163).
side of the firewall.
(1) Position the gasket and install the takeoff
a. Solenoid (with Mounting Brackets).
adapter in place.
(1) R e m o v a l ( f i g . 2 - 1 6 2 ) .
(2) Install the drive adapter and shaft to the
(a) R e m o v e t h e t w o b a y o n e t - t y p e c o n -
takeoff adapter.
n e c t o r s from the clips on the left side of the
solenoid, and disconnect both connectors.
2-167. Temperature Gage Sending Unit
(b) Unscrew the connector securing the
a. Removal. The procedure for removing the
horn-to-air governor line to the elbow at the base of
temperature gage sending unit is the same as for the
t h e solenoid, and remove the line from the elbow.
air pressure gage sending unit. Refer to paragraph
(c) Unscrew the elbow from the base of the
2-144 a .
solenoid.
b. Installation. The procedure for installing the
(d) Loosen the two nuts and screws
temperature gage sending unit is the same as for the
c l a m p i n g the solenoid mounting brackets to the
air pressure gage sending unit. Refer to paragraph
projectors, a n d u n s c r e w b o t h p r o j e c t o r s f r o m t h e
2-144 b.
horn base assembly.
(e) U n s c r e w t h e s o l e n o i d f r o m t h e h o r n
a. Removal.
base assembly.
(1) Disconnect the bayonet type connector on
(2) Installation
the low air pressure sending unit-to-air pressure
(a) Screw the threaded end of the solenoid
warning buzzer cable, at the terminal connector on
into the threaded hole in the horn base assembly,
top of the sending unit, mounted on the back side of
a n d aline the solenoid mounting brackets with the
the cab cowl behind the instrument panel.
p r o j e c t o r holes in t h e b a s e a s s e m b l y .
(2) Disconnect the bayonet type connector on
(b) Position both projectors between the
the ignition switch-to-low air pressure sending unit
e n d s of the solenoid mounting brackets, and screw
cable at the terminal connector on the bottom of the
both projectors into the horn base assembly.
sending unit.
