2-19. DIFFERENTIAL LOCK LEVER. The differential
(4) and, because of pressure differential within the
lock lever (10) controls the differential action of the
chamber, forces the booster plunger (7) forward to
transfer case. When the lever is in forward position, the
hydraulically actuate the wheel cylinders. The booster
differential is unlocked. When in the rear position, the
plunger is spring loaded to return to normal position
differential is locked.
when the brake pedal is released. If for any reason there
should be no vacuum, the system will operate as a
2-20. PARKING BRAKE. The parking brake lever (1)
conventional hydraulic brake system.
controls the mechanical brake on the transmission. Pulling
the lever up and back applies the brake. In forward
position the brake is released. Clockwise rotation of the
2-14. ELECTRICAL SYSTEM. The tractor electrical
slack adjustment tip will take up slack.
system (figure 2-3) is a 12 volt system. Electrical power
is produced by the generator (10) and stored in the
2 - 2 1 . TRANSMISSION SHIFT LEVER. The
battery (7). The battery is protected from overcharging
transmission shift lever (5) operates the transmission
by a voltage regulator (1 1). A key operated ignition
starter switch controls all circuits, other than horn or
through five forward speeds and one reverse speed. Gear
lights, energizes the starter motor (9) and provides for
positions are shown on the instruction plate mounted to
the left of the instrument cluster.
accessory operation without engine operation. All circuits,
other than the starter motor circuit and clutch actuating
2-22. DIMMER SWITCH. Foot operation of the dimmer
circuit are protected by circuit breakers which are
switch (3) selects high headlight beam or low headlight
automatically reset after circuit overload. The starter
motor control is contained within the ignition switch. A
spotlight (4), floodlight (5), combined stop, and tailight
2-23. CLUTCH CONTROL. The solenoid valve control
(6), and headlights (1 and 8) are provided for night
switch located on the gearshift knob (6) disengages the
operation. The heater fan (2) and windshield wipers (3)
clutch when pressed. When pressure is released the clutch
are electrically operated. Tractors are radio suppressed in
will automatically engage.
accordance with Military Specification MIL-S-13079 for
2-24. BRAKE PEDAL. The brake pedal (2) is used to
slow and stop the tractor. Gradual pressure should be
applied for smooth operation. The pedal will return to
2-15. OPERATING INSTRUCTIONS.
normal position when pressure is released.
2-16. CONTROLS AND GAGES. Prior to actual tractor
2-25. ACCELERATOR. The accelerator pedal (9)
operation, the operator shall be familiar with the purpose
actuates the carburetor throttle linkage to increase or
and use of all controls and gages.
decrease engine speed. The accelerator should work
smoothly and return to idle position when pressure is
2-17. STEERING WHEEL. Movement of the steering
wheel (8, figure 2-4) actuates the front wheels to steer
the tractor in the conventional manner.
2-26. CHOKE CONTROL. The choke control (1, figure
2-5) is used to provide richer fuel mixture during engine
2-18. REAR WHEEL STEERING LEVER. The rear
wheel steering lever (7) controls the rear wheel steering
warmup or for cold weather starting. To operate the
mechanism. By pushing the lever left or right, the rear
choke, pull control out from the panel as necessary.
wheels will be directed right or left thus turning the
During engine warmup, adjust choke as required.
tractor in the same direction as the motion of the lever.
2-27. IGNITION STARTER SWITCH. The ignition
Upon release of the lever, the rear wheels will return to
starter switch (2) is key operated. To actuate the
the straight ahead position.
electrical system, insert the key and turn clockwise to the
first position. To actuate starter motor, turn clockwise to
second position. Upon release, key will return to the first
position. T o operate accessories only, turn key
The differential lock lever should be in the
rear position only when one axle is slipping.
2-28. WINDSHIELD WIPER SWITCH. The windshield
Never drive under good tractive conditions
wiper switch (3) controls both windshield wipers. Pull
with the lever in the rear position.
switch out to start wipers; push switch in to stop.