Model MA TOW Tractor. Manual - part 7

Chapter 1: General Information and Operating Instructions   Dec. 1995           Section 1-1                     p. 3

a.

Engine

1.

Gasoline

The gasoline engine is a heavy duty, industrial type with a short stroke and
exhaust valve rotators.

2.

Diesel

The diesel engine is a heavy duty, industrial type with four (4) stroke cycle and
direct injection.

b.

Transmission

The tractor’s transmission is a 3-speed transmission with a torque converter.

2.

Drive Shaft

The tractor’s drive shaft is an automotive type with double universal joints and a sliding
spline coupling.

3.

Drive Axle

The drive axle assembly, comprising the differential assembly, the reduction gears and the
axle shafts is mounted to the chassis by two (2) axial steel mounting pads incorporating
four (4) isolator mounts.

4.

Steer Axle

The steering axle is of welded steel tube construction mounted to the chassis by two semi-
elliptic, multi-leaf spring assemblies.  This is to insure constant ground contact of both
wheels over uneven ground.

CAUTION:  DESPITE THIS SUSPENSION SYSTEM, IT IS RECOMMENDED THAT THE
TRACTOR, WHEN POSSIBLE, IS DRIVEN OVER SMOOTH, EVEN GROUND.

Turning movement from the steering wheel is transmitted to the axle via a steering box
and sealed ball jointed linkage.  This arrangement provides a high angle of lock with
minimum amount of steering effort.

5.

Braking System

There are two braking systems, mechanical and hydraulic, incorporated into this tractor.
The mechanical brake is operated by a strap attached to the hand brake lever and to the
parking brake drum attached to the rear of the transmission. (See figure 3)  The hydraulic
braking system uses a dual -line master cylinder, providing two independent braking
systems for the rear axle. The brake warning valve (if equipped) is incorporated into the
hydraulic lines to detect leaks in the system.

Chapter 1: General Information and Operating Instructions   Dec. 1995           Section 1-1                     p. 4

Figure 3

I.

DESCRIPTION

B.

COMPONENT/SYSTEM (CONT)

Chapter 1: General Information and Operating Instructions   Dec. 1995           Section 1-1                     p. 5

6.

Wheels

a.

Steer Axle

The steer axle utilizes wheels that have 5 bolts on a 5 1/2“ bolt circle.

b.

Drive Axle

The drive axle employs wheels that have 8 bolts on a 6 1/2“ bolt circle.

7.

Tires

a.

Pneumatic

The tractor’s pneumatic tires are 6-ply tubeless on the front and 8-ply tubeless for

the rear.  The pneumatic tire gives a smooth ride combined with maximum tractive
effort.  Remember to check the pressure of your pneumatic tires regularly.  Uneven
tire pressure will not only increase tire wear, but will also decrease traction.

b.

Solid Mount

When your tow tractor is working in a application that is detrimental to pneumatic

tires (e.g., stones, debris, etc.), it can be fitted with solid rubber tires.  While these
tires have better wear properties and are not sub subject to puncture failure, they do
not run as smoothly as pneumatic tires.  When solid tires are fitted, the drawbar
rating will vary slightly.

8.

Suspension

The steer axle incorporates two semi-elliptic, multi-leaf springs. The drive axle is

attached to a pair of solid mounts.

9.

Fuel Cell

a.

Gasoline or Diesel Fuel

The tractor fuel cell is constructed of stainless steel and is all-seam welded and

pressure tested to 6 psi. The fuel cell is equipped with a Protecto-seal filler cap unit.
On serials 0024 and up a fuel gauge is installed in the top of the fuel cell.  The cell
has a fuel capacity of approximately 15.5 U.S. gallons and is encased in an all steel
compartment mounted to the aft floor board.  Fuel capacity is adequate for eight
hours operation without refueling.

b.

LP Gas

The liquid propane gas is mainly used for in-plant use.  The fuel cells all vary slightly

in size, capacity and options, but all mount on the running board to the right of the
operator.

Chapter 1: General Information and Operating Instructions   June 1997           Section 1-1                     p. 6

I.

DESCRIPTION

B.

COMPONENT/SYSTEM (CONT)

10.

Electrical System

The tractor utilizes a 12-Volt, automotive type, negative ground, electrical system.  This
system includes a 42 or 60 ampere alternator, a 70 ampere hour battery, voltage regulator,
ignition switch, master power switch on tractors 001 through 267, light switch, two
headlights, strobe rotating light (optional), turn signals (optional), tail light, horn button and
horn, ignition equipment, various gauges and all other circuits.

If tractor is equipped with a cab, the following is added to the above list:  Wiper motor,
clearance lights, heater blower motor and interior cab light.

11.

Frame and Bumper

The chassis frame is a welded assembly fabricated from channeled steel beams.  The
frame consists essentially of two frame rails, forward and aft cross beams, and a floor
plate.  The frame rails are fabricated from a 5-inch channel beam.  The aft cross-beam is
fabricated from a heavy steel plate.  For corrosion resistance the entire frame is finished
with an oxide primer.

The front bumper plate is constructed of inch thick steel plate attached to the forward
crossbeam and the forward edge of the running board.  The front bumper plate includes an
array of 1-3/4-inch diameter holes for ventilation to the radiator, two 6-inch diameter holes
for headlight beam passage and two 4-inch holes for turn signals or reflection.  The front
bumper plate is detachable by removing all readily accessible bolts, thus permitting direct
frontal access to the radiator.

12.

Seat

The tractor utilizes a two-passenger, shock mounted seat having a 4-inch thick foam
rubber seat cushion and a 2-inch thick foam rubber back cushion.  The cushion covers are
fabricated from waterproof, heavy gauge vinyl.  The seat frame is of all-steel construction
and measures approximately 33 inches wide, 17 inches deep, and 16 inches high.

13.

Fasteners

All major structural fasteners are Grade 8, heat treated and use high strength locknuts.

14.

Towing Bracket

Alternative towing brackets can be fitted to both the front and rear of the tow tractor.

15.

Cab

(a)

The Tug cab, which fully encloses the driving compartment, was designed for and
fitted to this tractor cabs have a front and back windshield, and two (2) doors.  All