TRACTOR OPERATION
Before running a new tractor it should be given a careful examination
to make sure that all nuts and bolts are tight, and not secured only
by paint; that all grease cups are in position and filled; that all
parts of the mechanism are properly lubricated; that oil holes are free
from grit, and that nothing is cracked, broken or missing. It should be
cleaned of cinders and mud that may have collected in shipment, and in
general it should be seen to be in proper condition.
A tractor, like any other piece of machinery, requires breaking in, and
for the first few days it should be run slowly and with light loads.
All parts should be plentifully oiled, for there will be rough and
uneven places on the bearings that must be worn smooth, and without oil
these would heat and be injured.
A continual watch should be kept for loose nuts and bolts, which should
be tightened without delay. Readjustments of the clutch and brake will
be found necessary, for their linings when new may be lumpy; as these
lumps wear down through use the clutch or brake will begin to slip and
must be tightened. When the linings are worn in, this trouble will
disappear, and readjustments will be necessary only at considerable
intervals.
Special care should be taken to keep the filler caps of the fuel and
oil tanks clean and free from dirt. If these are dirty, the dirt will
be carried into the tank when filling, and will sooner or later cause
trouble.
The vent holes in the filler caps should be kept clear. If they are
plugged with dirt, air cannot enter the tank to take the place of the
fuel that flows out, and the feed of fuel will stop.
Beginning when the tractor is new, a system of daily inspection should
be started, and should be continued for the working season. Big trouble
starts with small trouble, and if small trouble is cured without delay,
big trouble will be avoided. Trouble usually begins with looseness,
which may be due to a slack nut or bolt, or may come with wear. If the
loose part is not tightened, it will begin to shift its position; it
will wear, and will rapidly lead to a breakdown.
Every day, without fail, all parts of the tractor should be inspected
for loose nuts, bolts, pipe and electrical connections, petcocks, drain
plugs, steering connections, etc. This is also the time for wiping off
the working parts, and cleaning mud and grit from rods, shafts, joints,
and other places at which dirt could make its way into bearings.
The change speed gears of a tractor should not be shifted while in
motion, this being one of the differences between a tractor and an
automobile. In the sliding gear type of change speed mechanism, the
gears slide into mesh sideways, a tooth of one being opposite a space
between two teeth of the other. If the gears are not in the right
position for this, one tooth will strike another, and the gears cannot
be meshed. In such a case the clutch is let in for a slight touch to
move one gear, not for a dozen or twenty revolutions, but enough to
bring a space between two teeth of one gear opposite a tooth of the
other.
If an attempt is made to shift the gears while they are in motion, the
result will be that one will grind against the other, and there will be
rapid wear and probable breakage. It is because gears cannot be shifted
while they are moving that manufacturers instruct users not to attempt
to shift on a hill without first blocking the wheels. The reason for
this is that the brakes may not hold the tractor, and if the gears are
pulled out of mesh, the machine may start to run down hill; as another
speed cannot then be engaged because the gears are moving, there will
be no control over the tractor.
Never coast down hill; always run with one of the speeds engaged. By
switching off the ignition the motion of the tractor will drive the
engine, and this provides the best possible brake. On low gear, the
engine will turn in the neighborhood of eighty revolutions to one turn
of the driving wheels, and the work required to do this will check the
tractor on the steepest of practicable grades.
A tractor is not built for as accurate and delicate steering as an
automobile and should always be slowed in making a turn; this is
especially true when hauling plows or other loads in the field. It is
difficult to control the tractor if a turn is made at high speed, and
the machine is liable to tip over.
In steering and in engaging the clutch, the action should not be jerky
and abrupt, but gradual and smooth. Letting in the clutch suddenly will
start the tractor with a jerk that will strain it from end to end, and
an abrupt swing of the steering wheel will have the same effect. Making
these motions smoothly and steadily will cause the tractor to change
its direction or pace with the least possible strain and effort. This,
of course, increases the tractor’s life.
In much of the work done by the tractor, the varying conditions of
field and soil make a continual change in the load, and the tractor
must be handled accordingly. The change from an uphill to a downhill
haul, and from sand or light loam to gumbo, will require the gears
to be shifted in order that the engine may neither labor nor race in
keeping the outfit at its work.
There should be no hesitation in coming down to low speed when the
engine shows by its laboring that the effort of working on high gear is
becoming too great. The engine cannot deliver its full power unless its
speed is maintained, and low gear is provided for those times when the
load is too great to be handled on high. Use high speed whenever it is
possible, but trying to force the tractor to run on high with too great
a load will lead to a breakdown.
High speed should be used for light work or for moving from place
to place, but the engine should never be run at a greater number of
revolutions than that specified by the manufacturers. It is very poor
policy to run the tractor fast over rough roads, as the pounding will
inevitably injure it.
Cold weather changes conditions in the handling and operation of a
tractor; there is difficulty in starting, lubrication is likely to be
faulty, and there is danger of breakage in engine, radiator, and air
washer through freezing.
Difficulty in starting comes from the use of the usual medium grade
of gasoline, which is satisfactory in mild weather, but will not
vaporize at low temperatures. Cold gasoline will not vaporize in a cold
engine; to form a mixture it is necessary to use high test gasoline,
which will vaporize at low temperatures, or to warm the engine to a
temperature at which medium grade gasoline will vaporize.
It is advisable to keep on hand a few gallons of high test gasoline to
use in starting, or even a mixture of high test gasoline and ether,
half-and-half, for extreme cold weather.
The engine may be warmed by pouring a bucket of hot water into the
cooling system, cranking the engine to get it into the water jackets of
the cylinders. Another plan is to wrap cloth around the intake manifold
and carburetor, soaking it with hot water, being careful not to get
water into the air intake.
A drop of liquid gasoline on the points of the spark plug will
short-circuit them and prevent the formation of a spark; the points
should be dry, and it is an advantage to heat the plugs, screwing them
hot into the engine at the last moment before trying to start.
Kerosene is thicker when cold than when warm; it will not flow so
freely, and the needle valve of the carburetor must be opened more in
winter than in summer to obtain a proper mixture.
Lubricating oil also thickens in cold weather, and flows much more
sluggishly. The lubrication adjustments that are correct for summer
will therefore be incorrect for winter. This may be provided for to
a great extent by using a thinner oil in winter than the oil used in
summer. A cold snap is likely to result in burned bearings if the
change in lubrication that it brings is not allowed for.
Grease thickens in cold weather more than oil does, and some kinds
freeze solid. In winter a light, soft grease should be used, and the
grease cups should be turned down several more turns than is usual when
the weather is warm.
While antifreezing compounds can be used in the cooling systems of
automobiles, they are not suitable for tractors because the greater
and more continuous heat quickly evaporates them. The danger of
freezing is very great, and must be avoided; the water in the radiator
and jackets is in thin sheets, and will freeze when a bucket of water
standing in the open will not show any signs of ice.
The only real protection against freezing is to drain out all the
water whenever the tractor is to stand idle for a sufficient time for
it to cool off. Petcocks are provided for this at the lowest points
of the system, and also in the pump when forced circulation is used.
The freezing of even a small pocket of water will be enough to crack a
cast-iron water jacket wall, and the best assurance that the system is
thoroughly drained is to open the drain cocks while the engine is still
running, shutting down as the flow stops.
When putting up a tractor for the winter it should be thoroughly
protected from rust and corrosion. The last time that the tanks are
filled a quart of light oil should be added for every five gallons of
gasoline or kerosene; as the tank empties this will leave a coating of
oil on the inside walls.
Fuel tanks and water system should be drained, and particular care
should be taken that all the water is out; the drain cocks should be
left open. A mechanical oiler should be filled full, to protect the
steel parts of the pumps from rust.
A half pint of thick oil should be put into each cylinder, and spread
to the cylinder and piston walls by cranking for a few turns. Oil
should be run between the valves and their seats.
All exterior parts should be protected by a coat of thick oil or
by paint. The governor rod, push rods, and similar parts should be
especially looked after. It is advisable to take off the magneto and
store it in a safe, dry place; spark plugs should be left in position.
The tractor should be covered with a tarpaulin and stored in a tight
shed.
When going over a tractor preparatory to laying it up, a list should
be made of all parts that need renewal. These parts should be procured
at once; they are more readily obtained during the winter than in the
operating season, and will be on hand for the spring overhaul.