INTRODUCTION
We believe that hit-and-miss automobile driving has been one of the largest, contributors to our national reckless extravagance. In view of the millions of automobiles now in use it can readily be seen that if more intelligent and more economical principles were employed in their operation, a saving-would be effected far greater annually than all of the gasoline and fuel consumed by all the automobiles in the world.
Our course has been divided into ten lessons, each one dealing with a separate subject. These are the subjects to be taken up and the rotation in which they will be discussed.
1. General Construction and Cooling System
2. Ignition
3. Fuel System
4. Starting and Lighting System
5. Motor
6. Transmission
7. Oiling System
8. Front System and Steering Gear
9. Rear Axle Assemblies
10. General Review, Tire Care and Road Laws.p>
These lectures and demonstrations will be given in the evenings, once a week for ten weeks. Every effort has been made to make our discussions very practical and easily understood. Our continuous system of lessons makes it possible for the student to enter our school at any time. For example, one starts on the 6th lesson and finishes the remaining lessons and continues on the second term, for four weeks, at which time he will have completed the course.
That the Ford car has furnished transportation at the lowest possible cost up to this time, is a well established fact but we are of the belief that with a greater knowledge of his car, the Ford owner will still reduce the cost of, operation, very materially. We want you to be able to make minor adjustments, to be able to identify approaching troubles and to be able to correct them.
Then our position as Ford dealers, where we claim to have no competitors, will be more firmly established than ever.
The reliable garages in this city as well as others, spend much time in showing and trying to make customers understand and appreciate the necessity of having certain repair jobs done on their cars and in some instances, even then the owner is not thoroughly convinced. With this unfortunate condition in mind, our school has met with the approval and hearty endorsement of many of our first class garage owners already. The fact that many garage owners have enrolled in our classes as well as have many mechanics, indicates in itself that the conscientious garageman is now anxious to have the Ford driving public know their cars mechanically. It will readily be seen that the ultimate result of such a confidence will result not only in the more economical operation of Ford cars on the part of the owner but a substantial and lasting relationship will be established between Ford owner and garageman.
For the Ford owner to have a practical knowledge of his car means a large saving annually on repair and operation costs. We want the Ford owner or driver to get the greatest amount of satisfaction out of the employment of his car at the lowest possible cost.
We will cover the operation and up-keep of Ford cars and trucks only and would request that questions and discussions concerning other cars be withheld. We will also show you that the Ford car is not a vehicle to be used for a few months during the summer and then stored away for the rest of the year. By knowing practical methods for cold weather starting and driving you will find as much enjoyment out of driving in the winter as in the summer.
Illustration No. 1
The chassis is that part of an automobile comprising all parts except the body and the rear fenders.
The chassis of an automobile can be considered in the same light as the running gear of a wagon.
First we have the RADIATOR (1) which is the storage and cooling place for the water which is utilized
in keeping the motor at a uniform temperature.
Then we have the MOTOR (2) itself, which is the generator of the power that propels the car.
The Ford motor is of a type known as unit power plant construction, that is, the transmission
is built into the motor.
The purpose of the TRANSMISSION (3) is to transmit the power thru the drive shaft to the rear
axle (4). The transmission also allows a change of speed thru the gears and permits reversing
direction.
Next, the UNIVERSAL JOINT (5) is the coupling between the transmission and the drive shaft. It
is constructed in a manner to permit the rotating of the drive shaft at an angle to the
crankshaft. This angle is necessary because the driving gears in the rear axle are lower than
the motor.
The DRIVE SHAFT (6) in turn transmits the power to the DIFFERENTIAL (7) the purpose of which is
to permit the rotating of one rear wheel faster than the other in turning corners, etc., thence
the AXLE SHAFT (8) and the rear wheels.
The FUEL TANK (9) is placed in the highest possible position in relation to the carburetor
as the flow of gasoline depends on gravity. The CARBURETOR (10) is located low on the right
side of the motor, mixes the gasoline with air to form a highly explosive vapor which is then
compressed and ignited in the cylinders or combustion chambers.
On the dash is the coil box containing the four COIL UNITS (11). These coil units change the
primary current as it comes from the magneto, to a secondary current. From the coil units,
wires lead to the COMMUTATOR or TIMER (12) the purpose of which is to distribute the ignition
to the cylinders at the proper time.
The FAN (13) driven by a belt from a pulley on the crank shaft, draws air thru the radiator
tubes and it also helps cool the motor.
The STEERING ASSEMBLY (14) by means of which direction of travel is obtained, turning the
front wheels left or right, is fastened to the dash and to the frame by a steering post
bracket. To the base of the steering post is fastened the steering gear ball arm which connects
with the steering gear connecting rod which in turn actuates the spindle arm connecting rod,
the spindle arms and then the front wheels.
The FRONT AXLE (15) is tilted backwards 5-1/2 degrees to obtain a castor effect and held in
place by the FRONT RADIUS ROD (16). This tends to stabilize the wheels and better enables them
to resist jolts and shocks.
The foregoing description has given a very general idea of the Ford chassis. With the
succeeding lectures we will take up in detail the various units heretofore mentioned.
In this particular lecture we will deal with:
SEE ILLUSTRATION NO. 2
Illustration No. 2
The extreme heat caused by the explosion of the gases in the cylinders and also the friction of the pistons on the cylinder walls, would soon cause the expansion of the pistons to such a degree that they would "seize" or stick if it were not for some adequate cooling system.
The radiator shell slips over the top tank and sides to present a neater finish. The purpose of the top tank is to hold water to absorb any steam which may form in the jackets and to keep the upper ends of the radiator tubes covered with water. When the water level falls below the top of the tubes there is no circulation and consequently the water in the jackets will boil. In the top tank is placed what is known as the splash plate. The splash plate directs the flow of water as it comes back into the top of the radiator and prevents loss thru the overflow pipe. The overflow pipe has its outlet in the filler neck and takes care of surplus water or steam which might cause breakage of the radiator.
The purpose of the "core" is to present a cooling surface by means of the tubes and fins. The fins radiate the heat away from the tubes. The combined cooling surface exposed to the air by the fins and tubes is 63.57 square feet, which is all remarkable when the size of the "core" is considered, 19 inches long, 2-5/8 inches in breadth and 17-3/8 inches high.
The most practical method is to mix a half pound of soda in four gallons of hot water and fill the radiator. Run this solution through several times until all scale is removed.
If there is a solution in the radiator designed to resist 10 below zero, it will often freeze up when the car is being driven in a temperature of only 5 below zero, if the motor had not been run long enough to heat the solution sufficiently before starting the car. The solution in such cases cannot be expected to resist the circulation of cold air thru the tubes. It is a good plan to throw a robe over your radiator in extreme weather and run your motor five or ten minutes and warm the solution in your radiator before starting the car. When the solution is once warmed, it is kept so with little effort.
As we have stated, the Ford car is equipped with the thermo-syphon system of radiation and the best circulation of water is not obtained until the water has reached a near boiling point. The very nature of the thermo-syphon system, as we have explained, provides for the warm water being at the top and the cooled water at the bottom of the system, hence the lower portion of the radiator usually freezes first.
When the tubes become so clogged with ice as to stop circulation, that uncirculating part of the water left in the upper part of the radiator and cooling system, is quickly heated and forced out through the over-flow pipe by the steam pressure generated in the cylinder head. It is only a moment's time then until the steam accumulates to such a great extent that it forces its way out through not only the overflow pipe, but the radiator cap as well and some times forces the radiator out of shape, with this extreme pressure.
When the first indications of a frozen motor appear it is advisable to stop the car, but not the motor. Then throw a robe or overcoat over the radiator and continue to run the motor slowly. If this plan is followed out you will find that the circulation is re-established in only a few minutes. Many drivers make the mistake of trying to get to a garage when signs of radiator freezing appear. This should not be done because when the tubes are once clogged with ice, they freeze very quickly and expand and burst in rapid succession. It is advisable in cold weather not to attempt to operate your car without a reasonable protection for the lower portion of the radiator at least. A hood or cardboard are the most common types of protection for that part of the Ford radiation system. When the weather becomes more extreme it is very advisable to add an alcoholic solution and so eliminate any possibility of freezing and bursting the radiator.
Illustration No. 3 shows this. If the proportions suggested in the diagram are rigidly adhered to, no difficulty will be experienced with leaky radiator tubes or cracked cylinder heads. Too much emphasis cannot be placed on the importance of preventing freezing. A motor block may be completely ruined by one hard freeze. This is one of the unnecessary upkeep expenditures which can be easily avoided by knowing how. We will now deal with the principle reasons for radiators boiling over. First look at the water level in the radiator and be sure there is enough for good circulation. Then look at the fan and see if the belt is on the pulley and not slipping. Then determine if you have been driving with the spark retarded too much or if the spark rod is disconnected, from the timer. Too rich or too light a mixture in the carburetor will also cause overheating. There are other reasons, such as carbon deposits in the motor, etc., which cause overheating and will be discussed thoroughly in the later lectures. |
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| Illustration 3 |
With the ignition switch turned off and the spark lever about 3 notches down on the quadrant and the throttle lever about 6 or 7 notches down on the quadrant, and the choke button pulled out, put your foot on the starter switch and let the motor turn over several revolutions. This will fill the cylinders with the necessary mixture of gasoline. Turn the ignition switch on the battery side and then press the starter switch again. As soon as the motor gives a few explosions, bring down the spark lever several notches and as the motor gains speed, turn the ignition switch on the magneto side. Should the motor seem to be dying down, pull choke button out and release quickly several times. Do not hold choke button out but a very short time because the motor is easily flooded. In extreme cold weather open up carburetor adjustment from a quarter to a half turn until motor gets well warmed up and then turn back to original position.
One of the reasons for a hard starting motor, is that of too heavy or worn out lubricating oil. The oil in the crank case should be changed every 500 or 1000 miles. A light medium oil should be used in the winter weather. Many Ford owners do not appreciate the importance of changing their oil regularly. Lubricating oil, after it is used a long time congeals and has a tendency to stick and corrode the discs in the high speed clutch. It is advisable in the extreme cold weather, especially if the car is left in a cold garage, to leave it in high speed after the motor has been stopped. At that time the oil is warm and if left in high speed after the motor has been stopped, the oil is squeezed out of the high speed discs which will allow free action of the discs when the clutch is disengaged upon starting the car again.
The battery should contain a maximum charge during the winter months so as to prevent its freezing and to insure prompt starting. This method of starting will never fail providing the car is supplied with gasoline and the ignition is working properly.
IGNITION
The magneto is composed of a stationery coil with sixteen spools upon it, each wound with insulated copper tape and connected by the tape. Then there are sixteen permanent horseshoe magnets on the flywheel which revolve past these coils or spools. This generates a low tension alternating current which is taken from the magneto plug or contact point. The Ford magneto is the simplest and most reliable because there are no brushes or moving contacts to become corroded or out of adjustment.
PLUGS Disconnect the wire at the magneto plug and providing there is a starter and battery
on the car, start the motor on the battery side and allow it to run moderately. Then place a
screw driver or knife blade on the top of the plug and slide such a tool on over to where its
end will touch the motor block which is the nearest metal and which connection will or will not
produce a spark.
If so shorting the plug produces a spark on the screwdriver at the block or at the plug, then
there is not a short circuit on the inside of the magneto plug. If shorting the plug does not
produce a spark it can be concluded that a short does exist on the plug and it will be necessary
to remove the plug and clean it.
Inasmuch as the magneto plug is held in place with a spring contact and sometimes difficulty is
experienced in putting it back into its place, we would advise that it is taken out only when
it is absolutely necessary.
ALTERNATING CURRENT is an electrical current which continually changes its direction of travel. It will not charge the battery as it alternates in polarity.
POLARITY is an electrical condition. The terminals on a battery, like the poles of a magnet are said to possess positive and negative polarity.
DIRECT CURRENT is an electrical current traveling in one direction only.
The AMPERE is the unit of the amount of flow of electrical current.
The VOLT is the unit of pressure of electrical current.
LOW TENSION CURRENT is electric current under low pressure or voltage, it is the type of current supplied by a battery or a Ford magneto.
HIGH TENSION CURRENT is electrical current under high pressure or voltage, it is the type of current in the spark plug wires.
It is interesting to note the care and accuracy used in building up the Coils of the unit. The core is made of 165 pieces of soft iron wire insulated with heavy paper from the primary coil which is wound around it.
The primary coil is made up of a comparatively few turns of copper insulated wire and then soaked in hot paraffin and rosin. The secondary coil is made up of 6,000 feet of enameled copper wire with insulation between each layer. It is wrapped in two spools to reduce the diameter of the coil.
The secondary coil is heated to 220 degrees Fahrenheit for twenty minutes in a vacuum to be sure and rid the coil of any moisture, it is then dipped in hot wax; the primary coil is wrapped with wax paper and placed in the secondary coil, completing the induction coil.
The CONDENSER serves as a regulator of the flow of current. It is built up of two pieces of tin foil seven feet long and three and one-half inches wide. They are placed one on the other insulated by waxed paper and rolled together. The condenser is then freed from moisture and boiled in paraffin.
These parts are placed in the coil box in their proper position and tar is poured around them to hold them in place and insulate them from each other. The upper bridge on top of the coil is made of brass. Riveted to it is a spring of bronze containing a tungsten steel point and held from the bridge by a spacer rivet. The lower bridge is made of copper. An armature of Swedish steel with a tungsten point on one side is fastened to the bridge by two screws. The point on the armature should be on a direct line with the point on the cushion spring. The coil is adjusted by changing the tension on the armature.
The diagram shows the construction of a coil unit. The coil units as a rule give very little trouble.
It is important to see that the tungsten steel contact points are not pitted or rough. It is
also necessary to have the proper tension on the vibrator or armature spring. Do not attempt to
adjust the coils without a coil tester, as it is almost impossible to get satisfactory results. |
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| Illustration No. 4 |
The commutator regulates the order and the time that the spark occurs at the spark plug in the cylinder. It is composed of the cover, roller brush, shaft and four segments and terminals. The segments are insulated from each other by a fiber ring. The roller brush revolving on the end of the cam shaft, comes in contact with the segments and completes the circuit. The cover is connected by a pull rod to the spark lever below the steering wheel on the quadrant.
The spark is advanced or retarded by moving the spark lever up and down which in turn changes the position of the relation to the roller brush.
A large percentage of ignition troubles are due to faulty commutators. This again is due to t he fact that it is neglected.
Illustration No. 5
In winter weather it is advisable to add a little kerosene to the oil put into the timer as the kerosene tends to cut the oil and so prevents the congealing of stiff cold oil over the contacts. It is advisable to keep this mixture in the small oil can supplied with your car.
The segments and fiber ring also become rough and worn so that the roller makes irregular contact. When this condition exists, about the only remedy is to replace the timer case and examine the roller, arm and spring, for a worn roller will soon ruin a new case. Satisfactory results are not obtained from timer oases that are put on a lathe and turned down or ground with a fine emery wheel.
Now as the current is grounded in the commutator the secondary current flows from the coil units to the spark plugs thru the spark plug wires.
The spark plugs are probably the most abused and the least deserving; of abuse of any part of the Ford car. Because they are easily accessible, when the motor goes wrong, first, out come the plugs. Consequently, unless great care is taken in cleaning the plugs, setting the points, and replacing them, the car runs worse than it did before they were removed.
Examine the porcelain for cracks. If evidence of cracks are discovered loosen the small nut on the top of the electrode and attempt to bend the porcelain between the fingers. This will determine if it is broken.
In assembling the plug see that the gaskets are in proper positions and screw the lock nut down firmly. Then adjust the gap to 1/32 of an inch using a steel shim for a gauge if available as it is very important to have the spark plugs accurate.
The first coil unit to the right serves the number one cylinder which is the front cylinder, and the order is carried thru.
Before removing the magneto plug to see if it has been shorted by some foreign matter, make the test referred to, earlier in this lecture. In general, in locating trouble and correcting it, go about it systematically. Trace the trouble down and correct it. Do not start at once to overhaul the nearest convenient part, until you discover where the fault lies.
With the advice given in this lecture and with the help of the diagrams, ignition troubles should be easily detected and corrected.
FUEL SYSTEM
A liquid is said to be volatile when it turns to vapor or gas on being exposed to the air. Gasoline is volatile at ordinary temperatures, so the biggest problem in obtaining the explosion in the motor is to mix the gasoline and air in the proper proportions, to have the most explosive mixture. This problem is taken care of by the carburetor. But in order to have the carburetor function properly, there must be a continuous, steady supply of gasoline.
From the sediment bulb the gasoline is lead to the carburetor by a quarter-inch copper tube.
The principal parts of the carburetor are the float chamber, which contains the cork float and inlet needle valve, the spray nozzle, the spray needle, the mixing chamber, the primary air inlet, the choke valve, the choke or strangling tube, the low speed tube, the overflow hole, and the throttle valve.
The carburetors which come as standard equipment on all Ford cars are the Holley and the Kingston. As they are very similar in construction, a general consideration of the carburetor will cover the important points of both.
The gasoline is first admitted to the float chamber where it is kept at the proper level to feed the spray nozzle by the inlet needle valve. The inlet needle valve is operated by the cork float which rises and falls with the gasoline level. The proper level is about 1/16 of an inch below the spray nozzle.
The suction of the pistons in the cylinders draws the gasoline out of the float chamber thru the spray nozzle in the form of a spray. The spray nozzle is a hole 1/16 of an inch long. The upper one-thirty second of an inch is tapered at a thirty degree angle to spray the gasoline and to receive the point of the spray needle. The spray needle has a hand adjustment on the dash and is the means of regulating the amount of gasoline in the mixture. Around the spray nozzle is what is known as the mixing chamber, as it is where the sprayed gasoline and air combine to form the explosive gas. The air is admitted by the primary air inlet which is designed to admit a certain set supply.
In the primary inlet is a choke valve which is held wide open by a coil spring on the choke lever. This is the valve which the driver closes by the lever on the dash or the wire in front of the radiator when starting the motor. This shuts off the air supply and allows a richer mixture to enter the cylinders.
The strangling tube or the Venturi tube is where the air passage narrows around the spray nozzle increasing the air velocity and the suction. Leading from the spray nozzle up thru the Venturi tube with an opening just inside the throttle valve in the intake, is the low speed tube. The low speed tube allows a rich mixture of gas to be drawn right into the cylinders when starting the car or when idling.
The diagram shows a cross section of the sediment bulb and the carburetor.
Illustration No. 6
The throttle valve is a butterfly valve controlled by the throttle lever on the steering post
quadrant. This permits the regulation of the amount of mixture admitted to the cylinders, thus
controlling the speed. There is an adjustment screw on the throttle valve lever which holds the
valve partly open and prevents the stalling of the motor.
As the mixture passes the throttle valve it is passed to cylinders thru the intake manifold,
which has a branch to each cylinder combustion chamber.
The mixture is said to be "lean" when there is too much air and not enough gasoline. This condition may be noted by missing and back-firing of the motor. The mixture is said to be "rich" when there is too much gasoline and not enough air. This condition is manifested by the motor choking and missing at slow speeds and a jerky galloping motion of the car. The best way to obtain the proper mixture or adjustment is to turn the needle valve down to the right until it rests lightly in the valve seat. Do not turn it down hard as this will score the point and destroy the monel metal seat. Then turn the valve open to the left one full turn. This will permit the motor to be started.
It is one of the most important points in the economical operation of a Ford car to be able to adjust the carburetor. When the carburetor is adjusted properly it is using from 17 to 14 parts of air to 1 part of gasoline. Too rich a mixture will cause the motor to run poorly just as readily as too lean a mixture.
A rich mixture may be detected by a black smoke from the exhaust and a disagreeable odor, or when driving there will be a jerky galloping motion of the car. It will also cause the motor to heat up as there are more heat units generated and the explosion does not give a complete combustion of the gases, causing carbon deposits to form on the pistons, valves and cylinder walls.
Other carburetors than the Ford are in the first place usually much more expensive, and too, generally have several delicate adjustments which are a source of constant trouble.
Good drivers obtain better mileage on long trips where a pretty good speed is maintained, by turning the needle valve nearly a quarter turn to the right, or more if it will permit. Then of course, after the motor has been stopped, to start again, the valve must be turned back to the left.
On cold mornings or when the car has been left standing for some length of time, it also aids in starting, to give the valve a quarter turn to the left, or not to exceed one-half a turn. Then after the motor has been heated up, return the valve to its usual running adjustment.
Particularly in cold weather, see that the hot air pipe that takes hot air from around the exhaust pipe and conducts it to the carburetor, is firmly in place. This aids in the vaporizing of the gasoline and allows a "leaner" mixture to be used.
The most economical gasoline is the one which will give the most powerful explosion, with the smallest amount of carbon deposit, and a relatively small loss due to evaporation. The only way to improve gasoline is to put a higher grade of gasoline in it.
Do not use any of these so-called gasoline intensifiers or the various patent tablets which, when put into the tank, are supposed to increase the power and mileage of the car. They are all designed on P.T. Barnum's fundamental principal that "there is a fool born every minute." These substances not only do not improve the gasoline but they actually decrease its efficiency, and in some instances, have an injurious effect on the lining of the gasoline tank and the carburetor. If some slight addition to gasoline would improve it, in the manner claimed for by these patent articles, it is only natural to suppose that large competing oil companies would manufacture gasoline containing ingredients of such a nature.
Sometimes in the winter, water collects in the carburetor and the sediment bulb and freezes, thus stopping up the line. They may be easily thawed out by applying hot cloths.
Occasionally some obstruction gets into the copper tube leading from the tank to the carburetor. This will be noticed by the motor missing or stopping entirely. By opening the drain cock in the bottom of the bowl of the carburetor, it can be determined if the gasoline is feeding properly. If the tube is clogged up, first shut off the gasoline under the tank and then disconnect the feed pipe from the carburetor and the gas tank. If available, use the tire air pressure to clear out the pipe or usually just blowing thru it will remove the obstruction.
It is also important to keep the unions between the sediment bulb ,and the copper tube and the carburetor turned up firmly. Vibration sometimes causes these unions to loosen up and gasoline is lost before the cause is discovered. But if the proper importance is attached to the adjustment of the carburetor for varying temperature and driving conditions, one of the main causes for unnecessary expense in the operation of Ford cars can be eliminated.
STARTING AND LIGHTING SYSTEM
For several years previous to the designing of the Ford starter, there were on the market, many starting and lighting systems for the Ford car, which were all more or less unsuccessful because the Ford motor at that time was not constructed in a manner to make the use of an electrical starter practical. These starters required the use of belts and chains, etc. and were at the best, a make shift outfit.
The GENERATOR is a small dynamo located on the right side of the motor with its armature shaft geared in with the large cam shaft gear.
The principle parts are the yoke, the poles, the field coils, the armature, the armature coils, the commutator, and the brushes.
The armature being geared to the crankshaft, revolves all the while the motor is running, so it is supported by ball bearings at both ends.
If the ammeter shows a discharge when the motor is running, disconnect the wire from the out-out to the ammeter. Then if the hand drops back to zero, the trouble is undoubtedly in the out-out. Ground the generator by connecting a wire from the generator contact post to one of the screws in the yoke. This will prevent the generator coils, etc., from being burnt out by current which is generated and not utilized. Then go immediately to the nearest service station and have your trouble repaired.
If the ammeter hand vibrates or does not show charge: First, see if all connections are tight. If this does not remedy the trouble, it is better to let an experienced generator man take care of you.
There are no particular precautions to be taken in the care of the generator except those mentioned. There is a place provided on the end of the generator to oil the bearing on that end, but the tendency is to over oil by most drivers. Too much oil on this bearing causes it to work thru and corrode the segments of the generator commutator. This is a very common trouble and can be easily avoided.
It is not advisable for the average driver to attempt any repairs or adjustments on the generator. By allowing only skilled electricians to make these adjustments much better results will be obtained.
As the cut-outs are accurately tested at the factory to close at 700 R.P.M. and open when there is no current flowing, it is not recommended that any adjustment be made except by experts.
In case the ammeter hand shows a discharge when the car is stopped, the trouble is usually due to the points in the out-out being stuck together or a short-circuit caused by the out-out cover. By tapping lightly on the out-out cover with a screw driver or a pair of pliers, the trouble is often remedied. However, the out-out should be inspected at a service garage as soon as convenient, to avoid the occurrence of the same trouble.
When the current is sent thru the starting motor it is divided, half to the field coils on one side and half to the field coils on the other side, as less resistance is offered. The current then passes to the positive brushes, to the commutator, to the armature coils, then to the negative brushes which are grounded. The current magnetizes the field coils and then as it passes thru the armature; poles are set up in the core. The magnetic attraction of the field poles and armature poles is what causes the starting motor armature to revolve.
It takes from 250 to 600 amperes to crank the engine by the starting motor and as the battery is an 80 ampere hour storage battery, it can readily be seen that continued pressure on the starter button would soon completely discharge the battery.
When the engine starts to run under its own power the flywheel gear turns faster than the starter gear which forces the starter gear back along the spiral thread until it is out of mesh with the flywheel.
A heavy spring absorbs the initial shook when the starter gear engages and prevents twisting or breaking of the armature shaft.
When starting the car always remember to have the spark retarded, as the motor is otherwise apt to "kick back" and break this Bendix spring. It is just as important to have the spark retarded when starting with the starter as when cranking the car.
If when starting the car, the starter does not respond and it seems impossible to crank it by hand, probably the Bendix gear has not meshed properly with the gear on the flywheel causing them to lock. Do not continue to press the starter button as this will tend to lock the gears all the harder. Shut off the ignition switch, put the car in high gear and take hold of the rear wheel and jerk the car backwards. This will have a tendency to reverse the direction of the Bendix gear and unlock it. Sometimes this will take quite a little effort but as soon as the gear is released the car will pull back readily.
When a battery is said to be completely discharged, it simply means that the plates have become covered with sulphate and that most of the acid has united with the plates leaving just the water of the electrolyte solution. The sulphate should be removed before it hardens. This is accomplished by sending a direct current back thru the battery the other way which drives the acid out of the plates back into the electrolyte, thus raising its specific gravity. By specific gravity is meant the relative weight of a cubic foot of a substance in comparison to a cubic foot of water. The specific gravity of water is 1.000 of sulphuric acid 1.835. Therefore, electrolyte to have the proper mixture of distilled water and sulphuric acid should have a specific gravity reading between 1.275 and 1.300. This gravity test is taken by an instrument palled a hydrometer. A hydrometer is a glass syringe in which is a floater which is weighted in a manner to float with the upper end of a scale reading 1.000 at the surface of distilled water.
To test the gravity draw up enough of the solution in the hydrometer to float the indicator. When the cell being tested reads 1.270 or more, it is fully charged. When it reads less than 1.225 but more than 1.150 it is completely discharged. If one cell tests 50 points different from the others the battery should receive skilled attention at once. Do not allow the battery to become less than one-half discharged. Particularly in the winter it should be kept fully charged or it will freeze.
If the top of the battery or the terminals become corroded, care should be taken to wash off the corrosion with a rag moistened with ammonia. Then grease the terminals with vaseline or heavy grease.
Use reason when starting your car and do not keep the starter switch on for a long period. Remember it takes about a half hour steady driving to replace the charge for one starting. Be sure and keep the battery clamps tight or the vibration will cause cracked jars and loose terminals. Do not neglect your battery, do not wait until it is completely run down or fails to turn your motor over, before you bring it to the service man, and you will save yourself unnecessary expense.
The lamps are con-nected in parallel instead of in series, so that the burning out of one will not effect the others. The headlamp bulbs are 6-8 volt double filament type. The double filament necessitates two wires to each head lamp.
The wire from the battery to the starter button and from the starter button to the starter motor is a heavy cable due to the fact that in cranking the car the starter motor requires heavy amperage from the battery which would burn out a smaller wire.
The electric system is controlled by the combination lighting and ignition switch on the instrument board. On the dash under the hood is located the junction box which serves as a distributing point for the wires to the various lamps, etc.
The diagram better shows the entire starting and lighting system.
Illistration No. 7
Usually starting and lighting troubles can all be traced back to the battery. If the battery
is kept in good shape and attention is paid to the ammeter, so that the generator is kept
charging, little trouble should be experienced. It-is a good plan to go over all terminals and
wiring at regular intervals and see that all connections are tight and that insulations are not
worn. Always carry a roll of rubberized friction tape in your tool kit, then you will be prepared
in case of emergency to cover worn or defective wiring and prevent short circuits.
But the simplicity and accessibility of the Ford starting and lighting system, which
characterizes the construction of the whole car, makes it easy to take care of, if a few practical
instructions are heeded.
MOTOR
An example of the external combustion type is the steam engine, as the heat which produces power is outside the engine under the boiler. In a gasoline engine the combustion or burning of fuel, which is gasoline, takes place inside the cylinder of the motor. This combustion takes place so quickly and forcibly that it is known as an explosion. The explosion or force of the expansion of the gases is exerted on the top of the pistons which are sent in a downward motion. This up and down motion or reciprocating motion is changed to a rotary motion so that the power can be transmitted to the wheels, by the connecting rods and the crankshaft. The connecting rods transmit the movement of the pistons to the crankshaft.
To obtain the rapid suction, compression, explosion and expulsion of the gases requires a series of four cycles or events.
1. The downward INTAKE or SUCTION STROKE during which time the cylinder sucks in the mixture of explosive gas from the carburetor.
2. The upward COMPRESSION STROKE, during which the mixture is compressed in the cylinder and prepared for ignition which occurs at the top of the stroke.
3. The rapid expansion of the compressed gases when ignited, forces the piston downward in the POWER STROKE.
4. The upward movement of the piston forces out the burned gases, this is the EXHAUST STROKE.
The diagram shows what takes place in one cylinder during the four cycles or two complete revolutions of the crankshaft.
We will now take up the names of various parts of the Model T motor and their functions. The cylinder head is cast separately and bolted on to the cylinder block by fifteen bolts. This makes the pistons and valves readily accessible and facilitates the cleaning out of carbon deposits. The pistons slide up and down in the cylinder bores, so great accuracy is used in boring and reaming the cylinders to a diameter 3.748 inches to 3.749 inches. They are then rolled and polished to a diameter of 3.750 inches by a special tool which produces a hard smooth surface to eliminate friction as much as possible. |
 Illustration No. 8 |
There are five steam holes in the top face of the cylinder block which connect with five holes in the cylinder head and allow the steam to escape which might collect in the lower jackets and impede circulation. There are three holes for the circulation of the water between the cylinder wall and the cylinder head jackets.
The valves are held seated at a pressure of 20 lbs. by the valve springs. The upper end of the springs rest on the guide bosses on the block and the lower end is fixed to the valve stem by a collar and a pin passing through a hole in the end of the stem.
There are eight pear-shaped cams machined on the shaft which operate against the push rods. The push rods in turn open the valves.
The fitting of the pistons, wrist pins and connecting rods is a very important operation and must be skillfully and carefully done. Poorly fitted pistons and connecting rods cause knocks and a noisy motor.
As the top of the push rods become worn it is impossible to check this clearance accurately on a motor which has been in use. For this reason it will not be necessary to check the clearance between the valves and push rods if the valves are properly timed with the piston travel.
In checking the gears, the mark "o" on the large cam shaft gear should fit opposite the tooth marked "Ford" on the small crank shaft gear.
To explain the timing of the opening and closing of the valves in relation to the position of the piston in the cylinder it will be necessary to understand what is meant by top and bottom dead center. "Top dead center" simply means the position of the piston when it is at the extreme top of its stroke. "Bottom dead center" is the lowest point in the stroke of the piston.
Let us consider the valve motion in the No. 1 cylinder. The exhaust valve should close at top center when the piston has just finished the exhaust stroke. The intake valve should open when the piston has traveled 1/16 of an inch downward on the intake stroke. In order to determine whether the exhaust valve is completely seated, in turning over the motor before the piston reaches top center, attempt to twist the valve head with the tips of the fingers. While the valve is open it will rotate freely but when it is seated it will not turn readily. Timing the valves in this manner will automatically cause the exhaust valve to open 5/16 of an inch before the piston reaches bottom center, and will cause the intake valve to close at 9/16 of an inch, after the piston has reached bottom center. It is very important that the valves be accurately timed according to this description, in order to have the valve motion in all four cylinders alike. This operation should be followed up with each cylinder.
The diagram shows the proper timing of the valves in a Ford Model T motor and the proper way to "mesh the timing gears."
Illistration No. 9
The foregoing explanation of the operation and construction of the engine has been given with the idea that the proper care of its mechanism cannot be taken unless it is understood exactly what the parts are made of and their purposes. With the various working parts of a motor its operation depends on five principal items, that is ignition, fuel, lubrication, compression and a cooling system. With these points considered, a gasoline motor will start and run. We will consider compression.
The greatest destroyer of compression is carbon deposits which get under the valves and causes them to warp and the edges to become pitted. This is what necessitates the "grinding in" of the valves at frequent intervals. It is not advisable for the individual owner to attempt to do this work as it is such dirty work and requires special tools. As the Ford labor charge on this operation is so low, the driver would undoubtedly save expense by having it done at an authorized service station.
It is poor policy to attempt to stop this trouble with so-called sure fire spark plugs. While it may seem to remedy it for the time being, still all this surplus oil is being burnt and forming carbon which will sooner or later cause more trouble. So the only remedy is to have new pistons or new piston rings fitted in the offending cylinders, which ever the case may require. However, if the precautions previously mentioned to avoid carbon deposits are heeded such as keeping the correct mixture in the carburetor, using good oil and gasoline, etc., the motor will operate for months at a time giving the maximum power with the minimum expense.
Below is a trouble chart which will help in determining the cause of various common "knocks" which occur in the motor. A chart of this sort must necessarily be of a very general nature. Only experience will enable the owner, driver or mechanic to distinguish the difference in the sounds of so-called "motor knocks." However, the chart, if carefully considered will undoubtedly be of great assistance to the student.
| Sharp metallic click, noticeable on hills | Carburetor mixture too "rich" or too "lean" | Adjust carburetor | ||
| Sharp metallic click, noticeable at all times, and all engine speeds. | Carburetor mixture too "rich" or too "lean" Overheating, due to: Water low in radiator. Oil low. Fan belt off. Spark rod disconnected. Oil feed pipe clogged. |
Adjust carburetor. Check up, water, oil, belt, and spark rod. After cooling, if motor still knocks take out front bolt in crank case plate. If oil does not gush out, feed pipe is clogged. | ||
| Sharp tap at regular intervals. | Valve clearance too great. Push rods or valves loose in guides. | Have valves and checked up at. Service Station. | ||
| Dull thud at regular intervals which can be traced to one cylinder by holding down vibrators on coils. | Loose connecting rod bearing. | Have bearing tightened at once or babbitt metal will be pounded out. | ||
| Pronounced knocking noticeable when motor is idling or when running down hill. | Piston slap, due to poorly fitting pistons high spots on pistons or bent connecting rods. | Have attended to at once or cylinder bores will be worn out of true diameter. | ||
| Pronounced heavy thud, noticeable on pull, which cannot be traced to one cylinder. | Main bearing of crank shaft loose, also causes pistons to knock. | Have crank shaft "rehung" at once or whole motor will have to be over-hauled. | ||
| Pronounced metallic knock, noticeable when opening the throttle and on hills. | Carbon deposits on cylinder head, pistons and valves. | Clean Carbon and grind valves. | ||
TRANSMISSION
For the reverse and low speeds, a band is tightened around the reverse and low speed drums respectively. The purpose of the low speed is to change the gear ratio, to permit the use of more power when first putting the car in motion and when climbing hills.
The normal pressure exerted by this spring is 90 pounds but with the lever action of the clutch fingers it is raised to 324 pounds. Thus, when the emergency lever of the car is forward and the low speed or clutch pedal is allowed to come back into high, this releases the spring which causes its pressure of 324 pounds to be exerted on the lugs of the clutch ring through the finger adjusting screws. The pressure on the push ring causes the clutch discs to come together and complete the connection between the crankshaft and the drive shaft.
The fact that the discs run in oil makes them come together gradually, as the oil between them must be squeezed out before the engagement is positive.
We will now take up the action of the gears thru the high speed clutch, the low speed drum and the reverse drum.
Illistration No. 10
If illustration No. 10 is closely followed no difficulty will be experienced in tracing the lines of power. On the flywheel are located three sets of planetary triple spur gears. Each set of three gears is riveted together and revolves on three pins, pressed into the web of the flywheel 120 degrees apart.
The second set of gears have 33 teeth and mesh with a central gear having 21 teeth out in to the end of the slow speed drum sleeve, which is attached to the slow speed drum and revolves around the brake drum sleeve.
The third set have 24 teeth and mesh with a central gear having 30 teeth, cut into the end of the reverse drum sleeve, which is attached to the reverse drum and revolves around the slow speed sleeve.
By having the three sets of triple gears, instead of one or two, the weight is more evenly balanced, the wear on any one set is reduced and consequently the gears are quieter.
To make a complete revolution of the driven gear it will take as many turns of the flywheel as 12/33 is contained in 33/33 or 2-3/4 turns. Thus 2-3/4 turns of the flywheel will cause one forward revolution of the drive plate attached to the driven gear assembly. Then since the drive shaft makes 3-7/11 turns to the rear axles one, in low speed the ratio of the motor to the rear axle is 2-3/4 times 3-7/11 or the motor turns 10 times to the rear axles one, in low speed.
By pulling back the emergency or control lever, the clutch pedal is held in this neutral position.
Now that the operation of the transmission has been described, we will discuss a few precautions which will enable the driver to avoid transmission troubles.
When the brake, low speed or reverse pedals are pushed forward, a band is tightened around each respective drum. These bands are lined with a heavy fabric about an eighth of an inch thick. These linings cause the bands to "take hold" gradually, quietly and without the friction that metal on metal would cause. But it is necessary to keep the bands adjusted properly to avoid their wearing out.
The low speed band is tightened by loosening the look nut on the right side of the transmission cover and turning the adjusting screw to the right. To tighten the reverse and brake pedal, remove the transmission case cover and turn the adjusting nuts on the shafts to the right.
Remember if the bands drag on the drums it will cause a loss of power and an overheated motor. Again let us advise that you keep clean oil in the crank case as this same oil also oils the transmission. Dirty oil causes the bands to deteriorate and also congeals on the clutch plates causing them to stick and the clutch to grab.
The rivets holding the band linings should be sunk deep into the lining, so that they will not come in contact with the drums.
In replacing the transmission cover great precaution must be taken that the gaskets fit properly to avoid oil leaks.
Learn how to save your bands. Do not apply your brake without first putting your clutch pedal in neutral.
When your bands commence to chatter or fail to hold after being repeatedly tightened, have them relined. Chattering bands are due to the surface of the fabric becoming glazed. This causes the band to take hold of the drum irregularly. Chattering bands are very injurious, not only to the transmission but to the entire car. The average driver gets only from three to six months wear out of his bands. But it has absolutely been proven that by using a little care and reason in the operation of your car, one set of bands will give you good service for a year or longer.
OILING SYSTEM
There is a hole bored in the top of each main bearing bushing support so that the oil runs down onto the babbitt bearing surface.
Illustration No. 11
There are two small holes which drain any oil which may work up between the push rods
and push rod guides back into the crank case.
The transmission drums bands, sleeves, and gears are running in a constant bath of oil. The oil
from the cam shaft gears also oils the generator drive gear. The starting motor drive gear and
the bearings which support it are also lubricated by the oil in the crank case as the flywheel
gear teeth which mesh with it, revolve in oil.
There are two pet cocks on the side of the crank case reservoir by means of which the oil level is tested. The best level is midway between these two pet cocks. If this level is maintained with a good high grade light oil which is renewed from time to time, no trouble will be experienced with improper lubrication.
To drain the crank case, unscrew the drain plug at the bottom of the flywheel casing and thoroughly drain off the old oil. Then replace the plug and pour in through the breather tube, a gallon of kerosene.
,center>OIL TESTS
It might be well for every Ford driver to understand exactly what constitutes a good
lubricating oil. We hear such expressions from time to time, as gravity test, flash test,
viscosity, etc. and few people know what they actually mean.
The viscosity is expressed by the number of seconds that it takes for a given volume of oil to flow through an opening of standard size, at a certain temperature. When we ask for light, medium or heavy oil we ask for oils of varying viscosities.
To get the most economical, fuel consumption and the best relative power, the lightest oil which will properly lubricate the motor, should be used. For example, an oil with a viscosity of 100 seconds would soon cause the pistons and bearings to "seize."
Road and laboratory tests have proven that the highest economy of fuel and oil, with the best relative horsepower is developed by using an oil with a viscosity ranging between 300 and 800 seconds.
The viscosity of an oil varies with the temperature. For this reason a much lighter oil should be used in winter. A heavy oil will make it almost impossible to start a motor in below zero weather.
There are many other tests which oil can be subjected to, but the ones mentioned are probably the most important and will give the driver some idea of determining the qualities of oils.
Because the lubrication of the motor has been considered first, do not think that the filling of the grease cups, the oiling of the rear axle, universal joint, etc. are of secondary importance.
Illustration No. 12
Diagram No. 12 shows the location of all the oil cups, grease cups and other places which it
is necessary to oil or grease from time to time. The oil caps on the front system, rear springs
etc. should be filled frequently with any good lubricating oil. Cylinder oil is satisfactory.
There is one small cup at the base of the steering column which should be filled every three or four weeks. Then on the universal ball cap joint to the rear of the transmission, is a large grease cup which oils the universal joint. This cup is often neglected with the result that the universal joint becomes completely worn out and must be replaced. This cup should be turned down to the right and taken off and filled with grease and replaced every week. There is no danger of getting too much grease in the universal joint.
Just to the rear of this cup is a smaller one which oils the drive shaft bearing. This should be filled every week as well. On the back of the rear axle housing near each wheel are two cups which supply grease to the axle roller bearings, these should be filled every week.
* This level refers to 1919 and later axle housings where the filler hole was located below the centerline of the housing. On earlier axles, where the filler was on the centerline, the level should be kept at about an inch below the filler hole.
Mix a small can of graphite with one quart of cylinder oil. Soak a handful of waste thoroughly in this mixture and place it over the springs and under the channel cross members of the frame both front and rear, right and left. Poke it in firmly so it will not work out. With this method, each time the car goes over a bump a small quantity of the grease will be squeezed out and the leaves of the springs will be kept thoroughly oiled all the time.
The brake rods, both right-and left, should be greased` at frequent intervals where they rub against the brake rod guides. The hangers that support the hand brake lever yoke or controller shaft on each side, should have a few drops of oil now and then also.
FRONT SYSTEM AND STEERING GEAR
DEVELOPMENT OF FRONT AXLES
It was soon discovered that this system was entirely inadequate as every jolt or jar that the front wheels received was transmitted directly to the horizontal steering lever. This made it very difficult for the driver to hold direction on rough roads.
Each spindle is controlled by a short lever arm and the lever arms are connected by a tie rod between them, so that when either the right or left lever or spindle arm is moved by the steering device, both wheels turn accordingly.
When the axles are bent they should be straightened cold as heating will draw the temper from the steel. The steel in the axle is put thru two different heat treatments and annealed at 1020 Fahrenheit. Its final tensile strength is 125,000 to 145,000 pounds per square inch.
The right spindle has a left-hand thread and the left spindle has a right-hand thread. This is to prevent the friction of the hubs from loosening the outer cones, and thus binding the bearings in their races. The spindle arms fit into the holes provided in the spindle bodies and are held rigid by a hex castellated nut. The other end of the arm is bored to receive the spindle arm bushing.
The tie rod or spindle arm connecting rod with a yoke at both ends, fastens the spindle arms together so that the wheels turn in unison. The right hand yoke is threaded on to the tie rod in order to adjust the alignment of the wheels. The spindle arm connecting rod is connected to the ball arm at the base of the steering column by the steering gear connecting rod. There is a ball socket at each end of this rod which connects with the spindle connecting rod ball on one end and the steering arm ball on the other.
Illustration No. 13
The diagram shows the front system in detail. This outward flare of the wheels at the top is known as the "camber." In order to counteract the tendency of the wheels to turn out away from each other, due to the camber, it is necessary when aligning the front wheels to "toe them in" from one eighth to one quarter of an inch. This "toeing in" of the wheels is called the "gather." The front axle is tilted bank five and one half degrees to obtain a "castor" effect. This also tends to make steering easier, and causes the car to hold the road. The axle is held at this angle thru the front spring and the spring perches on the upper side, and the radius rod on the lower side.
The radius rod is fastened at the rear to the crank case by a ball and socket joint. The two front ends are fastened to the lower side of the axle by nuts over the end of the spring perches.
Care should be taken to keep the spring clips tight or the tie bolt might become sheared and the body would shift to one side. On each spring are two rebound clips which hold the leaves in alignment on a rebound and cause the spring to act as a unit rather than throwing the strain on the main leaf.
The leaves are given a special heat treatment, shaped in a special bending machine and cooled in oil. The temper is then drawn in sodium nitrate. Each spring is thoroughly tested before it is finally passed.
This is known as the semi-reversible type of steering gear. Since the Ford car is so light, it does not require a large gear reduction and is consequently much simpler than the larger cars.
The entire Ford steering gear and front system is constructed of the very best of steel. Each part being built of a grade of metal particularly designed for its purpose. Since the lives of the occupants of the car depend upon the ability of the steering mechanism to receive severe shocks, and to respond quickly in cases of emergency, the steel used must be tough rather than extremely hard, so that the parts will not crystallize and snap off.
In the first place the front wheels must be absolutely true. It is foolish to attempt to line up wheels that are untrue. In nine cases out of ten the wheels that appear to be untrue simply have rims on which the rim lugs have not been tightened evenly and the tire gives the wheel a wobbly appearance.
To determine if the wheel itself is out of true, jack up the front axle and hold a piece of chalk steadily but lightly against the outside edge of the felloe or the rim into which the outer ends of the spokes fit, and spin the wheel. If the chalk marks the felloe for a complete revolution, the wheel is true; if not, the nearest service station will undoubtedly have bending blocks for straightening wheels.
BE SURE YOUR FRONT WHEELS ARE ALIGNED AT ALL TIMES. It will make steering easier, prevent the racking of the front system and save the tires. Driving with the front wheels out of alignment will completely ruin a set of new tires in a few miles.
Keep the spindle bolts and the spindle arm bolts up snug at all times but not tight enough to bind. The spindle body and spindle arm bushings need to be replaced after continued wearing. To determine if the looseness is in the bushings jack up the front axle and attempt to shake the wheel with both hands, if the wheel is tight on the spindle and still there is play, it is probably in the bushings.
The ball caps should also be drawn up snug. If the ball and cap has become so worn that it will not draw up closely, a little filing on the face of the cap will fix it. Keep the front system tight all around and the axle tipped at the correct angle and the trembling trouble will not be experienced. Keep the spindle bolts and ball naps oiled and they will give longer service without adjustment or replacement.
The steering gear itself seldom causes any trouble. The triple gears. in the shell at the top of the post should be greased about every five thousand miles. Sometimes a cracking noise is heard in the steering column, when the car is being maneuvered; this is usually due to the steering gear ball arm not being driven firmly on the tapered end of the steering gear post and the retaining nut drawn up tightly. The steering post bracket bolts thru the dash should also be kept tight.
REAR AXLE ASSEMBLY
TYPES OF REAR AXLES
Live axles are axles to which the wheels are directly fastened. They revolve in housings and the motive power is transmitted to them by means of a drive shaft from the motor to drive gears in the axle. "Live axles" are designated as "plain live axles," "semi-floating," "three-quarter floating" and "full floating according to the manner in which the .axle shafts take the bending and torque stresses.
The universal joint is built up of a male and female knuckle joint of case hardened steel, assembled between two rings which are riveted together. The Ford universal joint will allow an angle of 45 degrees, however the actual angle of the drive shaft to the crank shaft is about 25 degrees.
The square end of the. male knuckle joint fits into a square hole in the transmission drive plate. The female knuckle joint fits over the square end of the drive shaft and is held by a quarter inch pin, which is riveted. The upper end of the drive shaft housing is a ball joint which serves as a housing for the universal joint and permits the turning and twisting of the drive shaft and housing over, uneven road conditions.
Just forward of the drive shaft pinion gear, at the rear end of the drive shaft, is a Hyatt roller bearing. Then just forward of the roller bearing, is a ball thrust bearing which takes care of the tendency of the drive shaft to thrust forward due to the fact that the drive shaft pinion and the differential drive gear are bevel type gears. This ball bearing does not form a bearing surface for the shaft to run on but prevents friction caused by this forward thrust of the drive shaft. This bearing rests against the flange in the drive shaft tubing.
The differential assembly is composed of the right and left half of the differential case, the spider with three arms, three differential pinion gears and the two differential gears which are keyed on to the inner ends of the axle shafts; the rear axle being constructed in two sections. The gears are keyed on to the shafts and also looked with a look ring which prevents the gears from coming off when the wheels are tightened on the other end of the shafts.
The other half of the differential case is next placed over the gear on the second axle shaft, the two differential gears are meshed with the three pinions and the two halves of the case are bolted together. Then the large ring gear is bolted to the left half of the differential case.
The action of the differential is simply this, that when the resistance offered by the back wheels is the same the differential pinion gears remain stationary and the whole differential revolves as a unit. However, when the resistance offered the back wheels is not the same, for example when the car is turning a corner, the pinions will not only revolve around the studs on the spindle but at the same time will run around the gears on the axle shaft. Thus if the resistance is uneven on the back wheels, the large ring gear will rotate forward with the wheel offering the least resistance. The differential pinions during this time turning on their own studs, and running over the surface of the gear, which tends to remain stationary.
The emergency brake should be used mainly for holding the car still when starting the motor or to hold the car in place when stopped on hills, etc.
Illustration No. 14
Illustration 14 shows the construction of the rear axle assembly.
In the winter time the grease or oil is apt to become hard so that the gears will out a track and then receive no benefit from the oil. This can be avoided by putting in the housing about a pint of cylinder oil which will mix in the other non-fluid oil and form a better lubricant.
It is a good plan to put a little grease on the emergency brake cams to prevent them from sticking. Also the two grease cups which lubricate the two outer roller bearings must be kept filled at all times.
Then all the various parts of the assembly must be kept tight. Such as the drive shaft ball housing, the radius rods and particularly the rear wheels must be drawn up on the axle shafts so that there is absolutely no play. Occasionally the keys in the rear hubs will become loose from vibration and particularly from chattering due to defective bands. Loose hubs will wear out the key in the hub and the axle shaft as well and might cause the keys to snap off sometime when the brake is suddenly applied, as the whole weight and momentum of the car is against them. It is not necessary to put grease in the rear axle hub caps as there are no bearings at these points.
When it is necessary to replace parts in the rear axle it is important to inspect the teeth of the ring and pinion gear. If the "pitch" or face of the teeth is worn it is advisable to replace both gears. When an attempt is made to mesh new gears with old ones a growling noise will result. It is much wiser to have the parts replaced while the axle is dismantled than to assemble the axle with some worn parts and in two or three weeks have a reoccurrence of axle trouble which will make it necessary to pay for the same shop operation.
The driving gears are the worm and worm gear type instead of the bevel gear type, as used in the model T chassis. That is, there is a worm on the end of the drive shaft, instead of a pinion gear, which meshes with a large worm drive gear.
Too much stress can not be laid on the oiling of the truck rear axle. A heavy fluid or semi-fluid oil should be used. Keep the housing full up to the upper oil plug at all times. The truck rear axle housing is provided with a drain plug on the lower side so that the oil may be drained off and renewed, particularly with a new truck it is a good plan to change the oil after the first 500 miles. Care must also be taken to keep the grease cups which oil the roller bearings full and turned-up.
TIRE CARE, ROAD LAWS & GENERAL REVIEW
TIRE CARE
PURPOSE OF PNEUMATIC TIRES
The form of pneumatic tire most commonly used is the double tube tire mounted on a demountable rim. With this method a spare tire can be carried inflated and ready for use in case of punctures or blow-outs.
In the first place more than three-fourths of all tire trouble is due to under inflation. The weight of the car on a soft tire causes the rubber tread to loosen from the fabric and crack, which makes the weak spots causing blow-outs. It is easy to understand that a tire inflated to the proper amount will present less wearing surface to the road and will consequently give longer wear. For this reason, it is important to check up the pressure in your tires with an air gauge at regular intervals and keep them inflated to the pressure designated by the tire manufacturer. A common rule is to inflate a tire about eighteen pounds for every inch in diameter. However about sixty-five pounds for the 30 x 3-1/2 tire will be very nearly correct for most makes.
Never drive with a flat tire even a very short distance. It will cut the tube all to shreds and ruin the casing as well. It is better to drive slowly and carefully on the rim. Do not drive with wheels out of alignment. New tires can be completely destroyed by driving a car with the wheels out of "line" to any extent. Also see that the wheels are true and the rims drawn up straight on the wheels.
As far as possible keep grease and oil from getting in contact with your tires as oil is very injurious to rubber. Avoid skidding, running in car tracks and ruts, or bumping the wheels against the curbing. These things all tend to shorten the life of your tires. Also do not set your brake suddenly enough to cause your tires to drag on the road.
Another point which very often is not considered, is the importance of using tires of the same diameter on the rear wheels and if chains are used apply them to both wheels.
If these few precautions are heeded a great difference will be noticed in the tire mileage obtained.
1. What is a chassis?
2. Explain the thermo-syphon system?
3. How much water should be kept in the radiator?
4. What is the best method to prevent the radiator from freezing?
5. Explain a practical method for starting a Ford car in cold weather.
LECTURE NO. 2
1. What are the sources of electrical current for ignition?
2. Explain the purpose and care of the timer.
3. Trace the current from the magneto to the spark plugs.
4. How are the coil units adjusted?
5. What should the "gap" be in the spark plugs? How are they adjusted and cleaned?
LECTURE NO. 3
1. What type of fuel supply is used on the Ford car?
2. What is the location, purpose and care of the sediment bulb?
3. What is the purpose of the carburetor? How is it adjusted?
4. Why does pulling out the choke lever help start a cold motor?
5. Explain how gasoline may be saved on long trips.
LECTURE NO. 4
1. Name the principle parts of the Ford starting and lighting system and their location.
2. How should the ammeter register at various speeds?
3. What action should be taken if the ammeter shows a disoharge?
4. How would you determine if the Bendix drive was "looked" and how free it?
5. What care should be given a storage battery?
LECTURE NO. 5
1. What is meant by a "four cycle internal combustion engine"?
2. Explain what takes place during the four "strokes" or "cycles."
3. What is a practical method of timing the valves?
4. What are the five principle items necessary for the operation of the motor?
5. What are some of the reasons for motor mocks and why should they be eliminated at once?
LECTURE NO. 6
1. What is the purpose of the transmission?
2. What is the purpose of the transmission bands?
3. What action should be taken if the car "chatters" when the foot pedals are applied?
4. How are the transmission bands adjusted?
5. How is unnecessary wear of the transmission bands prevented?
LECTURE NO. 7
1. What type of oiling system does the Ford car use?
2. What is the proper oil level and how often should the oil be changed?
3. How do you determine when the oil feed pipe is clogged up?
4. Explain the method of draining and flushing out the crank case.
5. Name the location of the grease cups and all other important points to oil and grease.
LECTURE NO. 8
1. What care should be given the front springs?
2. Explain method to use in "lining up" front wheels.
3. What is meant by castor, gather, and camber?
4. What should be done when the spindle bolts, spindle arms, and ball cap joints become loose?
What will prolong the life of these parts?
5. What causes cracking noise on the steering post?
LECTURE NO. 9
1. What type of rear axle does the Ford car employ?
2. What is the purpose of the universal joint?
3. How do you determine "end play" in the drive shaft? What causes it?
4. What parts should be watched for looseness and kept tight?
5. What is the main purpose of the emergency brake and how is it adjusted?
LECTURE NO. 10
1. What is the purpose of pneumatic tires?
2. Explain the importance of keeping the tires inflated to proper pressure.
3. Why should the traction be the same on both rear wheels?