Hudson SIX-40 1915 User manual

INSTRUCTION BOOK
HUDSON SIX-40
1915
Fourth Editon
HUDSON MOTOR CAR CO.
DETROIT MICHAGAN

Instruction Book
Hudson Six “40”
1915
Fourth Editon

INDEX
USEFUL INFORMATION
How to Start Motor
Notes on Oiling
Diagnosis of Common Trouble
How to Learn to. Drive a Hudson Six-40
The Hudson Clutch
Front Axle
The Hudson Rear Axle
Brake Adjustment
The Action of the Zenith Carburetor
Transmission
Steering Gear
Care of Springs
Storing Your Car for the Winter
The Action of Lubricants at Low Temperature
Anti-Freezing Mixture
Washing Car
Cleaning of Nickel Plated Parts
Advice to Drivers
THE HUDSON 1915 SIX-40 ELECTRIC SYSTEM
How to Start Engine
The Motor Generator
The Motor Clutch
The Generator Clutch
Regulation of Output
The Combination Switch
The Circuit Breaker
The Distributor and Timer
To Time Ignition
Ignition Resistance Unit
Regulation of Resistance Units
The Ignition Coil.
Varying the Dimming of the Headlights
Lubrication
STORAGE BATTERY INFORMATION
Storage Battery
List of Service Stations and Sales Offices
Charging Battery from an Outside Source
Putting Battery in Service Again
Hydrometer Syringe and Directions for Using
Removal of a Complete Cell
Sediment
Care of Battery When Car is in Storage or Laid Up for the Winter
Adding Water
3
3-6
6-7
7-8
8-12
12-14
14-17
17-18
18-22
22
23
23
23-24
24
28
28-30_,
3t.
30-31-32-33-34
36
38
39
39
39
39-40
41
41-42
42-43
43
43-44
44
44-45
45
46
46
48
48
48-49-50
50
50
50-51
52

INDEX-Continued
INDEX-Continued
ILLUSTRATIONS
Functions of Fittings and Levers in Driver's Compartment
Preparing Car for Running
Valve Tappet Adjustment
Clutch Illustration
Wheel Alignment Illustration
Rear Axle Illustration No. 1
Rear Axle Illustration No. 2
Brake Adjustment
Carburetor
Lubricating Chart
Manner of Turning into Another Road
ILLUSTRATIONS HUDSON SIX-40 ELECTRIC SYSTEM AND STOR-
AGE BATTERY
Simplified Circuit Diagram
View Rear End of Generator
View Front End of Generator
Wiring Diagram Six-40-1915
Distributor .
Dimmer Illustration
Charging Circuit Diagram
Hydrometer Syringe
Storage Battery
2
4
5
10
13
53
15
17
19
26-27
31
37
38
39
40
41
44
47
49
51

2

How To Start Motor
Follow Instructions by Paragraphs
See Fig. 1.
1. Pull out "M" button on Ignition Switch.
2. Place spark lever about halfway up quadrant, and throttle lever all the way
down.
3. To stop the motor, both "M" and "B" buttons must be pushed in.
There are three positions of the carburetor air control operated by the small pull rod which terminates in a handle
on the cowl apron. When this handle is pulled half way out, hot air is drawn from the exhaust manifold through the
carburetor.
This position is most suitable for cold weather as warm air helps volatilize the fuel.When the handle is pushed all
the way in, cold air is taken in through the carburetor, and when the handle is pulled out as far as it will go, the control
is in the "strangled" position. In this instance, the air supplied to the carburetor is materially decreased and suction
from the motor increases the quantity of gasoline drawn into the cylinders.
In general, this handle should be pushed in, in warm weather and pulled half way out in cold weather. In starting,
especially in cold weather, it may be pulled clear out to assist in priming the cylinders, but the hand throttle must be
opened about one-third when cranking. By pulling out the handle, thus applying the strangler before turning off the
ignition, the cylinders will be supplied with a rich mixture of gas which will materially assist in starting at a future time.
There are various other positions between these three indicated, which may be used for different weather conditions,
the correct point being determined more or less by experimenting with the car in operation.
If the motor fails to start when the electric cranking device has been in operation for 30 seconds, with the strangler
closed, and with the spark and throttle levers in the correct position, discontinue cranking until you have made sure of
the cause of the failure to start. This will save your storage battery.
A reserve Ignition System, consisting of A SET OF DRY BATTERIES, is furnished, and this may be used in case
the storage battery is disabled by accident or other cause. In this event, the dry cells are used for Ignition, tiut it is good
practice to start on the dry cells occasionally because this procedure will test the dry batteries and assure you that they
are in proper condition for an emergency.
NOTE—DO NOT KEEP THE MOTOR RACING WHEN CAR IS NOT IN MOTION OR NOT PULLING. THIS
SHORTENS ITS LIFE MATERIALLY.
DO NOT ATTEMPT TO START MOTOR WITH CAR IN ANY GEAR. THROW CONTROL LEVER INTO
NEUTRAL POSITION.
Notes On Oiling
Every week or so the car should be looked over thoroughly and oil applied through the various oil holes provided
for the purpose; also such moving parts as rod ends, pins, devises, etc., should be well lubricated.
USE GOOD MOTOR OIL—Test all your lubricants with blue litmus paper to be sure no acids are present. It is
difficult for us to recommend any particular grade of motor oil, as the same grade does not necessarily give the same
results in different parts of the country, due partly to climatic conditions. We also find that some motor oils (sold un-
der trade names), vary considerably in different parts of the country perhaps due to the fact that the origin of the crude
oil from which they are made is not necessarily always the same.
Attempted economy by the purchase of inferior or cheap grades of lubricating oil always results in carbonized
3

Fig. 3

oil always results in carbonized motors, burned-out bearings, overheating and loss of power, or other serious
troubles. Like every other commodity, the payment of a fair price secures the best article.
In winter, a thinner grade of oil may be used than in summer. A tendency to overheat, which is indicated by
a rapid evaporation of the water from the radiator, may often be eliminated by using a medium grade, rather than
a thin grade, of motor oil of good quality.
Diagnosis of Common Trouble
IF MOTOR STOPS.
1. Out of gasoline.
2. Disconnected spark plug cables or other loose electrical connections.
3. Dirty contact points in the distributor or accumulation of oil or dirt on the
underside of the distributor cover.
4. Out of motor oil, indicated usually by knocking in the motor, followed by an abrupt stop. If this occurs,
do not attempt to use either the electric starter or hand crank until the motor has been allowed to cool off.
Kerosene should be applied to the pet cocks while the motor is still warm. This usually is a serious matter, and
the motor should have the attention of a good mechanic before attempting to put the car into service again.
5. Cannot crank motor. Frozen water pump. Seized motor bearings, due to lack of oil. Transmission
engaged.
REASONS FOR MOTOR MISSING.
1. Short circuited spark plug. Points not adjusted to .025".
2. Partially short circuited or broken secondary terminals.
3. Poor contact between the various ends and clips of wiring.
4. Loss of compression in one or more cylinders. Valves may be stuck. Valves may need regrinding or
reseating. Valve springs may be weak or broken.
5. Water in gasoline—the motor runs spasmodically. (This is the most difficult to separate from other
causes, and should be one of the last things looked for.)
6. When motor misses, you may locate the missing cylinder by opening the priming cock on top of the
cylinders, one at a time. After replacing with a new one the spark plug in the missing cylinder, or with one from
another cylinder, you will have to determine whether missing is caused by defective plugs or wires leading to
same. If the trouble is still continuing, turn over the motor slowly by hand in an endeavor to detect a defect in the
compression in the different cylinders.
7. If missing is not due to any of the items mentioned above, there may be an air leak between the carburetor
and intake manifold, or between the manifold and cylinder block.
8. If any wires in the entire electrical system have been tampered with at any time, refer to the wiring
diagram in this Instruction Book. Page 40.
IF MOTOR LACKS POWER.
The motor will run but not pull on grades or under heavy loads.
1. Loss of compression due to leaky valves.
2. Too rich a mixture through some defect in carburetor, probably flooding due to grit under float valve.
3. Late Ignition. (See directions for timing of the distributor, page 42, retarded spark.)
4. Lack of water in radiator or oil in motor causing the motor to run hot.
5. Lack of gasoline. If lack of gasoline through stoppage of pipe, the motor will spit back through
carburetor when throttle is opened.
6. Poor grade of gasoline, in cold weather, causing too weak a mixture.
7. Dragging brakes. See that the car can be rolled by hand easily or that it will coast down hill when clutch
is released and not slow down. Feel the brake drum with your hand to determine over-heating.
8. Flat tires.
9. Stoppage of the jets in carburetor due to dirt or sediment.
6

ELECTRIC CRANKING FAILS.
1. Loose battery connections.
2. Depleted battery.
3. Motor brush contact on commutator faulty.
FAILURE OF MOTOR TO START.
1. Switch not turned on.
2. Gasoline not turned on, or out of gasoline.
3. Poor grade of gasoline in cold weather, or water in gasoline.
4. Weak ignition due to depleted dry cells when starting on the "B" button or to depleted storage battery when
starting on the "M" button.
5. If the motor turns over very slowly your storage battery has become depleted, due to continuous cranking,
prolonged burning of the lamps, with insufficient running of the motor or lack of care in filling with distilled water.
6. Contact points out of adjustment. See page 42.
7. Ignition unit shorted.
8. Water on coil or terminals.
9. Over rich mixture caused by continued use of strangler.
IF THERE IS GOOD CLEAN GASOLINE IN THE CARBURETOR AND A GOOD SPARK AT THE PLUGS,
YOUR MOTOR WILL START IF PROPERLY HANDLED.
MOTOR KNOCKING.
1. Spark advanced too far. (See directions for timing Ignition, page 42.)
2. Too rich a mixture. Open the strangler, if in "Strangled" position, or run carburetor on cold air instead of "hot
air."
3. Motor speed too low in pulling on hills or through bad roads, on direct drive-shift to a lower speed. Loose
connecting rod bearings. (Light knock at high speed.)
4. Crank shaft bearing loose. Heavy pounding at low motor speeds and under heavy loads.
5. Too much play in valve push rods. (Light tapping sound.)
6. Tapping noise due to improper adjustment. (See instructions for adjusting page 5.)
7. Carbon in cylinders.
8. Automatic governor does not return to retard position easily.
REASONS FOR OVERHEATING.
1. Low supply of water.
2. Too rich a mixture of gasoline.
3. Carbonized cylinders.
4. Lack of motor oil.
5. Late ignition or retarded spark.
6. Broken or inoperative pump.
7. Radiator core stopped up with mud or other matter.
8. Loose or broken fan belt.
9. License tag is obstructing front of radiator.
How To Learn To Drive The Hudson Six-40
Start the Motor as Instructed on page 3.
Before shifting gear lever, advance the spark lever to the top of the quadrant, and the throttle lever about 1/2 inch
from bottom of the quadrant. Press out the clutch pedal with the left foot and holding it in this position, move the gear
shifting lever into the first speed position (inside back position). Gently let in the clutch, giving the motor sufficient
advance of the hand control to prevent stopping of the motor as the clutch takes hold. Keep the car in this speed until
you have learned the art of steering.
While it is more difficult to steer at this speed than at a faster speed, you should be cautious until you are thoroughly
familiar with the operation which you have just gone through. Repeat this process a number of times so that you have
7

confidence in yourself before shifting. Before repeating the operation each time, throw out the clutch, push shift
lever forward to the neutral or center position and bring the car to rest with the foot brake operated by the right
foot.
With the car running in the first position and with the hand throttle almost closed, push out the clutch and shift
lever to neutral position then through "H" plate into second speed position (outside forward).
This operation does not necessarily have to be done quickly provided the car and motor are running at the
proper speeds. Never try to make this shift without first pushing out the clutch.
Just prior to shifting, the car may be accelerated by opening the throttle slightly. To shift to third position,
accelerate the car slightly in second position and after pushing out the clutch, place the lever in third position
(outside back).
To reverse the car, the shift lever is placed in the inside forward position.
NEVER ATTEMPT TO REVERSE THE CAR WHEN IT IS IN MOTION.
NEVER CHANGE SPEEDS WITHOUT HOLDING OUT THE CLUTCH AS THE GEARS IN THE
TRANSMISSION WILL BE DAMAGED BY SUCH ACTION.
Always let the clutch in gently, after shifting gears, as there is nothing so hard on the car as violent action in
this regard.
Do not continually slip the clutch to reduce the speed of the car; use gear shift lever instead and change speeds.
Continual slipping of the clutch will burn the cork inserts and result in subsequent difficulty.
When preparing to stop, push out the clutch and apply the foot brake, gently allowing the car to coast to the
point where you wish to stop rather than retarding its motion suddenly with the brakes.
Get in the habit of pushing out the shift lever while your car is coming to a stop, and after the car has stopped,
apply the emergency brake so that the car will not roll or change its position after you have left it.
Use the brakes and clutch pedal as little as possible, controlling the car by means of the throttle. With the clutch
engaged, closing of the throttle causes the motor to act as a brake which will relieve wear on the brakes and
prolong the life of these parts.
Never switch off the ignition when coasting down a long hill, using the motor as a brake. By so doing the
entire generator output will pass through the regulating resistance ("C" Fig. 3, page 39) and may cause it to burn
out. If it is desirable to coast down a long hill with the motor as a brake—shut off the gasoline—IT IS MORE
ECONOMICAL. The shut-off cock is placed conveniently at hand for this purpose.
In case of emergency, close the throttle and apply the foot brake at the same time.
DO NOT DRIVE FAST UNTIL THOROUGHLY FAMILIAR WITH THE CAR IN EVERY WAY.
When not using the car, see that both the "B" and "M" buttons are pushed in, in the "OFF" position.
Until you are familiar with the action of the clutch and brake pedal, it is often easier to learn to drive with the
hand throttle, rather than the foot throttle or accelerator.
However, when you have mastered the points so far referred to, you will find it perfectly natural to operate the
car with the accelerator pedal rather than with the hand throttle, and probably better ultimate results will be
obtained.
WHEN IN DOUBT, DON'T DO ANYTHING. THINK THE MATTER OVER AND ANALYZE THE
PROBLEM.
The Hudson Clutch
For the past four seasons' models, the Hudson Company has retained the same design of clutch, and it gives
so little trouble that few have seen the inside of one.
8

The principle upon which it operates is the most simple one conceivable, based on the theory
that there is a great deal of friction between cork and steel, but that the former element is extremely
soft. In consequence the Hudson clutch is very smooth in action, but once engaged, it seldom slips.
The fact that the cork inserts become saturated with oil makes it difficult, compared with other
types, to abuse the clutch. Except for an occasional cleaning out with gasoline, the only attention it
requires is the maintaining of the lubricant, one-half kerosene and one-half engine oil, not more than
a half pint of this mixture to be put in at a time.
In case of continued slippage, application of a small quantity of pure kerosene to the mixture
alreadyinthe clutchwillbe ofbenefit,or addingasmall quantityofmotor oilwillrelieve thegrabbing.
The Discs
The driving discs, which are secured in the flywheel by four specially heat treated studs, are
stampings, carefully flattened and machined so as to slide freely on the studs. The driven discs are
also stampings but are thicker and have numerous holes in them; into these holes the cork inserts are
pressed.
The corks are first soaked in warm water to make them pliable, then they are forced into the
holes by a special machine. A considerable amount of cork is left projecting on either side of the disc
and this is shaped off to leave about l-32" after the corks have thoroughly dried out, then the corks
are ground flat on a surface grinder.
In making a replacement of corks in a repair shop not properly equipped, the surfacing of the
corks is usually accomplished by rubbing the disc on a piece of sand paper. The result is seldom
satisfactory, as the corks are not flat and even, and do not give the full bearing surface which is
necessary in order to have the friction to hold the power of the engine.
It is absolutely necessary that the corks be perfectly dry and show a full bearing surface. This
latter point can only be ascertained by rubbing them flat on a surface that has been covered with
Prussian blue or lamp black, using only a very thin coating. The greater the bearing surface obtained,
the longer the corks will wear and the less the spring tension necessary.
The spring tension can be varied to suit the necessity by putting shims, about the size of a
fifty-cent piece, at the back of the spring. This compresses it more, making it shorter when the clutch
is engaged.
The cork insert discs drive the clutch drum on which they slide and this sliding, or separating
motion is facilitated and equalized by small coil springs interposed between the driving discs.
Assembling the Clutch
In assembling the clutch great care must be exercised or these little springs will slip out of place
and, becoming jammed between the moving parts of the clutch will cause it to drag instead of
releasing properly. Usually the noise made by the interference will indicate that something is wrong.
Another important feature is to see that the driven disc nearest the cover, at the back or
transmission end of the clutch, does not slip out of the slots in the drum; this will cause a loud
scraping sound when the clutch is released.
In assembling a clutch ready for inserting in the flywheel the following method is recommended:
1. Put the clutch drum on the bench and drop the discs on—a cork-insert disc first and then a
plain disc. The discs should be selected so that they slide freely in the grooves of the drum and with
the minimum amount of backlash.
2. After all the discs have been fitted in this manner, take the clutch cover and slip the studs
9

through the holes in the driving discs, placing the separating springs one at a time.
3. This accomplished, and with the spring, the ball thrust bearing and the shims in place in the
crankshaft, the clutch cover can be slipped into place.
4. By means of a lever looped into a wire on the motor foot and bearing against the driving jaws of
the clutch, the whole clutch assembly can now be forced into place against the pressure of the spring very
easily. When it has been entered sufficiently to allow of two cover bolts being started into place, the
pressure of the lever may be released.
5. The cover should then be secured, care being taken to screw up the bolts evenly so that the tension
on them will be the same all around. Unless this is carefully accomplished the cover will be strained and
the lubricant will leak out.
Making Clutch Oil Tight
The gasket between the cover and the flywheel should be in good condition and shellacked onto the
cover; it should be allowed to set for a while before using so that the shellac is "tacky" and will hold the
gasket securely to the cover during the assembling operation. It is advisable to wind a little wicking
around the heads of the bolts before screwing them down so as to prevent leakage.
The assembling and rendering oil-tight of the clutch is greatly facilitated by the driving studs being
riveted into the cover. In this way there are no packed joints in the flywheel except the cover and the
screws which secure it.
Also the cover and clutch can be assembled as a unit with no possibility of the discs slipping out of
place by the simple expedient of clamping the jaws at the point where they project through the cover.
As a hint to the man who ever has to do this job on a 1915 model clutch, the bronze throw-out sleeve
may be utilized as a clamp temporarily, by wrapping some paper or thin shim metal around the jaws and
then pressing the sleeve over it. There should be just enough shimming to make the sleeve a tight fit, but
not so much that the sleeve will be distorted or otherwise damaged in removing it.
Conditions Governing the Clutch
The thrust of throwing out the clutch is taken on a bronze washer which fits into a recess in the face
of the sleeve. It is highly important that this washer be sufficiently lubricated at all times or it will burn
out. Other reasons for the shortened life of these washers are as follows:
1. The spring which keeps the pedal from coming back farther than is necessary may be adjusted to
too great a tension, thus putting a constant thrust on the washer.
2. The driver may have a habit of driving with his foot resting quite heavily on the pedal. This is
unnecessary. See Bulletin No. 8, Volume 3.
3. The pedal may be improperly adjusted so that it is touching the toe-plate The result is the same
except that in a case of this kind the clutch will probably slip so badly as to be noticeable.
4. The grease cup lubricating the pivot pin of the throw-out fork may be empty and the fork seized
up so that it will not move freely.
5. There is a stop provided for the purpose of limiting the amount of throw given. Since the corks
wear slightly with use and since too much throw is unnecessary, this adjustment should be inspected
occasionally and always in the event of any repairs occasioning the dismantling of the transmission or
pedals.
11

On the 1915 model this stop is on the left, on the cap that carries the gear-shift rods. The adjustment
is simple to determine. Whenever you find that the transmission gears stop and the gears can be engaged
without the pedal being thrown all the way out, the adjustment needs attention and should be screwed out
to meet the sleeve lever until it stops its travel at the correct moment. Too much throw means more effort
to release the clutch, and often makes the clutch noisy when disengaged.
The two most important instructions are: Don't slip your clutch more than is absolutely necessary,
and then only when you KNOW it has sufficient lubricant to stand it. Don't drive with your foot resting
heavily on the pedal, and if you must do so owing to congested traffic or natural nervousness, remember
that the throw- out sleeve will need more frequent attention.
Front Axle
This is of the conventional "Elliott" type, of selected high carbon steel, dropforged and heat
treated.The steering knuckles are also of nickel steel and turn on hardened steel bushings.The thrust
bearings are steel, the upper one being held stationary by a tongue which fits into a groove in the king-bolt.
The adjustment for wear is accomplished by introducing shims between the top thrust washer and the axle
fork.The king-bolt is provided with a passage which conveys the lubricant to the upper bearing and the
thrust washers.There is a second grease cup which lubricates the lower bearing.Whenever it is obtainable
we recommend Whitmore Anti-Friction No. 5 as the most desirable lubricant.This also applies to all other
steering connections.
Timken bearings are used in the front wheels.The wheel hubs are of pressed steel construction and
thus extremely sturdy.The bearing retainers are for the purpose of confining the lubricant and are not
disturbed by the removal of the wheel
.
The wheel bearings should be adjusted by the nut so that a slight amount of play is noticeable when
the wheel is shaken by grasping the tire. If the bearings are adjusted so that there is no play at all it will
be impossible for any lubricant to penetrate between the rollers and cones, and on account of the excessive
pressures that may result from such adjustment, the life of the bearings will be impaired.
Since it is to be expected that any bearing will wear sooner or later, we would caution all against
overlooking this important point of inspection. Too much play is almost as bad as a tight bearing, but is
more objectionable on account of the rattle it causes.
The alignment of the wheels is an important factor in the life of the front tires. The front of the tires
should be about 5/16" closer together than the rear, measured at the same height from the ground. The
easiest way to check this adjustment is as follows: Jack up the front of the car from the centre of the axle
so that the distance rod is not interfered with. With both wheels free to revolve, a centre line can be
marked on each tire by holding a soft lead pencil against it when spinning. The pencil must be held steady
or the result will not be a straight line. Next measure with a tape or stick the distance between these lines
at points opposite the hubs at the extreme front of the front tires.Next, measure the distance at the points
opposite the hubs at the extreme rear of the front tires.This dimension should be from 5/16" to 3/8" greater
than the measurement obtained at the front, allowing for any slight wobble of the wheel.
12

The handiest way to check this alignment is with the distance stick shown in the illustration
To adjust the distance rod it is necessary to remove one of the bolts when the clamp screw can be loosened
and the clevis adjusted by turning on the threads of the distance rod. Any backlash is the axle knuckles and
13.

devises should be taken up by straining the wheels outwards in front before setting the distance by the rod,
and the job should always be checked after the wheels have been let down on the ground with the weight
of the car on them.
The Hudson Rear Axle
The 1915 model axle is a semi-floating type, but with the difference that the live axle drive shafts are
butted in the centre and the load on the wheel bearings is compensated.
In the illustration No. 1, page 53, it will be noted that the live axles are tapered, not only at the point
where the wheels are secured, but also extending through the inner race of the bearings "B."
This construction offers several advantages. The wheels are held in place side-ways and the shafts
cannot become loosened in the bearings and thus be cut away, as is the case with straight bore bearings.
The thrust of each wheel bearing is in a direction outward from the centre of the axle.
Since the shafts butt in the centre it is obvious that the thrust load will be taken by the bearing opposite to
the side upon which the thrust is applied. In turning a corner to the left, for instance, the right hand rear
wheel will be carrying the weight of the rear end of the car entirely and the left wheel will have a tendency
to leave the ground. The weight load will be all that is carried by the right wheel and the entire thrust load
will be transferred to the wheel bearing on the left, which being
off the ground, carries absolutely no weight load.
Thus the live axles are actually "floating," a great deal more so than if the driveshafts were rigidly
secured to wheels mounted on a fixed, immovable axle housing.
So much for the question of the degree of "float."
This type of axle is used extensively abroad because of its stability combined with light weight and high
efficiency in transmission of power.
The two cars which made such a wonderful showing at Indianapolis this year—Delage and Peugot—
were equipped with axles almost identical with the one herein described.
In this country the Packard, Pierce and White, all high-grade cars, are the most notable examples.
In taxicab service it is a recognized fact that the semi-floating type of axle is the most suitable for heavy
duty.
The advantage of strength is obtained through the use of the most desirable materials in places where a
full-floating design renders it impossible without an abnormal increase in weight.
The following examples serve to illustrate this.
Since the destroying effect upon wheel bearings is due to thrust, or load occasioned by other conditions
than the weight of the car and power transmitted through the live-axles, it is easy to comprehend that the
difference between the bearings required to withstand the same amount of destructive effort will be
proportionate to the difference between the distances "A" and "B" in the illustration No. 2.
The load upon the differential bearing in "A" is exactly one tenth of the load on the inner wheel bearing
at "B." Of course the load on the outer wheel bearing "B" is also greater than the load on the wheel-bearing
at "A," force applied the same in both cases.
The live-axle shaft is made of solid chrome-nickel steel, heat treated to resist the bending strain of such
a load.
In the full-floating type "B" the leverage is ten times as great under any condition, but the bending
stresses must be resisted by the axle housing, which is of necessity a pressing grade of carbon steel and
14

No. 2
not nearly as strong as the solid shaft at "A."
Furthermore, to facilitate the mounting of the wheel bearings the axle housing is invariably reduced at
this point. The sectional area of the housing is usually half the area of the solid shaft. There is less
tendency to bend the shaft (which is inexpensive to replace compared with the housing), and the safety
factor is twice as great as that of the housing (which is very expensive to replace).
From the standpoint of the car owner this is an advantage.
It should also be remembered that the live axle on a semi-floating type may be bent to a considerable
degree without any resulting damage other than the wheel wobbling. On the full-floating type the bending
of the housing in the least degree results in the destruction of the alignment of the drive shaft. This latter
condition cannot exist for any length of time without either crystallizing the shaft or destroying the wheel
bearings.
It is claimed that it is a commercial impossibility to manufacture an axle of the full-floating type in
which the alignment of the two wheels and differential will be perfect. For this reason we have said that
a full-floating axle must have two universal joints on each drive shaft, one at each wheel end and one at
each differential end. Such an axle is in use on a car of French manufacture but it is not by any means a
commercial proposition.
Another advantage in the semi-floating construction is the elimination of backlash in the driving
mechanism.
There are no slip joints at the connection of the drive shafts with the wheels as is essential in any axle
claimed to be full-floating. Also the enormous reduction in the bending stresses at the differential end,
where there is a joint, make wear at that point an easy matter to resist by the use of suitable materials.
A fewer number of parts is another result of this construction.
Weight, especially un-sprung weight, which is a constant load upon the tires, is reduced without
sacrifice of sturdiness. The wheel bearings are unrestricted by hubs and may be proportioned to give a
greater factor of safety without presenting a cumbrous appearance. The axle housing proper may be made
lighter and shorter over-all. The differential bearings are much smaller and the carrier is also lighter. The
live-axle shaft is heavier but not much so compared with the great increase in strength. This 1915 axle
15

is many pounds lighter yet much stronger in every way than the 1914 type.
From the standpoint of accessibility the 1915 axle has many advantages. To remove the wheel is only
a matter of a few minutes. One nut must first be removed and the wheel puller does the rest. Compare
this with the task of removing eight nuts, then a wheel bearing lock-nut then a washer and finally another
nut. All this was necessary before an adjustment of the wheel bearings could be made and the appearance
of the flange and nuts after such an operation left something to be desired.
The gasket too was usually spoiled in the operation. Now we have only to remove one nut to take off
the wheel, one more to release the bearing adjustment, and we have a very much more accessible form
of wheel bearing adjustment to deal with.
The spring saddles are solid with the brake supports so that all the braking effort is transmitted directly
to the springs through a single casting, not through rivets in the housing as in 1914 construction.
The driving torque is transmitted through the rivets, but it is negligible compared with the brake effort,
and the rivets are placed to better advantage on the longer expanse of support available.
Adjustment of Wheels
Through usage the wheel bearings or drive shaft bearings shown at "B" in illustration No. l, are subject
to a certain amount of natural wear which in turn allows end play to develop in the drive shafts. As the
wheels are rigidly fastened to drive shafts by being pulled up on a taper on the shafts, bearing wear will
cause side play in the wheels, which can be taken up in the following manner after wheels have been
removed. For this operation we provide a special puller included in the tool kit.
"A" in the illustration is the adjusting nut for the bearing "B," and "C" the locking bolt for adjusting
nut "A." After removing locking bolt "C," tighten "A" turning toward right to tighten or toward left to
loosen. A special wrench is furnished with tool equipment for this purpose.
Care should be taken in making this adjustment not to take up all play on one side, but it should be
equalized. The lining-up of the brake drum and the axle housing on the opposite side to that on which the
adjustment is being made will indicate whether the wheel is out too far on that side.
Take up the adjusting nut so that the drive shafts show no end play but are perfectly free and the bearings
do not bind. Should it be impossible to lock the adjusting nuts "A" when the above results are obtained,
back off rather than tighten so that notches will line up in the adjusting nuts. This adjustment does not
affect the ring gear or drive gear in any way due to the fact that drive shafts float through.
Adjustment of Gears
Before attempting to make any adjustments, remove the Inspection Plug— left side of gear set and
differential carrier. (See illustration No. l.) See that the back face of the teeth on both pinion and ring gear
are flush. The pinion adjustment can be reached by first removing the pinion adjustment lock held in
place by two bolts on top of carrier (shown in small cut in illustration). End play in pinion shaft should
be taken up by turning front bearing adjustment toward left (when looking at the axle from front end).
This is the inner nut. The outer nut which is for rear bearing adjustment should be held against movement
during this operation.
Take up play between bearings until there is no end motion, but do not bind or cause shaft to turn hard.
Line up slots in both adjusting nuts, then turn both toward right to bring pinion deeper into mesh with
ring gear, or toward left to withdraw. The proper amount of back lash between teeth of ring gear and
pinion is from .006" to .008".
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