1948-1952 Shop Service Manual - - Hudson-Essex-Terraplane Club

12 - 16 FRONT SUSPENSION
This action will place the front springs and shock
absorbers in their "Normal" position. Do not rock at the
bumper, but at the side of the car.
Make sure the tire pressure is correct in all four tires
and the car on a level floor.
NOTE: The car is under curb load when it is loaded with
oil, water, spare tire, tools and a full tank of gasoline, but
without passengers.
NOTE: When checking the caster the wheels should be
turned on their bearings to bring the high spot or that
portion of the tire with the greatest run-out toward the
front or the rear.
The amount of caster a front end requires depends on the
friction in the spindle pins, tie rod ends and the steering
linkage. A well-lubricated car requires less caster than one
infrequently lubricated.
Replace any bent parts and check the steering geometry
whenever new parts are installed because new parts may
affect the turning angle of the wheels.
Whenever the eccentric bushing is turned, the caster,
(camber, and pivot pin inclination must be checked as all
three are affected.
FIGURE 22
When the car is set to 3-15/16" dimension at the front,
Figure 6, and 5-1/4" at the rear (curb height), Figure 21, the
camber should be 1/2º to 1-1/2° positive. The total variation
in camber between right and left side must not exceed
1/2°.
The correct pivot pin inclination is 3° 36'. If the pivot pin
inclination and the camber are off, it is probably due to
worn pivot pin bushings. If the camber is off the pivot pin
inclination is correct, the spindle is bent. Camber should not
be more than the specified 1-1/2º; however, a decrease in
camber, if pivot pins are not loose in the bushing, is not
detrimental to steering unless an actual reverse camber exists.
Positive caster is the tilting of the top of the pivot pin
toward the rear of the car, while negative or reverse caster
is the tilting of the top of the pivot pin toward the front of
the car.
Positive caster imparts a trailing action to the front wheels
while negative or reverse caster causes a leading action. The
correct amount of caster helps to keep the front wheels in
the straight-ahead position. When turning a curve, caster
and king pin inclination act as a lever, assisting the driver in
returning the front wheels to the straight-ahead position.
No caster correction should be made until after the
camber angle and pivot pin inclination angle have been
checked.
NOTE: It is seldom necessary to turn the eccentric bushing
over a half turn to obtain 1/20 for camber and this half
turn should be all that is ever necessary for camber adjustment
and give a minimum of caster change.
If camber is increased, pivot pin inclination is decreased
and if camber is decreased, pivot pin inclination is increased.
NOTE: One complete turn of eccentric bushing changes
caster 1/20. Set caster to 1° preferred with 1/2° negative
or 1/2° positive permissible, but in equal amounts on both
wheels if possible, but never over 1/20 variation Right
and Left. Set camber with the least possible change of
caster. Set the camber to 1/20.
TOE - IN
Toe-in is the setting or adjusting of the front wheels by
means of tie rods, so that the distance between the wheels is
less at the front than at the rear. Camber tends to cause the
wheels to run out or separate at the front and sufficient
toe-in is necessary to compensate this tendency and make
the wheels run straight.
Accurate toe-in is of great importance in obtaining the
maximum of tire life. Toe-in must be within definite limits
of 0" to 1/16" measured at the wheel rim.