Caster Angle; Caster Adjustment - Cadillac 1937 LaSalle VVI Information

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F R O N T W H E E L S U S P E N S I O N
Wheel and Tire Balance—Accurate balance 4. C a s t e r A n g l e
of the front wheels, tires, and brake drums is i m -
portant because any unbalanced condition will
tend to produce wheel tramp and high speed
shimmy.
The procedure for balancing wheels accurately
is explained on page 141.
Tracking of Wheels—-Another essential factor
in the maintenance of good steering and the pre-
vention of excessive tire wear is the proper track-
ing of the front and rear wheels. F a i l u r e of the
wheels to track can be determined b y m a r k i n g the
position of the wheels on a clean level floor and
making a diagram of the rectangle, or b y follow-
ing the car on the highway.
If the wheels are out of track, check the posi-
tion of the rear axle on the springs to make sure
that the spring center bolts are not sheared.
These bolts serve to keep the axle in place. T h e
type and condition of the springs, as well as the
alignment of the frame, should also be checked.
It will be necessary to replace or straighten any
broken, bent, or otherwise damaged parts to cor-
rect these troubles.
Wheel Bearings—Correct adjustment of the
front wheel bearings must be maintained for
proper functioning of the front wheel suspension
system. T h e procedure for adjusting these bear-
ings is explained on page 142.
Shock Absorbers — G o o d steering requires
properly performing shock absorbers. M o s t of
the trouble that develops here is due to insufficient
fluid, incorrect operation of shock absorber valves,
or worn or damaged parts.
A careful check and servicing to insure that the
shock absorbers are i n good mechanical condition
and filled w i t h the proper grade of fluid will usu-
ally serve to correct these troubles. (See N o t e 10,
Page 55.)
Steering Gear and Steering Connections—The
proper adjustment and lubrication of the steering
gear and steering connections is of obvious i m -
portance to the satisfactory performance of the
steering system. A n incorrectly adjusted steering
system m a y cause any of the steering c o m -
plaints, even though the front wheels are i n
correct alignment.
A n y adjustments to this unit should be pre-
ceeded b y a careful check of all steering connec-
tions to insure that there is no binding nor exces-
sive looseness at these points. Tests can be made
by raising the front wheels off the floor and mov-
ing the connections b y hand.
Complete instructions for the servicing of this
unit are given i n the Steering Gear section, page
135.
(The four factors now to be explained
—caster, camber, toe4n and toe-out,
can be properly considered the essential
elements of wheel alignment. In check-
ing these elements, the use of precision
equipment and careful workmanship
is essentiaL)
Caster is the angle of backward inclination be-
tween the steering knuckle bolt and vertical. See
P l a t e 9, F i g . 4. T h e purpose of caster is to
stabilize steering by i m p a r t i n g a trailing action
to the front wheels.
Excessive caster causes hard steering due,
among other factors, to the increasing tendency of
the front wheels to toe-in. U n d e r these conditions
the weight of the car has a tendency to t u r n the
wheels in at the front around their respective
steering knuckle bolts, resulting i n front wheel
shimmy.
Insufficient caster may result in car wander.
Excessive reverse caster will cause erratic steering
with a tendency to turn one way or the other,
instead of traveling in a straight course.
5. Caster A d j u s t m e n t
The proper caster setting for series 37-50 and
60 cars is 14° to 1°, for series 37-65, 70, 75, 85,
and 90 cars, - - ¼ 0 to + ¾ 0 .
W h e n checking the caster angle, it is impor-
tant to take the reading w i t h the weight of the
car on the front wheels, and to position the
wheels as shown in Plate 9, F i g . 6. The caster
angle should come within the limits given above
and be equal within 3 4 ° on both sides of the car.
The procedures for setting the caster angle on
37-series cars are as follows:
Series 37-50 and 60—1. Loosen clamp screw
at upper end of steering knuckle support.
2. R e m o v e lubrication fitting from front bush-
ing for threaded p i n at upper suspension arm.
3. Insert A l l e n wrench, T o o l J-619, through
the hole from which the lubrication fitting was
taken and adjust the caster b y turning the
threaded p i n u n t i l the desired caster setting is
secured, as shown i n P l a t e 10, F i g . 9.
Note: Turning threaded pins in a clockwise di-
rection increases caster and vice versa.
It is important to turn the pin in com-
plete turns only so as not to change the
camber setting. See Plate 10.
4. After completing the adjustment to recom-
mended specifications, tighten clamp screws and
reinstall the lubrication fittings.
Note: The above procedure can be used to
change the caster angle two or three
degrees. If caster is out more than this,
check the front suspension parts for
misalignment and make correction by
replacing bent or misaligned parts rather
than by excessive adjustment.