Buick LeSabre 1965 Service Manual page 433

7 - 6 SHOCK ABSORBERS CHASSIS SUSPENSION
bushed upper control arms, an-
gularly mounted with respect to
the center line of the car, control
sideways movement of the axle
assembly.
The upper control a r m s are
shorter than the lower a r m s ,
causing the a x l e housing to
''rock" or tilt forward on com-
pression. This rocking or tilting
lowers the rear propeller shaft
to make possible the use of a
much lower tunnel through the
rear floor pan than would be pos-
sible with a conventional rear
suspension.
The upper control arms are also
shimmed at their attachment to
the frame. In this way pinion
angle adjustment is provided.
Pinion a n g l e adjustment can
greatly affect car smoothness and
must be maintained as specified
in paragraph 6-28.
The rear coil chassis springs are
located between brackets on the
rear a x l e housing and spring
h o u s i n g s in the frame. The
springs are held in place by the
weight of the car and by the
shock absorbers which limit axle
movement during rebound.
d. Wheels and Tires
Wheels are demountable steel
disk type. The wheels have wide
drop center type rims designed
to give ample support for the tire
sizes used as standard equipment.
The rims have a tapered tire bead
seat on the inboard side and a
hump-type bead seat on the out-
board side which cause tire beads
to wedge tightly in place when
tires are inflated.
CAUTION: When mounting a tire
on this type of wheel, it is im-
perative to apply mounting soap
around the b e a d s for ease of
mounting and to prevent damage
to the beads.
Tires are tubeless low pressure
balloon type. U.S. Royal, Fire-
stone, Goodyear and Goodrich
tires are used in production with-
out optional selection of any spec-
ified make.
All tires used as standard factory
equipment have been developed by
the tire manufacturer for stabil-
ity. This does not imply that
other makes and types of tires
are not suitable for Buick cars,
but owing to the large number of
tire makes and designs it is im-
possible for ride and handling
calibrations to be worked out for
each one.
Standard production tire sizes are
given in paragraph 7-1. Tires
other than those used as standard
equipment may cause a wander.
Larger tires will reduce clear-
ance at fenders and be difficult to
mount in spare carriers. Tires
with more plys may cause hard
riding. Some types of tire and
tube combinations are difficult to
balance and may cause "tramp' \
7 - 3 SHOCK ABSORBERS
a. Shock Absorber Type
and Location
Both front and rear shock ab-
sorbers are Delco, double, direct-
action, (telescoping) h y d r a u l i c
type. All shocks are filled with a
calibrated amount of fluid and
sealed during production; there-
fore, no refilling or other service
is possible other than replace-
ment of deteriorated rubber
bushings.
Each front shock absorber is ver-
tically mounted inside the front
spring. The upper stem i s
attached to the frame by means of
grommets and grommet retainers
held in place by a nut. The lower
insulated bracket is bolted to the
lower control arm.
Each r e a r shock absorber is
mounted on an angle with the
upper end "in" toward the center
of the car. The upper end is at-
tached to a frame bracket. The
lower end is attached to a bracket
welded to the rear axle housing.
The shock absorbers are basi-
cally the same for all models but
vary as to calibration. Front
shock absorbers are interchange-
able in respect to right and left,
as are the rear. However, front
and rear are not interchangeable
with each other.
b. Shock Absorber Construc-
tion and Operation
The shock absorber consists of
two concentric tubes, a piston
and rod, and valves for control-
ling hydraulic resistance. The
rear shock absorber has an ad-
ditional tube which acts as a stone
shield. See Figure 7-5.
The pressure (inner) tube pro-
vides a cylinder in which the
piston and rod operate. The upper
end is sealed by a piston rod seal,
and the lower end is closed by the
MOUNTING
EYE
PISTON ROD SEAL
SEAL SPRING
STONE
SHIELD
RESERVOIR TUBE
PRESSURE TUBE
PISTON ROD
INTAKE VALVE
PISTON
REBOUND ORIFICE
PLATE
REBOUND SPRING
COMPRESSION VALVE
ASSEMBLY
MOUNTING EYE
Figure 7-5—Typical Shock Absorber
(Rear Shown)