Page 531
a
GENERAL
All wheels are equipped with coil springs. The front wheels
are individually suspended and are mounted on the steering
knuckle housings, which are connected to the control arms
by permanently lubricated ball joints. The inner ends of
the control arms are journaled to the body in rubber bear-
ings. The spring movement of the wheels is limited by rub-
ber buffers. As from model 1973 the lower spring sup-
ports are pivot suspended.
FRONT SUSPENSION, UP TO AND INCL. MODEL 1972
1, Upper contro! arm
2. Lower spring support
3. Coil spring
4. Rubber buffer
5. Rubber buffers
6. Shock absorber
Jan, 1973 SAAB
FRONT SUSPENSION, AS FROM MODEL 1973
1. Upper control arm
2. Lower spring support
3. Coil spring
4. Rubber buffer
5. Rubber buffers
6. Shock absorber
600-1
Page 532
Steering knuckle housings
The front suspension consists of separate left-hand and
In steering, the steering knuckle housing pivots about an
imaginary axis, the “king-pin” or steering knuckle axis,
which passes through the centers of both the ball joints
right-hand units. The steering knuckle housing, on which
the wheel is mounted, consists of a bearing housing with
two inward-curving pivot arms. The wheel is journaled
on two tapered roller bearings. The outer drive shaft is
splined and force-fitted to the hub. The brake disc with
integral parking brake drum is mounted on the hub, and
the brake shield and parking brake mechanism are bolted
to the steering knuckle housing. The steering arm is fas-
and intersects the ground at a point close to the center
line of the wheel. The outer and inner drive shafts are
connected by the outer universal joint, which is protected
from dirt by a rubber bellows.
tened to the steering knuckle housing by two screws.
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$ 3232
FRONT AXLE ASSEMBLY
1, Castle nut 7. Inner shaft seal 13. Inner drive shaft
2. Washer 8. Outer drive shaft 14. Steering knuckle housing
3. Wheel hub 9. Lock ring 15. Upper ball joint (upper end piece)
4. Outer shaft seal 10. Ball 16. Lower ball joint (lower end piece)
5. Wheel bearings 11, Hub 17. Stop ring
6. Spacer ring 12. Rubber bellows
600-2
Jan. 1972
Page 533
Control arms
The front axle, forming a separate unit on each side, is
bolted to ball joints forming the outer ends of the con-
trol arms. There are two control arms on each side, each
journaled in rubber bushings in two bearing brackets.
The upper control arms carry the coil spring supports,
which also serve as compression stops for the rubber buff-
ers.
CONTROL ARMS, BEARINGS A\
1. Upper contro! arm
2. Lower control arm 5,
3. One-piece rubber bushing
. 1973
Popmt® SAAB
NO BUSHINGS
4. Two-piece rubber bushing
6. Bearings
7. Spacers
600~—3
Page 534
Steering mechanism
The steering gear is of rack-and-pinion type. It consists
of an angled spiralcut pinion gear engaging teeth on
arack. The rack is journaled in a housing consisting of a
cast light-alloy unit with a steel tube pressed into it. The
pinion bearing is provided with a spring-loaded plunger
that presses the rack against the pinion. The other end of
the rack is journaled in a bushing. Steering-wheel move-
ment is transmitted to the pinion by a two-piece steering
column and two joints. This imparts an axial movement
to the rack, which moves the two tie rods connected by.
ball joints to the ends of the rack. The tie rods in turn
move the steering arms fastened to the steering knuckle
housings and connected by ball joints to the tie rods.
S$ 2348
STEERING MECHANISM
Nov. 1969
Page 535
Power steering gear
On model 1974, some models are equipped with a hydrau-
lic power steering gear.
The assembly consists of a rack-and-pinion steering gear
with a servo valve which regulates the oil flow to a servo
plunger on the rack. The hydraulic pressure is generated
by an oil pump which is driven by a V-belt from the belt
pulley on the crankshaft. A separate oil tank by the right
wheel housing supplies the system with hydraulic oil.
The steering gear is permanently lubricated with oil. A
tube running between the two ends of the steering gear
housing leads the lubricating oil past the hydraulic por-
tion of the rack.
Dec. 1975 SAU
Page 537
ae
WHEEL ALIGNMENT
Checking and adjustment
If there is reason to suspect that the front wheels are out
of true, a condition which shows up in the form of abnor-
mal tire wear, impaired steering and road-holding charac-
teristics, etc., the front wheel alignment must be checked
and adjusted. Before the wheel alignment is measured,
the following preparations must be made:
1. Check that the tires are inflated to the correct pressure
and that one front tire is not much more heavily worn
than the other.
2. Check the front wheel bearings, control arm bearings,
steering knuckle joints and tie-rod joints, and adjust
or exchange parts as necessary to eliminate any faults
of alignment that may be due to worn components.
3. Check the steering gear and make good any defects
(see section 642).
4. Check the operation of the shock absorbers and ex-
change damaged shock absorbers and rubber bushings.
5. If the car has been involved in a collision, crash, etc.,
any resulting damage must be repaired before wheel
alignment is measured. If the suspension control arms
are bent, no attempt must be made to straighten them,
they must be replaced by new ones.
6. Just before the measurements are made, the car should
be driven without hard cornering and with normal
suspension movement to work the wheels into their
natural positions. For the same reason, the car should
be rocked up and down a few times on its springs.
When the measurements are made, the car should be empty
and should be standing on a flat horizontal surface; this is
the only way to get reliable readings. Adjustment with the
help of spacers must be kept within reasonable limits. If
there are any deformations due to body damage, the body
must be straightened up properly. If the suspension control
arms are bent out of true, they must be replaced by new
ones. For checking the wheel alignment there are various
instruments, which are fitted either on the rim or directly
on the axle. Each instrument has its own instruction man-
ual explaining exactly how it is to be used.
NOTE
With front-wheel-drive cars it is important that the
wheels are immobilized by the brakes while the mea-
surements are being made in cases where the wheels
are set up on turntables or the like, or when a mea-
suring instrument is mounted on the end of the axle.
WARNING
When the car is on a hoist, do not seize a front wheel
and twist it by main force to full steering-wheel lock.
There is a very serious risk of damaging the steering
mechanism if this is done, as the rack-and-pinion gear
will cause the steering wheel to spin at high speed, im-+
posing a severe torsional strain on the steering column]
when the rotation is arrested by the stop in the steer-
ing gear.
Dec. 1975
Toe-in
Seen from above, the wheels run ata certain angle to each
other. Measurements A and B, made from rim to rim level
with the axles, must bear a given relationship to each other
(see illustration). If A is smaller than B, the wheels are
said to converge or toe in, and if A is greater than B, the
wheels diverge or toe out.
Wheel toe-in or toe-out is expressed in fractions of an
inch or millimeters, being the difference between A and
B.
Toe-in is zero if the wheels are parallel, in which case both
measurements are exactly the same.
The correct toe-in is 0 + 0.04” (0+ 1 mm), i.e. A is less
than B by this much.
TOE-IN
Checking and adjustment
S$ 2060
1. Roll the car straight forward on a level floor and stop
it without using the brakes. It must not be moved
backward after this.
2. Take a reading of measurement A with the toe-in
gauge between the front wheel rims level with the
axles. Mark the measurement points with chalk. Roll
the car forward until the chalk marks are level with
but behind the axles, and take a reading of B.
Any necessary adjustment is made by altering the
length of the tie rod.
SAAB 601-1
Page 538
ADJUSTING THE TIE ROD
4.
3. Undo the nut on the outer end of the tie rod and the
outer clip on the steering gear rubber bellows.
WARNING
Oil lubricated steering gears (as from model 1973)
are equipped with screw clamps that absolutely
must be loosened so that the bellows are not twisted
during adjustment. Hold the bellows during the
turning.
Use a suitable pair of grippers to twist the tie rod right
or left; adjust until the toe-in is right.
NOTE
With the correct toe-in and the wheels lined up
straight ahead, both tie rods should be the same
length — or so adjusted that both wheels have the
same clearance to the fenders and wheel housings at
full right and left lock respectively. Check also that
the steering wheel spokes are horizontal when the
front wheels are pointing straight ahead. Do not
forget to tighten the tie rod nut after adjusting.
NOTE
After adjustment of toe-in, the free length of thread
on the tie rod (length A, see illustration) must not
on any account be more than 1” (25 mm) (power
steering gear 26 mm). The free thread lengths (A)
on both tie rods must not differ from each other by
more than 0.08” (2 mm).
601-2
S$ 2062
CHECKING THE LENGTH OF THE TIE ROD
A= 1 in. (25 mm), power steering gear max 26 mm
Camber
Camber is the angle by which the centerlines of the
wheels lean from the vertical (see illustration). The cam-
ber is positive (+) if the wheels lean outward, and nega- ,)
tive (—) if they lean inward. The correct front-wheel
camber is +3/4 + 1/49,
{kes 5)
| S 3496 )
CAMBER
Sept. 1973
Page 539
Checking and adjustment
The camber, and with it the “king pin” angle, can be ad-
justed with spacers placed under the two bearing brackets
of the upper control arms. The desired result can thus be
obtained by increasing or reducing the number of spacers
used. To increase or reduce camber, use the same number
of spacers under both brackets. The rear bearing bracket
is available in a lower design that gives bigger adjustment
possibilitys, See the spare parts catalogue.
LOCATION OF CAMBER ADJUSTMENT SPACERS
Caster
The caster is the angle by which the king pin axis (or,
in the case of the Saab 99, the steering knuckle axis)
departs from the vertical when viewed from the side and
is generally expressed in degrees. Caster varies a great deal
from one type of car to another, although in most cases
the “king pin’ leans backward as illustrated below; in
such cases the caster is said to be positive (+), whereas
if the ‘’king pin” leans forward the caster is negative (—).
If the “king pin” is vertical, the caster is zero. The cor-
rect caster angle up to and incl. model 1971 is +1 1/4 +
1/4°. As from model 1972: +3/4 + 1/4°.
S 2065
CASTER
Dec. 1975
Checking and adjustment
If the caster angle needs adjusting, this is done with the
help of spacers placed under the bearing brackets of the
upper control arms.
To increase the caster, transfer spacers from the front
bracket to the rear bracket.
To reduce the caster, transfer spacers from the rear bracket
to the front bracket.
In either case, the total spacer thickness removed from
one bracket must be added to the other one.
Spacers for caster adjustment are supplied in thicknesses
of 0.5, 1.0 and 2.0 mm (0.02”. 0.04” and 0.08").
"King pin” angle
The car does not have king pins as such; the wheels
pivot on two ball joints instead. It is thus more correct
in this case to speak of the steering knuckle axis, i.e. the
line passing through the centers of the ball joints and in-
tersecting the ground near the wheel centerline. In the
Saab 99, the steering knuckle axis should incline side-
ways from the vertical by 11 1/2 + 1°.
$ 3497
“KING PIN” ANGLE
Checking and adjustment
When the wheel camber is adjusted, the inclination of the
steering knuckle axis is automatically altered by the same
amount at the same time. The latter angle cannot be ad-
justed independently, as it is determined by the dimen-
sions of the steering knuckle housing. If the steering knuck-
le axis is found to be out of true when the camber is cor-
rectly adjusted, this indicates that there is something
wrong with the steering knuckle housing, which should
therefore be exchanged.
601-3
Page 540
Wheel turning angles
When the car corners with properly aligned wheels, all
four wheels should travel in an arc about the same center;
since the alignment of the back wheels is fixed, the cen-
ter of the arc must lie somewhere on an extension of the
back wheel axle centerline. As the illustration below shows,
this means that the inside front wheel must turn furthur
out of the fore-and aft position than the outside front
wheel if both are to describe arcs about the same center.
This “steering geometry” is achieved mainly by the con-
figuration of the steering arms, but the tie rod configura-
tion also plays a certain part, especially in conjunction
with the movement of the springs.
aseqjaaum
dl
WHEEL ANGLES DURING CORNERING
A. Up to and incl. model 1972: 21 1/2 +19
| A. As from model 1973: 20 1/2 +1° |
S 2067
CORNERING POSITIONS OF FRONT WHEELS
A. Up to and incl. model 1972: 21 1/2 + 1°
A. As from mode! 1973: 20 1/2 + 1°
601-4
SAME Dec. 1975