FRONT SUSPENSION 3-3
by means of a lower control arm inner pivot cam; on the
Chevelle, Camaro and Corvette by means of upper control
arm inner support shaft shims.
Caster angle is adjusted, on the Chevrolet and Chevy n
by means of a strut rod which runs from the lower con-
trol arm forward to a frame brace; on the Chevelle,
Camaro and Corvette by means of upper control arm
inner support shaft shims.
A stabilizer bar is used on all Chevelle and Corvette
models. Chevrolet Impalas, station wagons and V-8
engine equipped models are fitted with the stabilizer bar.
UPPER CONTROL ARM
STABILIZER
SPRING
LOWER CONTROL ARM
STEERING KNUCKLE
Fig.
3 - Front Suspension - Corvette
MAINTENANCE AND ADJUSTMENTS
Maintenance intervals recommended for lubrication of
front suspension components have been fully covered in
Section 0 of this manual. Only actual adjustment proce-
dures will be covered here.
NOTE:
Unless otherwise indicated all proce-
dures will apply to all five vehicles covered in
this manual.
FRONT WHEEL BEARING ADJUSTMENT
Proper front wheel bearing adjustment has a definite
bearing on the safe operation of a vehicle. Improperly
adjusted front wheel bearings will result in a lack of
steering stability causing wheel wander, shimmy and ex-
cessive tire wear. Very accurate adjustment is possible
because the spindles are drilled both vertically and hori-
zontally and the adjusting nuts are slotted in all six sides.
NOTE:
Wheel bearings should not
be.
repacked
or adjusted as a part of "New Car Conditioning".
1.
With wheel raised, remove hub cap and dust cap and
then remove the cotter pin from the end of the
spindle.
2.
While rotating wheel, tighten spindle nut to 12 lbs. ft
torque.
3.
Back off adjusting nut one flat and insert cotter pin.
If slot and pin hole do not line up, back off the adjust-
ing nut an additional 1/2 flat or less as required to
insert cotter pin.
4.
Spin the wheel to check that it rolls freely and then
lock the cotter pin by spreading the end and bending
it around.
NOTE:
Bearings should have zero preload and
.001"
to .008" end movement when properly ad-
justed on Chevrolet, Chevelle, Camaro and Cor-
vette; .000" to .004" on Chevy H.
5.
Install dust cap, hub cap or wheel disc and lower
wheel.
6. Perform the same operation on each front wheel.
CHEVROLET CHASSIS SERVICE MANUAL
FRONT SUSPENSION 3-5
FRONT END ALIGNMENT
Front end alignment, that is alignment of the inter-
related steering components of the front suspension sys-
tem, must be correctly maintained to assure ease and
stability of steering and satisfactory tire life.
Alignment Preliminary Steps
Several different types of machines are available for
checking all the factors of front end alignment. The in-
structions furnished with each particular machine should
be followed. In all cases, however, checks should be
made with the vehicle level and at curb weight.
Since steering complaints are not always the result of
improper alignment a check should be made to see if any
of the following conditions exist. Any such conditions
should be corrected before proceeding further.
1.
Steering gear loose or improperly adjusted.
2.
Steering gear housing loose at frame.
3.
Excessive wear or play in spherical joints or steer-
ing shaft coupling.
4.
Tie rod or steering connections loose.
5.
Improper front spring heights.
6. Unbalanced or underinflated tires.
7.
Improperly adjusted wheel bearings.
8. Shock absorbers not operating properly.
Wheel alignment should always be made with the vehi-
cle rolled forward taking out any slack in the same man-
ner as when the vehicle is traveling forward.
Caster and Camber Adjustment
NOTE: Before adjusting caster and camber
angles, the front bumper should be raised and
quickly released to allow car to return to its
normal height.
Chevelle, Camaro and Corvette
Caster and camber adjustments are made by means of
shims inserted between the upper control arm inner sup-
port shaft and the support bracket attached to the frame
(fig. 6). Shims may be added, subtracted or transferred
to change the readings as follows:
Fig.
6 - Caster and Camber Adjustment - Chevelle
Typical of Corvette and Camaro
Caster - change shims at either the front or rear of
the shaft.
The addition of shims at the front bolt or removal
of shims at the rear bolt will decrease positive
caster. One shim (1/3 2") will change caster (ap-
prox.) 1/4°.
Camber - change shims at both the front and rear of
the shaft.
Adding an equal number of shims at both front and
rear of the support shaft will decrease positive cam-
ber. One shim (1/32") at each location will move
camber (approx.) 1/5° (Chevelle and Camaro); 1/6°
(Corvette).
TIGHTEN TO LOCK
ADJUSTMENT
Fig.
7 - Caster and Camber Adjustment Points - Chevrolet
CHEVROLET CHASSIS SERVICE MANUAL
FRONT SUSPENSION 3-7
CAMARO
CHEVROLET
AND
CORVETTE
LOWER
CONTROL
ARM
CHEVELLE
CHEVY
II
Fig.
9- Checking Riding Height
not the vehicle riding height is correct.
1.
Place the vehicle on a smooth, level floor and bounce
and rock the front end several times. Raise vehicle,
then allow it to settle to a normal height.
2.
Measure the following two distances (fig. 9):
a. From the floor to the center of the inner pivot of
the lower control arm. (On the Chevrolet and
Camaro, this measurement must be made at the
rear end of the pivot.)
b.
Chevrolet--Measure the distance from the floor
to the lower face of the lower steering knuckle
boss for the spherical joint on the same side of
the vehicle.
Chevelle—From the floor to the outer pivot
which is located 1/8" (.12) inboard from the ball
stud boss at the lower surface of the arm.
Chevy II--Measure the distance from the floor
to the lower ball joint seat.
Corvette—Measure the distance from the floor
to the lower face of the lower steering knuckle
boss for the spherical joint on the same side of
the vehicle.
Camaro—From the floor to the lower inboard
edge of ball seat.
3.
The difference between these two measurements
should be as outlined in the Specifications given at
the end of the book with the vehicle at curb weight
(full tank of gas, spare tire and jack in trunk, no
passengers).
4.
Measure the opposite side of the vehicle in the same
manner. The measurements for both sides should
differ no more than 1/2".
5. To correct the height, springs must be replaced.
These springs do not have flat ends and shims should
not be used.
CHEVROLET CHASSIS SERVICE MANUAL
FRONT SUSPENSION 3-8
REPAIR PROCEDURES
Unless otherwise indicated all repair procedures will
apply to all five vehicles covered in this manual.
CAUTION: During any operations which in-
clude breaking the ball stud loose from the
knuckle boss extreme care must be used to as-
sure that the ball stud seal is not damaged or
cut. A recommended way to loosen the stud is to
place a flat bar stock against the knuckle boss
and strike the bar rather than the knuckle.
FRONT BRAKE DRUM-CHEVROLET, CAMARO,
CHEVELLE, CHEVY It
Removal
1.
Remove hub caps, partially loosen wheel nuts and
raise vehicle from floor. Remove wheel nuts and
wheel.
2.
Remove brake drum. In some cases it may be nec-
essary to back off brake adjustment because of
scored drum or unevenly worn brake linings.
3.
Check brake drum for concentricity, damaged pilot
diameter or scored braking surface. Lightly sand
braking surface and wipe clean.
Installation
1.
Install drum over hub bolts making sure alignment
dowel on drum web indexes with hole in wheel hub.
This will assure proper drum alignment with hub
bolts and hub pilot diameter.
2.
Install wheel and partially tighten wheel nuts.
3.
Re-adjust brake shoes to original setting. It may be
necessary to re-adjust brake shoes on both front
and/or rear wheels to assure balanced brake adjust-
ment. See Section 5 for brake adjustment procedure.
4.
Lower vehicle to floor, tighten hub wheel nuts and in-
stall hub cap.
FRONT WHEEL HUB
Replacement
1.
Remove hub caps, break loose the wheel stud nuts
VM" DIA. PIPE OR ARBOR
>l
INNER CUP
OUTER CUP
JL
RADIUS
e^
Fig.
10 - Pressing Front Hub Bolts (Typical)
Fig.
11 - Front Wheel Bearing Cop Removers
and raise vehicle. Remove wheel nuts, wheel and
tire and brake drum or (on Corvette) brake caliper
and brake disc.
NOTE:
On the Corvette, the hub and brake disc
are serviced as a complete assembly.
2.
Pry out hub grease cap, cotter pin, spindle nut and
washer,
and
remove hub. Do not drop wheel bearings.
3.
Reverse this procedure to install.
Replacement of Wheel Hub Bolts
It may be necessary to replace damaged wheel hub
bolts.
In this case, service the hub in the following
manner.
1.
Remove the hub bolts with a press or hammer.
These bolts are not peened into the hub. Do not
damage wheel mounting surface on hub flange.
2.
Install new serrated bolt into hole in
hub.
Tap lightly
with a hammer to start bolt serrations in hole, mak-
ing sure that bolt is square with hub flange.
3.
Press bolt into flange until head is fully seated
against hub flange (fig. 10).
FRONT WHEEL BEARINGS
Removal '
1.
Remove wheel hub as described above.
NOTE: Discard cotter pin. Install new cotter
pin when assembling.
2.
Remove outer roller bearing assembly from hub with
fingers. The inner bearing assembly will remain in
the hub and may be removed after prying out the
inner bearing lip seal assembly. Discard seal.
3.
Wash all parts thoroughly in cleaning solvent and
blow dry.
CHEVROLET CHASSIS SERVICE MANUAL
FRONT SUSPENSION 3-15
4.
Insert Spring Compressor J-
6874-
4-
5 with Adapters
J-6874-8-9 into upp^r spring tower so that lower
MU"
bolt fits into shock absorber mounting holes in
spring seat (fig. 23). Secure the two lower studs to
the spring seat with nuts.
5.
Fit the tool upper pilot to top of spring and compress
spring by tightening upper nut (fig. 24). Compress
spring until screw is bottomed out.
6. Remove lower spring seat retaining nuts, lift spring
and seat assembly from control arm and guide it
down and out through fender skirt (fig. 25).
Spring Seat Replacement (Fig. 26)
1.
Release spring tension and disconnect spring com-
pressor from spring seat.
2.
Install new spring seat to spring compressor.
Installation
1.
If spring is to be replaced, install new spring into
tool and compress spring until screw is bottomed
out.
NOTE: Spring coil ends must be against spring
stops in upper and lower seats.
2.
Lift spring and tool assembly into place and position
so that the upper spring stop is inboard.
NOTE: Locating tab on upper spring seat may
be flattened before reinstalling spring.
3.
Install lower spring seat to control arm and torque
nuts as shown in the Specifications.
4.
Loosen spring compressor until spring is properly
seated in upper spring tower and remove.
5.
Install shock abosrber as outlined under Shock Ab-
sorber—Installation in this section.
Corvette
Removal
1.
With car on suitable hoist or jack, (support vehicle
by frame so control arms may swing free) remove
wheel and tire assembly, stabilizer bar and shock
absorber. Loosen the lower ball joint to steering
knuckle nut, and the' two lower control arm cross
shaft bushing bolts.
2.
Place Tool J-6874-1 across top of sixth coil (ap-
prox.),
then loosely secure Tool J-6874-2 to the up-
per shoe, with attaching capscrews and lock washers.
The upper shoe "V" notch and lower shoe raised land
should contact spring.
3.
Insert Tool J-6874 up through center of spring and
attach to upper and lower shoe assembly.
4.
Position spacers under shock absorber mounting hole
and against bottom of lower control arm. Install
special bearing washer and Tool J-6874-5. Locate
bearing against spacer and large washer against
bearing. Feed screw up through large washer bear-
ing and spacer and thread into Tool J-6874 and
tighten snugly (fig. 22).
5.
Center shoe assembly on spring and tighten screw
until a very slight compression is placed on spring
(fig. '22). Then firmly tighten down the two cap-
screws securing the upper and lower shoes to lock
these shoes to spring.
6. Turn head of screw until spring is compressed just
enough to clear the spring tower, then remove the
lower ball joint to steering knuckle nut (fig. 22).
NOTE: It may be necessary to assist the
spring out of the spring tower with a pry bar or
a similar tool.
7.
Disconnect the lower ball joint from the steering
knuckle and lower the control arm with the com-
pressed spring. Immediately release compression
on spring by backing off long screw. Release spring
and tool and withdraw spring.
CAUTION: The spring force under compres-
sion is very large. Exercise every safety pre-
caution when performing this operation to see
that individuals and materials subject to damage
are removed from the path of the spring when
the control arm is being lowered. Also, the
compressed spring
be relaxed immedi-
ately after lowering the control arm to reduce
the time of exposure to the large compressive
force.
Installation
1.
Position spring with closely coiled end up. Place
Tool J-6874-1 across the top of the sixth coil (ap-
prox.) then loosely secure Tool J-6874-2 to the
upper shoe with attaching capscrews and lock wash-
ers.
The upper shoe MV" notch and lower shoe
raised land should contact spring.
2.
Insert Tool J-6874 up through center of spring and
attach to upper and lower shoe assembly with bolt
and nut.
3.
Set spring in its seat on the lower control arm.
4.
Position spacers centrally under shock absorber
mounting hole and against bottom of lower control
arm. Install bearing, large washer and Tool
J-6874-5.
Locate bearing against spacer and large
washer against bearing. Feed the screw up through
large washer, bearing and spacer and thread into
yoke rod. Tighten snugly, but do not start to draw
down yet
5.
Center the shoe assembly on the spring and tighten
the lag screw until a very slight compression is
placed on spring, then firmly tighten down the two
capscrews securing the upper and lower shoes. This
will lock the shoes to the coil spring.
6. Turn head of screw until spring is compressed just
enough to clear the spring tower.
NOTE: It may be necessary to assist the
spring into the spring tower with a pry bar or
similar tool.
7.
Immediately install the lower ball joint into steering
knuckle and secure in place with attaching nut.
8. Release compression on spring and at the same time
use a drift to guide the coil spring into its proper
seat. End of coils must be 3/8" from coil stops in
spring seat.
9. Tighten the lower ball joint to steering knuckle nut
and lock with cotter key.
10.
Install shock absorber and stabilizer bar.
11.
Install wheel, tire and drum assembly.
12.
Remove car from hoist or jack stands.
13.
Tighten the two lower control cross shaft bushing
bolts to 45-55 lbs. ft. torque.
NOTE: If a suitable adjustable jack-stand is
CHEVROLET CHASSIS SERVICE MANUAL
REAR SUSPENSION AND DRIVE LINE 4-6
Fig.
10—Toe-in Adjusting Shim Location (Corvette)
Toe-in
Wheel toe-in is adjusted by inserting shims of varying
thickness inside the frame side member on both sides
of the torque arm pivot bushing (fig. 10). Shims are
available in thicknesses of
1/64",
1/32",
1/8" and 1/4".
To adjust toe-in, remove torque arm pivot bolt; then
position torque arm to obtain specified toe-in. Shim gap
toward vehicle centerline between torque arm bushing
and frame side inner wall.
NOTE: Do not use thicker shim than necessary,
and do not use undue force when shimming inner
side of torque arm - to do so may cause toe
setting to change.
Shim outboard gap as necessary to obtain solid stack-
up between torque arm bushing and inner wall of frame
side member. After correct shim stack has been se-
lected, install pivot bolt and hardened washers (fig. 10) -
making sure that all shims are retained - torque nut to
specifications and install cotter pin. If specified torque
does not permit cotter pin insertion, tighten nut to next
flat.
WHEEL BEARING ADJUSTMENT (CORVETTE)
inspection
The tapered-roller spindle bearings should have end
play of .001" to
.008".
During inspection, check end
play and, when necessary, adjust as outlined in this
section.
1.
Raise rear of vehicle until wheels clear ground.
2.
Disengage bolt lock tabs and disconnect outboard end
of axle drive shaft from wheel spindle flange.
3.
Mark camber cam in relation to bracket. Loosen and
turn camber bolt until strut rod forces control arm
outward. Position loose end of axle drive shaft to
one side for access to spindle.
4.
Remove wheel and tire assembly. Mount dial in-
dicator (Tool J-8001) on torque arm or adjacent
surface and rest pointer on flange or spindle end
(fig. H).
5.
Grasp brake disc and move axially (in and out) while
reading movement on dial indicator. If end movement
is within the .001" to .008" limit, bearings do not
require adjustment. If not within .001" to .008"
limit, record reading for future reference and adjust
bearings as outlined below.
Adjustment
1.
Apply parking brake to prevent spindle from turning
and remove cotter pin and nut from spindle.
2.
Release parking brake and remove drive spindle
flange from splined end of spindle.
3.
Remove brake caliper and brake disc as outlined in
Section 5.
4.
Install Thread Protector J-21859-2 over spindle
threads; then remove drive spindle from spindle
support, using Tool J-22602 as shown in Figure 12.
CAUTION: When using Tool J-22601 to remove
drive spindle, make sure puller plate is posi-
Fig.
11—Checking Wheel Bearing Adjustment (Corvette)
Fig. 12—Removing Drive Spindle from Support (Corvette)
CHEVROLET CHASSIS SERVICE MANUAL
REAR SUSPENSION AND DRIVE LINE 4-7
tioned vertically in the torque arm before ap-
plying pressure to the puller screw.
5.
Remove shim and bearing spacer from spindle
support.
6. Note size of shim used. If dial indicator reading
was more than
.008",
select a shim thinner by the
amount needed to bring end play within limits. If
dial indicator reading was less than
.001",
select a
shim thicker by the amount needed to bring end play
within limits.
NOTE: Shims are available in thicknesses from
.097"
to .148" in increments of
.003".
EXAMPLE: Bearing end play reading obtained
on dial indicator was
.011",
.003" over limit.
Bearing shim removed from spindle measures
.145".
New shim installed measures .139", .006"
smaller. End play is now decreased by .006" and
is
.005",
which is within the .001" to .008" limit.
7.
After determining shim thickness, install bearing
spacer and shim on spindle. Position spindle in
spindle support.
8. Press inner bearing race and roller assembly on
spindle as follows.
a. Position Tool J-4731 over spindle and against
bearing inner race.
b.
Position washer and spindle nut on spindle and
proceed to tighten nut until bearing is forced on
spindle sufficiently to allow spindle drive flange
to be installed (fig. 13). Remove spindle nut,
washer and Tool
J-4731.
Discard nut and use a
new one for final assembly.
9. Position drive flange over spindle, making sure
flange is aligned with spindle splines. Install washer
Fig.
13—Installing Drive Spindle to Support (Corvette)
and nut on spindle then tighten nut to specifications
and install cotter pin. If specified torque does not
permit cotter pin insertion, tighten nut to next flat.
10.
Seat spindle support outer seal in bore by using
screw driver, or other suitable tool, to press against
metal portion of seal.
11.
Install brake disc and caliper. Refer to Section 5
for details of brake disc and caliper installation.
12.
Install axle drive shaft, wheel and tire assembly,
adjust camber cam to original position and torque
all components to specifications.
COMPONENT PARTS REPLACEMENT
(Chevrolet, Chevelle, Chevy II and Camaro)
COIL SPRING
Chevrolet
Removal
To remove either or both rear coil springs proceed
as follows.
1.
Raise rear of vehicle and place jack stands under
frame. Support vehicle weight at rear, using either
a jack or post of twin-post hoist under axle.
2.
Remove both rear wheels from vehicle.
3.
With the car supported as in Step 1, so that the rear
springs are compressed by weight of vehicle; per-
form the following:
a. Disconnect both rear shock absorbers from the
anchor pin lower attachment.
b.
Loosen the upper control arm(s) rear pivot bolt
(do not remove the nut).
C. Loosen both the left and the right lower control
arm rear attachment (do not disconnect from axle
brackets).
d. Remove the rear suspension tie rod from the
stud on the axle tube.
4.
At the lower seat of both rear coil springs, slightly
loosen the nut on the bolt that retains the spring and
seat to the control arm. When the nut has been
backed off the maximum permissible, all threads of
the nut should still be engaged on the bolt.
CAUTION: Under ,no condition should the nut,
at this time, be removed from the bolt in the
seat of either spring.
5.
Slowly lower the support (jack or hoist post) that has
been in place under the rear axle, thereby allowing
the axle to swing down, carrying the springs out of
their upper seat and providing access for spring
removal.
6. Remove the lower seat attaching parts from each
spring, then remove the springs from the vehicle
(fig. 14).
Installation
1.
Position the springs in their upper seat so that end
of top coil is 3/8" ± 1/8" from end of stop. Install
the lower seat parts on the control arm, with the nut
finger tight on the spring retainer bolt.
NOTE: Omit the lock washer under the special
high carbon bolt, so that sufficient bolt thread
will be available to start the nut. The lock
washers will be installed later (in Step 4).
2.
By alternately raising the axle slightly and then
re-snugging the nut on each spring lower seat bolt,
move the axle upward until vehicle weight is fully
CHEVROLET CHASSIS SERVICE MANUAL
REAR SUSPENSION AND DRIVE LINE 4-21
Fig.
54—Marking Camber Cam and Bracket (Corvette)
bracket, so they may be reassembled in same loca-
tion (fig. 54).
5.
Loosen camber bolt and nut. Remove four bolts se-
curing strut rod bracket to carrier and lower
bracket.
6. Remove cam bolt nut and cam and bolt assembly.
Pull strut down out of bracket and remove bushing
caps.
7.
Inspect strut rod bushings for wear and replace
where necessary. Replace strut rod if it is bent or
damaged in any way.
Repairs
1.
With strut rod bushing centered over Tool J-7877-2
and with strut rod supported horizontally, press or
drive bushing from rod, using Tools J-7877-i and
J-7079-2 as shown in Figure 55.
2.
With strut rod end centered over Tool J-7877-2 and
rod supported horizontally, press or drive bushing
into arm using Tools J-7877-3 and J-7079-2 as
shown in Figure 55. Tool J-7877-3 should bottom
on strut rod when bushing is fully installed.
Installation
1.
Place bushing caps over inboard bushing and slide
rod into bracket. Install cam and bolt assembly and
adjust cam to line up with mark on bracket. Tighten
nut but do not torque at this point.
SPRING
LINK BOLT
SPRING
CUSHION
SPRING
CUSHION
CENTER
CLAMP
PLATE
J-7877-3
J-7877-1
STRUT ROD 11 s* ^#3 STRUT ROD
BUSHING
Fig.
56—Spring Mounting (Corvette)
2.
Raise bracket and assemble to carrier lower mount-
ing surface. Torque bolts to specifications.
3.
Raise outboard end of strut rod into spindle support
fork and insert strut rod shaft into fork so that flat
on shaft lines up with corresponding flat in spindle
fork. Install retaining nut, but do not torque.
4.
Place shock absorber lower eye and bushing over
strut shaft, install washer and nut and torque to
specifications.
5.
Lower vehicle to floor and torque camber cam nut
and strut rod shaft nut to specifications. Then in-
stall cotter pin through rod bolt.
6. Check rear wheel camber and adjust where
necessary.
SPRING (Fig. 56)
Removal
1.
Raise rear of vehicle and support on frame slightly
forward of torque control arm pivot points. Remove
wheels and tires.
Fig.
55—Strut Rod Bushing Replacement
Fig.
57—Chain Installation (Corvette)
CHEVROLET CHASSIS SERVICE MANUAL