
FRONT SUSPENSION 3-10
CHEVROLET, CHEVELLE, CAMARO AND CORVETTE (TYPICAL)
CHEVY H
Fig.
14- Shock Absorber
NOTE:
If necessary, tighten one more notch to
insert cotter pins.
3.
Place brake backing plate and wheel cylinder in posi*-
tion on steering knuckle and insert anchor pin.
4.
Place steering arm in position on back of steering
knuckle and insert two bolts through backing plate,
steering knuckle and steering arm. Install locknuts
and tighten. (See Specifications.)
5. Torque brake anchor pin (See Specifications).
6. Install brake shoes, except Corvette. (See Section 5.)
7. Install wheel hub, brake drum (or, on Corvette--
brake caliper and disc and hub assembly), wheel and
tire assembly over spindle.
8. Insert outer wheel bearing race and roller assembly,
washer and nut. Adjust front wheel bearing as shown
under Maintenance and Adjustments in this section.
Install new cotter pin, dust cap and hub cap.
9. Lower vehicle, recheck and readjust wheel alignment
where necessary.
SHOCK ABSORBER
Chevrolet, Chevelle, Comoro and Corvette (Fig. 14)
Removal
1.
With an open end wrench hold the shock absorber
upper stem from turning, and then remove the upper
stem retaining nut, retainer and rubber grommet.
2.
Remove the two bolts retaining the lower shock ab-
sorber pivot to the lower control arm and pull the
shock absorber assembly out from the bottom.
Installation
1.
With the retainer and rubber grommet in place over
the upper stem, install the shock abosrber (fully ex-
tended) up through the lower control arm and spring
so that the upper stem passes through the mounting
hole in the upper support arm.
2.
Install the rubber grommet, retainer' and attaching
nut over the shock absorber upper stem.
3.
With an open end wrench, hold the upper stem
from turning and tighten the retaining nut. (See
Specifications.)
4.
Install the two bolts attaching the shock abosrber
lower pivot to the lower control arm and tighten.
(See Specifications.)
Fig.
15 - Upper Control Arm Support Installed - Chevy II
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

FRONT SUSPENSION 3-16
available the following procedure may also be
used (fig. 22-Alternate Method).
1.
Support car on suitable hoist or jack (so control
arms may swing free) and remove the wheel and
tire assembly, shock absorber, and stabilizer link
at control arm.
2.
Place suitable jack stand under the lower control
arm cross shaft.
3.
Follow Steps 2-5 as outlined on previous page.
4.
Turn head of tool screw to partially compress
spring.
5. Remove the three control arm cross shaft attaching
bolts,
washers and nuts.
6. Carefully lower jack stand and if necessary increase
compression on spring and when coil spring is out of
its upper seat, relax tension on spring (fig. 22).
7. By using a pry bar to assist, if necessary, remove
the coil spring from the lower control arm.
8. Installation is the reverse of the above procedure.
Carefully follow instructions for installing spring
tool.
LOWER CONTROL ARM SPHERICAL JOINT
Chevrolet, Chevelle, Comoro and Corvette
Inspection
The lower control arm spherical joint should be re-
placed whenever wear is indicated in the upper joint
inspection.
NOTE: The lower control arm spherical joint
is a loose fit in the assembly when not connected
to the steering knuckle.
Only if inspection of each upper joint indicates them
both to be within limits, inspect each lower joint for ex-
cessive wear as follows:
1.
After reconnecting upper joints to steering knuckles,
support vehicle weight on wheels or wheel hubs.
2.
With outside micrometer or caliper, measure dis-
tance from top of lubrication fitting to bottom of ball
stud, and record the dimensions for each side.
3.
Then support vehicle weight at outer end of each
lower control arm, so that wheels or wheel hubs are
free,
then repeat Step 2.
4.
If the difference in dimensions on either side is
greater than 1/16" (.0625"), the joint is excessively
worn and both lower joints should be replaced.
If inspection of lower spherical joints does not indicate
excessive wear, inspect further as follows:
5.
On Chevrolet Only--Examine lubrication hole in each
joint assembly after cleaning out hole. Look for evi-
dence of the liner partially or fully blocking lubrica-
tion opening. Such evidence indicates that liner is
disintegrating and that both lower spherical joints
should be replaced.
Another indication of lower spherical joint excessive
wear is indicated when difficulty is experienced when
lubricating the joint. If the liner has worn to the point
where the lubrication grooves in the liner have worn
away, then abnormal pressure is required to force lubri-
cant through the joint. This is another reason to recom-
mend replacement of both lower joints.
If the above inspections do not indicate any reason for
spherical joint replacements, test the torque tightness of
Fig. 27 - Removing Lower Ball Joint - Chevelle
&
Camaro
the lower ball stud in the knuckle on each side as follows:
1.
Wire-brush off nut and cotter pin attaching spherical
joint ball stud to steering knuckle and examine for
evidence of looseness of stud in knuckle.
2.
If no evidence of looseness, remove cotter pin and
with prick punch or equivalent, mark nut stud and
knuckle to identify relative location.
3.
Tighten nut as installed and observe torque reading.
If less than 45 lbs. ft., stud may have been loose in
steering knuckle and replacement of both lower
spherical joints may be recommended.
4.
Check to see if torque of 60-94 lbs. ft. can be ob-
tained without bottoming stud or ball joint against
knuckle. If bottoming occurs, replace ball joint or
steering knuckle.
Chevrolet and Corvette
Removal
1.
Support lower control arm at outer end on floor jack,
with hoist or jack pad clear of lower ball stud nut.
2.
Remove upper and lower ball stud nuts, free ball
studs from steering knuckle and wire knuckle and
brake drum assembly up to fender skirt to preclude
interference while performing next step.
3.
Being careful not to enlarge the holes in control arm,
cut off rivets.
Installation
1.
Install new joint against underside of control arm and
CHEVROLET CHASSIS SERVICE MANUAL

FRONT SUSPENSION 3-17
4.
Replace the wheel and tire.
5.
Lower the vehicle.
Chevy II
inspection
Fig.
28 - Installing Lower Ball Joint - Chevelle & Camaro
retain in place with special bolts and nuts supplied
with new joint.
CAUTION: Use only alloy bolts supplied for
this operation. The special thick headed bolt
must be installed in the forward side of the
control arm.
2.
Tighten bolts and nut on ball stud to Specification
shown at the end of this book.
3.
Lubricate the joint.
Chevelle and Camaro
Removal
1.
Support lower control arm at outer end of floor jack,
with hoist or jack pad clear of lower ball stud and
remove the wheel.
2.
Remove the upper and lower ball stud nuts, free the
ball studs from the steering knuckle and wire the
knuckle and brake drum assembly out of the way to
preclude interference while completing the lower ball
stud removal procedure.
3.
Use a screw driver to pry off the seal and retainer.
Install Tools J-9519-10, J-9519-17 and J-9519-7 as
shown in Figure 27 and turn down on the hex head
screw until the ball stud is pushed out.
Installation
1.
Start the replacement ball stud into the control arm
and install Tools J-9519-10, J^9519-16 and J-9519-17
as shown in Figure 28.
2.
Turn down on the hex head screw until the ball stud
is seated properly in the control arm.
3.
Install the stud into the steering knuckle, secure in
place with the attacking nut and install the cotter pin.
1.
With upper control arm support in position as in
Figure 15, disconnect the lower ball stud from steer-
ing knuckle.
2.
Assemble nut to lower ball stud and check rotating
torque with torque wrench. Specifications for new
joints are 9 lbs. ft. If torque readings are exces-
sively high or low, replace ball joint.
Removal
1.
While vehicle weight is still on front wheels, position
support between upper control arm and frame side
rail (fig. 15).
2.
Raise vehicle and remove cotter pin and nut from
lower ball joint stud (fig. 29).
3.
Disconnect stabilizer at upper link. Break loose the
lower ball stud. Drop lower control arm until lower
ball joint is easily accessible.
, 4. Using a large chisel, cut off the three ball joint re-
taining plate rivet heads. It may be necessary to
drill out rivet heads before chiseling.
NOTE: Additional support to lower control
arm will be necessary to perform this operation.
5.
Remove ball joint from arm and clean arm.
6. Inspect ball joint seat and rivet holes for evidence of
fatigue such as cracking or bending. If defects are
evident, replace lower control arm as outlined later
in this section.
Installation
1.
Install ball joint in arm using special bolts furnished
with replacement kit.
NOTE: Use only special hardened bolts fur-
nished with this replacement kit. Do not attempt
to use other non-hardened bolts and do not at-
tempt to rivet replacement ball joint to arm.
Fig.
29- Disassembling Lower Ball Stud - Chevy
CHEVROLET CHASSIS SERVICE MANUAL

FRONT SUSPENSION 3-18
CHEVROLET
CHEVELLE
CAMARO (TYPICAL)
CHEVY U
LOWER CONTROL ARM
CORVETTE
Fig.
30 - Lower Control Arm Attachment
2.
Raise lower control arm and insert ball stud into
steering knuckle lower boss. Install nut and insert
new cotter pin. Install stabilizer linkage.
Lube Fittings
Special self threading type lube fittings are used in the
spherical joint assemblies. If it is necessary to replace
a fitting a standard threaded type may be used. However,
replacement spherical joint assemblies are supplied less
the lube fitting. Therefore it will be necessary to install
a self threading type fitting into the untapped hole pro-
vided when replacing the entire assembly.
LOWER CONTROL ARM
Chevrolet (Fig. 30)
Removal
1.
Remove the coil spring as outlined previously.
2.
Remove lower control arm ball stud cotter pin and
loosen nut. Loosen the ball stud, then remove nut
and lower control arm.
CAUTION: Use extreme care not to damage
the seal during this operation.
Installation
1.
Insert lower control arm ball stud into the steering
boss,
install the nut and insert new cotter pin.
2.
Install the coil spring as outlined previously.
3.
Tighten nuts to torque shown in Specifications.
Chevelle and Camaro (Fig. 30)
Removal
1.
Remove the front coil spring as outlined previously.
2;
Remove the two control arm to frame and cross-
member bracket attaching bolts and lock washers.
3.
Remove the lower control arm assembly.
Installation
1.
With the control arm in place in frame and cross-
member brackets, install the front and rear attaching
bolts,
nuts and lock washers.
2.
Install the coil spring as outlined under "Front Coil
Spring - Installation".
3.
Tighten the nuts to torque shown in Specifications.
Chevy II (Fig. 30)
Removal
1.
With vehicle weight still on front wheels, install
CHEVROLET CHASSIS SERVICE MANUAL

FRONT SUSPENSION 3-21
Chevy II
Removal
1.
Support control arm on Tool J-7 574-4 and insert
Spacer J-9514 (fig. 34).
2,
Press bushing out with Tool J-9226 and Handle
J-7079-2 (fig. 34).
Installation
With Spacer J-9514 still in control arm, invert control
arm and press in new bushing with Tool, J-7474-2 and
Handle J-7079-2 until bushing is fully seated.
CAUTION: It should be noted that control arm
bushing diameters are unequal and bushing must
be pressed into position through larger diameter
only.
CROSS SHAFT AND/ON BUSHINGS
Corvette
Removal
1.
Remove bolt, lock washer and collar from each end
of cross shaft.
2.
Thread a 7/16 x 20 capscrew (furnished with Tool
J-5888) to the bottom of the threads in one end of the
cross shaft.
3.
Support control arm in an arbor press on Tool
J-5888-3,
as shown in Figure 35.
NOTE:
Be certain bushing flange does not
contact support.
4.
Press on cap screw until bushing is free of control
arm. Discard bushing.
5. Remove cap screw from cross shaft. Insert it in
other end of shaft. Invert control arm on support.
Again be certain bushing flange does not contact
support.
6. Press on cap screw until bushing is free of control
arm. Discard bushing.
Installation
1.
With cross shaft in control arm and Tool J-7052-1
in position, place control arm on Tool J-5888-3.
Hand start bushing into control arm and over end of
cross shaft.
NOTE:
The end of the shaft with the two bolt
holes should be toward front of control arm.
2.
Install Tool J-7052-5 over bushing. Be certain
three-piece spacer is not over-lapping bushing holes
in control arm.
3.
Press bushing into control arm until flange contacts
control arm (fig. 36).
4.
Invert arm in press and repeat the process on the
other bushing. After installation, cross shaft should
be free enough to be rotated by hand.
5. Install collar, lock washer and cap screw in each end
of cross shaft. Tighten to torque shown in Specifica-
tions after spring installation.
UPPER CONTROL ARM SPHERICAL JOINT
Chevrolet, Chevelle, Comoro and Corvette
Inspection
The upper spherical joint is checked for wear by
checking the torque required to rotate the ball stud in the
assembly. After performing the first four steps under
"Replacement" below, install a stud nut on the stud and
measure the torque required to turn the stud in the as-
sembly with a torque wrench. Specified torque for a new
joint is 9 lbs. ft. If torque readings are excessively
high or low, replace the ball joint. If excessive wear is
indicated in upper joint, both upper and lower joints
should be replaced.
NOTE:
This inspection does not necessitate
upper control arm removal.
Replacement
1.
Support the vehicle weight at the outer end of the
lower control arm.
2.
Remove the wheel and tire assembly.
3.
Remove cotter pin and nut from upper control arm
ball stud.
4.
Remove the stud from knuckle.
5. Cut off the ball joint rivets with a chisel.
6. Install new joint and retain in place with the special
nuts and bolts supplied.
7. Reassemble ball stud to the steering knuckle.
Chevy II
Inspection
The following on-the-vehicle check is to determine ball
joint wear.
NOTE:
The upper ball joint is a loose fit when
not connected to the steering knuckle. Wear may
be checked without disassembling the ball stud
by
using'
the following procedure:
1.
While vehicle weight is still on front wheels, insert
upper control arm support as shown in Figure 14.
2.
Raise vehicle and allow wheel and tire to hang free.
3.
Measure distance from tip of ball stud to top surface
of control arm.
4.
Place adjustable jackstand under tire and raise
slightly to take up ball joint looseness.
5. Repeat Step 3 and if the difference in measurements
exceeds 3/32", the joint is excessively worn and
should be replaced.
Replacement
1.
With vehicle weight still on front wheels, install
spacer between upper control arm and frame side
rail (fig. 15). Raise vehicle.
2.
Remove wheel and tire.
3.
Disconnect stabilizer link (if present) and strut rod
at lower control arm.
4.
Remove cotter pin and nut from upper ball joint stud.
5. Break ball stud loose. Drop lower control arm,
steering knuckle and brake assembly with an adjust-
able jackstand until upper control arm ball joint is
easily accessible.
6. Using a large chisel, cut off the three ball joint re-
taining plate rivet heads. It may be necessary to
drill out rivet heads before chiseling.
CHEVROLET CHASSIS SERVICE MANUAL

FRONT SUSPENSION
3-22
CHEVROLET
s-L 1 \
TYPICAL
OF
-^-x ^K CORVETTE, CHEVELLE AND CAMARO
CHEVY n
Rg.
37 - Upper Control Arm Attachment
NOTE:
Additional support to upper control
arm may be necessary while chiseling.
7. Clean ball joint seat in arm and inspect for cracking
or other evidence of fatigue. If cracks are present at
the rivet holes or ball joint opening, replace arm as
outlined later in this section.
8. Attach replacement ball joint assembly to the control
arm, using special bolts furnished with replacement
kit.
NOTE:
Use only special hardened bolts fur-
nished with this replacement kit. Do not attempt
to use other non-hardened bolts and do not at-
tempt to rivet replacement ball joint to arm.
9. Raise lower control arm and steering knuckle as-
sembly into position, insert upper ball stud into up-
per steering knuckle and install stud nut. Torque
nut as shown in the specifications and insert new
cotter pin. Install stabilizer and strut rod.
10.
Lubricate ball joint, install wheel and tire and re-
move adjustable jackstand.
11.
Lower vehicle and remove upper control arm spacer.
12.
Check and readjust caster and camber angles where
necessary.
LUBE FITTINGS
Special self threading type lube fittings are used in the
spherical joint assemblies. If it is necessary to replace
a fitting a standard threaded type may be used. However,
replacement spherical joint assemblies are supplied less
the lube fitting. Therefore it will be necessary to install
a self threading type fitting into the untapped hole pro-
vided when replacing the entire assembly.
UPPER CONTROL ARM
Chevrolet, Chevelle, Camaro and Corvette
(Fig.
37)
Removal
1.
Support vehicle weight at outer end of lower control
arm.
2.
Remove wheel and tire assembly.
3.
Remove cotter pin and nut from upper control arm
ball stud. ,
4.
REMOVE The stud from knuckle.
5. Remove two nuts retaining upper control arm shaft to
front crossmember. (Chevelle, Camaro and Cor-
vette—Note number of shims at each bolt.)
6. Remove the bolts attaching the control arm to the
frame to allow proper clearance for control arm
removal if necessary.
7. Remove upper control arm from vehicle.
Installation
1.
Install upper control arm in vehicle.
2.
Install nuts, bolts and lock washers retaining upper
control arm shaft to frame. (Chevelle, Camaro and
Corvette—Install same number of shims as removed
at each bolt.)
3.
Torque nuts as shown in the Specifications at the end
of this book.
4.
Install ball stud through knuckle, install nut, tighten
and install cotter pin.
5. Install wheel and tire assembly.
6. Lower vehicle to floor.
7. Bounce front end of vehicle to centralize bushings
and tighten bushing collar bolts as shown in the
Specifications.
Chevy II (Fig. 37)
Removal
1.
Remove spring and shock absorber as outlined above.
2.
Position adjustable jackstand under lower control
arm.
3.
Remove cotter pin and nut from upper ball joint stud
and strike steering knuckle boss to loosen stud.
4.
Drop lower control arm and steering knuckle
assembly.
CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-29
REAR AXLE NOISE DIAGNOSIS
Mechanical failures of the rear axle are relatively
simple to locate and correct. Noise in a rear axle is a
little more difficult to diagnose and repair. One of the
most essential parts of rear axle service is proper
diagnosis.
Ail rear axles are noisy to a certain degree. The
action of transmitting the high engine torque through a
90° turn reducing propeller shaft speed produces noise
in rear axles. This point establishes the need for a line
between normal and abnormal or unacceptable axle
noises.
Slight axle noise heard only at a certain speed or under
remote conditions must be considered normal. Axle noise
tends to "peak" at varying speeds and the noise is in no
way indicative of trouble in the axle.
If noise is present in an objectionable form, loud or at
all speeds, an effort should be made to isolate the noise
as being in one particular unit of the vehicle. Axle noise
is often confused with other noises such as tire noise,
transmission noise, propeller shaft vibration and uni-
versal joint noise. Isolation of the noise as in any one
unit requires skill and experience. An attempt to elimini-
ate a slight noise may baffle even the best of diagnos-
ticians. Such practices as raising tire pressure to
eliminate tire noise, listening for the noise at varying
speeds and on drive, float and coast, and under proper
highway conditions, turning the steering wheel from left
to right to detect wheel bearing noise, will aid even the
beginner in detecting alleged axle noises. Axle noises
fall into two categories: gear noise and bearing noise.
GEAR NOISE
Abnormal gear noise can be recognized since it pro-
duces a cycling pitch and will be very pronounced in the
speed range at which it occurs, appearing under either
"drive," "float" or "coast" conditions. Gear noise
tends to peak in a narrow speed range or ranges, while
bearing noise will tend to remain constant in pitch. Ab-
normal gear noise is rare and usually originates from
the scoring of the ring gear and pinion teeth as a result
of insufficient or improper lubrication in new assemblies.
Side gears seldom give trouble as they are used only
when the rear wheels travel at different speeds.
BEARING NOISE
Defective bearings will always produce a whine that is
constant in pitch and varies with vehicle speed. This fact
will allow you to distinguish between bearing noise and
gear noise.
1.
Pinion bearing noise resulting from a bearing failure
can be identified by a constant rough sound. Pinion
bearings are rotating at a higher speed than differen-
tial side bearings or axle shaft bearings. This
particular noise can be picked up best by testing the
car on a smooth road (black top). However, care
should be taken not to confuse tire noise with bear-
ing or gear noise. If any doubt exists, tire treads
should be examined for irregularities that would
produce such noise.
2.
Wheel bearing noise may be confused with rear axle
noise. To differentiate between wheel bearings and
rear axle, drive the vehicle on a smooth road at
medium-low speed. With traffic permitting, turn
Fig.
74—Scored Hypoid Ring Gear
the vehicle sharply right and left. If noise is caused
by wheel bearings, it will increase in the turns be-
cause of the side loading. If noise cannot be isolated
to front or rear wheel bearings, inspection will be
necessary.
3.
Side bearings will produce a constant rough noise of
a slower nature than pinion bearings. Side bearing
noise will not fluctuate in the above wheel bearing
test.
Failure Analysis
The most common types of rear axle failures are
hypoid gear tooth scoring and fracture, differential gear
fracture. and/or differential bearing failure, and axle
shaft bearing failure.
Fig.
75-Cracked Hypoid Ring Gear
CHEVROLET CHASSIS SERVICE MANUAL