torque CHEVROLET CAMARO 1967 1.G Chassis Owner's Guide

REAR SUSPENSION AND DRIVE LINE 4-14

Fig.
32—Upper Control Arm Bushing Installation (Chevrolet)

Installation

1.
Position rear of control arm into axle bracket and

loosely install the pivot bolt.

2.
Align the forward end of the control arm with the

rear crossmember and install front bracket bolts

through holes. Raise or lower nose of carrier as

/ required to help align bracket and crossmember.

3.
Install crossmember reinforcement plate, lock

washers and nuts to retain bracket in place.

4.
Position vehicle so that weight is on suspension

components and torque all affected parts to

specifications.

Chevrolet Lower

Removal

1.
Raise vehicle and remove shock absorber and spring

as outlined in this section.
NOTE:
If both rear suspension lower control

arms are to be removed, support the rear axle

in such a manner to prevent damage to brake

lines and to prevent assembly from falling.

2.
Note position of control arm in forward attaching

bracket and disconnect control arm at forward and

rearward attaching points. Remove assembly from

vehicle.

Bushing Replacement

Lower control arm front and rear bushing assemblies

are not interchangeable and require separate removal

and installation procedures.

1.
Replace the front bushing as follows.

a. Center Receiver J-7574-4 over flanged end of

bushing and position Spacer J-7574-3 over bush-

ing and between sides of control arm. Using

Remover J- 7574-1 against small end of bushing,

press bushing from control arm. Refer to Figure

33 for installed view of tools.

b.
Position bushing in control arm making sure of

correct installation. Small end of bushing will

pass through one side without any interference.

c. Position Puller Screw J-21058-15 through In-

staller Adapter J-7574-2--head of puller screw

should rest against flat side of adapter.

d. Install adapter and screw through bushing with

adapter resting against flange portion of bushing.

Install Receiver J-21058-6 and Bridge J^-21058-7

on opposite side of control arm (fig. 34).

e. Install thrust bearing and Nut J-21058-8. Screw

nut against J-21058-7 to maintain proper relation-

Fig.
33—Lower Control Arm Front Bushing Removal (Chevrolet)
Fig. 34—Lower Control Arm Front Bushing Installation

(Chevrolet)

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-15

ship of parts, then install Spacer J-
7574-
3 over

the partially installed bushing and between the

sides of the control arm.

f. Continue to tighten J-
21058-
8
until bushing is

pulled flush against control arm. Do not exert

undue force against control arm after bushing is

installed. Overtightening of J-21058-
8
will cause

damage to walls of control arm.

g. Disassemble tools and inspect bushing for proper

installation.

Replace the rear bushing as follows:

a. Position Puller Screw J-21058-8 through Re-

mover Adapter J-21830-2 so that head of screw

is opposite button end of remover. Install this

assembly, threaded end of sc'rew first, through

bushing to be removed.

b.
Install Receiver J-21830-4 and Bridge J-21830-7

. over screw and against control arm. Position

thrust bearing against J-21830-7 and screw

J-21058-8 snugly against bearing. Install Spacer

J-
2183d-
3
between sides of control arm and over

bushing.

c. Check tool installation for proper alignment and

tighten J-21058-8 to withdraw bushing from con-

trol arm. Refer to Figure 35 for installed view

of tools.

d. Disassemble tools and position Installer Adapter

J-21830-2 on flanged end of new bushing. Posi-

tion bushing in control arm making sure of cor-

rect installation. Small end of bushing will pass

through one side of arm without any interference.

e. Install J-21830-4, J-21830-7, thrust bearing and

J-21058-8 on threaded end of J-21058-15 as

shown in Figure 36. Tighten J-21058 to main-

tain proper relationship of parts; then position

Spacer J- 21830- 3 over bushing and between sides

of control arm.

f. Tighten J-21058-8 until bushing is fully seated
J-21058-8 J-21830-7 J-21830-4 J-21830-3 J-21830-2

\

J-2K

X
D58-8
J-218
30-7

IP

•he?

21830-4
J-21830-2

JfSir

J-21830-3

Fig.
35—Lower Control Arm Rear Bushing Removal

(Chevrolet)
Fig.
36—Lower Control Arm Rear Bushing Installation

(Chevrolet)

against side of control arm. Do not apply undue

pressure to J-21058 after bushing is seated--to

do so may cause permanent distortion to control

arm.

g. Disassemble tools and check bushing for proper

installation.

Installation

NOTE:
Make sure control arm is reinstalled

in proper forward attaching position. Reinstall

in same hole as noted during removal. Top

attaching hole is used for all installations except

station wagons and heavy-duty suspension (RPO

F41).
Opposite arm must be installed in cor-

responding position.

1.
Position the control arm between the mounting

brackets and loosely install the pivot bolt retaining

nuts in the proper position.

2.
Install spring and shock absorber as outlined in this

section.

3.
Lower vehicle so that weight is placed on sus-

pension components and torque all affected parts to

specifications.

Chevelle Upper and Lower

Removal

NOTE:
If both upper control arms and both

lower control arms are to be removed at the

same time, remove both coil springs as outlined

under "Coil Spring Removal".

1.
Raise vehicle to a height that will allow axle assem-

bly to hand freely and position supports under both

frame side rails.

2.
Support axle assembly with an adjustable lifting de-

vice and raise rear axle assembly until tension is

relieved in control arm being removed.

3.
Disconnect control arm at forward and rearward

attaching points and remove from vehicle.

Bushing Replacement

The upper arm front bushing and carrier ear bushings

are of the same part number and are interchangeable.

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-17

Fig.
41—Carrier Mounted Suspension Bushing Removal

(Heavy-Duty) (Chevelle)

c. Turn Nut J-21058-8 to remove bushing from

carrier ear, making sure Remover Adapter

J-21474-2 is centered and will clear hole in

carrier ear.

d. Disassemble puller tools and position Installer

Adapter J-
21474-
2 on flanged end of bushing.

Install Puller Screw J-21058-15 through receiver

so that screw head is seated against receiver.

Position this assembly through inboard side of

carrier ear.

e. Position bushing and Installer Adapter J-21474-2

onto puller.screw with small end of bushing to-

ward carrier ear. Refer to Figure 40 for in-

stalled view of tools.

f. Install Thrust Bearing and Nut J-21058-8 onto

puller screw. Turn nut to pull bushing into car-

rier ear. Check position of bushing when install-

ing to make sure bushing is properly aligned.
b.

c.

d.
Fig.
43—Upper and Lower Control Arm Assembly

(Chevelle)

Heavy-Duty
Carrier

a. Install a 1/2 x 20 nut on Puller Screw J-21058-15,

install thrust bearing against nut. Position puller

screw through Bridge and Receiver J-21830-4

and 7.

Position puller screw through flanged end of

bushing then install Remover Adapter J-21991

on threaded end of puller screw.

Align tools on carrier ear and center remover

adapter on bushing. Hold head of puller screw

and turn 1/2 x 20 nut to withdraw bushing from

carrier ear. Refer to Figure 41 for installed

view of removal tools.

Position Installer J-21474-2 on flanged end of

new bushing and install Driver Handle J-7079-2

to opposite end of installer.

e. Position bushing in carrier ear and drive bush-

ing until it seats against carrier. Bushing is

properly seated when shoulder on bushing con-

tacts carrier. Refer to Figure 42 for installation.

NOTE:
Do not attempt to seat flange of bush-

ing against ear of carrier. Bushing is properly

installed when shoulder on bushing seats against

chamfer on carrier ear.

Installation

1.
Place control arm into position between the forward

and rearward mounting brackets and install retaining

bolts.
Refer to Figure 43 for installation view of

control arms.

Support vehicle at axle and remove supports from

beneath the frame side rails.

Install lock washer and nut to retaining bolts and
2.

3.

torque to specifications.

Fig.
42—Carrier Mounted Suspension Bushing Installation

(Heavy-Duty) (Chevelle)
REAR SUSPENSION TIE ROD-CHEVROLET

Removal

1.
Remove the nut, washer and bolt from the leftside

and the nut and washer from the stud on the right

side that secure the tie rod to the brackets (fig. 44).

Withdraw the rod from under the vehicle. An ex-

ternal shell service bushing is available for left side

on all models and both right and left on station

wagons.

NOTE:
The above operations need not be per-

formed on a hoist. However, to provide ample

working space, the use of a hoist or proper jack

stand is recommended.

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-18

ig.
44—Rear Suspension Tie Rod Attaching Points (Chevrolet)

Bushing
Replacement

The following bushing removal procedure is effective

for both ends of the tie rod used on station wagons and

the left end of the tie rod used on all models except

station wagons.

1,
With tie rod bushing centered over Tool J-7877-2

and with tie rod supported horizontally, press or

drive bushing from rod, using Tools J-7877-1 and

J-7079-2 as shown in Figure 45.

2.
With tie rod 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 45. Tool J-7877-3 should bottom on tie

rod when bushing is fully installed.
fig.
45—Tie Rod Bushing Replacement (Chevrolet)

Installation

1.
Mount the tie rod to the axle bracket stud. Install

nut and special washer but do not tighten.

NOTE:
On the tie rod used on all models except

station wagons, place flanged portion of bushing

against attaching bracket.

2.
Install the bolt, lock washer and nut to the frame

bracket (fig. 44). Do not tighten.

NOTE:
Bolt may be installed from either

direction.

3.
Lower vehicle to floor (if raised) and bounce rear

end several times to settle bushings. Tighten af-

fected parts to specifications.

COMPONENT PARTS REPLACEMENT (CORVETTE)

WHEEL SPINDLE AND SUPPORT (Fig. 46)

Removal

Hemdve wheel drive spindle as outlined previously in

this section under "Wheel Bearing Adjustment".

Repairs

Out of 3/8" square steel bar stock, make bearing

removers and use as shown in Figure 47.

After removing deflector, spindle inner grease seal

and inner bearing race, bearing cups may be re-

moved while spindle support is still mounted to the

torque arm, by inserting remover tool and tapping

cup out. New bearing cups are installed using Tool

J-7817 cup installer and handle J-8092 (fig. 48).

To remove spindle support from torque arm, pro-

ceed as follows.

a. Disconnect parking brake cable from actuating

lever.

b.
Remove four nuts securing support to torque arm

and withdraw brake backing plate and position it

out of the way.

c. Disconnect shock absorber lower eye from strut

rod mounting shaft. It may be necessary to sup-

port spring outer end before disconnecting shock
absorber, as shock absorber has internal rebound

control.

d. Remove cotter pin and nut from strut rod mount-

ing shaft, then pull shaft from support and strut

rod.

e. Spindle support may then be removed and bearing

cups serviced as in Step 2 above.

4.
To remove drive spindle outer bearing and seal

proceed as follows.

a. Position Tool J-8331 between chamfered edge of

bearing seat and inner race of bearing (fig. 49).

Clamp Tool J-8331 in a vise and apply pressure

to unseat bearing.

CAUTION: Use extreme caution when position-

ing Tool J-8331 against machined surface of

spindle. Make sure all tool imperfections such

as nicks and burrs are removed from spindle

contact area before applying pressure to unseat

bearing.

b.
Position Tool J-8331 and spindle in an arbor

press and press bearing from spindle (fig. 50).

c. Remove outer seal and inspect for damage--re-

place if necessary. Outer seal must be placed on

spindle before outer bearing inner race and roller

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-20

Fig.
51—Shock Absorber Installation (Corvette)

6. Tap new spindle inner grease seal into seal bore

and install deflector over support inner end.

Installation

1.
Position support over torque arm bolts with strut

rod fork toward center of vehicle and downward.

Place backing plate over studs and torque nuts to

specifications.

2.
Connect parking brake cable to actuating lever.

3.
Install drive spindle assembly as outlined previously

in this section under "Wheel Bearing Adjustment".

4.
If new spindle support or associated parts are in-

stalled, determine correct shim size as follows.

a. Assemble spindle to support, using a .145" shim.

b.
Check bearing adjustment and correct as neces-

sary, following adjustment procedures previously

outlined.

DIFFERENTIAL CARRIER SUPPORT

BRACKET REPLACEMENT

1.
Place a 1/2" thick block of wood or steel between

nose of differential carrier and floor pan. This will

prevent carrier from twisting upward when support

bracket is disconnected.

2.
Remove carrier support-to-crossmember attaching

bolt.

3.
Remove nut from both of the bracket-to-carrier

through bolts.

4.
Slide bolts to one side until bolt head contacts floor

well. Mark the floor well at this point and drill a

3/4"
diameter hole for each bolt in floor well and

remove bolts.

5. Assemble carrier support bracket by reversing

above procedure. Torque all affected parts to

specifications.

6. Insert plastic plugs from the inside of the floor well

holes to prevent dust and water entry.
STRUT ROD SHAFT STRUT ROD

CAMBER CAM

AND BOLT

Fig.
52—Strut Rods (Corvette)

SHOCK ABSORBER (Fig. 51)

Removal

1.
Disconnect shock absorber upper mounting bolt*

2.
Remove lower mounting nut and lock washer.

3.
Slide shock upper eye out of frame bracket and pull

lower eye and rubber grommets off strut rod mount-

ing shaft.

4.
Inspect grommets and shock absorber upper eye for

excessive wear.

Installation

1.
Slide upper mounting eye into frame mounting

bracket and install bolt, lock washer and nut.

2.
Place rubber grommet, shock lower eye, inboard

grommet, washers and nut over strut rod shaft.

3.
Torque nuts to specifications.

STRUT ROD AND BRACKET (Fig. 52)

Removal

1.
Raise vehicle enough to provide working clearance.

2.
Disconnect shock absorber lower eye from strut

rod shaft.

3.
Remove strut rod shaft cotter pin and nut. With-

draw shaft by pulling toward front of vehicle (fig. 53).

4.
Mark relative position of camber adjusting cam and

Fig.
53-Removing Strut Rod Shaft (Corvette)

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

REAR SUSPENSION AND DRIVE LINE 4-23

Fig.
62—Torque Control Arm (Corvette)

2.
Place center clamp plate in position and install four

bolts and washers. Tighten bolts and torque to

specifications.

3.
Raise spring outer end with floor jack until spring

is nearly flat and secure with chain as in Step 3-

Removal.

.4.
Lower jack, align torque control arm with spring

end and insert link bolt, rubber cushions and re-

tainers. Install castellated nut on link bolt and

tighten until cotter pin hole in bolt is visible. In-

sert new cotter pin and bend ends around.

5. Raise spring end with jack under link bolt, and re-

move chain and C clamp when loose.

6. Carefully lower jack, making sure rubber cushions

remain indexed in retainers.

7. Remove jack and repeat on opposite side. Install

wheels and tires, remove frame supports and lower

vehicle to floor.

TORQUE CONTROL ARM (Fig. 62)

Removal

1.
Disconnect spring on side torque arm is to be re-

moved. Follow Steps 1-6, Spring-Removal.

NOTE:
If vehicle is so equipped, disconnect

stabilizer rod from torque arm - refer to

"Stabilizer Rod Replacement".

2.
Remove shock absorber lower eye from strut rod

shaft.

3.
Disconnect and remove strut rod shaft and swing

strut rod down.

4.
Remove four bolts securing axle drive shaft to

spindle flange and disconnect drive shaft.

NOTE:
It may be necessary to force torque

arm outboard to provide clearance to drop drive

shaft.

5. Disconnect brake line at wheel cylinder inlet or

caliper and from torque arm. Disconnect parking

brake cable.

6. Remove torque arm pivot bolt and toe-in shims and

pull torque arm out of frame. Tape shims together

and identify for correct reinstallation.
RETAINER

RETAINER

PLATE

BUSHING

CONTROL ARM

Fig.
63—Torque Control Arm Bushing Cross-Sect ion (Corvette)

NOTE:
For service operations pertaining to

the spindle support assembly, refer to service

operations under Wheel Spindle and Support

earlier in this section.

Repairs (Fig. 63)

1.
Using 11/16" drill, drill out flared end of bushing

retainer (fig. 64).

2.
Remove special retainer plate and tap retainer out

of bushing.

3.
Remove bushings by spreading them apart with a

chisel and tap out of arm (fig. 65).

NOTE:
If bushing diameters are severely

rusted in torque arm, and arm tends to spread

during removal, clamp arm in a C-clamp to

prevent spreading.

Fig.
64—Drilling Out Retainer Flare (Corvette)

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-24

4

i*
5

Fig.
65—Removing Bushings (Corvette)

4.
Lightly oil new bushing diameters (not rubber por-

tion) and start bushings squarely in arm.

5. Install Tool J-7055-1 as shown in Figure 66 and

press bushings into place.

6. When bushings are fully installed, place special

plate over flared portion of new bushing retainer

and insert retainer into bushing.

7. Out of 5/8" thick steel plate 1-1/2" wide make flar-

ing tool support to the dimensions shown in Figure

67 and drill clearance holes as shown for 2
—
1/2"

bolts.

8. Place fabricated back-up plate on flared end of bush-

ing retainer and assembly Tool J-8111-23 to plate

with 2-1/2" bolts 5" long. Make sure threaded hole

in J-8111-23 is centered over unflared end of bushing

retainer and that chambered retainer plate is cen-

tered over retainer tube.

9. Lightly oil pointed end of J-8880-5 screw and thread

into J-
8111-23
until pointed "end contacts bushing

retainer. Continue threading J-8111-23 until retainer

is flared (fig. 68).

Installation

1.
Place torque arm in frame opening.

2.
Place toe-in shims in original position on both sides

of torque arm, install pivot bolt and tighten but do

not torque at this point.
Fig.
67—Flaring Tool Back-Up Plate (Corvette)

3.
Raise axle drive shaft into position and install to

drive flange. Torque bolts to specifications.

4.
Raise strut rod into position and insert strut rod

shaft so that flat lines up with flat in spindle sup-

port fork. Install nut and torque to specifications.

5. Install shock absorber lower eye and tighten nut

to specifications.

6. Connect spring end as outlined under Spring-

Bistallation, Steps 3-6'.

NOTE:
If vehicle is so equipped, connect sta-

bilizer shaft to torque arm - refer to "Sta-

bilizer Shaft Replacement".

7. Install brake disc and caliper, wheel and tire and

lower vehicle. Tighten torque arm pivot bolt. Bleed

brakes as outlined in Section 5-Brakes.

SUSPENSION CROSSMEMBER

Removal

1.
Disconnect and remove spring as outlined under

Spring-Removal.

2.
Remove differential carrier assembly as outlined

under Differential Carrier-Removal in this section.

3.
Support crossmember, remove bolts securing

crossmember isolation mounts to frame and lower

crossmember (fig. 69).

Fig.
66—Installing Bushings (Corvette)
Fig.
68—Flaring Retainer (Corvette)

CHEVROLET CHASSIS SERVICE MANUAL

REAR SUSPENSION AND DRIVE LINE 4-25

Fig.
69—Removing Crossmember (Corvette)

4.
Remove bolts securing carrier cover to cross-

member.

5.
Inspect rubber isolation mounts for aging and re-

place where necessary.

Repairs—Isolation Mount

1.
Bend back isolation mount tabs to allow mount re-

moval (fig. 70).

2.
Place crossmember on a suitable support and press

mount out of arm using a piece of suitable size pipe

or tubing on outer shell or inner insert.

3.
Place new mount into position on crossmember,

compress outer sleeve and press mount into place

until it is fully and squarely seated.

4.
After installation, bend over locking tabs.

Installation

1.
Install carrier cover to crossmember and torque

bolts to specifications.

2.
Raise crossmember into position and install mount-

ing bolts. Torque bolts to specifications.

3.
Install differential carrier assembly as outlined

under Differential Carrier
-
Installation in this

section.

4.
Install wheels and tires, remove frame supports and

lower vehicle.

STABILIZER SHAFT REPLACEMENT

1.
Raise rear of vehicle and support at frame side rail

with stand jacks.

2.
Disconnect stabilizer shaft at both torque arms (fig.

71).
Remove stabilizer shaft brackets from the

frame and withdraw assembly from vehicle.
ISOLATION MOUNT

CROSSMEMBER

BEND OVER TABS AFTER INSTALLATION

Fig.
70—Crossmember Mount Cross-Section (Corvette)

3.
Inspect bushings for signs of deterioration, and in-

spect shaft for bends, breaks or other defects - do

not attempt to straighten shaft - replace parts as

deemed necessary.

4.
Position bushings on shaft and loosely install shaft

to torque arms and at frame brackets.

5.
Align shaft to assume proper placement when bolts

are torqued, and torque attaching bolts to

specifications.

Fig.
71—Stabilizer Shaft Installation (Corvette)

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