1993 DODGE TRUCK wheel alignment

•

FRONT SUSPENSION
AND
AXLE
2 - 1
CONTENTS

page

FRONT SUSPENSION—2WD VEHICLES
......
7

FRONT SUSPENSION—4WD VEHICLES
14

FRONT WHEEL
ALIGNMENT
...............
3

GENERAL INFORMATION
1
page

MODEL
44
FRONT AXLE
17

MODEL
80
FRONT AXLE
49

TORQUE SPECIFICATIONS
75

GENERAL
INFORMATION

FRONT SUSPENSION—2WD VEHICLES
All two-wheel drive (2WD)
Ram
Truck
and
Ram­
charger vehicles
are
equipped with (Fig
1);

• Steering knuckles
• Stabilizer
bar
(optional) • Suspension arms
• Strut
rod

• Coil springs
• Dual-action shock absorbers
• Jounce bumpers (used
to
limit
the
travel
of the

suspension) The upper and lower suspension arms (Fig.
1)
have
replaceable bushings located
at the
inboard end.
Re­

placeable ball studs
are
located
at
the
outboard end.
The lower suspension arms
are
equipped with ten­ sion-type ball studs. The upper suspension arms also
provide
for
caster
and
camber adjustments.
STABILIZER
BAR
J9102-67

Fig. 1 Front Suspension—2WD Vehicles

FRONT SUSPENSION—4WD VEHICLES
All four-wheel drive (4WD) Ram Truck
and
Ram­
charger vehicles
are
equipped with (Fig
2);
• Leaf-springs (fixed-rate type)
• Dual-action shock absorbers • Stabilizer
bar
(optional)
• Jounce bumpers (used
to
limit
the
travel
of the

suspension)
Air-adjustable shock absorbers
are
installed
on
ve­

hicles equipped with
the
Heavy Duty Snow Plow Package with
the
Diesel engine. Refer
to
the Own­
ers Manual
for
additional information.
FRONT DRIVE AXLE The front axle
on 4WD Ram
Truck
and
Ram­
charger vehicles
has a
hypoid gear differential.
Model
44
and
60
axles consists
of
an iron center cast­
ing with axle shaft tubes extending from either side.
Ram Truck
and
Ramcharger vehicles equipped
for

standard duty 4WD operation use
the
Model
44
front
axle.
Vehicles equipped
for
heavy duty 4WD operation
use

a Model 60 front axle. The Model 60 front axle has lock­
ing hubs that must
be
engaged
for
4WD operation.
The steel cover provides
a
means
for
service with­
out removing
the
complete axle. A metal axle gear ratio identification
tag is at­

tached
to the
housing cover
via one of the
cover

bolts.
This
tag
also identifies
the
number
of
ring and
pinion gear teeth.
IDENTIFICATION Model
44 and 60
axles have
the
assembly part
number
and
gear ratio listed
on a
tag. The
tag
is at­

tached
to
the
left side
of
the housing cover (Fig.
3,
4).
Build date identification codes
on
axles
are
stamped
on
the
axle shaft tube cover side.

LUBRICANTS
Multi-purpose API
GL
5
quality hypoid gear lubri­
cant should
be
used
for
front axles. MOPAR Hypoid Gear Lubricant conforms
to
these specifications. The axle
has a
fitting
for a
vent hose used
to re­

lieve internal pressure. If the front axle
is
submerged
in
water,
the
lu­

bricant must
be
replaced immediately.

FRONT
SUSPENSION
AND
AXLE

FRONT SUSPENSION
AND
AXLE
2 - 3

FRONT
WHEEL
ALIGNMENT

GENERAL
INFORMATION
Front wheel alignment involves
the
correct posi­
tioning
of the
tire contact patch
in
relation
to the

pavement.
The
positioning
is
accomplished through
the suspension
and
steering linkage adjustments.
An
alignment
is
essential
for
efficient steering
and
direc­
tional stability.
The
most important factors
of
front
end alignment
are
camber, caster
and toe
position. Routine inspection
of
the front
suspension
and
steering components
is a
good
preventative

maintenance practice.
Inspection
also
helps
to
ensure
safe operation
of the
vehicle.

• CAMBER
is the
number
of
degrees
the top of the

wheel
is
tilted either inward
or
outward.
An
excessive
negative camber angle will cause tread wear
at the in­
side
of
the tire.
An
excessive positive camber angle will
cause tread wear
at the
outside
of
the tire (Fig.
1),
• CASTER
is the
number
of
degrees
of
forward
or

rearward tilt
of the
steering knuckles. Forward tilt
provides
a
negative caster angle. Rearward tilt pro­ vides
a
positive caster angle
(Fig. 1).

• WHEEL
TOE
POSITION
is the
difference between
the leading
and
trailing inside edges
of the
front
tires (Fig.
1).
Incorrect wheel
toe
position
is the
most common cause
of
unstable steering
and
steering wheel off-center.
The
wheel
toe
position
is the
final
front wheel alignment adjustment. • STEERING AXIS INCLINATION ANGLE
is
mea­
sured
in
degrees
and is the
angle that
the
steering
knuckles
are
tilted (Fig. 1).
The
inclination angle
has

a fixed relationship with
the
camber angle. This will
not change except when
a
spindle
or
ball stud
is

damaged
or
bent.
The
angle
is not
adjustable
and the

damaged component(s) must
be
replaced
to
correct
mis-alignment.

CAUTION:
Do not
attempt to modify
any
suspension

or steering
component
by
heating
and
bending.

PRE-ALIGNMENT INSPECTION
Before starting
a
front wheel alignment,
the
follow­
ing inspection
and
necessary corrections must
be
completed.
(1)
Tires with
the
same recommended
air
pressure,

size,
and
tread wear. Refer
to
Group
22,
Wheels
and

Tires
for
diagnosis information. (2) Front wheel bearings
for
wear
or
adjustment.
(3) Ball studs
and
linkage pivot points, steering
gear
for
looseness, roughness, binding
or a
sticking
condition. Refer
to
Group
19,
Steering
for
additional information.
CASTER

POSITIVE CASTER
STEERING
WHEEL CENTER

i 0.5
CCW
0
5
CW

CCW
=
COUNTER CLOCKWISE
CW
-
CLOCKWISE
CAMBER

NEGATIVE CAMBER (SHOWN)
TOP
OF
WHEEL INBOARD
POSITIVE CAMBER
(NOT
SHOWN)
TOP
OF
WHEEL OUTBOARD
NOMINAL-PREFERRED

THE NOMINAL VALUE
IS

THE
PREFERRED
VALUE

LEFT/RIGHT
DIFFERENCE

THE VALUE
Of
THE LEFT SIDE
MINUS THE VALUE
OF
THE
RIGHT SIDE

EX.

If
FT CASTER
- +6 5

RIGHT
CASTER
»
+8.0

LEFT/RIGHT DIFFERENCE

65 8.0
=
1
5
TOE

NEGATIVE TOE (TOE
OUT)
B>A
POSITIVE TOE (TOE
IN) 6 FRONT
Of
VEHICLE
ft
THRUST
ANGLE

ANGLE
OF
REAR
AXLE RELATIVE
TO
VEHICLE CENTERUNE

(+)
AXLE POINTS LEFT
(-)
AXLE POINTS RIGHT

PRODUCTION
TOLERANCE
THE RANGE
Of
ACCEPTABLE

VALUES
AROUND THE NOMINAL

-
PREFERRED PRODUCTION
+6.5A7.5

PREFERRED:
+7.0

TOLERANCE:
0.5
J9302-61

Fig.
1
Wheel
Alignment
Measurements

2 - 4 FRONT SUSPENSION AND AXLE
•

I
FRONT END
|
|*?£E;
LOOSE
OR WORN
FRONT WHEEL
BEARINGS

LOOSE
C

SHOCKS

MOUNTir
WAR

SHOCK
A )RWORN

JSORBER

nIG
HARD-

E
OR
BSORBER
EXCiSSIVE
PLAY

STEERING

LINKAGE
LOOSE
OR WORN
FRONT WHEEL
BEARINGS

LOOSE
C

STEERINC
SHAFT
C
)RWORN

7
COLUMN
OUPLING
DIFFICULT

STEERING
LOOSE
OR WORN
WHEEL BEARINGS
TIRE/V
OUT OF
f
VHEEL
JA
LANCE
LOW OR UNEVEN
TIRE
AIR
PRESSURE

LO(
WHEEL B
DSE

EARINGS
LOW OR UNEVEN
TIRE AIR
PRESSURE
1vsnciEi

I
1
PULLS
TO I

I
|
ONE SIDE
j
LOOSE,
WORN
OR

GLAZED
P/S PUMP BELT LOW OR UNEVEN
TIRE PRESSURE
WHILE BR
REFE

BRAKES
AKING—

R
TO

SERVICE

LOOSE
STEERING
GEAR-TO-FRAME
RAIL BOLTS
LOOSE
STEERING

GEAR-TO-FRAME
RAIL BOLTS UNEVEN TIRE TREAD
WEAR,
OR
EX­

CESSIVELY
WORN TIRE TREAD
BROKEN
OR WEAK

REAR
SPRING LOW
POWER STEERING
FLUID
LEVEL
BROKEN
OR WEAK

REAR
SPRING
WORN

UPPER
SUSPENSION ARM BUSHINGS WORN TIE-

ROD
END

BALL
STUDS WORN TIE-

ROD
END

BALL
STUDS
SHOCK
ABSORBER

NOT FUNCTIONING
CORRECTLY
LACK
OF ASSIST
FROM POWER

STEERING
PUMP
LOOSE
OR WORN

SUSPENSION
BUSHINGS

WORN LOWER

SUSPENSION
ARM
PIVOT
BUSHINGS INCORRECT

STEERING
GEAR ADJUSTMENT
LOOSE
OR WORN

SUSPENSION
ARM
BUSHINGS
INCORRECT

STEERING
GEAR ADJUSTMENT
BALL
STUDS

REQUIRE

LUBRICATION INCORRECT FRONT
WHEEL ALIGNMENT (EITHER CASTER OR CAMBER)

LOOSE
LOWER

SUSPENSION
ARM
LOOSE
OR WORN

UPPER
SUSPENSION ARM BALL STUDS
LOOSE
OR WORN

SUSPENSION
ARM
BUSHINGS
STEERING
GEAR
LUBRICANT LEVEL LOW
WORN ISOLATOR

PAD
BETWEEN COIL
SPRING
AND

FRAME
BRACKET INCORRECT FRONT-
WHEEL ALIGNMENT (PARTICULARLY
CASTER)
INCORRECT FRONT
WHEEL ALIGNMENT INCORRECT

STEERING
GEAR ADJUSTMENT

STEERING
GEAR

MALFUNCTION
INCORRECT FRONT
WHEEL ALIGNMENT (PARTICULARLY
CASTER)

J9002-97
SUSPENSION AND STEERING
SYSTEM
DIAGNOSIS

•

FRONT
SUSPENSION
AND
AXLE
2 - 5 (4) Front wheels for excessive radial, lateral
runout and unbalance. Refer to Group 22, Wheels and Tires for diagnosis information.
(5) Suspension components for wear and noise. Check
components for correct torque. Refer to Groups 2 and 3, Suspension and Axle for additional information.

WHEEL
ALIGNMENT
MEASUREMENTS/ADJUSTMENTS
The front wheel alignment positions must be set to
the specified limits. This will prevent abnormal tire
tread wear. The equipment manufacturer's recommenda­
tions for use of their
equipment
should always
be followed. All
damaged
front suspension sys­
tem components
should
be replaced. Do not at­ tempt to straighten any
bent
component.

CAMBER AND CASTER-2WD VEHICLES Camber and caster angle adjustments involve repo­
sitioning the upper suspension arm cam adjustment
bolts (Fig. 2). Alignment adjustments are accom­
plished by loosening the nuts and changing the posi­
tion of the cam bolt.
(1) Remove all foreign material from the adjust­
ment bolt threads.
(2) Record the camber and caster measurements
before loosening the adjustment bolt nuts.
(3) The camber angle should be adjusted as near as
possible to the preferred angle. The caster should be
the same at both sides of the vehicle. Refer to the Specifications chart.
CAMBER AND CASTER—4WD VEHICLES For 4WD vehicles, the correct wheel camber (verti­
cal tilt) angle is factory preset at zero degree (0°).
Camber cannot be altered by adjustment.
CAUTION: Do not attempt to
adjust
the
camber
an­
gle by
heating
or bending the axle or any
suspen­

sion
component. If camber angle is
incorrect,
the
component(s)
causing
an
incorrect
angle must be replaced.
(1) It is important that the camber (vertical tilt)
angle be the same for both front wheels.
(2) The camber angle should be measured with ac­
curate wheel alignment equipment. The acceptable
range is -1° to +1°. Refer to the Specifications chart.
Road test the vehicle and observe the steering
wheel return-to-center position. Before road testing,
check
and
correct
the tire
inflation pressures. Inflate
both
of the front tires
with exactly the
same
pressure.
During the road test, make vehicle turns to both
the left and right. If the steering wheel returns to­
ward the center position unassisted, the caster angle is correct. However, if the steering wheel does not re­ turn toward the center position unassisted, an incor­
rect caster angle is probable.
(1) The caster angle is factory preset at positive
two degrees
(
+
2°).
The acceptable range is +1/2° to +
3
1/2°.
(2) The caster angle should be measured with ac­
curate wheel alignment equipment.
(3) Caster angle can be adjusted by installing ta­
pered shims between the front axle pads and the spring brackets. The caster angle should be adjusted
as near as possible to the preferred angle.
(4) Record the caster measurement before remov­
ing the original shims from the spring pads.
(5) The caster should be the same at both sides of
the vehicle. Refer to the Specifications chart.
RN1030

Fig.
2 Caster &
Camber
Adjustment Location—2WD
Vehicles

WHEEL TOE POSITION The wheel toe position adjustment should be the fi­
nal front wheel alignment adjustment. In all in­ stances, follow the equipment manufacturer's
recommended procedure.
(1) Secure the steering wheel with the front wheels
in the straight-ahead position. For vehicles equipped
with power steering, start the engine before straight­ ening the wheels.
With power steering, the engine should be op­
erating during the wheel toe position adjust­
ment.
(2) Loosen the tie rod adjustment sleeve clamp
bolts (Fig. 3).
(3) Adjust the wheel toe position by rotating the
tie rod adjustment sleeve (Fig. 3). Rotate each tie-rod end in the direction of
sleeve rotation during the adjustment (Fig. 3).
This will ensure that both tie-rod ends are at the center of their travel.
(4) If applicable, turn the ignition switch off.

•

FRONT SUSPENSION
AND
AXLE
2 - 31
Fig. 35 Disconnect Axle Service Tools ASSEMBLY/INSTALLATION
(1) Install the needle bearing in the end of the in­
termediate shaft with Installer D-328 and Driver Handle C-4171 (Fig. 36).
RK
727
Fig. 36 Intermediate Shaft Bearing installation (2) Install the intermediate axle shaft bearing with
Tool D-354-4, Tool 354-2 and Slide Hammer C-637 (Fig. 34, 35).
(3) Install the intermediate axle shaft with Tool
D-354-4 and Adaptor Tool D-354-3.
(4) Install the C-lock in the axle shaft and side
gear.
(5) Clean the tube bore and remove any rust from
the seal area.
(6) Place the axle shaft seal on Tool 5041-1 and po­
sition in housing. Thread Tool 5041-2 through the
seal into Tool
5041-1.
Install Tool 5041-3 and nut on
the end of the threaded bar tool. Tighten the nut un­
til the tool contacts the threaded bar shoulder.
(7) Install the shift collar on the splined end of the
intermediate axle shaft.
(8) Lubricate the splined end of the intermediate
axle shaft with multi-purpose lubricant.
(9) Install the axle shaft, spindle and hub, refer to
the installation procedures above. (10) Install the shift motor housing, refer to Vac­
uum Shift Motor Installation.
STEERING
KNUCKLE
ARM

REMOVAL
(1) Install Puller C-4150 on each drag-link ball
stud. Apply sufficient force with the tool to loosen
the drag-link ball stud from the steering arm.
(2) Remove the lock nuts that attach the steering
arm to the knuckle (Fig. 37). Tap the steering arm to
loosen it from the knuckle. Pry upward to remove. Fig. 37 Steering Knuckle Arm Removal

INSTALLATION

(1) Position the steering arm on the knuckle. In­
stall the nuts. Tighten the nuts to 122 N«m (90 ft.

lbs.).

(2) Position the drag link at steering knuckle arm.
(3) Install and tighten the ball stud nut to 81 N*m
(60 ft. lbs.) torque. Install new cotter pins.

COMPLETE
AXLE REMOVAL/INSTALLATION
SERVICE
INFORMATION
It is not necessary to remove the complete front
axle from the vehicle for routine service. If the hous­
ing or axle shaft tubes are damaged, the complete axle can be removed and installed via the following
procedures.
REMOVAL (1) Remove the front wheels/tires.
(2) Mark the front drive shaft and the pinion yoke
for installation alignment reference.
(3) Disconnect the front drive shaft from the axle
yoke. Attach the drive shaft to the frame rail with

wire.

(4) Remove the cotter pin, nut, and disconnect the
drag link from the steering knuckle arm (left side

only).
Discard the cotter pin.

•

TAPERED

BUSHING

J9202-53

Fig.
32 Tapered
Bushing
Installation

J9202-52

Fig.
33
Lower
King
Pin and Retainer
Installation
(12) Install the axle shaft, refer to Axle Shaft and
U-Joint Installation.

COMPLETE
AXLE REMOVAL/INSTALLATION SERVICE
INFORMATION
It is not necessary to remove the complete front
axle from the vehicle for routine service. If the hous­
ing or axle shaft tubes are damaged, the complete axle can be removed and installed via the following
procedures.

REMOVAL
(1) Block the brake pedal in the up position. Raise
and support the vehicle at a comfortable working
height.
(2) Remove the front wheels/tires.
FRONT SUSPENSION
AND
AXLE
2 - 59
(3) Mark the front drive shaft and the pinion yoke
for installation alignment reference.
(4) Disconnect the front drive shaft from the axle
yoke. Attach the drive shaft to the frame rail with
wire.

(5) Remove the cotter pin, the nut, and disconnect
the drag link from the steering knuckle arm (left side only). Discard the cotter pin.
(6) Disconnect flexible brake fluid hose fittings at
the frame crossmember. Plug the hoses at the fit­

tings.
(7) Remove the shock absorber lower nut and stud
from the axle shaft tube bracket. Remove the nuts and disconnect the stabilizer bar links from the
spring brackets. (8) Remove nuts and the washers from the spring
U-bolts. Remove the complete front axle from the ve­
hicle.
INSTALLATION (1) Position the front axle under the front of the
vehicle with the axle spring pads under the springs.
Place the spring brackets over the springs. Make sure the stabilizer bar link bolt holes face toward the
rear of the vehicle.
(2) Install the spring U-bolts, washers and nuts.
Refer to Front Suspension — 4WD Vehicles within
this group. (3) Install the shock absorber. Refer to Front Sus­
pension—4 WD Vehicles within this group.
(4) Connect the stabilizer bar links to the spring
brackets. Refer to Front Suspension—4WD Vehicles within this group.
(5) Remove plugs and connect the brake hose fit­

tings.
Refer to Group 5, Brakes. (6) Connect the drag-link ball stud to the steering
knuckle arm. Refer to Group 19, Steering. (7) Connect the drive shaft to the pinion yoke with
the installation reference marks aligned. Install the
washers and the nuts and tighten to 19 N-m (14 ft. lbs.) torque.
(8) Remove the supports, lower the vehicle and re­
move the block from the brake pedal.
(9) Raise the vehicle.
• Bleed and adjust the brakes
• Lubricate all the ball stud fittings
• Inspect the differential housing lubricant level. Re­
fer to Group 0, Lubrication and Maintenance.
(10) Lower the vehicle and test the axle and sus­
pension operation.

DIFFERENTIAL DISASSEMBLY
REMOVAL/DISASSEMBLY
(1) Note the installation reference letters
stamped on the bearing caps and housing ma­
chined sealing surface (Fig. 34).
(2) Remove the differential bearing caps.

3
- 6
REAR SUSPENSION
AND
AXLE

•

NUT PIPE
SOCKET
WRENCH
(DRIVER)

FLAT
THREADED
WASHER
ROD
J8917-20

Fig.
6
Spring
Eye
Bushing
Removal
(3) Align
the
bushing with
the
spring
eye and

tighten
the nut
located
at the
socket wrench
end of

the threaded
rod.
Tighten until
the
bushing
is
forced into
the
spring
eye.

The bushing must
be
centered
in the
spring

eye.
The
ends
of the
bushing must
be
flush
or
slightly recessed within
the end
surfaces
of the

spring
eye.
8ERW1GE DIAGNOSIS
INDEX
page

Driveline
Snap
8

Gear
and
Bearing Noise
7

General
Information
6
Limited
Slip
Differential
8
page
Low Speed Knock
.........................
8
Rear
Axle
Alignment
.......................
7

Tire
Noise
7
Vibration
8

GENERAL INFORMATION
Axle bearing problem conditions
are
usually caused
by: • Insufficient
or
incorrect lubricant
• Foreign matter/water contamination
• Incorrect bearing preload torque adjustment When serviced,
the
bearings must
be
cleaned thor­
oughly. They should
be
dried with lint-free shop tow­

els.
Never
dry
bearings with compressed
air.

This will overheat them
and
brinell
the
bearing surfaces. This will result
in
noisy operation after
repair. Axle gear problem conditions
are
usually
the
result

of:

• Insufficient lubrication
• Incorrect
or
contaminated lubricant
• Overloading (excessive engine torque)
• Incorrect clearance
or
backlash adjustment Insufficient lubrication
is
usually
the
result
of a

housing cover leak.
It can
also
be
from worn axle shaft
or
pinion gear seals. Check
for
cracks
or
porous
areas
in the
housing
or
tubes.
Using
the
wrong lubricant will cause overheating
and gear failure. Gear tooth cracking
and
bearing
spalling
are
indicators
of
this.
Axle component breakage
is
most often
the
result

of:

• Severe overloading
• Insufficient lubricant
• Incorrect lubricant • Improperly tightened components
Common causes
of
overloading
is
from full-throttle
acceleration. Overloading occurs when towing
heavier than normal loads. Component breakage
can
occur when
the
wheels
are
spun excessively. Insuffi­
cient
or
incorrect lubricants contribute
to
breakage
through overheating. Loose differential components can also cause breakage. Incorrect bearing preload
or
gear backlash will
not

result
in
component breakage. Mis-adjustment will
produce enough noise
to
cause service repair before
a

•

RfAR SUSPENSION
AND
AXLE
3 - 7 failure occurs. If a mis-adjustment condition is not
corrected, component failure can result.

REAR
AXLE ALIGNMENT

MEASUREMENT The following procedure can be used to determine
if abnormal rear tire tread wear is the result of a
bent or deformed rear axle shaft.
(1) Raise both rear wheels off the surface with a
frame contact hoist. (2) Attach a one-inch long piece of masking tape at
the center of each tire tread for use as reference marks.
(3) Rotate the rear wheels until both reference
marks face the front of the vehicle. Measure the dis­
tance between the outside edges of the two pieces of
tape.
Record this measurement as the front of tire (FTR) measurement.
(4) Rotate the rear wheels until both reference
marks face the rear of the vehicle. Measure the dis­
tance between the outside edges of the two pieces of
tape.
Record this measurement as the rear of tire (RTR) measurement.
(5) Subtract the (RTR) measurement from the
(FTR) measurement to obtain the amount of wheel

toe.
The acceptable rear wheel toe-in position is 1/16 inch (1.6 mm) to 3/16 inch (4.8 mm) toe-out.
(6) Rotate the rear wheels until the reference
marks are facing downward. Measure the distance
between the outside edges of the two pieces of tape. Record this measurement as the bottom of tire (BTR)
measurement.
(7) Average the (FTR) and the (RTR) distance
measurements. Subtract the (BTR) measurement
from this average distance to obtain the camber. The acceptable amount of camber is 1/16 inch to 3/32 inch
(1.6 to 2.4 mm).
(FTR + RTR) DIVIDED BY 2 (TWO) MINUS
BTR EQUALS CAMBER
If the (BTR) distance measurement is less than
the average FTR and RTR distance measure­
ment, the camber will be positive ( + ). If the (BTR) distance measurement is greater than the average FTR and RTR distance, the camber will
be negative ( - ).
If the toe position or camber is not acceptable, a
bent or deformed rear axle shaft is most likely the cause.

TIRE
NOISE
Check tires that are damaged, unbalanced, incor­
rectly inflated. Tires that have deep treads can emit sounds like axle noise. Differentiate between tire and
axle noise during a road test. Tire noise will usually vary with different road
conditions. Tire noise is sensitive to inflation pres­
sure.
The pitch of tire noise changes when the vehi­
cle speed is varied.
Drive the vehicle over different road surfaces. Note
the changes in the noise. If the noise changes, the
tires are the source of the noise.
Refer to Group 22, Wheels and Tires for additional
information.

GEAR
AND BEARING NOISE
GEAR
NOISE
Axle gear noise can be caused by insufficient lubri­
cant. Incorrect backlash, tooth contact, or worn/dam­ aged gears can cause noise.
Gear noise usually happens at a specific speed
range. The range is 30 to 40 mph, or above 50 mph.
The noise can also occur during a specific type of driving condition. These conditions are, acceleration,
deceleration, coast, or constant load.
When road testing, accelerate the vehicle to the
speed range where the noise is the greatest. Shift
out-of-gear and coast through the peak-noise range.
If the noise stops or changes greatly, check for
insuf­

ficient lubricant. Incorrect ring gear backlash, or gear damage can cause noise changes.
Differential side and pinion gears can be checked
by turning the vehicle. They usually do not cause noise in straight-ahead driving. These gears are
loaded during vehicle turns. If noise does occur dur­
ing vehicle turns, the side or pinion gears could be
worn or damaged. A worn pinion gear mate shaft can also cause a snapping or a knocking noise.

BEARING NOISE
The axle shaft, differential and pinion gear bear­
ings can all produce noise when worn or damaged.
Bearing noise can be either a whining, or a growling sound.
Pinion gear bearings have a constant-pitch noise.
This noise changes only with vehicle speed. Pinion
bearing noise will be higher because it rotates at a faster rate. Drive the vehicle and load the differen­

tial.
If bearing noise occurs the pinion rear bearing is the source of the noise. If the bearing noise is heard during a coast, front bearing is the source.
Worn, damaged differential bearings usually pro­
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing. The pitch of differential
bearing noise is also constant and varies only with vehicle speed.
Axle shaft bearings produce noise and vibration
when worn or damaged. The noise generally changes
when the bearings are loaded. Road test the vehicle. Turn the vehicle sharply to the left and to the right.
This will load the bearings and change the noise