1993 DODGE TRUCK Service Repair Manual

3
- 8
REAR SUSPENSION
AND
AXLE

• level. Where axle bearing damage is slight, the noise
is usually not noticeable at speeds above 30 mph.

LOW SPEED KNOCK
Low speed knock is generally caused by a worn
U-joint or by worn side-gear thrust washers. A worn
pinion gear shaft bore will also cause low speed knock.

VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
• Damaged drive shaft
• Missing drive shaft balance weight
• Worn, out-of-balance wheel and tires
• Loose wheel lug nuts
• Worn U-joint • Loose spring U-bolts
• Loose/broken rear springs or shackles
• Damaged axle shaft bearings
• Loose pinion gear nut
• Excessive pinion yoke run out
• Bent axle shaft Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rear-end vi­
bration. Do not overlook engine accessories, brackets and drive belts. All driveline components should be examined be­
fore starting any repair. Refer to Group 22, Wheels and Tires for additional
information.

DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by: • High engine idle speed
• Loose engine/transmission/transfer case mounts

9
Worn U-joints
• Loose spring shackles or U-bolts
• Loose pinion gear nut and yoke
• Excessive ring gear backlash
• Excessive differential side gear-to-case clearance A worn bushing in the transmission extension
housing can also cause noise. The source of a snap or a clunk noise can be deter­
mined with the assistance of a helper. Raise the ve­
hicle on a hoist with the wheels free to rotate. Instruct the helper to shift the transmission into gear. Listen for the noise, a mechanics stethoscope is
helpful in isolating the source of a noise.

LIMITED
SLIP DIFFERENTIAL
Under normal traction conditions, engine torque is
divided evenly. With low-traction surfaces, engine
torque is transferred to the wheel with the most tire
traction. When diagnosing a limited-slip differential
problem condition, the wheel with the least traction can continue spinning. The most common problem is a chatter noise when
turning corners. Check for incorrect or contaminated lubricant. Replace the gear lubricant if necessary.
• With Sure-Grip differentials add a container of
MOPAR® Hypoid Gear Additive This will correct the condition in most instances. If
the chatter persists, clutch damage could have oc­ curred. After changing the lubricant, drive the vehicle and
make 10 to 12 slow, figure-eight turns. This maneu­
ver will pump lubricant through the clutches.

REAR
SUSPENSION
AND
AXLE
3 - 9
SERVICE DIAGNOSIS
Condition
Possible
Cause
Correction

WHEEL
NOISE

AXLE
SHAFT
NOISE

AXLE
SHAFT
BROKE

DIFFERENTIAL
CASE

CRACKED

DIFFERENTIAL
GEARS

SCORED

LOSS
OF
LUBRICANT
(a) Wheel loose.
(b) Faulty, brinelled
wheel
bearing.
(a) Misaligned axle shaft tube.
(b) Bent or sprung axle shaft. (c) End play in drive pinion bearings.
(d) Excessive gear backlash
between
ring
gear
and pinion gear.
(e) Improper adjustment of drive pinion
gear
shaft bearings.
(f) Loose drive pinion gearshaft yoke nut.
(g) Improper
wheel
bearing adjustment. (h) Scuffed gear tooth contact surfaces.
(a) Misaligned axle shaft tube.
(b) Vehicle overloaded.
(c) Erratic clutch operation
(d) Grabbing clutch.
(a) Improper adjustment of
differential
bearings.

(b) Excessive ring gear backlash.
(c) Vehicle overloaded. (d) Erratic clutch operation.
(a) Insufficient lubrication.
(b) Improper grade of lubricant.
(c) Excessive spinning of one
wheel/tire.

(a) Lubricant
level
too high. (a) Tighten loose nuts.
(b) Faulty or brinelled bearings must be
replaced.
(a) Inspect axle shaft
tube
alignment. Correct as necessary.
(b) Replace bent or sprung axle shaft.
(c) Refer to Drive Pinion Bearing Pre-Load Adjustment.
(d) Check adjustment of ring gear
backlash
and pinion gear. Correct as
necessary.

(e) Adjust drive pinion shaft bearings.
(f) Tighten drive pinion gearshaft yoke nut
with
specified torque.
(g) Readjust as necessary.
(h) If necessary, replace scuffed gears.
(a) Replace broken axle shaft
after
correcting axle shaft
tube
alignment.
(b) Replace broken axle shaft. Avoid
excessive
weight on vehicle.
(c) Replace broken axle shaft
after
inspecting for other possible
causes.

Avoid
erratic
use of clutch.
(d) Replace broken axle shaft. Inspect clutch and make necessary repairs or adjustments.
(a) Replace cracked case; examine gears and bearings for possible damage. At
reassembly,
adjust

differential
bearings properly.
(b) Replace cracked case; examine gears and bearings for possible damage. At

reassembly,
adjust ring gear backlash properly.
(c) Replace cracked case; examine gears and bearings for possible damage.

Avoid
excessive weight on vehicle.
(d) Replace cracked case.
After
inspecting for other possible
causes,
examine
gears
and bearings for possible

damage.
Avoid
erratic
use of clutch.
(a) Replace scored gears. Scoring marks
on
the drive face of gear
teeth
or in
the bore are caused by instantaneous

fusing
of the mating surfaces. Scored
gears
should be replaced.
Fill
rear

differential
housing to
required
capacity

with
proper lubricant. Refer to
Specifications.

(b) Replace scored gears. Inspect all
gears
and bearings for possible

damage.
Clean and
refill
differential
housing
to
required
capacity
with

proper lubricant.
(c) Replace scored gears. Inspect all
gears,
pinion bores and shaft for

damage.
Service as necessary.
(a) Drain excess lubricant by removing
fill
plug and allow lubricant to
level
at lower edge of
fill
plug hole.

J9003-49

3-10
REAR SUSPENSION
AND
AXLE

SERVICE DIAGNOSIS (CONT'D)

Condition
Possible
Cause
Correction

AXLE OVERHEATING
GEAR TEETH BROKE
(RING GEAR
AND
PINION)

AXLE NOISE
(b) Worn axle
shaft
seals.

(c) Cracked
differential
housing.
(d) Worn
drive
pinion
gear
shaft
seal.
(e) Scored and worn yoke.
(f) Axle cover not
properly
sealed.
(a)
Lubricant
level
too low. (b)
Incorrect
grade of
lubricant.

(c) Bearings
adjusted
too
tight.

(d) Excessive gear wear.
(e)
Insufficient
ring
gear backlash,
(a) Overloading.
(b)
Erratic
clutch
operation.
(c) Ice-spotted pavements.
(d) Improper adjustments.
(a)
Insufficient
lubricant.

(b) Improper
ring
gear and
drive
pinion
gear
adjustment.

(c) Unmatched
ring
gear and
drive
pinion
gear.
(d) Worn
teeth
on
ring
gear or
drive
pinion
gear.
(e) Loose
drive
pinion
gear
shaft
bearings.
(f) Loose
differential
bearings.
(g) Misaligned or sprung
ring
gear.
(h) Loose
differential
bearing cap bolts. (b) Replace worn
seals.

(c) Repair or replace housing as
necessary.

(d) Replace worn
drive
pinion
gear
shaft
seal.

(e) Replace worn or scored yoke and seal.
(f) Remove cover and clean flange and reseal.
(a)
Refill
differential
housing. (b) Drain,
flush
and
refill
with
correct
amount of the
correct
lubricant.

(c) Readjust bearings.
(d) Inspect gears for excessive wear or scoring. Replace as necessary.
(e) Readjust
ring
gear backlash and inspect gears for possible scoring.
(a) Replace gears. Examine
other
gears and bearings for possible damage. Replace parts as needed. Avoid
overloading of vehicle.
(b) Replace gears and examine the remaining parts for possible damage.
Avoid
erratic
clutch
operation.
(c) Replace gears. Examine the remaining parts for possible damage. Replace
parts as required.
(d) Replace gears. Examine
other
parts for possible damage. Ensure
ring
gear
backlash is
correct.

(a)
Refill
axle
with
correct
amount of the proper
lubricant.
Also inspect for leaks
and
correct
as necessary.
(b) Check
ring
gear and
pinion
gear
teeth
contact
pattern.

(c) Remove unmatched
ring
gear and
drive
pinion
gear. Replace
with
matched gear and
drive
pinion
gear
set.
(d) Check
teeth
on
ring
gear and
drive
pi­ nion gear for
correct
contact.

If necessary, replace
with
new
matched set.
(e) Adjust
drive
pinion
gearshaft bearing preload
torque.

(f) Adjust
differential
bearing preload
torque.

(g) Measure
ring
gear
runout.

(h) Tighten
with
specified
torque.

J9003-50

•

REAR
SUSPENSION
AND
AXLE
3 - 11 8 3/8 and 9 1/4
AXLE

INDEX

page
Axle Shaft, Seal
and
Bearing Service
......... 11
Complete Axle Removal/Installation
16

Differential
Service
16
Information
11

INFORMATION
The 8 3/8 and 9 1/4 axle (Fig. 1) housing consist of
a cast iron center section. They also have two steel
axle shaft tubes that are pressed into and welded to
the differential housing. The removable, stamped steel cover provides a
means for inspection and service without removing
the complete axle from the vehicle.

LUBRICANT
Multi-purpose, hypoid gear lubricant should be
used for 8 3/8 and 9 1/4 axles. The lubricant should
have MIL-L-2105C and API GL 5 quality specifica­

tions.
MOPAR® Hypoid Gear Lubricant conforms to
both of these specifications.
Refer to Group 0, Lubrication and Maintenance for
additional information.

CAUTION:
If a
rear axle
is
submerged
in
water,
the

axle lubricant must
be
replaced immediately.
DRAIN
AND
REFILL
(1) Drive the vehicle until the gear lubricant
reaches normal operating temperature.
(2) Raise and support the vehicle.
(3) Remove the lubricant fill hole plug from the
differential housing cover.
(4) Remove the differential housing cover. Allow
the original lubricant to completely drain from the
housing and axle shaft tubes. (5) With standard differential, clean the differen­
tial and the housing cavity with a flushing oil (or light engine oil). This will remove the residual lubri­
cant and foreign matter.Do not use water, steam,
kerosene or gasoline for flushing.

CAUTION:
DO NOT
FLUSH
Sure-Grip differentials.

Sure-Grip
differentials
may be
cleaned only
by
wip­
ing
with
clean,
lint-free
cloths.
(6)
Scrape the residual sealant from the housing
and cover mating surfaces. Clean the mating sur­
faces with mineral spirits. Apply a bead of MOPAR® Silicone Rubber Sealant on the housing cover (Fig.

2).
Allow the sealant to cure for a few minutes.
page

Lubricant
11
Pinion Depth Measurement
and
Adjustment
with
Gauge
Set 20

Pinion
Seal
Replacement
14
Install the housing cover within 5 minutes af­
ter applying the sealant. If not installed, the sealant must be removed and another bead ap­
plied. (7) Install the cover on the differential. Install the
identification tag. Tighten the cover bolts to 47 N#m (35 ft. lbs.) torque.

CAUTION:
Overfilling
the
differential
can
result
in

the lubricant foaming
and
overheating.

(8) Refill the differential with the specified quan­
tity of MOPAR® Hypoid Gear Lubricant. With Sure- Grip differentials, add a container of MOPAR®
Hypoid Gear Lubricant Additive.
(9) Install the fill hole plug.
(10) Road test the vehicle.

AXLE
SHAFT, SEAL AND BEARING
SERVICE
CAUTION:
When rear axle service
is
necessary, both rear wheels must
be
raised
off the
surface
so

that
they
are
free
to
rotate.
Be
cautious when
the

tires
are
being rotated
by the
engine
or by
other
means.

CAUTION:
If
equipped
with
a
Sure-Grip
differential,

do
not
rotate
either
axle shaft unless both
are
prop­

erly
in-place. Rotation
of one
axle shaft without
the
other being installed
can
result
in
misalignment
of

the side gears/splines. This
will
necessitate side
gear
re-alignment before
the
axle shaft
can be in­

stalled.
AXLE SHAFT REMOVAL
(1) Raise and support the vehicle.
(2) Remove the wheel.
(3) Remove the brake drum.
(4) Clean all the foreign material from housing
cover area.
(5) Loosen the housing cover bolts. Drain the lubri­
cant from the housing. Remove the housing cover.

(6)
Rotate the differential case so the pinion mate
gear shaft lock screw is accessible. Remove the lock screw and the pinion mate gear shaft from the case (Fig. 3).

3
- 12
REAR
SUSPENSION
AND
AXLE

•
HUB

AXLE

SHAFT
DIFFERENTIAL
HOUSING FRONT

BEARING

VENT

FITTING

SEAL
AXLE
AXLE

SHAFT SHAFT

BEARING
TUBE

BEARING
CAP

WASHER
LOCK
STUD

SIDE

GEAR

CLIP
NUT

BOLT

DIFFERENTIAL
BEARING BEARING

CUP

ADJUSTER

LOCK

COVER
BOLT

PLUG
HOUSING

COVER
BOLT
J9003-109

Fig. 1 8 3/8-Inch Or 9 1/4-Inch Axle

•

REAR SUSPENSION
AND
AXLE
3 - 13

SEALANT
1/16-TO

3/32-INCH
(1.59-TO
38-AAM)
THICK
BEAD

DIFFERENTIAL HOUSING
COVER

(TYPICAL)
J9003-85 Fig, 2 Sealant On Homing
Cower

PINION

GEAR
MATE
SHAFT

O

DIFFERENTIAL CASE
LOCK
SCREW
J9003-110

Fig. 3 Pinion Mate Shaft Lock Screw (7) Push the axle shaft in toward the center of the
vehicle. Remove the axle shaft C-clip lock from the axle shaft (Fig. 4).
(8) Remove the axle shaft. Use care to prevent
damage to the axle shaft bearing.
(9)
Inspect the axle shaft bearing contact surface
area for indications of wear. if
wear exists,
the
axle shaft
and
bearing

should be
replaced. Normal bearing
contact on
the shaft
will
be a dull gray and it
could appear
to be lightly
dented.
ADJUSTER
, SIDE

LOCK
^
GEAR
AXLE

SHAFT
•!
C-CLIP LOCK
J9003-111

Fig.
4 Axle Shaft C-Clip
Lock
(10) If any of these conditions exist, the axle shaft
and bearing must be replaced.
The normal appearance will be a dull gray
surface that could appear slightly dented.
AXLE SHAFT SEAL AND BEARING REMOVAL (1) Remove the axle shaft seal with a small pry
bar.
(2) Remove the bearing if it appears damaged or
the axle shaft shows any of the conditions described above. (3) Remove the axle shaft bearing.
• 8 3/8-inch diameter (Fig. 5), use Remover C-4167 and Slide Hammer C-637
• 9
1/4-inch
diameter (Fig. 6), use Remover C-4828
SPECIAL
TOOL

C-637
SPECIAL
TOOL

C-4167

AXLE
SHAFT

TU1E

J9103-11

Fig.
5 Bearing
Removal
(8
3/8-Axle)

3
- 14
REAR SUSPENSION
AND
AXLE
3
- 18
REAR SUSPENSION Fig.
6 Bearing
Removal
(9
1/4-Axle)

(4) Inspect the axle shaft tube bore for roughness
and burrs. Remove as necessary.

CAUTION:
Inspect
the
housing
bore for
burrs.
Re­
move
as
necessary.

BEARING
AND
SEAL
INSTALLATION
Always install a new seal. (1) Wipe the bore in the axle shaft tube clean.
(2) If the original bearing is not reusable, install a
new bearing.
• 8 3/8-Axle use Installer C-4198 with Handle
C-4171
• 9
1/4-Axle
use Installer C-4826 with Handle
C-4171

CAUTION:
DO NOT use the new axle
shaft
seal
to

position
or
seat
the bearing in the axle
shaft
bore.
(3) Insert the bearing into the tube. Ensure that
the bearing is not cocked and is seated firmly against
the tube shoulder.
(4) Install the new axle shaft seal (Fig. 7).
• 8 3/8-Axle use Installer C-4203 and Handle C-4171
• 9
1/4-Axle
use Installer C-4826 and Handle C-4171
SPECIAL
TOOL
SPECIAL
TOOL

Fig.
7 Axle Shaft
Seal
Installation
(5) When the tool cont

(face),
the seal will be a
depth.
AXLE SHAFT INSTALL* (1) Lubricate the bearin
the axle shaft and engage gear. Use care to prevei damaging the axle shaft
(2) Insert the C-clip loi
(Fig. 4). Push the axle s
C-clip lock.
(3) Insert the pinion ge
Install through the thrust
Align the hole in the shaf
Install the lock screw wit
Tighten the screw to 11 Is
3).

(4) Clean the cover anc
Refer to the Drain and Re
(5) Install the brake drv
(6) Install the wheel an
Tire Installation within th
cle.

(7) Raise or lower the
level.
(8) Remove the fill hole
housing with lubricant. I chart for the type and th
hole plug.
(9) Lower the vehicle. T
correct operation.

PINION
SEAL REPLACE!!

CAUTION:
The following

so
the correct pinion bea

tained.
If not completely f
failure
of the rear axle.
REMOVAL (1) Raise and support tr
(2) Mark the U-joint, pi]
for reference.
(3) Disconnect the drh
yoke. Secure the drive sha
prevent damage to the re*
(4) Remove the rear w
drums to prevent any dr
false bearing preload torq
(5) Use a Newton-mete
wrench to measure the p
tate the pinion shaft sev( wrench. Note the indicate moved through several re' (13) Install the brake drums.
(14) Install the wheels. Lower
(15) Adjust hoist so vehicle k
Check the differential housing h
essary, add sufficient amount.

COMPLETE AXLE REMOVAL/IN!
It is not necessary to remov
from the vehicle for routine or d
the differential housing or axle aged, the complete axle can 1
stalled.
REMOVAL (1) Raise the vehicle to a <
height that will permit support t at the front of the rear springs. (2) Block the brake pedal in tl
position with a wooden block. (3) Remove the rear wheels. '.
brake drum retaining clips oi
(4) Disconnect the brake flui
the wheel cylinders. Cap the fit of brake fluid.
(5) Remove the vent hose froi

pie.

(6) Remove the brake tee be
the brake fluid tubes from the c (7) Disconnect the parking bn
U-joint, pinion yoke, and pinion
Mark the U-joint, pinion yol
for reference. (8) Disconnect the drive she
yoke. Secure the drive shaft in a prevent damage to the rear U-jc
(9) Remove the shock absorl
nuts and bolts. Remove the reai
the U-bolts and the spring brad
(10) Remove the complete axL
(11) Wash and clean the outei
ing and tubes. Use an appropri; and dry the surface with comprc

INSTALLATION
(1) Position the rear axle sj
spring center bolts.
(2) Install the spring U-bolts
absorber lower bolts. Tighten tl
fled torque.
(3) Connect the parking brake
(4) Connect the brake fluid
wheel cylinders. Bleed and adjui (5) Align the installation refer
the drive shaft yoke to the pinii U-joint clamp bolts to 19-23 N
torque.
(6) Install the rear wheels. Ti|
correct tightening sequence.

REAR SUSPENSION
ANi
AXLE
3 - 17
(3) Eliminate any side play in the differential case.
Attach Dial Indicator to Pilot stud C-3288-B. Place
the indicator plunger at a right angle (90°) to the ring gear (Fig. 11). The plunger should exert a slight
force against the gear face.

DIAL

INDICATOR

Fig.
11
Ring
Gear
Runout
Measurement
(4) Measure the runout by turning the ring gear
several complete revolutions. Observe the dial indica­
tor pointer. Mark the ring gear and the differential
case at the areas of maximum runout. The ring gear
runout should not exceed 0.005 inch (0.13 mm). If the
runout exceeds 0.005 inch (0.13 mm), a damaged
dif­

ferential case could be the cause.
The marking on the differential case will be
very useful later during the differential case
runout. Remove the rear wheel anti-lock (RWAL) sensor.
(5) Mark the differential housing and the differen­
tial bearing caps for installation reference (Fig. 12).
(6) Remove the bearing threaded adjuster lock
from each bearing cap. Loosen the bolts, but do not
remove the bearing caps.
(7) Loosen the threaded adjusters with Wrench
C-4164 (Fig. 13).
(8) Hold the differential case in place. Remove the
bearing caps (Fig. 14), adjusters and the differential
case.

Each differential bearing cup and threaded
adjuster must be kept with their respective bear­
ing.

PINION
GEAR
SHAFT
REMOVAL
(1) Remove the pinion gear nut and washer. Use
Puller C-452 and Wrench C-3281 to remove the pin­
ion gear yoke.
Fig.
12
Housing
&
Caps
Marked For
Installation

Reference
Fig.
13 Threaded Adjuster Tool

Fig.
14
Differential
Bearing Cap
Removed

(2) Use Puller C-748 to remove the pinion seal.
Discard the seal. (3) Force the pinion gear out the front bearing to