DODGE RAM 2003 Service Repair Manual

(7) Install pinion into the housing and place front
pinion bearing onto the pinion shaft. Draw the pinion
shaft into the front bearing with Installer 8982 (Fig.
52).
(8) Installnewpinion seal (Fig. 53) with Installer
8882 and Handle C-4171.
(9) Apply a light coat of teflon sealant to the pin-
ion flange splines.
(10) Hold pinion and lightly tap the pinion flange
onto the pinion shaft, until a few threads are show-
ing.
(11) Install pinion flange washer andnewpinion
nut.
(12) Hold pinion flange with Flange Wrench 8979
and tighten pinion nut until end play is taken up.
(13) Rotate pinion several times to seat bearings.
(14) Measure pinion rotating torque with an inch
pound torque wrench (Fig. 54). Tighten pinion nut in
small increments until pinion rotating torque is:²New Pinion Bearings:1.7-2.8 N´m (15-25 in.
lbs.)
²Original Pinion Bearings:1.1-2.2 N´m (10-20
in. lbs.)
(15) Rotate pinion several times then verify pinion
rotating torque again.
(16) Position the ring gear on differential case and
start twonewring gear bolts.
(17) Install the rest of thenewring gear bolts and
tighten them alternately to seat the ring gear.
(18) Torque ring gear bolts to 140 N´m (103 ft.
lbs.).
(19) Install differential in housing.
(20) Measure final rotating torque with an inch
pound torque wrench. The final pinion rotating
torque plus differential case bearing preload is:
²New Bearings:3.4-5.6 N´m (30-50 in. lbs.)
²Original Bearings:2.8-5.1 N´m (25-45 in. lbs.)
(21) Install axle shafts.
(22) Verify ring gear backlash and gear contact
pattern.
(23) Install the propeller shaft with the reference
marks aligned.
(24) Install differential cover with gasket and
tighten to 40 N´m (30 ft. lbs.).
(25) Fill differential with fluid and tighten fill plug
to 32 N´m (24 ft. lbs.).
Fig. 52 PINION GEAR INSTALLER
1 - INSTALLER
2 - DIFFERENTIAL HOUSING
Fig. 53 PINION SEAL INSTALLER
1 - HANDLE
2 - INSTALLER
Fig. 54 PINION ROTATING TORQUE
1 - PINION FLANGE
2 - TORQUE WRENCH
3 - 68 FRONT AXLE - 9 1/4 AADR
PINION GEAR/RING GEAR (Continued)

REAR AXLE-91/4
TABLE OF CONTENTS
page page
REAR AXLE-91/4
DESCRIPTION.........................69
OPERATION...........................69
DIAGNOSIS AND TESTING................69
REMOVAL.............................74
INSTALLATION.........................74
ADJUSTMENTS........................74
SPECIFICATIONS.......................79
SPECIAL TOOLS.......................80
AXLE SHAFTS
REMOVAL.............................83
INSTALLATION.........................83
AXLE SHAFT SEALS
REMOVAL.............................84
INSTALLATION.........................84
AXLE BEARINGS
REMOVAL.............................84
INSTALLATION.........................84
PINION SEAL
REMOVAL.............................85INSTALLATION.........................85
DIFFERENTIAL
DESCRIPTION.........................86
OPERATION...........................86
REMOVAL.............................86
DISASSEMBLY.........................88
ASSEMBLY............................88
INSTALLATION.........................88
DIFFERENTIAL-TRAC-LOK
DESCRIPTION.........................89
OPERATION...........................89
DIAGNOSIS AND TESTING................89
DISASSEMBLY.........................90
ASSEMBLY............................92
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................93
INSTALLATION.........................94
PINION GEAR/RING GEAR/TONE RING
REMOVAL.............................94
INSTALLATION.........................96
REAR AXLE-91/4
DESCRIPTION
The axle consist of a cast iron center section with
axle tubes extending from either side. The tubes are
pressed into and welded to the differential housing to
form a one-piece axle housing (Fig. 1). The axles are
equipped with semi-floating axle shafts, meaning
vehicle loads are supported by the axle shaft and
bearings. The axle shafts are retained by C-locks in
the differential side gears.
OPERATION
The axle receives power from the propeller shaft.
The propeller shaft is connected to the pinion gear
which rotates the differential through the gear mesh
with the ring gear bolted to the differential case. The
engine power is transmitted to the axle shafts
through the pinion mate and side gears. The side
gears are splined to the axle shafts.
DIAGNOSIS AND TESTING
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, toothcontact, worn/damaged gears, or the carrier housing
not having the proper offset and squareness.
Gear noise usually happens at a specific speed
range. The noise can also occur during a specific type
of driving condition. These conditions are accelera-
tion, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by
driving the vehicle at least 5 miles and then acceler-
ate 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:
²Check for insufficient lubricant.
²Incorrect ring gear backlash.
²Gear damage.
Differential side gears and pinions can be checked
by turning the vehicle. They usually do not cause
noise during straight-ahead driving when the gears
are unloaded. The side gears are loaded during vehi-
cle turns. A worn pinion shaft can also cause a snap-
ping or a knocking noise.
BEARING NOISE
The axle shaft, differential and pinion bearings can
all produce noise when worn or damaged. Bearing
noise can be either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This
noise changes only with vehicle speed. Pinion bearing
DRREAR AXLE - 9 1/4 3 - 69

Fig. 1 9 1/4 AXLE
3 - 70 REAR AXLE-91/4DR
REAR AXLE - 9 1/4 (Continued)

noise will be higher pitched because it rotates at a
faster rate. Drive the vehicle and load the differen-
tial. If bearing noise occurs, the rear pinion bearing
is the source of the noise. If the bearing noise is
heard during a coast, the front pinion bearing is the
source.
Worn or damaged differential bearings usually pro-
duce a low pitch noise. Differential bearing noise is
similar to pinion bearing noise. The pitch of differen-
tial 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
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 shaft bore will also cause low speed knock.
VIBRATION
Vibration at the rear of the vehicle is usually
caused by a:
²Damaged drive shaft.
²Missing drive shaft balance weight(s).
²Worn or out-of-balance wheels.
²Loose wheel lug nuts.
²Worn U-joint(s).²Loose/broken springs.
²Damaged axle shaft bearing(s).
²Loose pinion gear nut.
²Excessive pinion yoke run out.
²Bent axle shaft(s).
Check for loose or damaged front-end components
or engine/transmission mounts. These components
can contribute to what appears to be a rearend vibra-
tion. Do not overlook engine accessories, brackets
and drive belts.
NOTE: All driveline components should be exam-
ined before starting any repair.
DRIVELINE SNAP
A snap or clunk noise when the vehicle is shifted
into gear (or the clutch engaged), can be caused by:
²High engine idle speed.
²Transmission shift operation.
²Loose engine/transmission/transfer case mounts.
²Worn U-joints.
²Loose spring mounts.
²Loose pinion gear nut and yoke.
²Excessive ring gear backlash.
²Excessive side gear to case clearance.
The source of a snap or a clunk noise can be deter-
mined with the assistance of a helper. Raise the vehi-
cle 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.
1 - HUB
2 - AXLE SHAFT
3 - VENT FITTING
4 - DIFFERENTIAL HOUSING
5 - CUP
6 - FRONT PINION BEARING CONE
7 - NUT
8 - WASHER
9 - COMPANION FLANGE
10 - SEAL
11 - AXLE SHAFT
12 - HUB
13 - STUD
14 - BEARING CUP
15 - REAR PINION BEARING CONE
16 - DIFFERENTIAL BEARING
17 - ADJUSTER
18 - LOCK
19 - BOLT
20 - BEARING CAP
21 - CAP BOLT
22 - BEARING CUP
23 - THRUST WASHER
24 - SIDE GEAR
25 - C-LOCK
26 - DIFFERENTIAL POSITIONS
27 - THRUST WASHER
28 - COVER29 - PLUG
30 - COVER BOLT
31 - WASHER
32 - CLIP
33 - SIDE GEAR
34 - THRUST WASHER
35 - DIFFERENTIAL BEARING CONE
36 - C-LOCK
37 - BOLT
38 - LOCK
39 - BEARING CUP
40 - ADJUSTER
41 - BEARING CUP
42 - BOLT
43 - PINION MATE SHAFT
44 - EXCITER RING
45 - DIFFERENTIAL CASE
46 - RING GEAR BOLT
47 - RING GEAR
48 - PINION
49 - PINION GEAR DEPTH SHIM
50 - PRELOAD COLLAPSIBLE SPACER
51 - SEAL
52 - AXLE SHAFT BEARING
53 - AXLE SHAFT TUBE
54 - AXLE TUBE
55 - AXLE SHAFT BEARING
56 - SEAL
DRREAR AXLE - 9 1/4 3 - 71
REAR AXLE - 9 1/4 (Continued)

DIAGNOSTIC CHART
Condition Possible Causes Correction
Wheel Noise 1. Wheel loose. 1. Tighten loose nuts.
2. Faulty, brinelled wheel bearing. 2. Replace bearing.
Axle Shaft Noise 1. Misaligned axle tube. 1. Inspect axle tube alignment.
Correct as necessary.
2. Bent or sprung axle shaft. 2. Inspect and correct as necessary.
Axle Shaft Broke 1. Misaligned axle tube. 1. Replace the broken shaft after
correcting tube mis-alignment.
2 Vehicle overloaded. 2. Replace broken shaft and avoid
excessive weight on vehicle.
3. Erratic clutch operation. 3. Replace broken shaft and avoid
or correct erratic clutch operation.
4. Grabbing clutch. 4. Replace broken shaft and inspect
and repair clutch as necessary.
Differential Cracked 1. Improper adjustment of the
differential bearings.1. Replace case and inspect gears
and bearings for further damage.
Set differential bearing pre-load
properly.
2. Excessive ring gear backlash. 2. Replace case and inspect gears
and bearings for further damage.
Set ring gear backlash properly.
3. Vehicle overloaded. 3. Replace case and inspect gears
and bearings for further damage.
Avoid excessive vehicle weight.
4. Erratic clutch operation. 4. Replace case and inspect gears
and bearings for further damage.
Avoid erratic use of clutch.
Differential Gears Scored 1. Insufficient lubrication. 1. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
2. Improper grade of lubricant. 2. Replace scored gears. Fill
differential with the correct fluid type
and quantity.
3. Excessive spinning of one
wheel/tire.3. Replace scored gears. Inspect all
gears, pinion bores, and shaft for
damage. Service as necessary.
3 - 72 REAR AXLE-91/4DR
REAR AXLE - 9 1/4 (Continued)

Condition Possible Causes Correction
Loss Of Lubricant 1. Lubricant level too high. 1. Drain lubricant to the correct
level.
2. Worn axle shaft seals. 2. Replace seals.
3. Cracked differential housing. 3. Repair as necessary.
4. Worn pinion seal. 4. Replace seal.
5. Worn/scored yoke. 5. Replace yoke and seal.
6. Axle cover not properly sealed. 6. Remove, clean, and re-seal
cover.
Axle Overheating 1. Lubricant level low. 1. Fill differential to correct level.
2. Improper grade of lubricant. 2. Fill differential with the correct
fluid type and quantity.
3. Bearing pre-loads too high. 3. Re-adjust bearing pre-loads.
4. Insufficient ring gear backlash. 4. Re-adjust ring gear backlash.
Gear Teeth Broke 1. Overloading. 1. Replace gears. Examine other
gears and bearings for possible
damage.
2. Erratic clutch operation. 2. Replace gears and examine the
remaining parts for damage. Avoid
erratic clutch operation.
3. Ice-spotted pavement. 3. Replace gears and examine
remaining parts for damage.
4. Improper adjustments. 4. Replace gears and examine
remaining parts for damage. Ensure
ring gear backlash is correct.
Axle Noise 1. Insufficient lubricant. 1. Fill differential with the correct
fluid type and quantity.
2. Improper ring gear and pinion
adjustment.2. Check ring gear and pinion
contact pattern. Adjust backlash or
pinion depth.
3. Unmatched ring gear and pinion. 3. Replace gears with a matched
ring gear and pinion.
4. Worn teeth on ring gear and/or
pinion.4. Replace ring gear and pinion.
5. Loose pinion bearings. 5. Adjust pinion bearing pre-load.
6. Loose differential bearings. 6. Adjust differential bearing
pre-load.
7. Mis-aligned or sprung ring gear. 7. Measure ring gear run-out.
Replace components as necessary.
8. Loose differential bearing cap
bolts.8. Inspect differential components
and replace as necessary. Ensure
that the bearing caps are torqued
tot he proper specification.
9. Housing not machined properly. 9. Replace housing.
DRREAR AXLE - 9 1/4 3 - 73
REAR AXLE - 9 1/4 (Continued)

REMOVAL
(1) Raise and support the vehicle.
(2) Position a lifting device under the axle.
(3) Secure axle to device.
(4) Remove wheels and tires assemblies.
(5) Remove RWAL sensor from the differential
housing.
(6) Remove brake hose at the axle junction block.
(7) Disconnect parking brake cables and cable
brackets.
(8) Remove brake calipers and rotors.
(9) Remove axle vent hose.
(10) Mark propeller shaft and companion flange
for installation alignment reference.
(11) Remove propeller shaft.
(12) Remove shock absorbers from axle.
(13) Remove U-bolets from axle.
(14) Separate the axle from the vehicle.
INSTALLATION
(1) Raise axle with lifting device and align to the
leaf spring centering bolts.
(2) Install axle U-bolts and tighten to 149 N´m
(110 ft. lbs.).
(3) Install shock absorbers to axle and tighten to
specification.
(4) Install the RWAL sensor to the differential
housing.
(5) Connect the parking brake cables and cable
brackets.
(6) Install brake rotors and calipers.
(7) Connect brake hose to the axle junction block.
(8) Install axle vent hose.
(9) Align propeller shaft and pinion companion
flange reference marks and tighten companion flange
bolts to 115 N´m (85 ft. lbs.).
(10) Install the wheels and tires.
(11) Fill differential to specifications.
(12) Remove lifting device from axle and lower the
vehicle.
ADJUSTMENTS
Ring gear and pinion are supplied as matched sets
only. The identifying numbers for the ring gear and
pinion are painted onto the pinion gear shaft (Fig. 2)
and the side of the ring gear. A plus (+) number,
minus (±) number or zero (0) along with the gear set
sequence number (01 to 99) is on each gear. This first
number is the amount (in thousandths of an inch)
the depth varies from the standard depth setting of a
pinion marked with a (0). The next two numbers are
the sequence number of the gear set. The standard
depth provides the best teeth contact pattern. Refer
to Backlash and Contact Pattern for additional infor-
mation.Compensation for pinion depth variance is
achieved with select shims. The shims are placed
behind the rear pinion bearing. (Fig. 3).
If a new gear set is being installed, note the depth
variance painted onto both the original and replace-
ment pinion. Add or subtract the thickness of the
original depth shims to compensate for the difference
in the depth variances. Refer to the Depth Variance
chart.
Note where Old and New Pinion Marking columns
intersect. Intersecting figure represents plus or
minus the amount needed.
Note the painted number on the shaft of the drive
pinion (±1, ±2, 0, +1, +2, etc.). The numbers repre-
Fig. 2 PINION ID NUMBER
1 - VARIANCE NUMBER
2 - SEQUENCE NUMBER
Fig. 3 ADJUSTMENT SHIM LOCATIONS
1 - DIFFERENTIAL HOUSING
2 - COLLAPSIBLE SPACER
3 - PINION BEARING
4 - PINION DEPTH SHIM
5 - PINION GEAR
6 - BEARING CUP
3 - 74 REAR AXLE-91/4DR
REAR AXLE - 9 1/4 (Continued)

sent thousands of an inch deviation from the stan-
dard. If the number is negative, add that value to the
required thickness of the depth shims. If the numberis positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.
PINION GEAR DEPTH VARIANCE
Original Pinion
Gear Depth
VarianceReplacement Pinion Gear Depth Variance
24232221 0 +1 +2 +3 +4
+4+0.008 +0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0
+3+0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.001
+2+0.006 +0.005 +0.004 +0.003 +0.002 +0.001 020.00120.002
+1+0.005 +0.004 +0.003 +0.002 +0.001 020.00120.00220.003
0+0.004 +0.003 +0.002 +0.001 020.00120.00220.00320.004
21+0.003 +0.002 +0.001 020.00120.00220.00320.00420.005
22+0.002 +0.001 020.00120.00220.00320.00420.00520.006
23+0.001 020.00120.00220.00320.00420.00520.00620.007
24020.00120.00220.00320.00420.00520.00620.00720.008
PINION DEPTH MEASUREMENT
Measurements are taken with pinion bearing cups
and pinion bearings installed in the housing. Take
measurements with Pinion Gauge Set and Dial Indi-
cator C-3339 (Fig. 4).
(1) Assemble Pinion Height Block 6739, Pinion
Block 8542 and rear pinion bearing onto Screw 6741
(Fig. 4).
(2) Insert assembled height gauge components,
rear bearing, and screw into the housing through
pinion bearing cups (Fig. 5).
(3) Install front pinion bearing and Cone-Nut 6740
hand tight (Fig. 4).
(4) Place Arbor Disc 8541 on Arbor D-115-3 in posi-
tion in the housing side bearing cradles (Fig. 6).
Install differential bearing caps on arbor discs and
tighten cap bolts to 41 N´m (30 ft. lbs.).
NOTE: Arbor Discs 8541 has different step diame-
ters to fit other axles. Choose proper step for axle
being serviced.
(5) Assemble Dial Indicator C-3339 into Scooter
Block D-115-2 and secure set screw.
(6) Place Scooter Block/Dial Indicator in position
in axle housing so dial probe and scooter block are
flush against the rearward surface of the pinion
height block (Fig. 4). Hold scooter block in place and
zero the dial indicator. Tighten dial indicator face
lock screw.
Fig. 4 PINION DEPTH GAUGE TOOLS
1 - DIAL INDICATOR
2 - ARBOR
3 - PINION HEIGHT BLOCK
4 - CONE
5 - SCREW
6 - PINION BLOCK
7 - SCOOTER BLOCK
8 - ARBOR DISC
DRREAR AXLE - 9 1/4 3 - 75
REAR AXLE - 9 1/4 (Continued)

(7) Slide the dial indicator probe across the gap
between the pinion height block and the arbor bar
with the scooter block against the pinion height block
(Fig. 7). Continue moving the dial probe to the crest
of the arbor bar and record the highest reading.
(8) Select a shim equal to the dial indicator read-
ing plus the drive pinion gear depth variance number
marked on the shaft of the pinion. For example, if
the depth variance is ±2, add +0.002 in. to the dial
indicator reading.
DIFFERENTIAL BEARING PRELOAD AND GEAR
BACKLASH
The following must be considered when adjusting
bearing preload and gear backlash:²The maximum ring gear backlash variation is
0.076 mm (0.003 in.).
²Mark the gears so the same teeth are meshed
during all backlash measurements.
²Maintain the torque while adjusting the bearing
preload and ring gear backlash.
²Excessive adjuster torque will introduce a high
bearing load and cause premature bearing failure.
Insufficient adjuster torque can result in excessive
differential case free-play and ring gear noise.
²Insufficient adjuster torque will not support the
ring gear correctly and can cause excessive differen-
tial case free-play and ring gear noise.
NOTE: The differential bearing cups will not always
immediately follow the threaded adjusters as they
are moved during adjustment. To ensure accurate
bearing cup responses to the adjustments:
²Maintain the gear teeth engaged (meshed) as
marked.
²The bearings must be seated by rapidly rotat-
ing the pinion gear a half turn back and forth.
²Do this five to ten times each time the threaded
adjusters are adjusted.
(1) Throught the axle tube use Wrench C-4164 to
adjust each threaded adjuster inward until the differ-
ential bearing free-play is eliminated. Allow some
ring gear backlash approximately 0.25 mm (0.01 in.)
between the ring and pinion gear. Seat the bearing
cups with the procedure described above.
(2) Install dial indicator and position the plunger
against the drive side of a ring gear tooth (Fig. 8).
Measure the backlash at 4 positions, 90 degrees
apart around the ring gear. Locate and mark the
area of minimum backlash.
Fig. 5 PINION HEIGHT BLOCK
1 - PINION BLOCK
2 - PINION HEIGHT BLOCK
Fig. 6 PINION DEPTH TOOLS
1 - ARBOR DISC
2 - PINION BLOCK
3 - ARBOR
4 - PINION HEIGHT BLOCK
Fig. 7 PINION GEAR DEPTH MEASUREMENT
1 - ARBOR
2 - SCOOTER BLOCK
3 - DIAL INDICATOR
3 - 76 REAR AXLE-91/4DR
REAR AXLE - 9 1/4 (Continued)

(3) Rotate the ring gear to the position of the least
backlash. Mark the gear so that all future backlash
measurements will be taken with the same gear
teeth meshed.
(4) Loosen the right-side, tighten the left-side
threaded adjuster. Obtain backlash of 0.076 to 0.102
mm (0.003-0.004 in.) with each adjuster tightened to
14 N´m (10 ft. lbs.). Seat the bearing cups with the
procedure described above.
(5) Tighten the differential bearing cap bolts 136
N´m (100 ft. lbs.).
(6) Tighten the right-side threaded adjuster to 102
N´m (75 ft. lbs.). Seat the bearing cups with the pro-
cedure described above. Continue to tighten the
right-side adjuster and seat bearing cups until the
torque remains constant at 102 N´m (75 ft. lbs.)
(7) Measure the ring gear backlash. The range of
backlash is 0.15 to 0.203 mm (0.006 to 0.008 in.).
(8) Continue increasing the torque at the right-
side threaded adjuster until the specified backlash is
obtained.
NOTE: The left-side threaded adjuster torque
should have approximately 102 N´m (75 ft. lbs.). If
the torque is considerably less, the complete
adjustment procedure must be repeated.
(9) Tighten the left-side threaded adjuster until
102 N´m (75 ft. lbs.) torque is indicated. Seat the
bearing rollers with the procedure described above.
Do this until the torque remains constant.
(10) Install the threaded adjuster locks and
tighten the lock screws to 10 N´m (90 in. lbs.).GEAR CONTACT PATTERN
Gear tooth contact pattern is used to verify the cor-
rect running position of the ring and pinion gears.
This will produce low noise and long gear life. Gears
which are not positioned properly may be noisy and
have shorten gear life.
(1) Wipe clean each tooth of the ring gear.
(2) Apply gear marking compound to all of the ring
gear teeth.
(3) Verify bearing cap bolts are torque specifica-
tion.
(4) Apply parking brakes lightly to create at 14
N´m (10 ft. lbs.) pinion rotating torque.
(5) Rotate the pinion/pinion yoke 4 full revolutions
in each directions.
(6) Read gear tooth contact pattern:
²Gear contact pattern is correct (Fig. 9). Backlash
and pinion depth is correct.
²Ring gear too far away from pinion gear (Fig.
10). Decrease backlash, by moving the ring closer to
the pinion gear using the adjusters.
Fig. 8 RING GEAR BACKLASH
1 - DIAL INDICATOR
2 - RING GEAR
3 - EXCITER RING
Fig. 9 CORRECT CONTACT PATTERN
Fig. 10 INCORRECT BACKLASH
1 - COAST SIDE TOE
2 - DRIVE SIDE HEEL
DRREAR AXLE - 9 1/4 3 - 77
REAR AXLE - 9 1/4 (Continued)