wheel DODGE RAM 2001 Service Manual PDF

AXLE VACUUM MOTOR
DESCRIPTION
The disconnect axle control system consists of:
²Shift motor.
²Indicator switch.
²Vacuum switch.
²Vacuum harness (Fig. 27).
OPERATION
The shift motor receives a vacuum signal from the
switch mounted on the transfer case when the vehi-
cle operator wants to switch from two wheel drive
mode to four wheel drive mode, or vice versa. Whenthis signal is received, the shift motor begins to move
the shift fork and collar within the axle housing. In
the four wheel drive mode, the shift collar connects
the axle intermediate shaft to the axle shaft to sup-
ply engine power to both front wheels. In two wheel
drive mode, the shift collar is disengaged from the
intermediate shaft and the intermediate shaft is
allowed to free-spin. When the two shafts are disen-
gaged, the load on the engine is reduced, thereby pro-
viding better fuel economy and road handling.
Fig. 26 Seal Installation
1 - DIFFERENTIAL HOUSING
2 - POSITION FOR OPEN-END WRENCH
3 - SPECIAL TOOL 5041-2
4 - SPECIAL TOOL 8417
5 - SEAL
6 - SPECIAL TOOL 8411
Fig. 27 Vacuum Control System
1 - CHECK VALVE
2 - CONTROL SWITCH ON TRANSFER CASE
3 - AIR VENT FILTER
4 - AXLE SHIFT MOTOR
5 - INDICATOR SWITCH
3 - 62 FRONT AXLE - 248FBIBR/BE
AXLE SHAFT SEALS (Continued)

(5) Position the yoke with the sockets in a vise
(Fig. 31).
(6) Tighten the vise jaws to force the bearing cap
into the larger socket (receiver).
(7) Release the vise jaws. Remove the sockets and
bearing cap that was partially forced out of the yoke.
(8) Repeat the above procedure for the remaining
bearing cap and remove spider from the propeller
shaft yoke.
INSTALLATION
(1) Pack the bearing caps 1/3 full of wheel bearing
lubricant. Apply extreme pressure (EP), lithium-base
lubricant to aid in installation.
(2) Position the spider in the yoke. Insert the seals
and bearings. Tap the bearing caps into the yoke
bores far enough to hold the spider in position.
(3) Place the socket (driver) against one bearing
cap. Position the yoke with the socket in a vise.
(4) Tighten the vise to force the bearing caps into
the yoke. Force the caps enough to install the retain-
ing clips.
(5) Install the bearing cap retaining clips.
(6) Install axle shaft.
PINION SEAL
REMOVAL
(1) Raise and support the vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove brake calipers and rotors
(4) Mark the propeller shaft and pinion yoke for
installation reference.
(5) Remove the propeller shaft from the yoke.
(6) Rotate the pinion gear three or four times.
(7) Measure the amount of torque necessary to
rotate the pinion gear with a (in. lbs.) dial-type
torque wrench. Record the torque reading for instal-
lation reference.
(8) Remove the pinion yoke nut and washer. Use
Remover C-452 and Wrench C-3281 to remove the
pinion yoke (Fig. 32).
(9) Use suitable pry tool or slide hammer mounted
screw to remove the pinion shaft seal.
INSTALLATION
(1) Apply a light coating of gear lubricant on the
lip of pinion seal. Install seal with an appropriate
installer (Fig. 33).
(2) Install yoke on the pinion gear with Installer
C-3718 and Holder 6719 (Fig. 34).
CAUTION: Do not exceed the minimum tightening
torque when installing the pinion yoke retaining
nut. Damage to collapsible spacer or bearings may
result.
Fig. 30 Axle Shaft Outer UÐJoint
1 - SHAFT YOKE
2 - BEARING CAP
3 - SNAP RINGS
4 - BEARING CAP
5 - SPINDLE YOKE
6 - BEARING
7 - BEARING CAP
8 - SNAP RINGS
9 - BEARING CAP
Fig. 31 Yoke Bearing Cap
1 - LARGE-DIAMETER SOCKET WRENCH
2 - VISE
3 - SMALL-DIAMETER SOCKET WRENCH
3 - 66 FRONT AXLE - 248FBIBR/BE
SINGLE CARDAN UNIVERSAL JOINTS (Continued)

(3) Install a new nut on the pinion gear. Tighten
the nut only enough to remove the shaft end play.
(4) Rotate the pinion shaft using an inch pound
torque wrench. Rotating torque should be equal to
the reading recorded during removal, plus an addi-
tional 0.56 N´m (5 in. lbs.) (Fig. 35).
(5) If the rotating torque is to low, use Holder 6719
to hold the pinion yoke (Fig. 36), and tighten the pin-
ion shaft nut in 6.8 N´m (5 ft. lbs.) until proper rotat-
ing torque is achieved.
(6) Align the installation reference marks and
attach the propeller shaft to the yoke.
(7) Check and add lubricant to axle, if necessary.
Refer to Lubricant Specifications in this section for
lubricant requirements.
(8) Install brake rotors and calipers.(9) Install wheel and tire assemblies.
(10) Lower the vehicle.
Fig. 32 Pinion
1 - YOKE HOLDER
2 - YOKE
3 - YOKE PULLER
Fig. 33 Pinion Seal Installation
1 - SPECIAL TOOL CÐ4171
2 - SPECIAL TOOL CÐ8108
Fig. 34 Install Pinion Yoke
1 - YOKE INSTALLER
2 - YOKE HOLDER
Fig. 35 Check Pinion Rotation
1 - PINION YOKE
2 - INCH POUND TORQUE WRENCH
BR/BEFRONT AXLE - 248FBI 3 - 67
PINION SEAL (Continued)

REAR AXLE-91/4
TABLE OF CONTENTS
page page
REAR AXLE-91/4
DESCRIPTION...........................77
OPERATION.............................77
DIAGNOSIS AND TESTING.................80
AXLE................................80
REMOVAL..............................83
INSTALLATION...........................84
ADJUSTMENTS..........................84
SPECIFICATIONS........................90
SPECIAL TOOLS.........................90
AXLE SHAFTS
REMOVAL..............................93
INSTALLATION...........................93
AXLE SHAFT SEALS
REMOVAL..............................94
INSTALLATION...........................94
AXLE BEARINGS
REMOVAL..............................94
INSTALLATION...........................95PINION SEAL
REMOVAL..............................95
INSTALLATION...........................95
DIFFERENTIAL
REMOVAL..............................96
DISASSEMBLY...........................97
ASSEMBLY.............................98
INSTALLATION...........................98
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING.................98
TRAC-LOK............................98
DISASSEMBLY...........................99
ASSEMBLY............................101
DIFFERENTIAL CASE BEARINGS
REMOVAL.............................103
INSTALLATION..........................103
PINION GEAR/RING GEAR/TONE RING
REMOVAL.............................103
INSTALLATION..........................105
REAR AXLE-91/4
DESCRIPTION
The 9 1/4 Inch axle housings 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 have a vent hose to relieve internal pres-
sure caused by lubricant vaporization and internal
expansion.
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.
The removable, stamped steel cover provides a
means for inspection and service without removing
the complete axle from the vehicle.
The axle has a date tag and a gear ratio tag. The
tags are attached to the differential housing by a
cover bolt.
The rear wheel anti-lock (RWAL) brake speed sen-
sor is attached to the top, forward exterior of the dif-
ferential housing. A seal is located between the
sensor and the wire harness connector. The seal must
be in place when the wire connector is connected to
the sensor. The RWAL brake exciter ring is press-fit-ted onto the differential case against the ring gear
flange.
The differential case is a one-piece design. The dif-
ferential pinion shaft is retained with a screw. Differ-
ential bearing preload and ring gear backlash are set
and maintained by threaded adjusters at the outside
of the differential housing. Pinion bearing preload is
set and maintained by the use of a collapsible spacer.
Axles equipped with a Trac-Lokydifferential are
optional. A differential has a one-piece differential
case, and the same internal components as a stan-
dard differential, plus two clutch disc packs.
AXLE IDENTIFICATION
The axle differential cover can be used for identifi-
cation of the axle (Fig. 2). A ratio tag is attached to
the top of the differential cover.
OPERATION
The axle receives power from the transmission/
transfer case through the rear propeller shaft. The
rear propeller shaft is connected to the drive pinion
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 differential pinions and side gears. The
side gears are splined to the axle shafts.
BR/BEREAR AXLE - 9 1/4 3 - 77

STANDARD DIFFERENTIAL
During straight-ahead driving, the differential pin-
ion gears do not rotate on the pinion shaft. Thisoccurs because input torque applied to the gears is
divided and distributed equally between the two side
gears. As a result, the differential pinion gears
revolve with the pinion shaft but do not rotate
around it (Fig. 3).
1 - HUB
2 - AXLE SHAFT
3 - VENT FITTING
4 - DIFFERENTIAL HOUSING
5 - CUP
6 - PINION FRONT BEARING CONE
7 - NUT
8 - WASHER
9 - COMPANION FLANGE
10 - SEAL
11 - AXLE SHAFT
12 - HUB
13 - STUD
14 - BEARING CUP
15 - PINION REAR 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 - COVER
29 - PLUG30 - 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 - BEARING PRELOAD COLLAPSIBLE SPACER
51 - SEAL
52 - AXLE SHAFT BEARING
53 - AXLE SHAFT TUBE
54 - AXLE TUBE
55 - AXLE SHAFT BEARING
56 - SEAL
Fig. 2 Differential Cover 9 1/4 Inch Axle
1 - DIFFERENTIAL COVER
2 - RATIO TAG
3 - PUSH-IN FILL PLUGFig. 3 Differential Operation - Straight Ahead Driving
1 - IN STRAIGHT AHEAD DRIVING EACH WHEEL ROTATES AT
100% OF CASE SPEED
2 - DIFFERENTIAL PINION GEAR
3 - SIDE GEAR
4 - DIFFERENTIAL PINIONS ROTATE WITH CASE
BR/BEREAR AXLE - 9 1/4 3 - 79
REAR AXLE - 9 1/4 (Continued)

When turning corners, the outside wheel must
travel a greater distance than the inside wheel to
complete a turn. The difference must be compensated
for to prevent the tires from scuffing and skidding
through turns. To accomplish this, the differential
allows the axle shafts to turn at unequal speeds (Fig.
4). In this instance, the input torque applied to the
differential pinions is not divided equally. The differ-
ential pinions now rotate around the pinion shaft in
opposite directions. This allows the side gears and
axle shaft attached to the outside wheel to rotate at
a faster speed.
TRAC-LOKYDIFFERENTIAL
The Trac-lokyclutches are engaged by two concur-
rent forces. The first being the preload force exerted
through Belleville spring washers within the clutch
packs. The second is the separating forces generated
by the side gears as torque is applied through the
ring gear (Fig. 5).
The Trac-lokydesign provides the differential
action needed for turning corners and for driving
straight ahead during periods of unequal traction.
When one wheel looses traction, the clutch packs
transfer additional torque to the wheel having the
most traction. Trac-lokydifferentials resist wheel
spin on bumpy roads and provide more pulling power
when one wheel looses traction. Pulling power is pro-
vided continuously until both wheels loose traction. If
both wheels slip due to unequal traction, Trac-loky
operation is normal. In extreme cases of differences
of traction, the wheel with the least traction may
spin.
DIAGNOSIS AND TESTING - AXLE
GEAR NOISE
Axle gear noise can be caused by insufficient lubri-
cant, incorrect backlash, incorrect pinion depth, tooth
contact, 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.
Fig. 4 Differential Operation - On Turns
1 - DIFFERENTIAL PINIONS ROTATE ON PINION SHAFTFig. 5 Trac-lokYLimited Slip Differential
1 - CASE
2 - RING GEAR
3 - DRIVE PINION
4 - DIFFERENTIAL PINION
5 - PINION SHAFT
6 - CLUTCH PACK
7 - SIDE GEAR
8 - CLUTCH PACK
3 - 80 REAR AXLE-91/4BR/BE
REAR AXLE - 9 1/4 (Continued)

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
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.
All driveline components should be examined
before starting any repair.
(Refer to 22 - TIRES/WHEELS - DIAGNOSIS AND
TESTING)
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.
BR/BEREAR AXLE - 9 1/4 3 - 81
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.
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.
3 - 82 REAR AXLE-91/4BR/BE
REAR AXLE - 9 1/4 (Continued)

Condition Possible Causes Correction
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.
REMOVAL
(1) Raise and support the vehicle.
(2) Position a suitable lifting device under the
axle.
(3) Secure axle to device.
(4) Remove the wheels and tires.
(5) Secure brake drums to the axle shaft.
(6) Remove the RWAL sensor from the differential
housing, if necessary. Refer to 5 Brakes for proce-
dures.
(7) Disconnect the brake hose at the axle junction
block. Do not disconnect the brake hydraulic lines at
the wheel cylinders. Refer to 5 Brakes for procedures.(8) Disconnect the parking brake cables and cable
brackets.
(9) Disconnect the vent hose from the axle shaft
tube.
(10) Mark the propeller shaft and companion
flange for installation alignment reference.
(11) Remove propeller shaft.
(12) Disconnect shock absorbers from axle.
(13) Remove the spring clamps and spring brack-
ets. Refer to 2 Suspension for procedures.
(14) Separate the axle from the vehicle.
BR/BEREAR AXLE - 9 1/4 3 - 83
REAR AXLE - 9 1/4 (Continued)

INSTALLATION
(1) Raise the axle with lifting device and align to
the leaf spring centering bolts.
(2) Install the spring clamps and spring brackets.
Refer to 2 Suspension for procedures.
(3) Install shock absorbers and tighten nuts to 82
N´m (60 ft. lbs.).
(4) Install the RWAL sensor to the differential
housing, if necessary. Refer to 5 Brakes for proce-
dures.
(5) Connect the parking brake cables and cable
brackets.
(6) Install the brake drums. Refer to 5 Brakes for
procedures.
(7) Connect the brake hose to the axle junction
block. Refer to 5 Brakes for procedures.
(8) Install axle vent hose.
(9) Align propeller shaft and pinion companion
flange reference marks. Install the companion flange
bolts. Tighten to 108 N´m (80 ft. lbs.).
(10) Install the wheels and tires.
(11) Add gear lubricant, if necessary. Refer to
Specifications for lubricant requirements.
(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 head (Fig. 6)
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. 7).
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-
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 number
is positive, subtract that value from the thickness of
the depth shim. If the number is 0 no change is nec-
essary.
Fig. 6 Pinion ID Number
1 - PRODUCTION NUMBER
2 - PINION GEAR DEPTH VARIANCE
3 - GEAR MATCHING NUMBER
Fig. 7 Adjustment Shim Locations
1 - AXLE HOUSING
2 - COLLAPSIBLE SPACER
3 - PINION BEARING
4 - PINION DEPTH SHIM
5 - DRIVE PINION GEAR
6 - BEARING CUP
3 - 84 REAR AXLE-91/4BR/BE
REAR AXLE - 9 1/4 (Continued)