change wheel DODGE RAM 2002 Service User Guide

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 issimilar 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.
Fig. 3 TRAC-LOK LIMITED SLIP DIFFERENTIAL
1 - CASE
2 - RING GEAR
3 - DRIVE PINION
4 - PINION GEAR
5 - MATE SHAFT
6 - CLUTCH PACK
7 - SIDE GEAR
8 - CLUTCH PACK
BR/BEREAR AXLE - 286RBI 3 - 109
REAR AXLE - 286RBI (Continued)

(12) Fill the differential with Mopar Hypoid Gear
Lubricant or equivalent to bottom of the fill plug
hole.
(13) Install fill hole plug and tighten to 34 N´m (25
ft. lbs.).
(14) Remove support and lower vehicle.
DIFFERENTIAL - TRAC-LOK
DIAGNOSIS AND TESTING - TRAC-LOKT
The most common problem is a chatter noise when
turning corners. Before removing a Trac-lokŸ unit
for repair, drain, flush and refill the axle with the
specified lubricant. A container of Mopar Trac-lokŸ
Lubricant (friction modifier) should be added after
repair service or during a lubricant change.
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. This
will correct the condition in most instances. If the
chatter persists, clutch damage could have occurred.
DIFFERENTIAL TEST
The differential can be tested without removing the
differential case by measuring rotating torque. Make
sure brakes are not dragging during this measure-
ment.
(1) Place blocks in front and rear of both front
wheels.
(2) Raise one rear wheel until it is completely off
the ground.
(3) Engine off, transmission in neutral, and park-
ing brake off.
(4) Remove wheel and bolt Special Tool 6790 or
equivalent tool to studs.
(5) Use torque wrench on special tool to rotate
wheel and read rotating torque.
(6) If rotating torque is less than 22 N´m (30 ft.
lbs.) or more than 271 N´m (200 ft. lbs.) on either
wheel the unit should be serviced.
DISASSEMBLY
The Trac-Loktdifferential on this axle has a one-
piece cross shaft and uses one dished disc, regular 5
disc and 7 plates.
NOTE: Pay attention to the clutch pack arrangement
during disassembly. Note the direction of the con-
cave and convex side of the plates and discs.
(1) Mark the ring gear half and cover half for
installation reference (Fig. 35).
(2) Remove case attaching bolts and remove the
button cover half (Fig. 36).
(3) Remove top clutch pack.
(4) Remove top side gear clutch ring.(5) Remove top side gear.
(6) Remove pinion mate gears and cross shaft.
(7) Remove the same parts listed above from the
ring gear flange half of the case. Keep these parts
Fig. 35 CASE MARKED
1 - REFERENCE MARKS
Fig. 36 COVER HALF REMOVAL
1 - CLUTCH PLATES
2 - BUTTON HALF
3 - FLANGE HALF
3 - 128 REAR AXLE - 286RBIBR/BE
DIFFERENTIAL (Continued)

SPONGY PEDAL
A spongy pedal is most often caused by air in the
system. However, thin brake drums or substandard
brake lines and hoses can also cause a spongy pedal.
The proper course of action is to bleed the system,
and replace thin drums and substandard quality
brake hoses if suspected.
HARD PEDAL OR HIGH PEDAL EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could
also be faulty.
PEDAL PULSATION
Pedal pulsation is caused by components that are
loose, or beyond tolerance limits.
The primary cause of pulsation are disc brake
rotors with excessive lateral runout or thickness vari-
ation, or out of round brake drums. Other causes are
loose wheel bearings or calipers and worn or dam-
aged tires.
NOTE: Some pedal pulsation may be felt during
ABS/EBD activation.
BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at one
wheel, all wheels, fronts only, or rears only.
Drag is a product of incomplete brake shoe release.
Drag can be minor or severe enough to overheat the
linings, rotors and drums.
Minor drag will usually cause slight surface char-
ring of the lining. It can also generate hard spots in
rotors and drums from the overheat-cool down pro-
cess. In most cases, the rotors, drums, wheels and
tires are quite warm to the touch after the vehicle is
stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and
drums to the point of replacement. The wheels, tires
and brake components will be extremely hot. In
severe cases, the lining may generate smoke as it
chars from overheating.
Common causes of brake drag are:
²Seized or improperly adjusted parking brake
cables
²Loose/worn wheel bearing
²Seized caliper or wheel cylinder piston
²Caliper binding on damaged or missing anti-rat-
tle clips or bushings
²Loose caliper mounting
²Drum brake shoes binding on worn/damaged
support plates
²Mis-assembled components²Long booster output rod
If brake drag occurs at all wheels, the problem
may be related to a blocked master cylinder return
port, or faulty power booster (binds-does not release).
BRAKE FADE
Brake fade is usually a product of overheating
caused by brake drag. However, brake overheating
and resulting fade can also be caused by riding the
brake pedal, making repeated high deceleration stops
in a short time span, or constant braking on steep
mountain roads. Refer to the Brake Drag information
in this section for causes.
BRAKE PULL
Front brake pull condition could result from:
²Contaminated lining in one caliper
²Seized caliper piston
²Binding caliper
²Loose caliper
²Damaged anti-rattle clips
²Improper brake shoes
²Damaged rotor
A worn, damaged wheel bearing or suspension
component are further causes of pull. A damaged
front tire (bruised, ply separation) can also cause
pull.
A common and frequently misdiagnosed pull condi-
tion is where direction of pull changes after a few
stops. The cause is a combination of brake drag fol-
lowed by fade at one of the brake units.
As the dragging brake overheats, efficiency is so
reduced that fade occurs. Since the opposite brake
unit is still functioning normally, its braking effect is
magnified. This causes pull to switch direction in
favor of the normally functioning brake unit.
An additional point when diagnosing a change in
pull condition concerns brake cool down. Remember
that pull will return to the original direction, if the
dragging brake unit is allowed to cool down (and is
not seriously damaged).
REAR BRAKE GRAB OR PULL
Rear grab or pull is usually caused by improperly
adjusted or seized parking brake cables, contami-
nated lining, bent or binding shoes and support
plates, or improperly assembled components. This is
particularly true when only one rear wheel is
involved. However, when both rear wheels are
affected, the master cylinder or proportioning valve
could be at fault.
BRAKES DO NOT HOLD AFTER DRIVING THROUGH DEEP
WATER PUDDLES
This condition is generally caused by water soaked
lining. If the lining is only wet, it can be dried by
driving with the brakes very lightly applied for a
5 - 6 BRAKES - BASEBR/BE
HYDRAULIC/MECHANICAL (Continued)

REMOVAL - FRONT
(1) Raise and support vehicle.
(2) Remove front wheel and tire assembly.
(3) Remove caliper brake hose bolt, washers and
hose (Fig. 8).
(4) Remove caliper mounting bolts.
(5) Tilt the top of the caliper up and remove it
from the adapter.
(6) Remove anti-rattle springs.
NOTE: Upper and lower anti-rattle springs are not
interchangeable.
DISASSEMBLY
(1) Drain the brake fluid from caliper.
(2) C-clamp a block of wood over one piston (Fig.
9).
(3) Take another piece of wood and pad it with
one-inch thickness of shop towels. Place this piece in
the outboard shoe side of the caliper in front of the
other piston. This will cushion and protect caliper
piston during removal (Fig. 10).
(4) To remove the caliper piston directshort
bursts of low pressure airwith a blow gun
through the caliper brake hose port. Use only enough
air pressure to ease the piston out.
Fig. 6 Lining Wear Compensation By Piston Seal
1 - PISTON
2 - CYLINDER BORE
3 - PISTON SEAL BRAKE PRESSURE OFF
4 - CALIPER HOUSING
5 - DUST BOOT
6 - PISTON SEAL BRAKE PRESSURE ON
Fig. 7 REAR CALIPER
1 - Banjo Bolt
2 - Caliper Pin Bolts
Fig. 8 Caliper
1 - WASHERS
2 - MOUNTING BOLTS
3 - HOSE BOLT
Fig. 9 C-Clamp One Piston
1 - BLOCK OF WOOD
2 - C-CLAMP
3 - CALIPER
BR/BEBRAKES - BASE 5 - 11
DISC BRAKE CALIPERS (Continued)

INSTALLATION - FRONT ± 2500
(1) On models with all-wheel antilock system
(ABS), check condition of tone wheel on hub/bearing.
If teeth on wheel are damaged, hub/bearing assembly
will have to be replaced (tone wheel is not serviced
separately).
(2) Install rotor onto the hub/bearing wheel studs.
(3) Install the caliper adapter assembly,(Refer to 5
- BRAKES/HYDRAULIC/MECHANICAL/DISC
BRAKE CALIPERS - INSTALLATION) and tighten
adapter bolts to:
²LD 1500: 176 N´m (130 ft lbs.)
²HD 2500: 285 N´m (210 ft lbs.)
(4) Install the wheel and tire assembly, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE) and lower vehicle.
(5) Apply brakes several times to seat brake shoes.
Be sure to obtain firm pedal before moving vehicle.
INSTALLATION - FRONT - 3500
(1) Position the rotor on the hub/bearing.
(2) Install the brake caliper adapter assembly
(Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/
DISC BRAKE CALIPERS - INSTALLATION) and
tighten adapter bolts to 285 N´m (210 ft. lbs).
(3) Install the wheel and tire assemblies, (Refer to
22 - TIRES/WHEELS/WHEELS - STANDARD PRO-
CEDURE).
(4) Remove the support and lower the vehicle.
(5) Apply brakes several times to seat brake shoes
and caliper piston. Do not move vehicle until firm
brake pedal is obtained.
BRAKE PADS/SHOES
REMOVAL
REMOVAL - REAR
(1) Raise and support the vehicle.
(2) Remove the rear wheel and tire assemblies.
(3) Compress the caliper.
(4) Remove caliper mounting bolts
NOTE: Do not allow brake hose to support caliper
assembly.
(5) Remove the caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- REMOVAL) and then tilt the top up and off the cal-
iper adapter (Fig. 37).
(6) Remove inboard brake shoe from the caliper
adapter (Fig. 38).
(7) Remove outboard brake shoe from caliper
adapter (Fig. 39).(8) Remove the anti-rattle springs from the caliper
adapter (Fig. 40) and (Fig. 41).
NOTE: Anti-rattle springs are not interchangeable.
Fig. 37 ROTOR / PADS/ CALIPER
1 - ROTOR
2 - BRAKE SHOES
3 - DISC BRAKE CALIPER
Fig. 38 Inboard Brake Shoe
1 - INBOARD SHOE
2 - CALIPER ADAPTER
BR/BEBRAKES - BASE 5 - 23
ROTORS (Continued)

REMOVAL - FRONT
(1) Raise and support vehicle.
(2) Remove front wheel and tire assemblies.
(3) Compress caliper.
(4) Remove caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- REMOVAL).
(5) Remove caliper by tilting the top up and off the
caliper adapter (Fig. 42).NOTE: Do not allow brake hose to support caliper
assembly.
(6) Remove inboard brake shoe from the caliper
adapter (Fig. 43).
(7) Remove outboard brake shoe from caliper
adapter (Fig. 44).
(8) Remove the anti-rattle springs from the caliper
adapter (Fig. 45) and (Fig. 46).
NOTE: Anti-rattle springs are not interchangeable.
Fig. 39 Outboard Brake Shoe
1 - OUTBOARD SHOE
2 - CALIPER ADAPTER
Fig. 40 Top Anti-Rattle Spring
1 - CALIPER ADAPTER
2 - ANTI-RATTLE SPRING
Fig. 41 Bottom Anti-Rattle Spring
1 - ANTI-RATTLE SPRING
2 - CALIPER ADAPTER
Fig. 42 Caliper
1 - CALIPER
2 - CALIPER ADAPTER
5 - 24 BRAKES - BASEBR/BE
BRAKE PADS/SHOES (Continued)

(7) Install caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION) (Refer to 5 - BRAKES/HYDRAU-
LIC/MECHANICAL/DISC BRAKE CALIPERS -
INSTALLATION).
(8) Install wheel and tire assemblies and lower
vehicle, (Refer to 22 - TIRES/WHEELS/WHEELS -
STANDARD PROCEDURE).
(9) Apply brakes several times to seat caliper pis-
tons and brake shoes and obtain firm pedal.
(10) Top off master cylinder fluid level.
INSTALLATION - FRONT
(1) Bottom pistons in caliper bore with C-clamp.
Place an old brake shoe between a C-clamp and cal-
iper piston.
(2) Clean caliper mounting adapter and anti-rattle
springs.
(3) Lubricate anti-rattle springs with Mopar brake
grease.
(4) Install anti-rattle springs.
NOTE: Anti-rattle springs are not interchangeable.
(5) Install inboard brake shoe in adapter.
(6) Install outboard brake shoe in adapter.
(7) Tilt the bottom of the caliper over rotor and
under adapter. Then push the top of the caliper down
onto the adapter.
(8) Install caliper, (Refer to 5 - BRAKES/HY-
DRAULIC/MECHANICAL/DISC BRAKE CALIPERS
- INSTALLATION).
(9) Install wheel and tire assemblies and lower
vehicle, (Refer to 22 - TIRES/WHEELS/WHEELS -
STANDARD PROCEDURE).
(10) Apply brakes several times to seat caliper pis-
tons and brake shoes and obtain firm pedal.
(11) Top off master cylinder fluid level.
MASTER CYLINDER
DESCRIPTION
A two-piece master cylinder is used on all models.
The cylinder body containing the primary and sec-
ondary pistons is made of aluminum. The removable
fluid reservoir is made of nylon reinforced with glass
fiber. The reservoir stores reserve brake fluid for the
hydraulic brake circuits. The reservoir is the only
serviceable component.
The fluid compartments of the nylon reservoir are
interconnected to permit fluid level equalization.
However, the equalization feature does not affect cir-
cuit separation in the event of a front or rear brake
malfunction. The reservoir compartments will retain
enough fluid to operate the functioning hydraulic cir-
cuit.Care must be exercised when removing/installing
the master cylinder connecting lines. The threads in
the cylinder fluid ports can be damaged if care is not
exercised. Start all brake line fittings by hand to
avoid cross threading.
The cylinder reservoir can be replaced when neces-
sary. However, the aluminum body section of the
master cylinder is not a repairable component.
NOTE: If diagnosis indicates that an internal mal-
function has occurred, the aluminum body section
must be replaced as an assembly.
OPERATION
The master cylinder bore contains a primary and
secondary piston. The primary piston supplies
hydraulic pressure to the front brakes. The secondary
piston supplies hydraulic pressure to the rear brakes.
DIAGNOSIS AND TESTING - MASTER
CYLINDER/POWER BOOSTER
(1) Start engine and check booster vacuum hose
connections. A hissing noise indicates vacuum leak.
Correct any vacuum leak before proceeding.
(2) Stop engine and shift transmission into Neu-
tral.
(3) Pump brake pedal until all vacuum reserve in
booster is depleted.
(4) Press and hold brake pedal under light foot
pressure. The pedal should hold firm, if the pedal
falls away master cylinder is faulty (internal leak-
age).
(5) Start engine and note pedal action. It should
fall away slightly under light foot pressure then hold
firm. If no pedal action is discernible, power booster,
vacuum supply, or vacuum check valve is faulty. Pro-
ceed to the POWER BOOSTER VACUUM TEST.
(6) If the POWER BOOSTER VACUUM TEST
passes, rebuild booster vacuum reserve as follows:
Release brake pedal. Increase engine speed to 1500
rpm, close the throttle and immediately turn off igni-
tion to stop engine.
(7) Wait a minimum of 90 seconds and try brake
action again. Booster should provide two or more vac-
uum assisted pedal applications. If vacuum assist is
not provided, booster is faulty.
POWER BOOSTER VACUUM TEST
(1) Connect vacuum gauge to booster check valve
with short length of hose and T-fitting (Fig. 47).
(2) Start and run engine at curb idle speed for one
minute.
(3) Observe the vacuum supply. If vacuum supply
is not adequate, repair vacuum supply.
5 - 26 BRAKES - BASEBR/BE
BRAKE PADS/SHOES (Continued)

During antilock braking, the solenoid valves are
opened and closed as needed. The valves are not
static. They are cycled rapidly and continuously to
modulate pressure and control wheel slip and decel-
eration.
During antilock braking, solenoid valve pressure
modulation occurs in three stages, pressure decrease,
pressure hold, and pressure increase. The valves are
all contained in the valve body portion of the HCU.
PRESSURE DECREASE
The inlet valve is closed and the outlet valve is
opened during the pressure decrease cycle.
A pressure decrease cycle is initiated when speed
sensor signals indicate high wheel slip at one or
more wheels. At this point, the CAB closes the inlet
to prevent the driver from further increasing the
brake pressure and locking the brakes. The CAB
then opens the outlet valve, which also opens the
return circuit to the accumulators. Fluid pressure is
allowed to bleed off (decrease) as needed to prevent
wheel lock.
Once the period of high wheel slip has ended, the
CAB closes the outlet valve and begins a pressure
increase or hold cycle as needed.
PRESSURE HOLD
Both solenoid valves are closed in the pressure
hold cycle. Fluid apply pressure in the control chan-
nel is maintained at a constant rate. The CAB main-
tains the hold cycle until sensor inputs indicate a
pressure change is necessary.
PRESSURE INCREASE
The inlet valve is open and the outlet valve is
closed during the pressure increase cycle. The pres-
sure increase cycle is used to counteract unequal
wheel speeds. This cycle controls re-application of
fluid apply pressure due to changing road surfaces or
wheel speed.
REMOVAL
(1) Disconnect battery negative cable.
(2) Push the harness connector locks to release the
locks, then remove the connectors from the CAB.
(3) Disconnect brake lines from HCU (Fig. 7).
(4) Remove the two mounting bolts on either side
of the assembly which attach the assembly to the
mounting bracket.
(5) Tilt the assembly upward were the brake lines
attach and remove the assembly from the mounting
bracket.
INSTALLATION
(1) Install the assembly into the mounting bracket.
(2) Install the mounting bolts and tighten to 12
N´m (102 in. lbs.).
(3) Connect the CAB harnesses.
(4) Connect the brake lines to the HCU. Tighten
brake line fittings to 19-23 N´m (170-200 in. lbs.).
(5) Connect battery.
(6) Bleed brake system, (Refer to 5 - BRAKES -
STANDARD PROCEDURE).
Fig. 7 Brake Lines
1 - BRAKE LINES
2 - HCU
BR/BEBRAKES - ABS 5 - 41
HCU (HYDRAULIC CONTROL UNIT) (Continued)

RADIO
DESCRIPTION
Available factory-installed radio receivers for this
model include an AM/FM/cassette (RAS sales code),
an AM/FM/CD/3-band graphic equalizer (RBR sales
code), or an AM/FM/CD/cassette/3-band graphic
equalizer (RAZ sales code). The factory-installed RAZ
sales code radio receivers can also communicate on
the Chrysler Collision Detection (CCD) data bus net-
work through a separate two-way wire harness con-
nector. All factory-installed receivers are stereo
Electronically Tuned Radios (ETR) and include an
electronic digital clock function.
These radio receivers can only be serviced by an
authorized radio repair station. See the latest War-
ranty Policies and Procedures manual for a current
listing of authorized radio repair stations.
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse that is removed when the vehicle is
shipped from the factory. This fuse feeds various
accessories that require battery current when the
ignition switch is in the Off position, including the
clock. The IOD fuse is removed to prevent battery
discharge during vehicle storage.
When removing or installing the IOD fuse, it is
important that the ignition switch be in the Off posi-
tion. Failure to place the ignition switch in the Off
position can cause the radio display to become scram-
bled when the IOD fuse is removed and replaced.
Removing and replacing the IOD fuse again, with the
ignition switch in the Off position, will correct the
scrambled display condition.
The IOD fuse should be checked if the radio or
clock displays are inoperative. The IOD fuse is
located in the junction block. Refer to the fuse layout
label on the back of the instrument panel fuse access
panel for IOD fuse identification and location.
OPERATION
The radio receiver operates on fused battery cur-
rent that is available only when the ignition switch is
in the On or Accessory positions. The electronic digi-
tal clock function of the radio operates on fused bat-
tery current supplied through the IOD fuse,
regardless of the ignition switch position.
For more information on the features, setting pro-
cedures, and control functions for each of the avail-
able factory-installed radio receivers, see the owner's
manual in the vehicle glove box. For complete circuit
diagrams, refer to the appropriate wiring informa-
tion. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
DIAGNOSIS AND TESTING - RADIO
If the vehicle is equipped with the optional remote
radio switches located on the steering wheel and the
problem being diagnosed is related to one of the
symptoms listed below, be certain to check the
remote radio switches and circuits. Refer to Audio,
Remote Radio Switch prior to attempting radio diag-
nosis or repair.
²Stations changing with no remote radio switch
input
²Radio memory presets not working properly
²Volume changes with no remote radio switch
input
²Remote radio switch buttons taking on other
functions
²CD player skipping tracks
²Remote radio switch inoperative.
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
CAUTION: The speaker output of the radio receiver
is a ªfloating groundº system. Do not allow any
speaker lead to short to ground, as damage to the
radio receiver may result.
(1) Check the fused B(+) fuse in the junction block.
If OK, go to Step 2. If not OK, repair the shorted cir-
cuit or component as required and replace the faulty
fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the junction block. If OK, go to Step 3. If not OK,
repair the open fused B(+) circuit to the Power Dis-
tribution Center (PDC) as required.
(3) Check the fused ignition switch output (acc/
run) fuse in the junction block. If OK, go to Step 4. If
not OK, repair the shorted circuit or component as
required and replace the faulty fuse(s).
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (acc/run) fuse in the junction block. If OK, go
to Step 5. If not OK, repair the open fused ignition
8A - 10 AUDIOBR/BE

Starter Motor and Solenoid
Solenoid Closing Maximum
Voltage Required7.5 Volts 7.5 Volts 8.0 Volts
* Cranking Amperage Draw
Test125 - 250 Amperes 125 - 250 Amperes 450 - 700 Amperes
* Test at operating temperature. Cold engine, tight (new) engine, or heavy oil will increase starter amperage draw.
SPECIFICATIONS - TORQUE - STARTING
SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Battery Cable Eyelet Nut
at Solenoid (large nut -
gas engines)25 19 221
Battery Cable Eyelet Nut
at Solenoid (large nut -
diesel engine)14 - 120
Starter Solenoid Nut
(small nut - diesel engine)6-55
Starter Mounting Bolts -
Gas Engines68 50 -
Starter Mounting Nut -
Gas Engines68 50 -
Starter Mounting Bolts -
Diesel43 32 -
STARTER MOTOR
DESCRIPTION
The starter motors used for the 5.9L diesel engine
and the 8.0L gasoline engine available in this model
are not interchangeable with each other, or with the
starter motors used for the other available engines.
The starter motor for the 5.9L diesel engine is
mounted with three screws to the flywheel housing
on the left side of the engine. The starter motor for
the 8.0L gasoline engine is mounted with two screws
to the flange on the left rear corner of the engine
block, while the starter motor for the 5.9L Gas
engine is mounted with one screw, a stud and a nut
to the manual transmission clutch housing or auto-
matic transmission torque converter housing and is
located on the left side of the engine.
Each of these starter motors incorporates several
of the same features to create a reliable, efficient,
compact, lightweight and powerful unit. The electric
motors of all of these starters have four brushes con-
tacting the motor commutator, and feature four elec-
tromagnetic field coils wound around four pole shoes.
The 5.9L and 8.0L gasoline engine starter motors are
rated at 1.4 kilowatts (about 1.9 horsepower) outputat 12 volts, while the 5.9L diesel engine starter
motor is rated at 2.7 kilowatts (about 3.6 horse-
power) output at 12 volts.
All of these starter motors are serviced only as a
unit with their starter solenoids, and cannot be
repaired. If either component is faulty or damaged,
the entire starter motor and starter solenoid unit
must be replaced.
OPERATION
These starter motors are equipped with a gear
reduction (intermediate transmission) system. The
gear reduction system consists of a gear that is inte-
gral to the output end of the electric motor armature
shaft that is in continual engagement with a larger
gear that is splined to the input end of the starter
pinion gear shaft. This feature makes it possible to
reduce the dimensions of the starter. At the same
time, it allows higher armature rotational speed and
delivers increased torque through the starter pinion
gear to the starter ring gear.
The starter motors for all engines are activated by
an integral heavy duty starter solenoid switch
mounted to the overrunning clutch housing. This
electromechanical switch connects and disconnects
BR/BESTARTING 8F - 37
STARTING (Continued)