2002 JEEP GRAND CHEROKEE parts

Condition Possible Causes Correction
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.
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.
VARI-LOKT
(1) Park the vehicle on a level surface or raise
vehicle on hoist so that the vehicle is level.
(2) Remove the axle fill plug.
(3) Verify that the axle fluid level is correct. The
fluid level is correct if the fluid is level with the bot-
tom of the fill hole.
(4) Shift the transfer case into the 4WD full-time
position.
(5) Drive the vehicle in a tight circle for 2 minutes
at 5mph to fully prime the pump.
(6) Block the tires opposite the axle to be tested to
prevent the vehicle from moving.
(7) Shift the transfer case into the 4WD Low posi-
tion and the transmission into the Park position.
(8) Raise both the wheels of the axle to be tested
off of the ground.(9) Rotate the left wheel by hand at a minimum of
one revolution per second while an assistant rotates
the right wheel in the opposite direction.
(10) The left wheel should spin freely at first and
then increase in resistance within 5 revolutions until
the wheels cannot be continuously rotated in opposite
directions.
(11) The Vari-loktdifferential has engaged prop-
erly if the wheels cannot be rotated in opposite direc-
tions for a moment. After the wheels stop rotating for
a moment, the fluid pressure will drop in the differ-
ential and the wheels begin to rotate once again.
(12) If the system does not operate properly,
replace the Vari-loktdifferential.
REMOVAL
(1) Raise and support the vehicle.
(2) Position a lifting device under the axle and
secure axle.
WJREAR AXLE - 226RBA 3 - 95
REAR AXLE - 226RBA (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - DOUBLE INVERTED
FLARING
A preformed metal brake tube is recommended and
preferred for all repairs. However, double-wall steel
tube can be used for emergency repair when factory
replacement parts are not readily available.
Special bending tools are needed to avoid kinking
or twisting of metal brake tubes. Special flaring tools
are needed to make a double inverted flare or ISO
flare.
(1) Cut off damaged tube with Tubing Cutter.
(2) Ream cut edges of tubing to ensure proper
flare.
(3) Install replacement tube nut on the tube.
(4) Insert tube in flaring tool.
(5) Place gauge form over the end of the tube.
(6) Push tubing through flaring tool jaws until
tube contacts recessed notch in gauge that matches
tube diameter.
(7) Tighten the tool bar on the tube
(8) Insert plug on gauge in the tube. Then swing
compression disc over gauge and center tapered flar-
ing screw in recess of compression disc (Fig. 4).
(9) Tighten tool handle until plug gauge is
squarely seated on jaws of flaring tool. This will start
the inverted flare.
(10) Remove the plug gauge and complete the
inverted flare.
STANDARD PROCEDURE - ISO FLARING
A preformed metal brake tube is recommended and
preferred for all repairs. However, double-wall steel
tube can be used for emergency repair when factory
replacement parts are not readily available.
Special bending tools are needed to avoid kinking
or twisting of metal brake tubes. Special flaring tools
are needed to make a double inverted flare or ISO
flare.
To make a ISO flare use Snap-OntFlaring Tool
TFM-428 or equivalent.
(1) Cut off damaged tube with Tubing Cutter.
(2) Remove any burrs from the inside of the tube.
(3) Install tube nut on the tube.
(4) Position the tube in the flaring tool flush with
the top of the tool bar (Fig. 5). Then tighten the tool
bar on the tube.
(5) Install the correct size adaptor on the flaring
tool yoke screw.
(6) Lubricate the adaptor.
(7) Align the adaptor and yoke screw over the tube
(Fig. 5).
(8) Turn the yoke screw in until the adaptor is
squarely seated on the tool bar.
Fig. 4 Inverted
Fig. 5 ISO Flaring
1 - ADAPTER
2 - LUBRICATE HERE
3 - PILOT
4 - FLUSH WITH BAR
5 - TUBING
6 - BAR ASSEMBLY
WJBRAKES - BASE 5 - 9
BRAKE LINES (Continued)

(6) Seat dust boot in caliper with Installer 8280
and Handle C-4171 (Fig. 45).
(7) Install caliper slide pin bushings into the cali-
per (Fig. 46).
(8) Install caliper bleed screw.
INSTALLATION
INSTALLATION - FRONT DISC BRAKE CALIPER
(1) Install the inboard brake shoe (Fig. 22).
(2) Lubricate the slide pins and slide pin bushings
with Dow Corningtgrease G807 or the grease pro-
vided with the caliper.
(3) Install the caliper on the anchor.(4) Install the caliper slide pin and tighten to
29-41 N´m (21-30 ft. lbs.).
(5) Install the caliper slide pin bushing caps.
(6) Install the caliper support spring in the top
end of the caliper and under the anchor. Then install
other end into the lower caliper hole. Hold the spring
into the caliper hole with your thumb while prying
the end of the spring out and down under the anchor
with a screw drive.
(7) Install brake hose to caliper withnew gasket
washersand tighten banjo bolt to 31 N´m (23 ft.
lbs.).
CAUTION: Verify brake hose is not twisted or
kinked before tightening banjo bolt.
(8) Fill and bleed brake system.
(9) Install wheel and tire assemblies.
(10) Remove supports and lower vehicle.
(11) Verify brake fluid level.
INSTALLATION - REAR DISC BRAKE CALIPER
(1) Install the inboard brake shoe (Fig. 26).
(2) Lubricate the slide pins and slide pin bushings
with Dow Corningtgrease G807 or the grease pro-
vided with the caliper.
(3) Install the caliper on the anchor.
(4) Install the caliper slide pin and tighten to
29-41 N´m (21-30 ft. lbs.).
(5) Install the caliper slide pin caps.
(6) Install the caliper support spring in the top
end of the caliper and under the anchor. Then install
other end into the lower caliper hole. Hold the spring
into the caliper hole with your thumb while prying
the end of the spring out and down under the anchor
with a screw drive.
CAUTION: Verify brake hose is not twisted or
kinked before tightening fitting bolt.
(7) Install brake hose to caliper with anewgasket
washers and tighten banjo bolt to 31 N´m (23 ft. lbs.).
(8) Fill and bleed brake system.
(9) Install wheel and tire assemblies.
(10) Remove supports and lower vehicle.
FLUID
DIAGNOSIS AND TESTING - BRAKE FLUID
CONTAMINATION
Indications of fluid contamination are swollen or
deteriorated rubber parts.
Swollen rubber parts indicate the presence of
petroleum in the brake fluid.
To test for contamination, put a small amount of
drained brake fluid in clear glass jar. If fluid sepa-
Fig. 45 Piston Dust Boot Installation
1 - HANDLE
2 - INSTALLER
3 - DUST BOOT
Fig. 46 Slide Pin And Bushing
1 - CALIPER SLIDE PIN
2 - BUSHING
5 - 22 BRAKES - BASEWJ
DISC BRAKE CALIPERS (Continued)

rates into layers, there is mineral oil or other fluid
contamination of the brake fluid.
If brake fluid is contaminated, drain and thor-
oughly flush system. Replace master cylinder with
reservoir, caliper seals, HCU and all hydraulic fluid
hoses.
SPECIFICATIONS
BRAKE FLUID
The brake fluid used in this vehicle must conform
to DOT 3 specifications and SAE J1703 standards.
No other type of brake fluid is recommended or
approved for usage in the vehicle brake system. Use
only Mopar brake fluid or an equivalent from a
tightly sealed container.
CAUTION: Never use reclaimed brake fluid or fluid
from an container which has been left open. An
open container of brake fluid will absorb moisture
from the air and contaminate the fluid.
CAUTION: Never use any type of a petroleum-based
fluid in the brake hydraulic system. Use of such
type fluids will result in seal damage of the vehicle
brake hydraulic system causing a failure of the
vehicle brake system. Petroleum based fluids would
be items such as engine oil, transmission fluid,
power steering fluid, etc.
FLUID RESERVOIR
REMOVAL
(1) Remove reservoir cap and remove fluid with a
cleansuction gun.
(2) Remove the wire connector from the brake fluid
level sensor.
(3) Insert the tool (Fig. 47) provided with the res-
ervoir to release the reservoir retaining tabs.
(4) Pull the reservoir straight up out of the cylin-
der.
(5) Remove and discard grommets from the cylin-
der body.
INSTALLATION
(1) Lubricate new grommets with clean brake
fluid. Install new grommets into the cylinder body.
CAUTION: Do not use tools to install the grommets.
Tools may cut, or tear the grommets. Install the
grommets using finger pressure only.(2) Start reservoir in grommets then press the res-
ervoir straight down to seat the reservoir into the
cylinder grommets.
CAUTION: Do not rock the reservoir during installa-
tion.
(3) Verify retaining tabs are seated.
(4) Install the wire connector to the brake fluid
level sensor.
(5) Fill master cylinder.
MASTER CYLINDER
DESCRIPTION
The master cylinder body is made of aluminum
and contains a primary and secondary piston assem-
bly. The cylinder body including the piston assem-
blies are not serviceable. If diagnosis indicates an
internal problem with the cylinder body, it must be
replaced as an assembly. The master cylinder has a
removable reservoir and fluid level indicator. The res-
ervoir, reservoir grommets, reservoir cap and fluid
level switch are the only replaceable parts on the
master cylinder.
Fig. 47 Release Tool
1 - RESERVOIR
2 - RELEASE TOOL
3 - RETAINING TABS
WJBRAKES - BASE 5 - 23
FLUID (Continued)

INSTALLATION
INSTALLATION - FRONT DISC BRAKE ROTOR
NOTE: If a new rotor is installed it must be match
mounted to the hub/bearing.
(1) Install rotor on hub studs in its original loca-
tion.
(2) Install the caliper anchor assembly on the
knuckle. Install anchor bolts and tighten to 90-115
N´m (66-85 ft. lbs.).
(3) Install wheel and tire assembly.
(4) Remove support and lower the vehicle.
(5) Pump brake pedal to seat caliper pistons and
brake shoes. Do not move vehicle until firm brake
pedal is obtained.
INSTALLATION - REAR DISC BRAKE ROTOR
(1) Install rotor on axle studs.
(2) Install the caliper anchor assembly.
(3) Install anchor bolts and tighten to 90-115 N´m
(66-85 ft. lbs.).
(4) Install wheel and tire assembly.
(5) Remove support and lower the vehicle.
(6) Pump brake pedal until caliper pistons and
brake shoes are seated.
PARKING BRAKE
OPERATION
The parking brakes operated by a automatic ten-
sioner mechanism built into the hand lever and cable
system. The front cable is connected to the hand
lever and the equalizer. The rear cables attached to
the equalizer and the parking brake shoe actuator.
A set of drum type brake shoes are used for park-
ing brakes. The shoes are mounted to the rear disc
brake adaptor. The parking brake drum is integrated
into the rear disc brake rotor.
Parking brake cable adjustment is controlled by an
automatic tensioner mechanism. The only adjust-
ment if necessary is to the park brake shoes if the
linings are worn.
DIAGNOSIS AND TESTING - PARKING BRAKE
NOTE: Parking brake adjustment is controlled by an
automatic cable tensioner and does not require
adjustment. The only adjustment that may be nec-
essary would be to the park brake shoes if they are
worn.
The parking brake switch is in circuit with the red
warning lamp in the dash. The switch will cause the
lamp to illuminate only when the parking brakes are
applied. If the lamp remains on after parking brake
release, the switch or wires are faulty.
If the red lamp comes on a fault has occurred in
the front or rear brake hydraulic system.
If the red warning lamp and yellow warning lamp
come on, the electronic brake distribution may be at
fault.
In most cases, the actual cause of an improperly
functioning parking brake (too loose/too tight/won't
hold), can be traced to a parking brake component.
NOTE: The leading cause of improper parking brake
operation, is excessive clearance between the park-
ing brake shoes and the shoe braking surface.
Excessive clearance is a result of lining and/or
drum wear, drum surface machined oversize.
Excessive parking brake lever travel (sometimes
described as a loose lever or too loose condition), is
the result of worn brake shoes, improper brake shoe
adjustment, or improperly assembled brake parts.
A too loose condition can also be caused by inoper-
ative or improperly assembled parking brake shoe
parts.
A condition where the parking brakes do not hold,
will most probably be due to a wheel brake compo-
nent.
Items to look for when diagnosing a parking brake
problem, are:
²Brake shoe wear
²Drum surface (in rear rotor) machined oversize
²Front cable not secured to lever
²Rear cable not attached to actuator
²Rear cable seized
²Parking brake lever not seated
²Parking brake lever bind
5 - 34 BRAKES - BASEWJ
ROTORS (Continued)

²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED
²STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.
²Increase engine speed for more air flow is recom-
mended.(1) TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
(2) AIR CONDITIONING; ADD-ON OR AFTER
MARKET:
A maximum cooling package should have been
ordered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
(3) RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump, or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, refer to following Cooling System Diagnosis
charts.
These charts are to be used as a quick-reference
only. Refer to the group text for information.
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
7 - 4 COOLINGWJ
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
COOLANT LEVEL
CHANGES IN COOLANT
RESERVE/OVERFLOW
TANK. TEMPERATURE
GAUGE IS IN NORMAL
RANGE1. Level changes are to be expected
as coolant volume fluctuates with
engine temperature. If the level in
the tank was between the FULL and
ADD marks at normal operating
temperature, the level should return
to within that range after operation
at elevated temperatures.1. A normal condition. No repair is necessary.
FAN RUNS ALL THE
TIME1. Fan control sensors inoperative. 1. Check for DTC's. Verify sensor readings.
2. Fan control solenoid stuck9on9. 2. Check fan operation speeds. Refer to fan
speed operation table.
3. Fan control solenoid harness
damaged.3. Check for DTC 1499. Repair as required.
4. Transmission temperature too
high.4. Check for transmission over temp. DTC.
5. Engine coolant temperature too
high.5. (a) Check coolant level. Correct level as
required.
(b) Thermostat stuck. Replace thermostat.
(c) Water pump failed. Replace water pump.
(d) Coolant flow restricted. Clean radiator.
(e) Air flow over radiator obstructed.Remove
obstruction.
DIAGNOSIS AND TESTING - COOLING SYSTEM
LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate engine until radiator
upper hose is warm to touch. Aim the commercially
available black light tool at components to be
checked. If leaks are present, black light will cause
additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 5).
PRESSURE TESTER METHOD
The engine should be at normal operating temper-
ature. Recheck the system cold if cause of coolant
loss is not located during the warm engine examina-
tion.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Fig. 5 Leak Detection Using Black LightÐTypical
1 - TYPICAL BLACK LIGHT TOOL
7 - 10 COOLINGWJ
COOLING (Continued)

INSPECTION..........................52
INSTALLATION.........................52
RADIATOR PRESSURE CAP
DESCRIPTION.........................53
OPERATION...........................53
DIAGNOSIS AND TESTINGÐRADIATOR
PRESSURE CAP......................53CLEANING............................53
INSPECTION..........................54
WATER PUMP INLET TUBE
REMOVAL.............................54
INSTALLATION.........................54
COOLANT
DESCRIPTION
DESCRIPTION - ENGINE COOLANT
ETHYLENE-GLYCOL MIXTURES
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
The required ethylene-glycol (antifreeze) and water
mixture depends upon the climate and vehicle oper-
ating conditions. The recommended mixture of 50/50
ethylene-glycol and water will provide protection
against freezing to -37 deg. C (-35 deg. F). The anti-
freeze concentrationmust alwaysbe a minimum of
44 percent, year-round in all climates.If percentage
is lower than 44 percent, engine parts may be
eroded by cavitation, and cooling system com-
ponents may be severely damaged by corrosion.
Maximum protection against freezing is provided
with a 68 percent antifreeze concentration, which
prevents freezing down to -67.7 deg. C (-90 deg. F). A
higher percentage will freeze at a warmer tempera-
ture. Also, a higher percentage of antifreeze can
cause the engine to overheat because the specific
heat of antifreeze is lower than that of water.
Use of 100 percent ethylene-glycol will cause for-
mation of additive deposits in the system, as the cor-
rosion inhibitive additives in ethylene-glycol require
the presence of water to dissolve. The deposits act as
insulation, causing temperatures to rise to as high as
149 deg. C (300) deg. F). This temperature is hot
enough to melt plastic and soften solder. The
increased temperature can result in engine detona-
tion. In addition, 100 percent ethylene-glycol freezes
at 22 deg. C (-8 deg. F ).
PROPYLENE-GLYCOL MIXTURES
It's overall effective temperature range is smaller
than that of ethylene-glycol. The freeze point of 50/50
propylene-glycol and water is -32 deg. C (-26 deg. F).
5 deg. C higher than ethylene-glycol's freeze point.
The boiling point (protection against summer boil-
over) of propylene-glycol is 125 deg. C (257 deg. F )at 96.5 kPa (14 psi), compared to 128 deg. C (263
deg. F) for ethylene-glycol. Use of propylene-glycol
can result in boil-over or freeze-up on a cooling sys-
tem designed for ethylene-glycol. Propylene glycol
also has poorer heat transfer characteristics than
ethylene glycol. This can increase cylinder head tem-
peratures under certain conditions.
Propylene-glycol/ethylene-glycol Mixtures can
cause the destabilization of various corrosion inhibi-
tors, causing damage to the various cooling system
components. Also, once ethylene-glycol and propy-
lene-glycol based coolants are mixed in the vehicle,
conventional methods of determining freeze point will
not be accurate. Both the refractive index and spe-
cific gravity differ between ethylene glycol and propy-
lene glycol.
DESCRIPTION - HOAT COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN. DISPOSE OF
GLYCOL BASE COOLANT PROPERLY, CONTACT
YOUR DEALER OR GOVERNMENT AGENCY FOR
LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN
THE ENGINE IS AT OPERATING TEMPERATURE OR
HOT UNDER PRESSURE, PERSONAL INJURY CAN
RESULT. AVOID RADIATOR COOLING FAN WHEN
ENGINE COMPARTMENT RELATED SERVICE IS
PERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less corrosion protection.
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves and
engine block. Then coolant carries the heat to the
radiator where the tube/fin radiator can transfer the
heat to the air.
WJENGINE 7 - 25