2002 JEEP GRAND CHEROKEE Gear oil

FRONT OUTPUT SHAFT AND DRIVE CHAIN
(1) Install front output shaft (Fig. 84).
(2) Install drive chain (Fig. 84). Engage chain with
front output shaft sprocket teeth.
(3) Install drive sprocket (Fig. 84). Engage drive
sprocket teeth with chain. Then engage sprocket
splines with mainshaft splines.
(4) Install drive sprocket snap-ring (Fig. 85).
OIL PUMP AND REAR CASE
(1) Insert oil pickup tube in oil pump and attach
oil screen and connector hose to pickup tube. Then
install assembled pump, tube and screen in rear case
(Fig. 86). Be sure screen is seated in case slot as
shown.
(2) Install magnet in front case pocket (Fig. 87).
(3) Apply 3 mm (1/8 in.) wide bead of Mopartgas-
ket maker or silicone adhesive sealer to seal surface
of front case.
(4) Align and install rear case on front case. Be
sure case locating dowels are in place and that main-
shaft splines are engaged in oil pump inner gear.
(5) Install and tighten front case-to-rear case bolts
to 41 N´m (30 ft. lbs.) torque.Be sure to install a
washer under each bolt used at case dowel
locations.
Fig. 84 Drive Chain And Sprocket Installation
1 - DRIVE SPROCKET
2 - DRIVE CHAIN
Fig. 85 Drive Sprocket Snap-Ring Installation
1 - DRIVE SPROCKET
2 - DRIVE SPROCKET SNAP-RING
Fig. 86 Oil Screen And Pickup Tube Installation
1 - OIL PUMP
2 - OIL SCREEN
3 - CONNECTOR
4 - PICKUP TUBE
WJTRANSFER CASE - NV242 21 - 305
TRANSFER CASE - NV242 (Continued)

FRONT OUTPUT SHAFT AND DRIVE CHAIN
(1) Remove oil pickup tube from rear case (Fig.
17).
(2) Remove drive gear snap-ring (Fig. 18).
(3) Disengage drive gear (Fig. 18). Pry gear
upward and off mainshaft as shown.
(4) Remove front output shaft, drive chain and
drive gear as assembly (Fig. 18).
(5) Remove output shaft drive gear snap ring.
(6) Remove output shaft drive gear from output
shaft.
SHIFT FORKS AND MAINSHAFT
(1) Remove detent plug, O-ring, detent spring and
detent plunger (Fig. 19).
(2) Remove shift rail from shift fork and transfer
case housing.
(3) Rotate range shift fork until it disengages from
shift sector.
(4) Remove mainshaft and shift fork from input
gear pilot bearing.
NOTE: Loose needle bearings are used to support
the drive sprocket hub on the mainshaft. Do not lift
mainshaft by drive sprocket hub or needle bearings
will become dislodged.
(5) Wrap rag around mainshaft underneath drive
sprocket hub and remove drive sprocket hub from
mainshaft. Be sure to retrieve all the drive sprocket
hub needle bearings.
(6) Remove snap ring holding clutch sleeve onto
mainshaft.
Fig. 17 Oil Pickup Tube Removal
1 - OIL PICKUP TUBE
Fig. 18 Front Output Shaft, Drive Gear And Chain
Removal
1 - REAR HOUSING
2 - OUTPUT SHAFT AND SPROCKET
3 - MAINSHAFT SPROCKET
4 - SNAP-RING
5 - DRIVE CHAIN
Fig. 19 Detent Plug, Spring And Plunger Removal
1 - DETENT PLUG
2 - DETENT SPRING
3 - DETENT PLUNGER
4 - PLUG O-RING
WJTRANSFER CASE - NV247 21 - 321
TRANSFER CASE - NV247 (Continued)

(4) Remove snap-ring that retains input gear shaft
in front bearing (Fig. 25).
(5) Remove input and low range gear assembly
(Fig. 26).
(6) Remove oil seals from following components:
²front bearing retainer.
²rear retainer.
²case halves.INPUT AND LOW RANGE GEAR
(1) Remove snap-ring that retains input gear in
low range gear (Fig. 27).
Fig. 24 Front Bearing Retainer Removal
1 - FRONT BEARING RETAINER
2 - RETAINER NOTCH
3 - FLAT BLADE SCREWDRIVER
Fig. 25 Input Gear Snap-Ring Removal
1 - INPUT GEAR
2 - SNAP-RING
Fig. 26 Input And Low Range Gear Assembly
Removal
1 - INPUT AND LOW RANGE GEAR ASSEMBLY
Fig. 27 Input Gear Snap-Ring Removal
1 - INPUT GEAR SNAP-RING
WJTRANSFER CASE - NV247 21 - 323
TRANSFER CASE - NV247 (Continued)

(2) Remove retainer (Fig. 28).
(3) Remove front tabbed thrust washer (Fig. 29).
(4) Remove input gear (Fig. 30).
(5) Remove rear tabbed thrust washer from low
range gear (Fig. 31).
CLEANING
Clean the transfer case components with parts
cleaning solvent. Flush the oil passages in the cases
and drivetrain components with solvent. This will
help remove dirt and particles from these passages.
Dry the transfer case components with compressed
air or allow them to air dry on clean shop towels.
Apply compressed air through all oil passages in
the cases and gear components to clear them of any
residue.
INSPECTION
MAINSHAFT
Examine the mainshaft components carefully for
evidence of wear or damage.
Replace the thrust washers if worn or damaged.
Replace the mainshaft and sprocket gears if the
teeth or gear bores are worn or damaged.
Replace the mainshaft bearings if worn, flat spot-
ted, brinelled, or damaged in any way.
Replace the mainshaft if it is bent, exhibits wear or
damage to the bearing surfaces, splines or gear teeth.
Fig. 28 Input Gear Retainer
1 - INPUT GEAR
2 - LOW RANGE GEAR
3 - RETAINER
Fig. 29 Front Tabbed Thrust Washer
1 - FRONT TABBED THRUST WASHER
Fig. 30 Input Gear Removal
1 - INPUT GEAR
2 - LOW RANGE GEAR
Fig. 31 Rear Tabbed Thrust Washer Removal
1 - LOW RANGE GEAR
2 - REAR TABBED THRUST WASHER
21 - 324 TRANSFER CASE - NV247WJ
TRANSFER CASE - NV247 (Continued)

INPUT AND LOW RANGE GEARS
Inspect the low range gear pinions and pinion pins.
Replace the low range gear if any of the pins or pin-
ions are worn or damaged.
Inspect the thrust washers, retainer, and snap-
ring. Replace the snap-ring if bent, or distorted.
Replace the thrust washers and retainer if worn,
cracked or damaged in any way.
Examine the input gear carefully. Be sure the gear
teeth and bearing surfaces are in good condition.
Replace the gear if wear or damage is evident.
Check the input gear pilot bearing. Rotate the
bearing and check for roughness or noise. Also check
bearing position in the bore. The bearing should be
recessed approximately 2.5 mm (0.100 in.) below the
top edge of the bore. The bearing should not be
seated at the bottom of the bore. Replace the bearing
if worn, or roughness is evident. Replace both the
gear and bearing if the bearing is a loose fit in the
bore.
GEAR CASE AND RETAINERS
Examine both case halves and retainers carefully.
Replace any retainer or case half if wear, cracks, or
other damage is evident.
Check condition of the low range annulus gear and
the shift rail bushing in the front case (Fig. 32). The
low range annulus gear is not a serviceable part.
Replace the gear and case as an assembly if the gear
is loose, worn, or damaged. The shift rail bushing is
a serviceable part and can be replaced if necessary.
Check the bushing in the rear retainer. Replace the
bushing if worn or scored.
Examine the sealing surfaces of both case halves
and retainers. Small burrs, or scratches on these sur-
faces can be reduced with crocus cloth or a fine tooth
file.
Examine condition of the shift rail bushing in the
front case. If the bushing is worn or damaged, it can
be removed with a blind hole type puller. A replace-
ment bushing can be installed with a suitable size
driver. Recess the bushing slightly below the edge of
the bore but do not seat it all the into the case.
GEARTRAIN
Inspect the mainshaft splines, gear teeth and bear-
ing surfaces carefully for evidence of wear, or dam-
age. Replace the shaft if necessary. do not attempt to
salvage it if damaged.
The shift rail and range fork are an assembly.
Replace both parts if either is damaged. However, the
nylon pads in the fork can be replaced if worn, or
cracked.
Inspect the transfer case snap-rings closely. Do not
attempt to salvage a distorted snap-ring by straight-ening or reshaping it. Replace any snap-ring that is
distorted, or worn.
Inspect the low range gear, input gear and the gear
thrust washers retainer, and snap-ring. The low
range gear is serviced as an assembly only. Replace
the gear if the case or pinions are damaged.
During inspection, also make sure the seal surface
of the input gear is in good condition. Minor nicks on
this surface can be reduced with crocus cloth. How-
ever, replace the gear if the seal surface is severely
scored or worn.
OIL PUMP AND PROGRESSIVE COUPLING
The oil pump and progressive coupling are not ser-
viceable components. Replace the coupling as an
assembly if it is damaged. Replace the oil pump as
an assembly if the gear teeth are worn, or if the
pump has become damaged.
BEARINGS AND SEALS
The transfer case seals should be replaced during
overhaul. Use new seals in the input gear bearing
retainer, front case and rear retainer. Also replace
the yoke seal washer and the detent plug O-ring.
Check condition of each transfer case bearing.
Replace any bearing exhibiting signs of roughness,
wear, or damage.
Fig. 32 Low Range Annulus Gear Location
1 - LOW RANGE ANNULUS GEAR
2 - SHIFT RAIL BUSHING
WJTRANSFER CASE - NV247 21 - 325
TRANSFER CASE - NV247 (Continued)

The high pressure relief valve vents only enough
refrigerant to reduce the system pressure, and then
re-seats itself. The majority of the refrigerant is con-
served in the system. If the valve vents refrigerant, it
does not mean that the valve is faulty.
The high pressure relief valve is a factory-cali-
brated unit. The valve cannot be adjusted or
repaired, and must not be removed or otherwise dis-
turbed. The valve is only serviced as a part of the
compressor assembly.
DIAGNOSIS AND TESTING - COMPRESSOR
NOISE
When investigating an air conditioning related
noise, you must first know the conditions under
which the noise occurs. These conditions include:
weather, vehicle speed, transmission in gear or neu-
tral, engine speed, engine temperature, and any
other special conditions. Noises that develop during
air conditioning operation can often be misleading.
For example: What sounds like a failed front bearing
or connecting rod, may be caused by loose bolts, nuts,
mounting brackets, or a loose compressor clutch
assembly.
Drive belts are speed sensitive. At different engine
speeds and depending upon belt tension, belts can
develop noises that are mistaken for a compressor
noise. Improper belt tension can cause a misleading
noise when the compressor clutch is engaged, which
may not occur when the compressor clutch is disen-
gaged. Check the serpentine drive belt condition and
tension as described in Cooling before beginning this
procedure.
(1) Select a quiet area for testing. Duplicate the
complaint conditions as much as possible. Switch the
compressor on and off several times to clearly iden-
tify the compressor noise. Listen to the compressor
while the clutch is engaged and disengaged. Probe
the compressor with an engine stethoscope or a long
screwdriver with the handle held to your ear to bet-
ter localize the source of the noise.
(2) Loosen all of the compressor mounting hard-
ware and retighten. Tighten the compressor clutch
mounting nut. Be certain that the clutch coil is
mounted securely to the compressor, and that the
clutch plate and pulley are properly aligned and have
the correct air gap. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH - INSTALLATION)
(3) To duplicate a high-ambient temperature condi-
tion (high head pressure), restrict the air flow
through the condenser. Install a manifold gauge set
to be certain that the discharge pressure does not
exceed 2760 kPa (400 psi).
(4) Check the refrigerant system plumbing for
incorrect routing, rubbing or interference, which cancause unusual noises. Also check the refrigerant lines
for kinks or sharp bends that will restrict refrigerant
flow, which can cause noises. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAU-
TION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
(5) If the noise is from opening and closing of the
high pressure relief valve, reclaim, evacuate, and
recharge the refrigerant system. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT RECOVERY)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)If the high pressure relief valve still
does not seat properly, replace the a/c compressor.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C COMPRESSOR - REMOVAL)
(6) If the noise is from liquid slugging on the suc-
tion line, check the refrigerant oil level and the
refrigerant system charge. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/REFRIGER-
ANT OIL - STANDARD PROCEDURE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
SPECIFICATIONS - CHARGE CAPACITY).
(7) If the noise continues, replace the compressor
and repeat Step 1.
REMOVAL
REMOVAL
The compressor may be removed and repositioned
without disconnecting the refrigerant lines or dis-
charging the refrigerant system. Discharging is not
necessary if servicing the compressor clutch or clutch
coil, the engine, the cylinder head, or the generator.
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
(1) Recover the refrigerant from the system. (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE - REFRIGERANT
RECOVERY)
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the serpentine drive belt. Refer to
Cooling for the procedures.
(4) Unplug the compressor clutch coil wire harness
connector.
24 - 58 PLUMBINGWJ
A/C COMPRESSOR (Continued)