1994 JEEP CHEROKEE service

NP231 SERVICE DIAGNOSIS
21 - 274 NP231 TRANSFER CASEJ

SHIFT LINKAGE ADJUSTMENT
LINKAGE ADJUSTMENTÐYJ
(1) Remove transfer case shift knob locknut and
remove knob (Fig. 4).
(2) Remove outer boot attaching screws and re-
move boot (Fig. 4).
(3) Remove inner boot attaching screws and re-
move boot (Fig. 4).
(4) Move shift lever into 4L position.
(5) Insert 3 mm (1/8 in.) spacer between shift lever
and forward edge of shift lever gate (Fig. 5). Secure
lever and spacer in place with tape or wire.
(6) Secure shift lever and spacer with tape or wire.
(7) Raise vehicle.
(8) Loosen lock bolt on adjusting trunnion (Fig. 6).
Linkage rod should now slide freely in trunnion.
(9) Verify that range lever is in 4L position (Fig. 6).
(10) Position linkage rod so it is a free fit in range
lever. Then tighten trunnion lock bolt (Fig. 6).
(11) Lower vehicle.
(12) Remove shift lever spacer and install inner
and outer boots and shift knob (Fig. 4).
LINKAGE ADJUSTMENTÐXJ
(1) Remove shift lever bezel.
(2) Move shift lever into 4L position.
(3) Insert 3 mm (1/8 in.) spacer between shift lever
and forward edge of shift lever gate (Fig. 7). Securelever and spacer in place with tape or wire.
(4) Raise vehicle.
(5) Loosen trunnion lock bolt (Figs. 8 and 9). Link-
age rod should now slide freely in trunnion.
(6) Verify that transfer case range lever is in 4L
position.
(7) Position linkage rod so it is a free fit in range
lever (Figs. 8 and 9). Then tighten trunnion locknut.
(8) Lower vehicle.
(9) Remove shift lever spacer and install bezel.SPEEDOMETER SERVICE
Speedometer service is covered in the automatic
transmission sections in this group. Refer to the ap-
propriate section as needed.
Fig. 4 Transfer Case Shift Lever And BootsÐYJ
Fig. 5 Installing Shift Lever SpacerÐYJ
Fig. 6 Shift Trunnion Lock Bolt PositionÐYJ
JNP231 TRANSFER CASE 21 - 275

(11) Adjust transfer case shift linkage.
(12) Lower vehicle.
TRANSFER CASE DISASSEMBLY AND OVERHAUL
Two versions of the NP231 are used in current
models. One version retains the synchronizer
components used in previous years. A newly intro-
duced version does not have synchro components.
The non-synchro version does not have a synchro
gear, struts, spring and stop ring. During over-
haul, note which version is being serviced and or-
der needed parts accordingly.
(1) Remove fill and drain plugs.
(2) Remove front yoke. Discard yoke seal washer
and nut. They should not be reused.
(3) Move transfer case range lever rearward to 4L
position.
(4) Remove extension housing attaching bolts.
(5) Tap extension housing in clockwise direction to
break sealer bead and remove housing (Fig. 1).
CAUTION: To avoid damaging the sealing surfaces
of the extension housing and rear retainer, do not
pry or wedge the housing off the retainer.
(6) Remove rear bearing snap ring (Fig. 2).
(7) Remove rear retainer attaching bolts.
(8) Remove rear retainer. Position screwdriver un-
der each tab on retainer housing (Fig. 3). Then care-
fully pry retainer upward and off rear case.
CAUTION: Do not pry against the sealing surfaces of
the retainer or rear case. The surfaces could be dam-
aged.
(9) Remove bolts attaching rear case to front case.
Retain bolts and washers.
(10) Separate rear case from front case (Fig. 4) Insert
screwdrivers into slots cast in case ends. Then gently
pry upward to break sealer bead and loosen rear case.
CAUTION: Do not pry against the sealing surfaces
of the retainer or rear case. The surfaces could be
damaged.
Fig. 1 Extension Housing Removal
Fig. 2 Rear Bearing Snap Ring Removal
Fig. 3 Rear Retainer Removal
Fig. 4 Loosening Rear Case
JNP231 TRANSFER CASE 21 - 277

(11) Remove oil pump and rear case as an assem-
bly (Fig. 5).
(12) Slide oil screen out of case pocket. Disconnect
screen from pickup tube and remove screen (Fig. 6).
(13) Remove pickup tube from oil pump (Fig. 6).
(14) Remove oil pump from rear case.
(15) Remove pickup tube O-ring from oil pump
(Fig. 7).
(16)The oil pump can be disassembled for
cleaning and inspection as described in steps(17) and (18). However, the pump parts are NOT
serviceable separately. If any pump component
is worn, or damaged, the pump must be re-
placed as an assembly.
(17) If oil pump will be disassembled for inspec-
tion, mark position of oil pump housings for reference
(Fig. 8). Remove screws that attach two halves of the
pump. Then remove feed housing from gear housing
(Fig. 8).
(18) Mark position of pump gears and remove
them from housing (Fig. 8).
(19) Remove mode spring (Fig. 9).
(20) Tap front output shaft upward with a rawhide
mallet to free it from shaft bearing.
(21) Remove front output shaft and drive chain as
assembly (Fig. 10).
Fig. 5 Rear Case And Oil Pump Removal
Fig. 6 Removing Oil Screen And Pickup Tube 16
Fig. 7 Pickup Tube O-Ring Location
Fig. 8 Oil Pump Components
21 - 278 NP231 TRANSFER CASEJ

NP242 TRANSFER CASE
INDEX
page page
Cleaning and Inspection.................. 305
General Information...................... 293
Shift Linkage Adjustment.................. 296
Speedometer Service.................... 296
Transfer Case Assembly.................. 306
Transfer Case Disassembly and Overhaul..... 297Transfer Case Fill Level.................. 294
Transfer Case Identification................ 293
Transfer Case Installation................. 296
Transfer Case Lubricant.................. 294
Transfer Case Removal................... 296
GENERAL INFORMATION
The NP242 is a both a full and part time transfer
case with four operating ranges (Fig. 1). The NP242
provides either 2-wheel drive or full time 4-wheel
drive operation. An interaxle differential is used to
control torque transfer to the front and rear axles. A
low range gear reduction system provides increased
low speed torque capability.
OPERATING RANGES
The NP242 transfer case operating ranges are: 2-
wheel drive, part-time 4-wheel drive, full time 4-
wheel drive and 4-wheel drive low.
The2Hand4x4full time ranges are for all road
surfaces. The 2H range provides 2-wheel drive. The 4
x 4 full time range provides differentiated, 4-wheel
drive. The vehicle can be operated on any road sur-
face in either of these ranges if desired.
The transfer case differential also has a locking
mechanism for undifferentiated operation in:4x4
part time and,4x4lowranges. These ranges are
only for use on low traction surfaces.
The4x4full time range is fully differentiated and
can be used at any time and on any road surface. The 4x 4 part time and low ranges are not differentiated.
They are for off road use only.
The low range reduction gear system is operative in
4-low range only. Low range reduction ratio is 2.72:1.
In summary, 2H and4x4full time ranges are for
normal on-road, highway operation. The4x4part-
time and low ranges are for off road operation exclu-
sively. Or, or when the vehicle is driven on surfaces
covered by snow, ice or similar low traction elements.
SHIFT MECHANISM
Transfer case operating ranges are selected with a
floor mounted shift lever. The shift lever is connected
to the transfer case range lever by an adjustable
linkage rod. Range positions are marked on the
shifter bezel plate (Fig. 2).
TRANSFER CASE IDENTIFICATION
A circular I.D. tag is attached to the rear case of
each NP242 transfer case (Fig. 3). The tag provides
the transfer case model number, assembly number,
serial number and low range ratio.
Fig. 1 NP242 Transfer Case
Fig. 2 NP242 Shift Pattern
JNP242 TRANSFER CASE 21 - 293

NP242 SERVICE DIAGNOSIS
JNP242 TRANSFER CASE 21 - 295

SHIFT LINKAGE ADJUSTMENT
(1) Remove shift lever bezel.
(2) Move shift lever into 4L position.
(3) Insert 3 mm (1/8 in.) spacer between shift lever
and forward edge of shift lever gate (Fig. 4). Secure
lever and spacer in place with tape or wire.
(4) Raise vehicle.
(5) Loosen trunnion lock bolt (Fig. 5). Linkage rod
should now slide freely in trunnion.
(6) Verify that transfer case range lever is in 4L posi-
tion.
(7) Position linkage rod so it is free fit in range le-
ver (Fig. 5). Then tighten trunnion lock bolt.
(8) Lower vehicle.
(9) Remove shift lever spacer and install bezel.
SPEEDOMETER SERVICE
Speedometer service is covered in the automatic
transmission sections within this group.
TRANSFER CASE REMOVAL
(1) Shift transfer case into Neutral.
(2) Raise vehicle.
(3) Drain transfer case lubricant.
(4) Mark front and rear propeller shaft yokes for
alignment reference.
(5) Place support stand under transmission.
(6) Remove rear crossmember.
(7) Disconnect front/rear propeller shafts at trans-
fer case.
(8) Disconnect vehicle speed sensor wires and re-
move sensor and adapter assembly if necessary.
(9) Disconnect transfer case shift rod from range lever.
(10) Disconnect transfer case vent hoses and elec-
trical switch connector.
(11) Support transfer case with transmission jack.
(12) Remove bolts attaching the transfer case to
transmission.
(13) Secure transfer case to jack with chains.(14) Pull transfer case and jack rearward to disen-
gage transfer case.
(15) Remove transfer case from under vehicle.
TRANSFER CASE INSTALLATION
(1) Mount transfer case on transmission jack. Se-
cure transfer case to jack with safety chains.
(2) Position transfer case under vehicle.
(3) Align transfer case and transmission shafts and
install transfer case on transmission.
(4) Install and tighten transfer case attaching nuts
to 35 Nzm (26 ft. lbs.) torque.
(5) Install vehicle speed sensor and adapter, if re-
moved. Then connect vehicle speed sensor wires, vent
hoses and electrical switch connector.
(6) Align and connect propeller shafts. Tighten shaft
U-joint clamp bolts to 19 Nzm (14 ft. lbs.) torque.
(7) Fill transfer case with recommended automatic
transmission fluid.
(8) Install rear crossmember. Tighten crossmember
bolts to 41 Nzm (30 ft. lbs.) torque.
(9) Remove transmission jack and transmission
support stand.
(10) Connect transfer case range lever to shift rod.
(11) Check and adjust transfer case shift linkage if
necessary.
(12) Lower vehicle.
Fig. 4 Installing Shift Lever Spacer
Fig. 5 Transfer Case Shift Linkage
21 - 296 NP242 TRANSFER CASEJ

(10) Remove bolts attaching rear case to front case.
Retain bolts and the washers.
(11) Loosen rear case with two screwdrivers (Fig.
10). Insert screwdrivers into slots cast in case ends.
Then gently pry upward to break sealer bead.
CAUTION: Do not pry against the sealing surfaces
of the front case or rear case. The surfaces could
be damaged.
(12) Remove rear case and oil pump as assembly
(Fig. 11).(13) Slide oil screen (Fig. 12) out of case pocket.
(14) Remove oil pump, pickup tube and oil screen
from rear case (Fig. 13).
(15) Remove pickup tube and screen from pump.
(16) Remove pickup tube O-ring from oil pump
(Fig. 14).
(17) Remove and discard oil pump seal.
(18) The oil pump can be disassembled for cleaning
and inspection as described in step (19).However,
pump parts are not serviceable separately. If
any pump component is worn, or damaged,
pump must be replaced as an assembly.
(19) If oil pump will be disassembled for inspec-
tion, mark position of oil pump housings for refer-
Fig. 10 Loosening Rear Case
Fig. 11 Removing Rear Case And Oil Pump
Fig. 12 Unseating Oil Screen
Fig. 13 Removing Oil Pump, Tube And Screen
21 - 298 NP242 TRANSFER CASEJ