JEEP CHEROKEE 1994 Service Repair Manual

(55) Remove extension housing bushing with Bush-
ing Installer Tools C-4171 and C-4338-A (Fig. 64).
(56) Install new extension housing bushing with
Installer Tools C-4171 and 5066 (Fig. 65).
(57) Install new seal in extension housing.(58) Apply 3 mm (1/8 in.) wide bead of Mopar gas-
ket maker, silicone adhesive sealer, or Loctite 518 to
mounting surface of extension housing.
(59) Install extension housing on case and tighten
housing bolts to 41 Nzm (30 ft. lbs.) torque.
(60) Install front yoke. Secure yoke with replace-
ment seal washer and nut. Tighten nut to 149 Nzm
(110 ft. lbs.) torque.
(61) Install replacement gasket on vacuum switch
and install switch in case.
(62) Install tighten drain plug to 47 Nzm (35 ft.
lbs.) torque.
(63) Install vacuum switch in case. Tighten switch
to 47 Nzm (35 ft. lbs.) torque.
(64) Install speedometer pinion and adapter (Fig.
66).
(65) Fill transfer case with Mopar ATF Plus or
Dexron II automatic transmission fluid after installa-
tion.
(66) Install and tighten fill plug to 41 Nzm (35 ft.
lbs.) torque.
Fig. 64 Removing Extension Housing Bushing
Fig. 65 Installing Extension Housing BushingFig. 66 Speedometer Components (YJ Shown)
21 - 290 NP231 TRANSFER CASEJ

NP231 TRANSFER CASE
JNP231 TRANSFER CASE 21 - 291

LEGEND FOR NP231 TRANSFER CASE
21 - 292 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

The transfer case serial number also represents the
date of build. For example, a serial number of 10-
5-91 would represent October 5, 1991.
TRANSFER CASE LUBRICANT
Recommended fluid for the NP242 transfer case is
Mopar Dexron II, or ATF Plus, Type 7176 automatic
transmission fluid.
Lubricant capacity of the Model 242 transfer case
is: 1.4 liters (1.48 qts.).
TRANSFER CASE FILL LEVEL
Correct fill level for the NP242 transfer case is to
the bottom edge of the fill plug hole.
Fig. 3 Transfer Case I.D. Tag
21 - 294 NP242 TRANSFER CASEJ

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

TRANSFER CASE DISASSEMBLY AND OVERHAUL
(1) Remove fill and drain plugs.
(2) Remove front yoke. Discard yoke seal washer
and nut.
(3) Move range lever rearward to 4L position.
(4) Remove extension housing attaching bolts.
(5) Tap extension housing in a clockwise direction
to break sealer bead and remove housing (Fig. 6).
CAUTION: To avoid damaging the sealing surfaces of
the extension housing and rear retainer, do not at-
tempt to pry or wedge the housing off the retainer.
(6) Remove rear bearing snap ring from mainshaft
(Fig. 7). Discard snap ring.(7) Remove rear retainer attaching bolts.
(8) Loosen rear retainer (Fig. 8). Position long
screwdriver under each tab at ends of retainer hous-
ing and pry retainer upward.
CAUTION: Do not pry against the sealing surfaces
of the retainer or rear case. The surfaces could be
damaged.
(9) Lift rear retainer up and off case and main-
shaft (Fig. 9).
Fig. 7 Removing Rear Bearing Snap Ring
Fig. 6 Extension Housing Removal
Fig. 8 Loosening Rear Retainer
Fig. 9 Remove Rear retainer
JNP242 TRANSFER CASE 21 - 297

(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

ence (Fig. 15). Remove screws that attach two halves
of the pump. Remove feed housing from gear housing
(Fig. 15). Then mark position of pump gears and re-
move them from housing (Fig. 15).(20) Remove magnet from front case.
(21) Remove drive sprocket snap ring (Fig. 16).
(22) Remove drive sprocket and chain (Fig. 17).
Fig. 14 Removing Pickup Tube O-Ring
Fig. 15 Oil Pump Components
Fig. 16 Removing Drive Sprocket Snap Ring
fig. 17 Removing Drive Sprocket And Chain
JNP242 TRANSFER CASE 21 - 299