1994 JEEP CHEROKEE torque

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
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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
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(17) Install new seal in front bearing retainer (Fig.
53).
(18) Apply 3 mm (1/8 in.) wide bead of Mopar gas-
ket maker. silicone adhesive sealer, or Loctite 518 to
seal surface of front bearing retainer.
(19) Install the front bearing retainer (Fig. 54).
Tighten the retainer bolts to 16 ft. lbs. (21 Nzm)
torque.(20) Install new sector shaft O-ring and bushing
(Fig. 55).
(21) Install the shift sector.
(22) Install new pads in low range fork (Fig. 56).
(23) Assemble low range fork and hub (Fig. 56).
Fig. 55 Installing Sector O-Ring And Bushing
Fig. 56 Assembling Low Range Fork And Hub
Fig. 53 Install Front Bearing Retainer Seal
Fig. 54 Installing Front Bearing Retainer
JNP242 TRANSFER CASE 21 - 309

(24) Position low range fork and hub in case. Be
sure low range fork pin is engaged in the shift sector
slot (Fig. 57).
(25) Lubricate differential components with auto-
matic transmission fluid.
(26) Install sprocket gear in differential bottom
case (Fig. 58).(27) Install differential planet gears and new
thrust washers (Fig. 59).Be sure thrust washers
are installed at top and bottom of each planet
gear.
(28) Install differential mainshaft gear (Fig. 59).
(29) Align and position differential top case on bot-
tom case (Fig. 60). Align using scribe marks made at
disassembly.
(30) Install and tighten the differential case bolts
to specified torque.
Fig. 57 Positioning Low Range Fork
Fig. 58 Installing Differential Sprocket Gear
Fig. 59 Installing Mainshaft And Planet Gears
Fig. 60 Differential Case Assembly
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(41) Install mode fork and mainshaft assembly in
case (Fig. 69). Rotate mainshaft slightly to engage
shaft with low range gears.
(42) Rotate mode fork pin into shift sector slot.
(43) Install shift rail (Fig. 70).Be sure rail is
seated in both shift forks.
(44) Rotate shift sector to align lockpin hole in low
range fork with access hole in case.(45) Insert an easy-out in range fork lockpin to
hold it securely for installation (Fig. 71).Lockpin is
slightly tapered on one end. Insert tapered end
into fork and rail.
(46) Insert lockpin through access hole and into
shift fork (Fig. 71). Then remove the easy-out and
seat the pin with pin punch.
(47) Install plug in lockpin access hole.
(48) Install transfer case shift lever and attaching
nut. Tighten nut to 30 Nzm (22 ft. lbs.) torque.
(49) Install detent plunger, detent spring and de-
tent plug in the case (Fig. 72).
Fig. 69 Installing Mainshaft And Mode Fork
Fig. 70 Installing Shift Rail
Fig. 71 Installing Low Range Fork Lockpin
Fig. 72 Installing Detent Pin, Spring And Plug
JNP242 TRANSFER CASE 21 - 313

(57) Install new seal in oil pump feed housing (Fig.
77).
(58) Install new pickup tube O-ring in oil pump
(Fig. 78).
(59) Insert oil pickup tube in oil pump and attach
oil screen and connecter hose to pickup tube. Then
install assembled pump, tube and screen in rear case
(Fig. 79). Be sure screen is seated in case slot as
shown.
(60) Install magnet in front case pocket (Fig. 80).(61) Apply 3 mm (1/8 in.) wide bead of Mopar gas-
ket maker, silicone adhesive sealer, or Loctite 518 to
seal surface of front case.
(62) 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.
(63) Install and tighten the front case-to-rear case
bolts to 41 Nzm (30 ft. lbs.) torque.Be sure to in-
stall a washer under each of the bolts used at
the case dowel locations.
(64) Tap rear retainer bearing out of retainer with
hammer and brass drift.
(65) Install new bearing in rear retainer with
driver tools (Fig. 81).
(66) Apply 3 mm (1/8 in.) wide bead of Mopar gas-
ket maker, silicone adhesive sealer, or Loctite 518 to
seal surface of rear retainer.
Fig. 77 Installing Oil Pump seal
Fig. 78 Installing Pickup Tube O-Ring
Fig. 79 Installing Oil Screen And Pickup Tube
Fig. 80 Installing Case Magnet
JNP242 TRANSFER CASE 21 - 315

(67) Install locating dowel in rear retainer (if re-
moved) and install the retainer on the case. Tighten
the retainer bolts to 41 Nzm (30 ft. lbs.) torque.
(68) Install new rear bearing snap ring (Fig. 82).
Lift mainshaft slightly to seat the snap ring if neces-
sary.
(69) Remove extension housing seal if not removed
previously.
(70) Replace extension housing bushing with driver
tools (Fig. 83).(71) Install new extension housing oil seal (Fig.
84).
Fig. 83 Replacing Extension Housing Bushing
Fig. 84 Replacing Extension Housing Seal
Fig. 81 Installing Rear Bearing In Retainer
Fig. 82 Installing Rear Bearing Snap Ring
21 - 316 NP242 TRANSFER CASEJ

(72) Apply 3 mm (1/8 in.) wide bead of Mopar gas-
ket maker, silicone adhesive sealer, or Loctite 518 to
seal surface of extension housing.
(73) Install extension housing on case. Tighten
housing bolts to 41 Nzm (30 ft. lbs.) torque.
(74) Install front yoke. Secure yoke with new seal
washer and nut. Tighten nut to 149 Nzm (110 ft. lbs.)
torque.
(75) Install new gasket on vacuum switch and in-
stall switch in the case. Tighten switch to 27 Nzm (20
ft. lbs.) torque.
(76) Install speedometer components (Fig. 85).
(77) Install and tighten drain plug to 47 Nzm (35
ft. lbs.) torque.
(78) After installing transfer case, refill with rec-
ommended transmission fluid.
(79) Tighten fill plug to 47 Nzm (35 ft. lbs.) torque.
(80) Adjust transfer case shift linkage.
Fig. 85 Speedometer Components
JNP242 TRANSFER CASE 21 - 317